Sample records for aborted pollen grains

  1. Insights into a hydration regulating system in Cupressus pollen grains

    PubMed Central

    Danti, R.; Della Rocca, G.; Calamassi, R.; Mori, B.; Mariotti Lippi, M.

    2011-01-01

    Background and Aims Hydration, rupture and exine opening due to the sudden and large expansion of intine are typical of taxoid-type pollen grains. A hemispheric outgrowth external to the exine was observed on Cupressus and Juniperus pollen grains before the intine swelling and exine release. However, the actual existence of this permanent or temporary structure and its precise role in pollen hydration is still being debated. The aim of this paper is to collect information on the actual presence of this peculiar outgrowth on the surface of the Cupressus pollen grain, its structure, composition and function. Methods Pollen grains of several Cupressus species were observed using various techniques and methodologies, under light and fluorescence microscopy, phase-contrast microscopy, confocal microscopy, scanning electron microscopy, and an environmental scanning electron microscope. Observations were also performed on other species with taxoid-type pollen grains. Key Results A temporary structure located just above the pore was observed on Cupressus pollen grains, as well as on other taxoid-type pollens. It is hemispheric, layered, and consists of polysaccharides and proteins. The latter are confined to its inner part. Its presence seems to regulate the entrance of water into the grains at the beginning of pollen hydration. Conclusions The presence of a temporary structure over the pore of taxoid-type pollen grains was confirmed and its structure was resolved using several stains and observation techniques. This structure plays a role in the first phases of pollen hydration. PMID:21685430

  2. [The development of pollen grains and formation of pollen tubes in higher plants : I. Quantitative measurements of the DNA-content of generative and vegetative nuclei in the pollen grain and pollen tube of Petunia hybrida mutants].

    PubMed

    Hesemann, C U

    1971-01-01

    The DNA-content of generative and vegetative nuclei in mature pollen grains of four Petunia hybrida mutants was determined by cytophotometry. In addition the DNA-content of generative and vegetative nuclei in the pollen tube of two of these four mutants (virescens-2 n and ustulata-2 n) was cytophotometrically measured.The DNA-values found in the generative nuclei indicate that the DNA-replication continues in the mature pollen grain and comes to an end only after the migration of the nuclei into the pollen tube. These data are in disagreement with the results of DNA-measurements described for a limited number of other species which all show completion of DNA-synthesis during the maturation stage of the pollen grains.The vegetative nuclei of the four Petunia mutants studied show significant differences in the onset of the degenerative phase. Extreme variation is manifested in the ustulata-2 n mutant in which the degeneration of nuclei may reach the final stage in the maturing pollen grain. However in this mutant vegetative nuclei with an unaltered DNA-content may also be demonstrated in the pollen tube. Some of the vegetative nuclei in the pollen tube of ustulata-2 n exhibit an increased amount of DNA which could be the result of differential DNA-replication in the vegetative nuclei. The decrease of the DNA-content in a certain fraction of the vegetative nuclei in the maturing pollen grain does not agree with observations made in other species by several authors who report DNA constancy until the pollen grain is fully mature.The data obtained from the analysis of the four Petunia hybrida mutants point to an important role of the vegetative nucleus in the development of the pollen tube. The Petunia hybrida mutants may be regarded as especially favourable material for investigations concerning the function of the vegetative cell in the development of the pollen grain and pollen tube.

  3. Polarization Analysis of Light Scattered by Pollen Grains of Cryptomeria japonica

    NASA Astrophysics Data System (ADS)

    Iwai, Toshiaki

    2013-06-01

    Pollinosis to airborne pollen grains is a severe problem that concerns the whole world. Almost spring allergies in Japan are caused by pollen grains of Japan cedar (Cryptomeria japonica) during the period of pollination from February to May. One of the key technologies in a pollen monitoring and forecast system is a pollen sensor. The pollen grain of Japan cedar is identified by introducing the degree of polarization to the optical sensor based on the scattered intensity. The detectability and discriminability in identifying the pollen grains of Japan cedar from the polystyrene spherical particles and the Kanto loam grains are achieved up to 95 and 86%, respectively.

  4. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    PubMed Central

    Sénéchal, Hélène; Visez, Nicolas; Charpin, Denis; Shahali, Youcef; Peltre, Gabriel; Biolley, Jean-Philippe; Lhuissier, Franck; Couderc, Rémy; Yamada, Ohri; Malrat-Domenge, Audrey; Pham-Thi, Nhân; Poncet, Pascal; Sutra, Jean-Pierre

    2015-01-01

    This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed. PMID:26819967

  5. PECTIN METHYLESTERASE48 Is Involved in Arabidopsis Pollen Grain Germination1[OPEN

    PubMed Central

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-01-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48−/− pollen grains. In contrast, the PME activity was lower in pme48−/−, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48−/− with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca2+ necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. PMID:25524442

  6. Ultrastructural Study of Some Pollen Grains of Prairie Flowers

    ERIC Educational Resources Information Center

    Kozar, Frank

    1973-01-01

    Discusses the importance of the electron microscope, and in particular the scanning electron microscope, in studying the surface topography, sectional substructures, and patterns of development of pollen grains. The production, dispersal methods, and structure of pollen grains are described and illustrated with numerous electron micrographs. (JR)

  7. Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance.

    PubMed

    Amari, Khalid; Burgos, Lorenzo; Pallas, Vicente; Sanchez-Pina, María Amelia

    2007-08-01

    ABSTRACT The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by approximately 24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

  8. Calcium in pollen-pistil interaction in Petunia hybrida Hort. I. Localization of Ca2+ ions in mature pollen grain using pyroantimonate and autoradiographic methods.

    PubMed

    Bednarska, E; Butowt, R

    1994-01-01

    The localization of Ca2+ in the mature pollen grain and the flow of these ions from the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca2+ ions have been localized in the sporoderm and in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grain.

  9. Interaction Between Air Pollutants and Pollen Grains: The Role on the Rising Trend in Allergy

    PubMed Central

    Sedghy, Farnaz; Varasteh, Abdol-Reza; Sankian, Mojtaba; Moghadam, Malihe

    2018-01-01

    Asthma and allergic diseases cases have risen in recent decades. Plant pollen is considered as the main aeroallergen causing allergic reactions. According to available data, urban residents experience more respiratory allergies than rural residents mainly due to the interaction between chemical air pollutants and pollen grains. This interaction can occur through several mechanisms; chemical pollutants might facilitate pollen allergen release, act as adjuvants to stimulate IgE-mediated responses, modify allergenic potential, and enhance the expression of some allergens in pollen grains. This review focuses on the most recent theories explaining how air pollutants can interact with pollen grains and allergens. PMID:29766006

  10. Counting pollen grains using readily available, free image processing and analysis software.

    PubMed

    Costa, Clayton M; Yang, Suann

    2009-10-01

    Although many methods exist for quantifying the number of pollen grains in a sample, there are few standard methods that are user-friendly, inexpensive and reliable. The present contribution describes a new method of counting pollen using readily available, free image processing and analysis software. Pollen was collected from anthers of two species, Carduus acanthoides and C. nutans (Asteraceae), then illuminated on slides and digitally photographed through a stereomicroscope. Using ImageJ (NIH), these digital images were processed to remove noise and sharpen individual pollen grains, then analysed to obtain a reliable total count of the number of grains present in the image. A macro was developed to analyse multiple images together. To assess the accuracy and consistency of pollen counting by ImageJ analysis, counts were compared with those made by the human eye. Image analysis produced pollen counts in 60 s or less per image, considerably faster than counting with the human eye (5-68 min). In addition, counts produced with the ImageJ procedure were similar to those obtained by eye. Because count parameters are adjustable, this image analysis protocol may be used for many other plant species. Thus, the method provides a quick, inexpensive and reliable solution to counting pollen from digital images, not only reducing the chance of error but also substantially lowering labour requirements.

  11. Are relationships between pollen-ovule ratio and pollen and seed size explained by sex allocation?

    PubMed

    Burd, Martin

    2011-10-01

    Positive correlations between pollen-ovule ratio and seed size, and negative correlations between pollen-ovule ratio and pollen grain size have been noted frequently in a wide variety of angiosperm taxa. These relationships are commonly explained as a consequence of sex allocation on the basis of a simple model proposed by Charnov. Indeed, the theoretical expectation from the model has been the basis for interest in the empirical pattern. However, the predicted relationship is a necessary consequence of the mathematics of the model, which therefore has little explanatory power, even though its predictions are consistent with empirical results. The evolution of pollen-ovule ratios is likely to depend on selective factors affecting mating system, pollen presentation and dispensing, patterns of pollen receipt, pollen tube competition, female mate choice through embryo abortion, as well as genetic covariances among pollen, ovule, and seed size and other reproductive traits. To the extent the empirical correlations involving pollen-ovule ratios are interesting, they will need explanation in terms of a suite of selective factors. They are not explained simply by sex allocation trade-offs. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  12. Aerobiological investigation and in vitro studies of pollen grains from 2 dominant avenue trees in Kolkata, India.

    PubMed

    Mandal, J; Roy, I; Chatterjee, S; Gupta-Bhattacharya, S

    2008-01-01

    Peltophorum pterocarpum and Delonix regia are dominant avenue trees in the city of Kolkata in India. They are well adapted to the humid tropical climate and also grow commonly in different parts of the country. Their pollen grains are reported to be airborne. The aim of this study was to conduct an aerobiological survey in Kolkata to determine the concentration and seasonal periodicity of pollen grains from P pterocarpum and D regia and to analyze the meteorological factors responsible for their levels in the atmosphere. In addition, we analyzed the prevalence of sensitization due to these grains among patients with seasonal respiratory allergy. An aerobiological survey was conducted with a volumetric Burkard sampler from 2004 to 2006. Correlations between meteorological parameters and pollen grain concentrations were assessed by Spearman correlation test. The protein profile of the pollen extracts was studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Finally, the allergenic potential of the pollen extracts was evaluated in patients with respiratory allergy by skin prick test, immunoglobulin (Ig) E enzyme-linked immunosorbent assay, and IgE immunoblotting. P pterocarpum and D regia pollen grains occur from March to June and April to July, respectively. The pollen concentrations showed statistically significant positive correlations with maximum temperature and wind speed. Positive reactions to P pterocarpum and D regia were observed in 26% and 22% of the patients, respectively. Many protein bands were detected in the pollen extracts over a wide molecular weight range. A total of 5 (P pterocarpum pollen) and 8 (D regia pollen) protein fractions were detected by IgE immunoblotting. P pterocarpum and D regia pollen grains are dominant in the atmosphere of south Kolkata and they are influenced by temperature. The pollen grains release proteins that may be responsible for immediate hypersensitivity reactions in sensitive patients.

  13. Analysis of the meiotic transcriptome reveals the genes related to the regulation of pollen abortion in cytoplasmic male-sterile pepper (Capsicum annuum L.).

    PubMed

    Qiu, Yilan; Liao, Lijuan; Jin, Xiaorui; Mao, Dandan; Liu, Rushi

    2018-01-30

    CMS, which refers to the inability to generate functional pollen grains while still producing a normal gynoecium, has been widely used for pepper hybrid seed production. Pepper line 8214A is an excellent CMS line exhibiting 100% male sterility and superior economic characteristics. A TUNEL assay revealed the nuclear DNA is damaged in 8214A PMCs during meiosis. TEM images indicated that the 8214A PMCs exhibited asynchronous meiosis after prophase I, and some PMCs degraded prematurely with morphological features typical of PCD. Additionally, at the end of meiosis, the 8214A PMCs formed abnormal non-tetrahedral tetrads that degraded in situ. To identify the genes involved in the pollen abortion of line 8214A, the transcriptional profiles of the 8214A and the 8214B anthers (i.e., from the fertile maintainer line) during meiosis were analyzed using an RNA-seq approach. A total of 1355 genes were determined to be differentially expressed, including 424 and 931 up- and down- regulated genes, respectively, in the 8214A anthers during meiosis relative to the expression levels in the 8214B. The expression levels of ubiquitin ligase and cell cycle-related genes were apparently down-regulated, while the expression of methyltransferase genes was up-regulated in the 8214A anthers during meiosis, which likely contributed to the PCD of these PMCs during meiosis. Thus, our results may be useful for revealing the molecular mechanism regulating the pollen abortion of CMS pepper. Copyright © 2017. Published by Elsevier B.V.

  14. Authentication of bee pollen grains in bright-field microscopy by combining one-class classification techniques and image processing.

    PubMed

    Chica, Manuel

    2012-11-01

    A novel method for authenticating pollen grains in bright-field microscopic images is presented in this work. The usage of this new method is clear in many application fields such as bee-keeping sector, where laboratory experts need to identify fraudulent bee pollen samples against local known pollen types. Our system is based on image processing and one-class classification to reject unknown pollen grain objects. The latter classification technique allows us to tackle the major difficulty of the problem, the existence of many possible fraudulent pollen types, and the impossibility of modeling all of them. Different one-class classification paradigms are compared to study the most suitable technique for solving the problem. In addition, feature selection algorithms are applied to reduce the complexity and increase the accuracy of the models. For each local pollen type, a one-class classifier is trained and aggregated into a multiclassifier model. This multiclassification scheme combines the output of all the one-class classifiers in a unique final response. The proposed method is validated by authenticating pollen grains belonging to different Spanish bee pollen types. The overall accuracy of the system on classifying fraudulent microscopic pollen grain objects is 92.3%. The system is able to rapidly reject pollen grains, which belong to nonlocal pollen types, reducing the laboratory work and effort. The number of possible applications of this authentication method in the microscopy research field is unlimited. Copyright © 2012 Wiley Periodicals, Inc.

  15. The Epidermal Cell Structure of the Secondary Pollen Presenter in Vangueria infausta (Rubiaceae: Vanguerieae) Suggests a Functional Association with Protruding Onci in Pollen Grains

    PubMed Central

    Tilney, Patricia M.; van Wyk, Abraham E.; van der Merwe, Chris F.

    2014-01-01

    Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex dehisce and release pollen grains which adhere to the pollen presenter. The epidermal cells of the pollen presenter facing the anthers are radially elongated with a characteristic wall thickening encircling the anticlinal walls of each cell towards the distal end. These cells were studied in the pollen presenter of Vangueria infausta using electron and light microscopy in conjunction with histochemical tests and immunohistochemical methods. Other prominent thickenings of the cell wall were also observed on the distal and proximal walls. All these thickenings were found to be rich in pectin and possibly xyloglucan. The terms “thickenings of Igersheim” and “bands of Igersheim” are proposed to refer, respectively, to these wall structures in general and those encircling the anticlinal walls of each cell near the distal end. The epidermal cells have an intricate ultrastructure with an abundance of organelles, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and secretory vesicles. This indicates that these cells are likely to have an active physiological role. The pollen grains possess prominent protruding onci and observations were made on their structure and development. Walls of the protruding onci are also rich in pectin. Pectins are hydrophilic and known to be involved in the dehydration and rehydration of pollen grains. We hypothesise that the thickenings of Igersheim, as well as the protruding onci of the pollen grains, are functionally associated and part of the adaptive syndrome of secondary pollen presentation, at least in the

  16. Effectiveness of traffic-related elements in tree bark and pollen abortion rates for assessing air pollution exposure on respiratory mortality rates.

    PubMed

    Carvalho-Oliveira, Regiani; Amato-Lourenço, Luís F; Moreira, Tiana C L; Silva, Douglas R Rocha; Vieira, Bruna D; Mauad, Thais; Saiki, Mitiko; Saldiva, Paulo H Nascimento

    2017-02-01

    The majority of epidemiological studies correlate the cardiorespiratory effects of air pollution exposure by considering the concentrations of pollutants measured from conventional monitoring networks. The conventional air quality monitoring methods are expensive, and their data are insufficient for providing good spatial resolution. We hypothesized that bioassays using plants could effectively determine pollutant gradients, thus helping to assess the risks associated with air pollution exposure. The study regions were determined from different prevalent respiratory death distributions in the Sao Paulo municipality. Samples of tree flower buds were collected from twelve sites in four regional districts. The genotoxic effects caused by air pollution were tested through a pollen abortion bioassay. Elements derived from vehicular traffic that accumulated in tree barks were determined using energy-dispersive X-ray fluorescence spectrometry (EDXRF). Mortality data were collected from the mortality information program of Sao Paulo City. Principal component analysis (PCA) was applied to the concentrations of elements accumulated in tree barks. Pearson correlation and exponential regression were performed considering the elements, pollen abortion rates and mortality data. PCA identified five factors, of which four represented elements related to vehicular traffic. The elements Al, S, Fe, Mn, Cu, and Zn showed a strong correlation with mortality rates (R 2 >0.87) and pollen abortion rates (R 2 >0.82). These results demonstrate that tree barks and pollen abortion rates allow for correlations between vehicular traffic emissions and associated outcomes such as genotoxic effects and mortality data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Poor correlation between the removal or deposition of pollen grains and frequency of pollinator contact with sex organs

    NASA Astrophysics Data System (ADS)

    Sakamoto, Ryota L.; Morinaga, Shin-Ichi

    2013-09-01

    Pollinators deposit pollen grains on stigmas and remove pollen grains from anthers. The mechanics of these transfers can now be quantified with the use of high-speed video. We videoed hawkmoths, carpenter bees, and swallowtail butterflies pollinating Clerodendrum trichotomum. The number of grains deposited on stigmas did not vary significantly with the number of times pollinators contacted stigmas. In contrast, pollen removal from the anthers increased significantly with the number of contacts to anthers. Pollen removal varied among the three types of pollinators. Also, the three types carried pollen on different parts of their bodies. In hawkmoths and carpenter bees, a large number of contacted body part with anthers differed significantly from the body part that attached a large number of pollen grains. Our results indicate that a large number of contacts by pollinators does not increase either the male or female reproductive success of plants compared to a small number of contacts during a visit.

  18. Comparative Actions of Barbiturates Studied by Pollen Grain Germination.

    ERIC Educational Resources Information Center

    Kordan, Herbert A.; Mumford, Pauline M.

    1979-01-01

    Describes a simple experimental system whereby the comparative actions of long, medium, and short-acting barbiturates can be demonstrated in a relatively short period of time under optical microscopy using pollen grains as the biological test or assay system. (Author/HM)

  19. Pollen donor composition during the early phases of reproduction revealed by DNA genotyping of pollen grains and seeds of Castanea crenata.

    PubMed

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2009-06-01

    In plants, pollen donor composition can differ during the early phases of reproduction through various selection mechanisms favouring self, related or nonrelated pollen donors, but such differences have not been examined under natural conditions because paternity is difficult to analyse in a natural setting. Here, we performed paternity analyses based on microsatellite genotyping of individual pollen grains deposited on female flowers (n = 773) and seeds (n = 304) to evaluate pollen donor composition from three individuals of the insect-pollinated monoecious tree Castanea crenata in a natural forest. Spatial genetic structure was also investigated. A mean self-pollen rate of 90.2% was observed at the pollination stage, but a low selfing rate of 0.3% was observed at the seed stage. In outcross events, however, pairwise distance and relatedness between maternal and paternal parents were not different between pollination and seed stages. We also observed significant positive relatedness, based on clear fine-scale genetic structure of individual trees within 80 m of one another, and 71% of seeds were derived using pollen grains of related trees within 80 m. The results suggest that the mechanism of self-incompatibility strongly avoids self-pollen before seed production. However, the avoidance of biparental inbreeding was not obvious between pollination and seed stages.

  20. The potential for adaptive evolution of pollen grain size in Mimulus guttatus.

    PubMed

    Lamborn, Ellen; Cresswell, James E; Macnair, Mark R

    2005-07-01

    We tested whether pollen grain size (PGS) shows heritable variation in three independent populations of Mimulus guttatus by imposing artificial selection for this character. In addition, we looked for correlated responses to selection in a range of 15 other floral characters. Heritable variation in PGS was found in all three populations, with heritabilities of between 19 and 40% (average 30%). After three generations, upward and downward lines differed on average by 30% in pollen volume. No consistent patterns of correlated response were found in other characters, indicating that PGS can respond to selective forces acting on PGS alone. Possible selection mechanisms on PGS in this species could include intermale selection, if large pollen grains produce more competitive gametophytes; or optimization of patterns of resource allocation, if local mate competition varies.

  1. [Does a lateral gradient of membrane potential on the plasma membrane of growing pollen tube of germinating pollen grain exist?].

    PubMed

    Andreev, I M

    2011-01-01

    The data presented in the article by Breigina et al. (2009) "Changes in the membrane potential during pollen grain germination and pollen tube growth" (Tsitologiya. 51 (10): 815-823) and concerning the measurement of electric membrane potential (Delta Psi) on the plasma membrane of growing pollen tube of germinating pollen grain with the use of fluorescent potential-sensitive dye, di-4-ANEPPS, were critically analyzed in order to clarify whether a lateral gradient of Delta Psi on this membrane indeed exists. This analysis showed that the main conclusion of the authors of the above article on the existence of polar distribution of Delta Psi along the pollen tube plasma membrane is not in accordance with a number of known peculiarities of di-4-ANEPPS behavior in biological membranes and requires a significant revision. The findings in question reported by the authors, in my opinion, might be interpreted as evidence for the presence on the plasma membrane of growing pollen tube not only the membrane potential Delta Psi but also lateral gradient of so called intra-membrane dipole potential. Based on the comments made, another interpretation of the experimental results described by Breigina et al. has been offered. In addition, some drawbacks in the methodology used by the authors for measurement of Delta Psi with other fluorescent potential-sensitive dye, DiBAC3(3), are also shortly considered.

  2. Molecular-Assisted Pollen Grain Analysis Reveals Spatiotemporal Origin of Long-Distance Migrants of a Noctuid Moth

    PubMed Central

    Chang, Hong; Guo, Jianglong; Fu, Xiaowei; Liu, Yongqiang; Wyckhuys, Kris A. G.; Hou, Youming

    2018-01-01

    Pollen grains are regularly used as markers to determine an insect’s movement patterns or host (plant) feeding behavior, yet conventional morphology-based pollen grain analysis (or palynology) encounters a number of important limitations. In the present study, we combine conventional analytical approaches with DNA meta-barcoding to identify pollen grains attached to migrating adults of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae) in Northeast China. More specifically, pollen grains were dislodged from 2566 A. segetum long-distance migrants captured on Beihuang Island (Bohai Sea) and identified to many (plant) species level. Pollen belonged to 26 families of plants, including Fagaceae, Oleaceae, Leguminosae, Asteraceae, Pinaceae and Rosaceae, including common species such as Citrus sinensis, Olea europaea, Ligustrum lucidum, Robinia pseudoacacia, Castanopsis echinocarpa, Melia azedarach and Castanea henryi. As the above plants are indigenous to southern climes, we deduce that A. segetum forage on plants in those locales prior to engaging in northward spring migration. Our work validates the use of DNA-assisted approaches in lepidopteran pollination ecology research and provides unique and valuable information on the adult feeding range and geographical origin of A. segetum. Our findings also enable targeted (area-wide) pest management interventions or guide the future isolation of volatile attractants. PMID:29438348

  3. 3D imaging of a rice pollen grain using transmission X-ray microscopy.

    PubMed

    Wang, Shengxiang; Wang, Dajiang; Wu, Qiao; Gao, Kun; Wang, Zhili; Wu, Ziyu

    2015-07-01

    For the first time, the three-dimensional (3D) ultrastructure of an intact rice pollen cell has been obtained using a full-field transmission hard X-ray microscope operated in Zernike phase contrast mode. After reconstruction and segmentation from a series of projection images, complete 3D structural information of a 35 µm rice pollen grain is presented at a resolution of ∼100 nm. The reconstruction allows a clear differentiation of various subcellular structures within the rice pollen grain, including aperture, lipid body, mitochondrion, nucleus and vacuole. Furthermore, quantitative information was obtained about the distribution of cytoplasmic organelles and the volume percentage of each kind of organelle. These results demonstrate that transmission X-ray microscopy can be quite powerful for non-destructive investigation of 3D structures of whole eukaryotic cells.

  4. Carbon-isotopic analysis of individual pollen grains from C 3 and C 4 grasses using a spooling-wire microcombustion interface

    NASA Astrophysics Data System (ADS)

    Nelson, David M.; Hu, Feng Sheng; Mikucki, Jill A.; Tian, Jian; Pearson, Ann

    2007-08-01

    Pollen grains from grasses using the C 3 and C 4 photosynthetic pathways have distinct ranges of δ 13C values that may be used to estimate their relative abundance in paleorecords. We evaluated a spooling-wire microcombustion device interfaced with an isotope-ratio mass spectrometer (SWiM-IRMS) for δ 13C analysis of individual grass-pollen grains. Pollen from four C 3 and four C 4 grass species was isolated through micromanipulation and analyzed as single grains suspended in water. A carbon yield greater than the 2 σ range of the carbon content of blanks containing only water was used to distinguish samples containing pollen ("pollen present") from those not containing pollen. This criterion resulted in the exclusion of ˜45% of the 946 samples applied to the wire. The average δ 13C values (±1 σ) of the remaining samples were -26.9‰ (±6.3‰) and -11.5‰ (±9.6‰) for C 3 grasses and C 4 grasses, respectively, after blank-correcting the δ 13C data. These results suggest that the SWiM-IRMS system can be used to distinguish C 3 from C 4 grass pollen. The high variability in measured δ 13C values is likely caused by a combination of factors. These include natural isotopic variability among individual pollen grains; the relatively poor precision that can be obtained when determining δ 13C values of such small samples; and the uncertainty in the magnitude, isotopic composition, and stability of the analytical blank. Nonetheless, high percentages of individual pollen grains were correctly classified as being of either C 3 or C 4 origin. On average, 90% (range = 78-100%) of pollen grains from C 3 grasses had δ 13C values more negative than the cutoff threshold of -19.2‰; while 84% (range = 77-90%) of pollen grains from C 4 grasses had δ 13C values more positive than -19.2‰. Compared with analysis using an elemental analyzer interfaced with an IRMS (EA-IRMS), the number of pollen grains required for δ 13C-based evaluation of C 3/C 4 grass composition

  5. Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

    PubMed

    House, Alisoun; Balkwill, Kevin

    2016-03-01

    External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance.

  6. Seed abortion in wind-dispersed pods of Dalbergia sissoo: maternal regulation or sibling rivalry?

    PubMed

    Ganeshaiah, K N; Shaanker, R Uma

    1988-10-01

    Dalbergia sissoo, a wind-dispersed tropical tree, shows a positively skewed distribution of seeds per pod. This is attributed to the enhanced dispersal advantage of few-seeded pods due to their reduced wing loading (ratio of weight to pod surface area) and low settling velocity. The proximate mechanisms causing the positively skewed distribution were investigated. The distribution could not be attributed to the distribution pattern of ovule number per ovary, pollen grain limitation, lack of ovule fertilization, or post-fertilization elimination of many-seeded pods. Rather, it was caused by the post-fertilization abortion of seeds within a pod 2 weeks after fertilization. This intra-pod seed abortion (IPSA) is due to a dominance hierarchy of fertilized ovules from the distal (near stigma) to the basal end, generated by the temporal differences in fertilization. The dominant developing seeds at the distal end cause the abortion of others through the production and diffusion of an aborting agent. When the dominance hierarchy of the siblings is not intense, pods are formed with more than one seed. We argue that the positively skewed distribution of seeds per pod is not due to maternal regulation but is a result of sibling rivalry. We propose that this sibling rivalry is generated by genetic differences in pollen grain fitness and disucss the results in the context of parent-offspring conflict.

  7. Biomonitoring of pollen grains of a river bank suburban city, Konnagar, Calcutta, India, and its link and impact on local people.

    PubMed

    Ghosal, Kavita; Pandey, Naren; Bhattacharya, Swati Gupta

    2015-01-01

    Pollen grains released by plants are dispersed into the air and can become trapped in human nasal mucosa, causing immediate release of allergens triggering severe Type 1 hypersensitivity reactions in susceptible allergic patients. Recent epidemiologic data show that 11-12% of people suffer from this type of disorders in India. Hence, it is important to examine whether pollen grains have a role in dissipating respiratory problems, including allergy and astma, in a subtropical suburban city. Meteorological data were collected for a period of two years, together with aerobiological sampling with a Burkard sampler. A pollen calendar was prepared for the city. A health survey and the hospitalization rate of local people for the above problems were documented following statistical analysis between pollen counts and the data from the two above-mentioned sources. Skin Prick Test and Indirect ELISA were performer for the identification of allergenic pollen grains. Bio-monitoring results showed that a total of 36 species of pollen grains were located in the air of the study area, where their presence is controlled by many important meteorological parameters proved from SPSS statistical analysis and by their blooming periods. Statistical analysis showed that there is a high positive correlation of monthly pollen counts with the data from the survey and hospital. Biochemical tests revealed the allergic nature of pollen grains of many local species found in the sampler. Bio-monitoring, together with statistical and biochemical results, leave no doubt about the role of pollen as a bio-pollutant. General knowledge about pollen allergy and specific allergenic pollen grains of a particular locality could be a good step towards better health for the cosmopolitan suburban city.

  8. Rice No Pollen 1 (NP1) is required for anther cuticle formation and pollen exine patterning.

    PubMed

    Liu, Ze; Lin, Sen; Shi, Jianxin; Yu, Jing; Zhu, Lu; Yang, Xiujuan; Zhang, Dabing; Liang, Wanqi

    2017-07-01

    Angiosperm male reproductive organs (anthers and pollen grains) have complex and interesting morphological features, but mechanisms that underlie their patterning are poorly understood. Here we report the isolation and characterization of a male sterile mutant of No Pollen 1 (NP1) in rice (Oryza sativa). The np1-4 mutant exhibited smaller anthers with a smooth cuticle surface, abnormal Ubisch bodies, and aborted pollen grains covered with irregular exine. Wild-type exine has two continuous layers; but np1-4 exine showed a discontinuous structure with large granules of varying size. Chemical analysis revealed reduction in most of the cutin monomers in np1-4 anthers, and less cuticular wax. Map-based cloning suggested that NP1 encodes a putative glucose-methanol-choline oxidoreductase; and expression analyses found NP1 preferentially expressed in the tapetal layer from stage 8 to stage 10 of anther development. Additionally, the expression of several genes involved in biosynthesis and in the transport of lipid monomers of sporopollenin and cutin was decreased in np1-4 mutant anthers. Taken together, these observations suggest that NP1 is required for anther cuticle formation, and for patterning of Ubisch bodies and the exine. We propose that products of NP1 are likely important metabolites in the development of Ubisch bodies and pollen exine, necessary for polymerization, assembly, or both. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  9. Developmental and ultrastructural characters of the pollen grains and tapetum in species of Nymphaea subgenus Hydrocallis.

    PubMed

    Zini, Lucía Melisa; Galati, Beatriz Gloria; Zarlavsky, Gabriela; Ferrucci, María Silvia

    2017-07-01

    Variations in pollen characters and tapetum behavior were recently acknowledged in the early-divergent family Nymphaeaceae and even within the genus Nymphaea, which probably is not monophyletic; some traits such as infratectum and tapetum type are also a matter of different interpretations. In this study, developmental characters of the pollen grains and tapetum in Nymphaea subgenus Hydrocallis are provided for the first time. Observations were made in N. amazonum, N. gardneriana, and N. prolifera using light, scanning, and transmission electron microscopy. Tapetum is of the secretory type and produces orbicules. At microspore and pollen grain stages, the distal and proximal walls differ considerably. This result supports the operculate condition of the aperture in Hydrocallis, and such aperture might be plesiomorphic for Nymphaeoideae. The infratectum is intermediate, composed of inter-columellae granular elements, robust columellae consisting of agglomerated granules, complete columellae, and fused columellae. Narrow microchannels are present and persist until the mature pollen grain stage. The membranous granular layer is often present in the pollen grains of Nymphaeaceae. In N. gardneriana, this layer is most probably a component of the intine because it is lost after acetolysis. Orbicules in the Nymphaeaceae are characterized as spherical or subspherical, with a smooth sporopolleninic wall that surrounds an electron-lucent core and with individual orbicules that usually merge to give irregular aggregations. The aperture, pollen wall ultrastructure, and the tapetum of the studied species are discussed in an evolutionary and systematic context, and these characters are also compared with those of other angiosperm lineages.

  10. Biphasic regulation of the transcription factor ABORTED MICROSPORES (AMS) is essential for tapetum and pollen development in Arabidopsis.

    PubMed

    Ferguson, Alison C; Pearce, Simon; Band, Leah R; Yang, Caiyun; Ferjentsikova, Ivana; King, John; Yuan, Zheng; Zhang, Dabing; Wilson, Zoe A

    2017-01-01

    Viable pollen is essential for plant reproduction and crop yield. Its production requires coordinated expression at specific stages during anther development, involving early meiosis-associated events and late pollen wall formation. The ABORTED MICROSPORES (AMS) transcription factor is a master regulator of sporopollenin biosynthesis, secretion and pollen wall formation in Arabidopsis. Here we show that it has complex regulation and additional essential roles earlier in pollen formation. An inducible-AMS reporter was created for functional rescue, protein expression pattern analysis, and to distinguish between direct and indirect targets. Mathematical modelling was used to create regulatory networks based on wild-type RNA and protein expression. Dual activity of AMS was defined by biphasic protein expression in anther tapetal cells, with an initial peak around pollen meiosis and then later during pollen wall development. Direct AMS-regulated targets exhibit temporal regulation, indicating that additional factors are associated with their regulation. We demonstrate that AMS biphasic expression is essential for pollen development, and defines distinct functional activities during early and late pollen development. Mathematical modelling suggests that AMS may competitively form a protein complex with other tapetum-expressed transcription factors, and that biphasic regulation is due to repression of upstream regulators and promotion of AMS protein degradation. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  11. Skin tests of pollen grains of taxodiaceae and cupressaceae in children with bronchial asthma.

    PubMed

    Midoro-Horiuti, T; Nouno, S; Seino, Y

    1992-10-01

    Atmospheric cedar pollen in the southern region of Okayama Prefecture (situated in south-western Japan) has been counted since 1988. Pollen of different species of the Taxodiaceae family (Cryptomeria japonica, Sequoia sempervirens and Metasequoia glyptostroboides) and Japanese juniper (Juniperus rigida) in the Cupressaceae family, which are propagated mainly in the southern region of Okayama Prefecture, were found among the atmospheric pollen. Scratch tests using the pollen extract from Taxodiaceae and Cupressaceae were performed on children with bronchial asthma. Forty (25%) and 30 (18.8%) of the 160 patients reacted positively to an allergen extract from the pollen grains of Japanese cedar (Cryptomeria japonica) and Japanese juniper, respectively.

  12. Wettable and Unsinkable: The Hydrodynamics of Saccate Pollen Grains in Relation to the Pollination Mechanism in the Two New Zealand Species of Prumnopitys Phil. (Podocarpaceae)

    PubMed Central

    SALTER, JOSHUA; MURRAY, BRIAN G.; BRAGGINS, JOHN E.

    2002-01-01

    The pollination mechanism of most genera of the Podocarpaceae involves inverted ovules, a pollination drop and bisaccate pollen grains. Saccate grains have sometimes been referred to as ‘non‐wettable’ due to their buoyant properties, while non‐saccate pollen grains have been described as ‘wettable’. The hydrodynamic properties of saccate pollen grains of seven podocarp species in five genera, Dacrydium Sol. ex G. Forst., Dacrycarpus (Endl.) de Laub., Manoao Molloy, Podocarpus L‘Hér. ex Pers. and Prumnopitys Phil. have been tested in water, together with saccate and non‐saccate pollen of four other conifer genera, Cedrus Trew (Pinaceae), Cephalotaxus Siebold & Zucc. ex Endl. (Cephalotaxaceae), Cupressus L. (Cupressaceae) and Phyllocladus Rich. ex Mirb. (Phyllocladaceae), and spores of three fern species and one lycopod species. All four spore types studied were non‐wettable, whereas the bisaccate and trisaccate pollen types, like all other conifer pollen types, were wettable, enabling the grains to cross the surface tension barrier of water. Once past this barrier, grain behaviour was governed by presence or absence of sacci. Non‐saccate and vestigially saccate grains sank, whereas saccate grains behaved like air bubbles, floating up to the highest point. In addition, the grains were observed to float in water with sacci uppermost, consistent with the suggestion that distally placed sacci serve to orientate the germinal furrow of the pollen grain towards the nucellus of an inverted ovule. Observations of pollen grains in the pollen chambers of naturally pollinated Prumnopitys ovules confirmed this. The combination of buoyancy and wettability in saccate pollen has implications for the efficiency of the typical podocarp pollination mechanism. PMID:12099344

  13. Over-expression of miR158 causes pollen abortion in Brassica campestris ssp. chinensis.

    PubMed

    Ma, Zhiming; Jiang, Jianxia; Hu, Ziwei; Lyu, Tianqi; Yang, Yang; Jiang, Jingjing; Cao, Jiashu

    2017-02-01

    We identified and cloned the two precursors of miR158 and its target gene in Brassica campestris ssp. chinensis, which both had high relative expression in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility, which was caused by the degradation of pollen contents from the binucleate microspore stage. These results first suggest the role of miR158 in pollen development of Brassica campestris ssp. chinensis. MicroRNAs (miRNAs) play crucial roles in many important growth and development processes both in plants and animals by regulating the expression of their target genes via mRNA cleavage or translational repression. In this study, miR158, a Brassicaceae specific miRNA, was functionally characterized with regard to its role in pollen development of non-heading Chinese cabbage (Brassica campestris ssp. chinensis). Two family members of miR158 in B. campestris, namely bra-miR158a1 and bra-miR158a2, and their target gene bra027656, which encodes a pentatricopeptide repeat (PPR) containing protein, were identified. Then, qRT-PCR analysis and GUS-reporter system revealed that both bra-miR158 and its target gene had relatively high expression levels in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility and pollen germination ratio, and the degradation of pollen contents from the binucleate microspore stage was also found in those deformed pollen grains, which led to pollen shrinking and collapse in later pollen development stage. These results first shed light on the importance of miR158 in pollen development of Brassica campestris ssp. chinensis.

  14. Concentrations of major grass group 5 allergens in pollen grains and atmospheric particles: implications for hay fever and allergic asthma sufferers sensitized to grass pollen allergens.

    PubMed

    Schäppi, G F; Taylor, P E; Pain, M C; Cameron, P A; Dent, A W; Staff, I A; Suphioglu, C

    1999-05-01

    Grass pollen allergens are the most important cause of hay fever and allergic asthma during summer in cool temperate climates. Pollen counts provide a guide to hay fever sufferers. However, grass pollen, because of its size, has a low probability of entering the lower airways to trigger asthma. Yet, grass pollen allergens are known to be associated with atmospheric respirable particles. We aimed (1) to determine the concentration of group 5 major allergens in (a) pollen grains of clinically important grass species and (b) atmospheric particles (respirable and nonrespirable) and (2) to compare the atmospheric allergen load with clinical data to assess different risk factors for asthma and hay fever. We have performed a continuous 24 h sampling of atmospheric particles greater and lower than 7.2 microm in diameter during the grass pollen season of 1996 and 1997 (17 October 1996-16 January 1997) by means of a high volume cascade impactor at a height of about 15 m above ground in Melbourne. Using Western analysis, we assessed the reactivity of major timothy grass allergen Phl p 5 specific monoclonal antibody (MoAb) against selected pollen extracts. A MoAb-based ELISA was then employed to quantify Phl p 5 and cross-reactive allergens in pollen extracts and atmospheric particles larger and smaller than 7.2 microm. Phl p 5-specific MoAb detected group 5 allergens in tested grass pollen extracts, indicating that the ELISA employed here determines total group 5 allergen concentrations. On average, 0.05 ng of group 5 allergens were detectable per grass pollen grain. Atmospheric group 5 allergen concentrations in particles > 7.2 microm were significantly correlated with grass pollen counts (rs = 0.842, P < 0. 001). On dry days, 37% of the total group 5 allergen load, whereas upon rainfall, 57% of the total load was detected in respirable particles. After rainfall, the number of starch granule equivalents increased up to 10-fold; starch granule equivalent is defined as a

  15. Does stronger pollen competition improve offspring fitness when pollen load does not vary?

    PubMed

    Pélabon, Christophe; Hennet, Lauriane; Bolstad, Geir H; Albertsen, Elena; Opedal, Øystein H; Ekrem, Runa K; Armbruster, W Scott

    2016-03-01

    Competition among pollen grains from a single donor is expected to increase the quality of the offspring produced because of the recessive deleterious alleles expressed during pollen-tube growth. However, evidence for such an effect is inconclusive; a large number of studies suffer from confounding variation in pollen competition with variation in pollen load. In this study, we tested the effect of pollen competition on offspring performance independently of pollen-load variation. We compared seed mass and early seedling performance in Dalechampia scandens (Euphorbiaceae) between crosses in which variation in pollen competition was achieved, without variation in pollen load, by manipulating the dispersion of pollen grains on the stigmas. Despite a large sample size (211 crosses on 20 maternal plants), we failed to find an effect of pollen competition on seed characteristics or early seedling performance. Paternal effects were always limited, and pollen competition never reduced the within-father (residual) variance. These results suggest that limited within-donor variation in genetic quality of pollen grains reduces the potential benefits of pollen competition in the study population. The lack of paternal effects on early sporophyte performance further suggests that benefits of pollen competition among pollen from multiple donors should be limited as well, and it raises questions about the significance of pollen competition as a mechanism of sexual selection. © 2016 Botanical Society of America.

  16. Whole genome amplification of single pollen grains from a sugarcane cultivar and analysis of the genetic relatedness based on SCoT markers

    USDA-ARS?s Scientific Manuscript database

    Single pollen grains were isolated from an intact anther of a sugarcane cultivar and collected using a pair of special forceps. The single pollen grains were lysed in an alkali/detergent solution respectively. The resulting solution was used as the template for Whole Genome Amplification. Genomic DN...

  17. BcMF11, a novel non-coding RNA gene from Brassica campestris, is required for pollen development and male fertility.

    PubMed

    Song, Jiang-Hua; Cao, Jia-Shu; Wang, Cheng-Gang

    2013-01-01

    KEY MESSAGE : BcMF11 as a non-coding RNA gene has an essential role in pollen development, and might be useful for regulating the pollen fertility of crops by antisense RNA technology. We previously identified a 828-bp full-length cDNA of BcMF11, a novel pollen-specific non-coding mRNA-like gene from Chinese cabbage (Brassica campestris L. ssp. chinensis Makino). However, little information is known about the function of BcMF11 in pollen development. To investigate its exact biological roles in pollen development, the BcMF11 cDNA was antisense inhibited in transgenic Chinese cabbage under the control of a tapetum-specific promoter BcA9 and a constitutive promoter CaMV 35S. Antisense RNA transgenic plants displayed decreasing expression of BcMF11 and showed distinct morphological defects. Pollen germination test in vitro and in vivo of the transgenic plants suggested that inhibition of BcMF11 decreased pollen germination efficiency and delayed the pollen tubes' extension in the style. Under scanning electron microscopy, many shrunken and collapsed pollen grains were detected in the antisense BcMF11 transgenic Chinese cabbage. Further cytological observation revealed abnormal pollen development process in transgenic plants, including delayed degradation of tapetum, asynchronous separation of microspore, and aborted development of pollen grain. These results suggest that BcMF11, as a non-coding RNA, plays an essential role in pollen development and male fertility.

  18. Pollen selection under acid rain stress

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Y.

    To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations inmore » vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.« less

  19. Pollen-imprinted polyurethanes for QCM allergen sensors.

    PubMed

    Jenik, Michael; Seifner, Alexandra; Lieberzeit, Peter; Dickert, Franz L

    2009-05-01

    Molecularly imprinted polymers for detecting plant pollen were designed as artificial recognition materials for quartz crystal microbalances in the gaseous phase. Imprints of birch (diameter, 25 mum) and nettle (diameter, 15 mum) pollen can be generated by polydimethylsiloxane stamping technique as proven by atomic force microscopy. If pollen grains are able to access the cavities and thus are incorporated, the resulting sensors display Sauerbrey-like negative frequency shifts. Non-Sauerbrey behaviour can be observed as soon as pollen is prevented from entering the selective hollows: this results in grain mobility on the electrode surface leading to frequency increases. Access to the cavities is determined by the diameter ratio between pollen grains and imprints as can be revealed during cross-selectivity measurements of nettle and birch pollen imprinted layers. When the amount of pollen grains on the electrode surface exceeds the number of available imprints, the excess particles move freely, resulting in positive, non-Sauerbrey frequency shifts.

  20. A 12,000-Yr Pollen Record off Cape Hatteras: Pollen Sources and Mechanisms of Pollen Dispersion

    NASA Technical Reports Server (NTRS)

    Naughton, F.; Keigwin, L.; Peteet, D.; Costas, S.; Desprat, S.; Oliveira, D.; de Vernal, A.; Voelker, A.; Abrantes, F.

    2015-01-01

    Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean-atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100-8800 cal yr BP, 8300-7500 cal yr BP, 5800- 4300 cal yr BP and 2100-730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170-10,150 cal yr BP and 4200- 2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 recordwas not affected by the DeepWestern Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic.

  1. Impact and correlation of environmental conditions on pollen counts in Karachi, Pakistan.

    PubMed

    Perveen, Anjum; Khan, Muneeba; Zeb, Shaista; Imam, Asif Ali

    2015-02-01

    A quantitative and qualitative survey of airborne pollen was performed in the city of Karachi, and the pollen counts were correlated with different climatic conditions. The aim of the study was to determine the possible effect of meteorological factors on airborne pollen distribution in the atmosphere of Karachi city. Pollen sampling was carried out by using Burkard spore Trap for the period of August 2009 to July 2010, and a total of 2,922 pollen grains/m(3) were recorded. In this survey, 22 pollen types were recognized. The highest pollen count was contributed by Poaceae pollen type (1,242 pollen grains/m(3)) followed by Amaranthaceae/Chenopodiaceae (948 pollen grains/m(3)), Cyperus rotundus (195 pollen grains/m(3)) and Prosopis juliflora (169 pollen grains/m(3)). Peak pollen season was in August showing a total of 709 pollen grains/m(3) and lowest pollen count was observed in January-2010. Pearson's chi-square test was performed for the possible correlation of pollen counts and climatic factors. The test revealed significant positive correlation of wind speed with pollen types of Amaranthaceae/Chenopodiaceae; Brassica campestris; Asteraceae; and Thuja orientalis. While the correlation of "average temperature" showed significant positive value with Asteraceae and Tamarix indica pollen types. Negative correlation was observed between humidity/ precipitation and pollen types of Brassica campestris; Daucus carota; Ephedra sp.; and Tamarix indica. In the light of above updated data one could identify various aeroallergens present in the air of Karachi city.

  2. Aerodynamics of saccate pollen and its implications for wind pollination.

    PubMed

    Schwendemann, Andrew B; Wang, George; Mertz, Meredith L; McWilliams, Ryan T; Thatcher, Scott L; Osborn, Jeffrey M

    2007-08-01

    Pollen grains of many wind-pollinated plants contain 1-3 air-filled bladders, or sacci. Sacci are thought to help orient the pollen grain in the pollination droplet. Sacci also increase surface area of the pollen grain, yet add minimal mass, thereby increasing dispersal distance; however, this aerodynamic hypothesis has not been tested in a published study. Using scanning electron and transmission electron microscopy, mathematical modeling, and the saccate pollen of three extant conifers with structurally different pollen grains (Pinus, Falcatifolium, Dacrydium), we developed a computational model to investigate pollen flight. The model calculates terminal settling velocity based on structural characters of the pollen grain, including lengths, widths, and depths of the main body and sacci; angle of saccus rotation; and thicknesses of the saccus wall, endoreticulations, intine, and exine. The settling speeds predicted by the model were empirically validated by stroboscopic photography. This study is the first to quantitatively demonstrate the adaptive significance of sacci for the aerodynamics of wind pollination. Modeling pollen both with and without sacci indicated that sacci can reduce pollen settling speeds, thereby increasing dispersal distance, with the exception of pollen grains having robust endoreticulations and those with thick saccus walls. Furthermore, because the mathematical model is based on structural characters and error propagation methods show that the model yields valid results when sample sizes are small, the flight dynamics of fossil pollen can be investigated. Several fossils were studied, including bisaccate (Pinus, Pteruchus, Caytonanthus), monosaccate (Gothania), and nonsaccate (Monoletes) pollen types.

  3. Atmospheric pollen count in Monterrey, Mexico.

    PubMed

    González-Díaz, Sandra N; Rodríguez-Ortiz, Pablo G; Arias-Cruz, Alfredo; Macías-Weinmann, Alejandra; Cid-Guerrero, Dagoberto; Sedo-Mejia, Giovanni A

    2010-01-01

    There are few reports of pollen count and identification in Mexico; therefore, it is important to generate more information on the subject. This study was designed to describe the prevalence of pollen in the city of Monterrey, Mexico, during the year 2004. Atmospheric pollen was collected with a Hirst air sampler, with an airflow of 10 L/minute during 2004. Pollen was identified with light microscopy; the average monthly pollen count as well as total was calculated from January 2004 to January 2005. The months with the highest concentration of pollen were February and March (289 and 142 grains/m(3) per day, respectively), and July and November had the lowest concentration (20 and 11 grains/m(3) per day, respectively). Most of the pollen recollected corresponded to tree pollen (72%). Fraxinus spp had the highest concentration during the year (19 grains/m(3) per day; 27.5% of the total concentration of pollen). Tree pollen predominated from January through March; with Fraxinus spp, Morus spp, Celtis spp, Cupressus spp, and Pinus spp as the most important. Weed pollen predominated in May, June, and December and the most frequently identified, were Amaranthaceae/Chenopodiaceae, Ambrosia spp, and Parietaria spp. The highest concentration of grass pollen was reported during the months of May, June, September, October, and December with Gramineae/Poaceae predominating. Tree pollen was the most abundant during the year, with the ash tree having the highest concentration. Weed and grass pollen were perennial with peaks during the year.

  4. Differential retention of pollen grains on clothing and the effectiveness of laboratory retrieval methods in forensic settings.

    PubMed

    Webb, Julia C; Brown, Harriet A; Toms, Hannah; Goodenough, Anne E

    2018-07-01

    Forensic palynology has been important in criminal investigation since the 1950s and often provides evidence that is vital in identifying suspects and securing convictions. However, for such evidence to be used appropriately, it is necessary to understand the factors affecting taphonomic variability (i.e. the variability in the fate of pollen grains before they are found during forensic examination). Here, we test the relative amount of pollen retained on clothing after a period of simulated light or heavy wear based on pollen and fabric characteristics. We also test the efficiency of forensic laboratory protocols for retrieving pollen from fabrics for analysis. There was no statistically significant difference in retention of fresh or dried pollen on any fabric type. There was a substantial difference in pollen retention according to wear intensity, with considerably more pollen being retained after light wear than after heavy wear. Pollen from insect-pollinated species was retained at higher concentrations than pollen from wind-pollinated species. This pattern was consistent regardless of wear intensity but pollination type explained more of the variability in pollen retention after light wear. Fabric type was significantly related to pollen retention, but interacted strongly with plant species such that patterns were both complex and highly species-specific. The efficiency of removing pollen with the standard washing protocol differed substantially according to plant species, fabric type, and the interaction between these factors. The average efficiency was 67.7% but this ranged from 21% to 93%, demonstrating that previous assumptions on the reliability of the technique providing a representative sample for forensic use should be reviewed. This paper highlights the importance of understanding pollen and fabric characteristics when creating a pollen profile in criminal investigations and to ensure that evidence used in testimony is accurate and robust. Crown

  5. First annual register of allergenic pollen in Talca, Chile.

    PubMed

    Mardones, P; Grau, M; Araya, J; Córdova, A; Pereira, I; Peñailillo, P; Silva, R; Moraga, A; Aguilera-Insunza, R; Yepes-Nuñez, J J; Palomo, I

    2013-01-01

    There are no data on atmospheric pollen in Talca. In the present work, our aim is to describe the amount of pollen grain in the atmosphere of the city of Talca likely to cause pollinosis of its inhabitants. A volumetric Hirst sampler (Burkard seven-day recording device) was used to study pollen levels. It was placed in the centre of Talca from May 2007 to April 2008. The highest airborne presence of pollen, as measured in weekly averages, was Platanus acerifolia with a maximum weekly daily average of 203 grains/m³ registered during September and October. The second highest was Acer pseudoplatanus with a maximum weekly daily average of 116 grains/m³. Populus spp. had a maximum weekly daily average 103 grains/m³. Olea europaea reached 19 grains/m³ in November. Grasses presented high levels of pollen counts with a maximum weekly daily average of 27 grains/m³ from the end of August until the end of January. Pollens of Plantago spp. Rumex acetosella and Chenopodium spp. had a similar distribution and were present from October to April with maximum weekly daily average of 7 grains/m³, 7 grains/m³ and 3 grains/m³ respectively. Significant concentrations of Ambrosia artemisiifolia were detected from February until April. The population of Talca was exposed to high concentrations of allergenic pollen, such as P. acerifolia, A. pseudoplatanus, and grasses in the months of August through November. The detection of O. europaea and A. artemisiifolia is important as these are emergent pollens in the city of Talca. Aerobiological monitoring will provide the community with reliable information about the level of allergenic pollens, improving treatment and quality of life of patients with respiratory allergy. Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.

  6. An investigation of airborne allergenic pollen at different heights.

    PubMed

    Xiao, Xiaojun; Fu, Aixiang; Xie, Xiongjie; Kang, Minxiong; Hu, Dongsheng; Yang, Pingchang; Liu, Zhigang

    2013-01-01

    Airborne pollen is an important source of allergens in a number of allergic diseases. Data on the concentrations of pollen at different heights in the air are scarce. The aim of the present study was to investigate different types and numbers of airborne pollen and their seasonal variation at different heights in the urban area of Shenzhen (China) and their associations with meteorological factors. The concentration of airborne pollen at different heights was monitored with Burkard traps from July 1, 2006, to June 30, 2007, in Shenzhen; the results were analyzed with SAS 9.13 software. In total, 1,095 films (at 3 heights, 365 films at each height) were exposed throughout the year, and 48 families and 85 genera of pollen taxa were identified. The total pollen count was 55,830 grains (25,204 grains at 1.5 m; 16,218 grains at 35 m, and 14,408 grains at 70 m); pollen grains were present in the atmosphere throughout the year, with two peaks of airborne pollen: one peak in February to April and the other in September to November. On the basis of our local investigations, the pollen concentrations and the pollen types in the air decrease gradually with increasing height. The distribution and concentrations of airborne pollen at different heights in the atmosphere were influenced by composite factors such as the season and meteorological factors. Copyright © 2012 S. Karger AG, Basel.

  7. Reevaluation of pollen quantitation by an automatic pollen counter.

    PubMed

    Muradil, Mutarifu; Okamoto, Yoshitaka; Yonekura, Syuji; Chazono, Hideaki; Hisamitsu, Minako; Horiguchi, Shigetoshi; Hanazawa, Toyoyuki; Takahashi, Yukie; Yokota, Kunihiko; Okumura, Satoshi

    2010-01-01

    Accurate and detailed pollen monitoring is useful for selection of medication and for allergen avoidance in patients with allergic rhinitis. Burkard and Durham pollen samplers are commonly used, but are labor and time intensive. In contrast, automatic pollen counters allow simple real-time pollen counting; however, these instruments have difficulty in distinguishing pollen from small nonpollen airborne particles. Misidentification and underestimation rates for an automatic pollen counter were examined to improve the accuracy of the pollen count. The characteristics of the automatic pollen counter were determined in a chamber study with exposure to cedar pollens or soil grains. The cedar pollen counts were monitored in 2006 and 2007, and compared with those from a Durham sampler. The pollen counts from the automatic counter showed a good correlation (r > 0.7) with those from the Durham sampler when pollen dispersal was high, but a poor correlation (r < 0.5) when pollen dispersal was low. The new correction method, which took into account the misidentification and underestimation, improved this correlation to r > 0.7 during the pollen season. The accuracy of automatic pollen counting can be improved using a correction to include rates of underestimation and misidentification in a particular geographical area.

  8. Horizontal pollen transmission of Gentian ovary ring-spot virus is initiated during penetration of the stigma and style by infected pollen tubes.

    PubMed

    Isogai, Masamichi; Kamata, Yukie; Ando, Syunpei; Kamata, Misaki; Shirakawa, Asuka; Sekine, Ken-Taro; Yoshikawa, Nobuyuki

    2017-03-01

    Gentian ovary ring-spot virus (GORV) infected gentian plants by pollination with GORV-infected gentian pollen grains, but the virus was not horizontally transmitted to gentian plants by transfer of pollen from GORV-infected Nicotiana benthamiana plants. However, N. benthamiana plants were infected with the virus by pollination with infected gentian pollen as well as by pollination with infected N. benthamiana pollen. When infected gentian pollen grains were placed on N. benthamiana stigmas, germinating pollen tubes penetrated into the stigmas and the styles (stigma-style). Virus infection occurred during penetration of the stigma-style, and the virus subsequently spread systemically to the mother plant. On the other hand, most infected N. benthamiana pollen grains failed to germinate on gentian stigmas, and virus infections were not detected in the stigma-style. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Preservation of cycad and Ginkgo pollen

    USGS Publications Warehouse

    Frederiksen, N.O.

    1978-01-01

    Pollen grains of Ginkgo, Cycas, and Encephalartos were chemically treated together with pollen of Quercus, Alnus, and Pinus, the latter three genera being used as standards. The experiments showed that: (1) boiling the pollen for 8-10 hours in 10% KOH had little if any effect on any of the grains; (2) lengthy acetolysis treatment produced some degradation or corrosion, particularly in Ginkgo and Cycas, but the grains of even these genera remained easily recognizable; (3) oxidation with KMnO4 followed by H2O2 showed that pollen of Ginkgo, Cycas, and Encephalartos remains better preserved than that of Quercus and Alnus, and although Ginkgo and Encephalartos probably are slightly less resistant to oxidation than Pinus, no great differences exists between these monosulcate types and Pinus. Thus the experiments show that, at least for sediments low in bacteria, cycad and Ginkgo pollen should be well represented in the fossil record as far as their preservational capabilities are concerned. ?? 1978.

  10. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    EPA Science Inventory

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  11. Flotation preferentially selects saccate pollen during conifer pollination.

    PubMed

    Leslie, Andrew B

    2010-10-01

    • Among many species of living conifers the presence of pollen with air bladders (saccate pollen) is strongly associated with downward-facing ovules and the production of pollination drops. This combination of features enables saccate pollen grains captured in the pollination drop to float upwards into the ovule. Despite the importance of this mechanism in understanding reproduction in living conifers and in extinct seed plants with similar morphologies, experiments designed to test its effectiveness have yielded equivocal results. • In vitro and in vivo pollination experiments using saccate and nonsaccate pollen were performed using modeled ovules and two Pinus species during their natural pollination period. • Buoyant saccate pollen readily floated through aqueous droplets, separating these grains from nonbuoyant pollen and spores. Ovules that received saccate pollen, nonsaccate pollen or a mixture of both all showed larger amounts and higher proportions of saccate pollen inside ovules after drop secretion. • These results demonstrate that flotation is an effective mechanism of pollen capture and transport in gymnosperms, and suggest that the prevalence of saccate grains and downward-facing ovules in the evolutionary history of seed plants is a result of the widespread use of this mechanism.

  12. Corn pollen deposition on milkweeds in and near cornfields.

    PubMed

    Pleasants, J M; Hellmich, R L; Dively, G P; Sears, M K; Stanley-Horn, D E; Mattila, H R; Foster, J E; Clark, P; Jones, G D

    2001-10-09

    The density of corn pollen on leaves of milkweed plants inside and outside of cornfields was measured in several studies from different localities. The purpose was to obtain a representative picture of naturally occurring pollen densities to provide a perspective for laboratory and field studies of monarch larvae feeding on milkweed leaves with Bt corn pollen. Pollen density was highest (average 170.6 grains per cm(2)) inside the cornfield and was progressively lower from the field edge outward, falling to 14.2 grains per cm(2) at 2 m. Inside the cornfield, and for each distance from the field edge, a frequency distribution is presented showing the proportion of leaf samples with different pollen densities. Inside cornfields, 95% of leaf samples had pollen densities below 600 grains per cm(2) and the highest pollen density observed was 1400 grains per cm(2), which occurred in a study with a rainless anthesis period. All other studies had rainfall events during the anthesis period. A single rain event can remove 54-86% of the pollen on leaves. Leaves on the upper portion of milkweed plants, where young monarch larvae tend to feed, had only 30-50% of the pollen density levels of middle leaves.

  13. The Cysteine Protease CEP1, a Key Executor Involved in Tapetal Programmed Cell Death, Regulates Pollen Development in Arabidopsis[W][OPEN

    PubMed Central

    Zhang, Dandan; Liu, Di; Lv, Xiaomeng; Wang, Ying; Xun, Zhili; Liu, Zhixiong; Li, Fenglan; Lu, Hai

    2014-01-01

    Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation. PMID:25035401

  14. Correlation between pollen morphology and pollination mechanisms in the Hydrocharitaceae.

    PubMed

    Tanaka, Norio; Uehara, Koichi; Murata, Jin

    2004-08-01

    The pollen morphology of 11 genera and 11 species of the Hydrocharitaceae and one species of the Najadaceae was studied using scanning and transmission electron microscopies, and the exine structures and sculptures are discussed in relation to pollination mechanisms and the molecular phylogeny. The pollen grains of the Hydrocharitaceae are spherical, inaperturate, and form monads or tetrads, while those of the Najadaceae are elliptical, inaperturate, and form monads. The entomophilous genera Egeria, Blyxa, Ottelia, Stratiotes, and Hydrocharis share pollen grains that have projections like spines or bacula. The anemophilous genus Limnobium has reticulate pollen grains. The hypohydrophilous genera Thalassia and Najas are characterized by pollen grains with reduced exine structures. The pollen-epihydrophilous genera Elodea and Hydrilla have tightly arranged small spinous pollen grains, and the male flower-epihydrophilous genera Enhalus and Vallisneria have reduced reticulate or gemmate exines. Character state reconstruction of the exine structures and sculptures using a molecular phylogenetic tree suggests that variation in the exine is generally correlated with the pollination mechanism; the selective pressures acting on the pollination mechanisms have reduced the exine structure in hypohydrophilous plants and resulted in various exine sculptures that are adapted to the different pollination mechanisms in entomophilous, anemophilous, and pollen-epihydrophilous plants.

  15. Stable Carbon Isotope Ratios of Individual Pollen Grains as a Proxy for C3- Versus C4-Grass Abundance in Paleorecords: A Validation Study

    NASA Astrophysics Data System (ADS)

    Nelson, D. M.; Hu, F.; Pearson, A.

    2007-12-01

    C3 and C4 grasses have distinct influences on major biogeochemical processes and unique responses to important environmental controls. Difficulties in distinguishing between these two functional groups of grasses have hindered paleoecological studies of grass-dominated ecosystems. We recently developed a technique to analyze the stable carbon isotope composition of individual grass-pollen grains using a spooling- wire microcombustion device interfaced with an isotope-ratio mass spectrometer (Nelson et al. 2007). This technique holds promise for improving C3 and C4 grass reconstructions. It requires ~90% fewer grains than typical methods and avoids assumptions associated with mixing models. However, our previous work was based on known C3 and C4 grasses from herbarium specimens and field collections and the technique had not been test using geological samples. To test the ability of this technique to reproduce the abundance of C3 and C4 grasses on the landscape, we measured δ13C values of >1500 individual grains of grass pollen isolated from the surface sediments of 10 North American lakes that span a large gradient of C3 and C4 grass abundance. Results indicate a strong positive correlation (r=0.94) between % C4-grass pollen (derived from classifying δ13C values from single grains as C3 and C4) and the literature-reported abundance of C4 grasses on the landscape. However, the measured % C4-grass pollen shows some deviation from the actual abundance at sites with high proportions of C4 grasses. This is likely caused by uncertainty in the magnitude, composition, and variability of the analytical blank associated with these measurements. Correcting for this deviation using regression analysis improves the estimation of the abundance of C4 grasses on the landscape. Comparison of the % C4-grass pollen with C/N and δ13C measurements of total organic matter in the same lake-sediment samples illustrates the distinct advantage of grass-pollen δ13C as a proxy for

  16. Classification of pollen species using autofluorescence image analysis.

    PubMed

    Mitsumoto, Kotaro; Yabusaki, Katsumi; Aoyagi, Hideki

    2009-01-01

    A new method to classify pollen species was developed by monitoring autofluorescence images of pollen grains. The pollens of nine species were selected, and their autofluorescence images were captured by a microscope equipped with a digital camera. The pollen size and the ratio of the blue to red pollen autofluorescence spectra (the B/R ratio) were calculated by image processing. The B/R ratios and pollen size varied among the species. Furthermore, the scatter-plot of pollen size versus the B/R ratio showed that pollen could be classified to the species level using both parameters. The pollen size and B/R ratio were confirmed by means of particle flow image analysis and the fluorescence spectra, respectively. These results suggest that a flow system capable of measuring both scattered light and the autofluorescence of particles could classify and count pollen grains in real time.

  17. A Comparison of the Human Buccal Cell Assay and the Pollen Abortion Assay in Assessing Genotoxicity in an Urban-Rural Gradient

    PubMed Central

    Fleck, Alan da Silveira; Vieira, Mariana; Amantéa, Sergio Luís; Rhoden, Claudia Ramos

    2014-01-01

    Air pollution is exacerbated near heavy traffic roads in cities. Air pollution concentration and composition vary by region and depend on urban-rural gradients. The aim of this study was to evaluate the distribution of air pollution in areas of varying population densities and to compare plant biomonitoring with an established biomarker of human exposure to traffic-related air pollution in children. The areas of study were selected near a major street in 3 different regions. Areas A, B and C represent high, intermediate and low population densities, respectively. Micronucleus assay, an established biomarker of human exposure, was performed in children from these areas. For a plant biomonitoring assay, the pollen abortion assay was performed on Bauhinia variegata in these areas. NO2 and O3 concentrations were determined by passive sampling. We report here that the pollen abortion frequency in Bauhinia variegata is correlated with NO2 concentration (P = 0.004) and is strongly associated with vehicular flow and population density in the studied areas. Micronuclei frequency in buccal cells of children was higher in the regions with more degree of urbanization (P < 0.001) following the same pattern of O3 concentrations (P = 0.030). In conclusion, our results demonstrate that high concentrations of air pollutants in Porto Alegre are related to both human and plant genotoxicity. Areas with different concentration of pollutants demonstrated to have an urbanization gradient dependent pattern which also reflected on genotoxic damage among these areas. PMID:25166920

  18. The cysteine protease CEP1, a key executor involved in tapetal programmed cell death, regulates pollen development in Arabidopsis.

    PubMed

    Zhang, Dandan; Liu, Di; Lv, Xiaomeng; Wang, Ying; Xun, Zhili; Liu, Zhixiong; Li, Fenglan; Lu, Hai

    2014-07-01

    Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation. © 2014 American Society of Plant Biologists. All rights reserved.

  19. Regulation of the Pollen-Specific Actin-Depolymerizing Factor LlADF1

    PubMed Central

    Allwood, Ellen G.; Anthony, Richard G.; Smertenko, Andrei P.; Reichelt, Stefanie; Drobak, Bjorn K.; Doonan, John H.; Weeds, Alan G.; Hussey, Patrick J.

    2002-01-01

    Pollen tube growth is dependent on a dynamic actin cytoskeleton, suggesting that actin-regulating proteins are involved. We have examined the regulation of the lily pollen-specific actin-depolymerizing factor (ADF) LlADF1. Its actin binding and depolymerizing activity is pH sensitive, inhibited by certain phosphoinositides, but not controlled by phosphorylation. Compared with its F-actin binding properties, its low activity in depolymerization assays has been used to explain why pollen ADF decorates F-actin in pollen grains. This low activity is incompatible with a role in increasing actin dynamics necessary to promote pollen tube growth. We have identified a plant homolog of actin-interacting protein, AIP1, which enhances the depolymerization of F-actin in the presence of LlADF1 by ∼60%. Both pollen ADF and pollen AIP1 bind F-actin in pollen grains but are mainly cytoplasmic in pollen tubes. Our results suggest that together these proteins remodel actin filaments as pollen grains enter and exit dormancy. PMID:12417710

  20. A Multiscale Vibrational Spectroscopic Approach for Identification and Biochemical Characterization of Pollen

    PubMed Central

    Bağcıoğlu, Murat; Zimmermann, Boris; Kohler, Achim

    2015-01-01

    Background Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by different multiscale vibrational spectroscopic techniques. Methodology Pollen from 15 different species of Pinales (conifers) were measured by seven infrared and Raman methodologies. In order to obtain infrared spectra, both reflectance and transmission measurements were performed on ground and intact pollen grains (bulk measurements), in addition, infrared spectra were obtained by microspectroscopy of multigrain and single pollen grain measurements. For Raman microspectroscopy measurements, spectra were obtained from the same pollen grains by focusing two different substructures of pollen grain. The spectral data from the seven methodologies were integrated into one data model by the Consensus Principal Component Analysis, in order to obtain the relations between the molecular signatures traced by different techniques. Results The vibrational spectroscopy enabled biochemical characterization of pollen and detection of phylogenetic variation. The spectral differences were clearly connected to specific chemical constituents, such as lipids, carbohydrates, carotenoids and sporopollenins. The extensive differences between pollen of Cedrus and the rest of Pinaceae family were unambiguously connected with molecular composition of sporopollenins in pollen grain wall, while pollen of Picea has apparently higher concentration of carotenoids than the rest of the family. It is shown that vibrational methodologies have great potential for systematic collection of data on ecosystems and that the obtained phylogenetic variation can be well explained by the biochemical composition of

  1. How honey bees carry pollen

    NASA Astrophysics Data System (ADS)

    Matherne, Marguerite E.; Anyanwu, Gabriel; Leavey, Jennifer K.; Hu, David L.

    2017-11-01

    Honey bees are the tanker of the skies, carrying thirty percent of their weight in pollen per foraging trip using specialized orifices on their body. How do they manage to hang onto those pesky pollen grains? In this experimental study, we investigate the adhesion force of pollen to the honeybee. To affix pollen to themselves, honey bees form a suspension of pollen in nectar, creating a putty-like pollen basket that is skewered by leg hairs. We use tensile tests to show that the viscous force of the pollen basket is more than ten times the honeybee's flight force. This work may provide inspiration for the design of robotic flying pollinators.

  2. Pollinator-mediated selection on flower color, flower scent and flower morphology of Hemerocallis: evidence from genotyping individual pollen grains on the stigma.

    PubMed

    Hirota, Shun K; Nitta, Kozue; Suyama, Yoshihisa; Kawakubo, Nobumitsu; Yasumoto, Akiko A; Yahara, Tetsukazu

    2013-01-01

    To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent.

  3. Pollinator-Mediated Selection on Flower Color, Flower Scent and Flower Morphology of Hemerocallis: Evidence from Genotyping Individual Pollen Grains On the Stigma

    PubMed Central

    Hirota, Shun K.; Nitta, Kozue; Suyama, Yoshihisa; Kawakubo, Nobumitsu; Yasumoto, Akiko A.; Yahara, Tetsukazu

    2013-01-01

    To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent. PMID:24376890

  4. The ultraviolet radiation environment of pollen and its effect on pollen germination

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The damage to pollen caused by natural ultraviolet radiation was investigated. Experimental and literature research into the UV radiation environment is reported. Viability and germination of wind and insect pollinated species were determined. Physiological, developmental, and protective factors influencing UV sensitivity of binucleate, advanced binucleate, and trinucleate pollen grains are compared.

  5. Variation in pollen-donor composition among pollinators in an entomophilous tree species, Castanea crenata, revealed by single-pollen genotyping.

    PubMed

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2015-01-01

    In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant. We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee) visiting Castanea crenata trees. The outcross-pollen rate was highest in bumblebees (66%), followed by small bees (35%), flies (31%), and small beetles (18%). The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71) than in flies (3.40), small bees (3.32), and small beetles (3.06). The high percentages of pollen from outside the plot on bumblebees (65.4%) and flies (71.2%) compared to small bees (35.3%) and small beetles (13.5%) demonstrated their longer pollen dispersal distances. All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata.

  6. Some physical properties of teosinte (Zea mays subsp. parviglumis) pollen.

    PubMed

    Aylor, Donald E; Baltazar, Baltazar M; Schoper, John B

    2005-09-01

    In parts of the world where teosinte and maize are grown in close proximity, there is concern about gene flow between them. Pollen is the primary vehicle for gene flow. Quantifying the biophysical properties of pollen, such as its settling speed and dehydration rate, is important for evaluating outcrossing potential. These properties were measured for teosinte (Zea mays subsp. parviglumis) pollen. Pollen was found to have an average settling speed of 0.165 m s(-1), which agrees well with theoretical values based on the size of the pollen grains. The conductance of the pollen wall for water was derived from the time rate of change of pollen grain size and gave an average conductance of 3.42x10(-4) m s(-1). Water potential, psi, of teosinte pollen was determined at various values of relative water content (dry-weight basis), theta, by using a thermocouple psychrometer and by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -4.13 theta(-1.23) (r2=0.77). Results for conductance and psi were incorporated into a model equation for the rate of water loss from pollen grains, which yielded results that agreed well (r2=0.96) with observations of water loss from pollen grains in air. The data reported here are important building blocks in a model of teosinte pollen movement and should be helpful in establishing the main factors influencing the degree and the direction of pollination between teosinte populations and between maize and teosinte.

  7. Plastidic phosphoglucomutase and ADP-glucose pyrophosphorylase mutants impair starch synthesis in rice pollen grains and cause male sterility

    PubMed Central

    Lee, Sang-Kyu; Eom, Joon-Seob; Hwang, Seon-Kap; Shin, Dongjin; An, Gynheung; Okita, Thomas W.; Jeon, Jong-Seong

    2016-01-01

    To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the plastidic large subunit of ADP-glucose (ADP-Glc) pyrophosphorylase, OsAGPL4. Both genes were up-regulated in maturing pollen, a stage when starch begins to accumulate. Progeny analysis of self-pollinated heterozygous lines carrying the OspPGM mutant alleles, osppgm-1 and osppgm-2, or the OsAGPL4 mutant allele, osagpl4-1, as well as reciprocal crosses between the wild type (WT) and heterozygotes revealed that loss of OspPGM or OsAGPL4 caused male sterility, with the former condition rescued by the introduction of the WT OspPGM gene. While iodine staining and transmission electron microscopy analyses of pollen grains from homozygous osppgm-1 lines produced by anther culture confirmed the starch null phenotype, pollen from homozygous osagpl4 mutant lines, osagpl4-2 and osagpl4-3, generated by the CRISPR/Cas system, accumulated small amounts of starch which were sufficient to produce viable seed. Such osagpl4 mutant pollen, however, was unable to compete against WT pollen successfully, validating the important role of this reserve in fertilization. Our results demonstrate that starch is mainly polymerized from ADP-Glc synthesized from plastidic hexose phosphates in rice pollen and that starch is an essential requirement for successful fertilization in rice. PMID:27588462

  8. Aberrant Meiotic Modulation Partially Contributes to the Lower Germination Rate of Pollen Grains in Maize (Zea mays L.) Under Low Nitrogen Supply.

    PubMed

    Zheng, Hongyan; Wu, Huamao; Pan, Xiaoying; Jin, Weiwei; Li, Xuexian

    2017-02-01

    Pollen germination is an essential step towards successful pollination during maize reproduction. How low niutrogen (N) affects pollen germination remains an interesting biological question to be addressed. We found that only low N resulted in a significantly lower germination rate of pollen grains after 4 weeks of low N, phosphorus or potassium treatment in maize production. Importantly, cytological analysis showed 7-fold more micronuclei in male meiocytes under the low N treatment than in the control, indicating that the lower germination rate of pollen grains was partially due to numerous chromosome loss events resulting from preceding meiosis. The appearance of 10 bivalents in the control and low N cells at diakinesis suggested that chromosome pairing and recombination in meiosis I was not affected by low N. Further gene expression analysis revealed dramatic down-regulation of Nuclear Division Cycle 80 (Ndc80) and Regulator of Chromosome Condensation 1 (Rcc1-1) expression and up-regulation of Cell Division Cycle 20 (Cdc20-1) expression, although no significant difference in the expression level of kinetochore foundation proteins Centromeric Histone H3 (Cenh3) and Centromere Protein C (Cenpc) and cohesion regulators Recombination 8 (Rec8) and Shugoshin (Sgo1) was observed. Aberrant modulation of three key meiotic regulators presumably resulted in a high likelihood of erroneous chromosome segregation, as testified by pronounced lagging chromosomes at anaphase I or cell cycle disruption at meiosis II. Thus, we proposed a cytogenetic mechanism whereby low N affects male meiosis and causes a higher chromosome loss frequency and eventually a lower germination rate of pollen grains in a staple crop plant. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.

    PubMed

    Shen, Yumin; Zhao, Zhigang; Ma, Hongyang; Bian, Xiaofeng; Yu, Yang; Yu, Xiaowen; Chen, Haiyuan; Liu, Linglong; Zhang, Wenwei; Jiang, Ling; Zhou, Jiawu; Tao, Dayun; Wan, Jianmin

    2015-11-01

    Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility. Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  10. Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

    PubMed Central

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2015-01-01

    Background In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant. Methods We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee) visiting Castanea crenata trees. Results The outcross-pollen rate was highest in bumblebees (66%), followed by small bees (35%), flies (31%), and small beetles (18%). The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71) than in flies (3.40), small bees (3.32), and small beetles (3.06). The high percentages of pollen from outside the plot on bumblebees (65.4%) and flies (71.2%) compared to small bees (35.3%) and small beetles (13.5%) demonstrated their longer pollen dispersal distances. Conclusions All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata. PMID:25793619

  11. Pollenkitt wetting mechanism enables species-specific tunable pollen adhesion.

    PubMed

    Lin, Haisheng; Gomez, Ismael; Meredith, J Carson

    2013-03-05

    Plant pollens are microscopic particles exhibiting a remarkable breadth of complex solid surface features. In addition, many pollen grains are coated with a viscous liquid, "pollenkitt", thought to play important roles in pollen dispersion and adhesion. However, there exist no quantitative studies of the effects of solid surface features or pollenkitt on adhesion of pollen grains, and it remains unclear what role these features play in pollen adhesion and transport. We report AFM adhesion measurements of five pollen species with a series of test surfaces in which each pollen has a unique solid surface morphology and pollenkitt volume. The results indicate that the combination of surface morphology (size and shape of echinate or reticulate features) with the pollenkitt volume provides pollens with a remarkably tunable adhesion to surfaces. With pollenkitt removed, pollen grains had relatively low adhesion strengths that were independent of surface chemistry and scalable with the tip radius of the pollen's ornamentation features, according to the Hamaker model. With the pollenkitt intact, adhesion was up to 3-6 times higher than the dry grains and exhibited strong substrate dependence. The adhesion enhancing effect of pollenkitt was driven by the formation of pollenkitt capillary bridges and was surprisingly species-dependent, with echinate insect-pollinated species (dandelion and sunflower) showing significantly stronger adhesion and higher substrate dependence than wind-pollinated species (ragweed, poplar, and olive). The combination of high pollenkitt volume and large convex, spiny surface features in echinate entomophilous varieties appears to enhance the spreading area of the liquid pollenkitt relative to varieties of pollen with less pollenkitt volume and less pronounced surface features. Measurements of pollenkitt surface energy indicate that the adhesive strength of capillary bridges is primarily dependent on nonpolar van der Waals interactions, with some

  12. Rejection of S-heteroallelic pollen by a dual-specific s-RNase in Solanum chacoense predicts a multimeric SI pollen component.

    PubMed Central

    Luu, D T; Qin, X; Laublin, G; Yang, Q; Morse, D; Cappadocia, M

    2001-01-01

    S-heteroallelic pollen (HAP) grains are usually diploid and contain two different S-alleles. Curiously, HAP produced by tetraploids derived from self-incompatible diploids are typically self-compatible. The two different hypotheses previously advanced to explain the compatibility of HAP are the lack of pollen-S expression and the "competition effect" between two pollen-S gene products expressed in a single pollen grain. To distinguish between these two possibilities, we used a previously described dual-specific S(11/13)-RNase, termed HVapb-RNase, which can reject two phenotypically distinct pollen (P(11) and P(13)). Since the HVapb-RNase does not distinguish between the two pollen types (it recognizes both), P(11)P(13) HAP should be incompatible with the HVapb-RNase in spite of the competition effect. We show here that P(11)P(13) HAP is accepted by S(11)S(13) styles, but is rejected by the S(11/13)-RNase, which demonstrates that the pollen-S genes must be expressed in HAP. A model involving tetrameric pollen-S is proposed to explain both the compatibility of P(11)P(13) HAP on S(11)S(13)-containing styles and the incompatibility of P(11)P(13) HAP on styles containing the HVapb-RNase. PMID:11560908

  13. Plant Sterol Diversity in Pollen from Angiosperms.

    PubMed

    Villette, Claire; Berna, Anne; Compagnon, Vincent; Schaller, Hubert

    2015-08-01

    Here we have examined the composition of free sterols and steryl esters of pollen from selected angiosperm species, as a first step towards a comprehensive analysis of sterol biogenesis in the male gametophyte. We detected four major sterol structural groups: cycloartenol derivatives bearing a 9β,19-cyclopropyl group, sterols with a double bond at C-7(8), sterols with a double bond at C-5(6), and stanols. All these groups were unequally distributed among species. However, the distribution of sterols as free sterols or as steryl esters in pollen grains indicated that free sterols were mostly Δ(5)-sterols and that steryl esters were predominantly 9β,19-cyclopropyl sterols. In order to link the sterol composition of a pollen grain at anthesis with the requirement for membrane lipid constituents of the pollen tube, we germinated pollen grains from Nicotiana tabacum, a model plant in reproductive biology. In the presence of radiolabelled mevalonic acid and in a time course series of measurements, we showed that cycloeucalenol was identified as the major neosynthesized sterol. Furthermore, the inhibition of cycloeucalenol neosynthesis by squalestatin was in full agreement with a de novo biogenesis and an apparent truncated pathway in the pollen tube.

  14. Pollen and spores of terrestrial plants

    USGS Publications Warehouse

    Bernhardt, Christopher E.; Willard, Debra A.; Shennan, Ian; Long, Antony J.; Horton, Benjamin P.

    2015-01-01

    Pollen and spores are valuable tools in reconstructing past sea level and climate because of their ubiquity, abundance, and durability as well as their reciprocity with source vegetation to environmental change (Cronin, 1999; Traverse, 2007; Willard and Bernhardt, 2011). Pollan is found in many sedimentary environments, from freshwater to saltwater, terrestrial to marine. It can be abundant in a minimal amount of sample material, for example half a gram, as concentrations can be as high as four million grains per gram (Traverse, 2007). The abundance of pollen in a sample lends it to robust statistical analysis for the quantitative reconstruction of environments. The outer cell wall is resistant to decay in sediments and allows palynomorphs (pollen and spores) to record changes in plant communities and sea level over millions of years. These characteristics make pollen and spores a powerful tool to use in sea-level research.This chapter describes the biology of pollen and spores and how they are transported and preserved in sediments. We present a methodology for isolating pollen from sediments and a general language and framework to identify pollen as well as light micrographs of a selection of common pollen grains, We then discuss their utility in sea-level research.

  15. Pollen grain morphology of Fabaceae in the Special Protection Area (SPA) Pau-de-Fruta, Diamantina, Minas Gerais, Brazil.

    PubMed

    Luz, Cynthia F P da; Maki, Erica S; Horák-Terra, Ingrid; Vidal-Torrado, Pablo; Mendonça Filho, Carlos Victor

    2013-01-01

    The presented paper considered the pollen morphology of thirteen species belonging to seven genera of the Fabaceae family occurring in the Pau-de-Fruta Special Protection Area (SPA), Diamantina, state of Minas Gerais, Brazil. The pollen grains of six species of Chamaecrista [C. cathartica (Mart.) H.S. Irwin & Barneby, C. debilis Vogel, C. flexuosa (L.) Greene, C. hedysaroides (Vogel) H.S. Irwin & Barneby, C. glandulosa (L.) Greene, and C. papillata H.S. Irwin & Barneby] have a similar morphology, characterized by three long colporated apertures with a central constriction. The species share specific morphological features regarding pollen size, endoaperture type (circular, lalongate or lolongate) and SEM ornamentation patterns of the exine (rugulate with perforations or perforate). Andira fraxinifolia Benth., Dalbergia miscolobium Benth, Galactia martii DC, Periandra mediterranea (Vell.) Taub., Senna rugosa (G.Don) H.S. Irwin & Barneby and Zornia diphylla (L.) Pers showed different pollen types in small to large size; oblate spheroidal to prolate form; colpus or colporus apertures; circular, lalongate or lolongate endoapertures and distinctive SEM ornamentation patterns of the exine (perforate, microreticulate, reticulate or rugulate with perforations). Only Stryphnodendron adstringens (Mart.) Coville presents polyads. The pollen morphology variation of these species allowed the Fabaceae family to be characterized as eurypalynous in the SPA Pau-de-Fruta.

  16. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia.

    PubMed

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m(3)) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m(3). Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  17. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    NASA Astrophysics Data System (ADS)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  18. Fullerene-Based Symmetry in Hibiscus rosa-sinensis Pollen

    PubMed Central

    Andrade, Kleber; Guerra, Sara; Debut, Alexis

    2014-01-01

    The fullerene molecule belongs to the so-called super materials. The compound is interesting due to its spherical configuration where atoms occupy positions forming a mechanically stable structure. We first demonstrate that pollen of Hibiscus rosa-sinensis has a strong symmetry regarding the distribution of its spines over the spherical grain. These spines form spherical hexagons and pentagons. The distance between atoms in fullerene is explained applying principles of flat, spherical, and spatial geometry, based on Euclid’s “Elements” book, as well as logic algorithms. Measurements of the pollen grain take into account that the true spine lengths, and consequently the real distances between them, are measured to the periphery of each grain. Algorithms are developed to recover the spatial effects lost in 2D photos. There is a clear correspondence between the position of atoms in the fullerene molecule and the position of spines in the pollen grain. In the fullerene the separation gives the idea of equal length bonds which implies perfectly distributed electron clouds while in the pollen grain we suggest that the spines being equally spaced carry an electrical charge originating in forces involved in the pollination process. PMID:25003375

  19. When did C4 Photosynthesis originate: New evidence from δ13C analysis of single grass-pollen grains

    NASA Astrophysics Data System (ADS)

    Urban, M. A.; Nelson, D. M.; Pearson, A.; Hu, F.

    2009-12-01

    C4 grasses account for >20% of global primary productivity and dominate tropical, subtropical, and warm-temperate grassland ecosystems. Thus it is vital to understand when and why C4 photosynthesis first evolved in the grass family (Poaceae). However, because of limitations of most proxies, the origin of C4 grasses remains ambiguous. Grass pollen is morphologically indistinct below the family level, making pollen analysis a crude instrument for studying C4-grass evolution. Previous studies have investigated the timing of C4 evolution using molecular tools and δ13C records from n-alkanes, ungulate teeth, and paleosols, but they yield disparate results. Molecular clocks suggest that C4 grasses first evolved between 27 and 36 Ma (million years before present), coincident with the Oligocene decline in pCO2 from >1000 to <500 ppm. In contrast, δ13C-based approaches do not detect the presence of C4 grasses until the middle Miocene, indicating that they were previously uncommon or absent on the landscape. To investigate when C4 photosynthesis first appeared in the grass family, we utilized Single Pollen Isotope Ratio AnaLysis (SPIRAL), a technique that reliably distinguishes C4 from C3 grass pollen via δ13C. We analyzed 837 single grains of grass pollen from eight lacustrine geological samples (~100 grains/sample) from France and Spain spanning the earliest Oligocene to middle Miocene. To distinguish C3/C4 ratios, we used an optimal threshold value of -19.2‰ adjusted for small (~1‰) temporal variations in atmospheric δ13C. Initial results provide unequivocal evidence of C4 grass pollen in all samples (24-57% C4 grass pollen ±9.2% on average) lending further credence to the molecular data, which posits that C4 grasses appeared as early as the Late Eocene, which is a plausible outcome when considering alternate schemes of dating phylogenetic trees. A C4 origin prior to pCO2 reaching its lowest levels of the Cenozoic at the Oligocene/Miocene boundary indicates that

  20. Hive-stored pollen of honey bees: many lines of evidence are consistent with pollen preservation, not nutrient conversion

    PubMed Central

    Anderson, Kirk E; Carroll, Mark J; Sheehan, Tim; Mott, Brendon M; Maes, Patrick; Corby-Harris, Vanessa

    2014-01-01

    Honey bee hives are filled with stored pollen, honey, plant resins and wax, all antimicrobial to differing degrees. Stored pollen is the nutritionally rich currency used for colony growth and consists of 40–50% simple sugars. Many studies speculate that prior to consumption by bees, stored pollen undergoes long-term nutrient conversion, becoming more nutritious ‘bee bread’ as microbes predigest the pollen. We quantified both structural and functional aspects associated with this hypothesis using behavioural assays, bacterial plate counts, microscopy and 454 amplicon sequencing of the 16S rRNA gene from both newly collected and hive-stored pollen. We found that bees preferentially consume fresh pollen stored for <3 days. Newly collected pollen contained few bacteria, values which decreased significantly as pollen were stored >96 h. The estimated microbe to pollen grain surface area ratio was 1:1 000 000 indicating a negligible effect of microbial metabolism on hive-stored pollen. Consistent with these findings, hive-stored pollen grains did not appear compromised according to microscopy. Based on year round 454 amplicon sequencing, bacterial communities of newly collected and hive-stored pollen did not differ, indicating the lack of an emergent microbial community co-evolved to digest stored pollen. In accord with previous culturing and 16S cloning, acid resistant and osmotolerant bacteria like Lactobacillus kunkeei were found in greatest abundance in stored pollen, consistent with the harsh character of this microenvironment. We conclude that stored pollen is not evolved for microbially mediated nutrient conversion, but is a preservative environment due primarily to added honey, nectar, bee secretions and properties of pollen itself. PMID:25319366

  1. Hive-stored pollen of honey bees: many lines of evidence are consistent with pollen preservation, not nutrient conversion.

    PubMed

    Anderson, Kirk E; Carroll, Mark J; Sheehan, Tim; Lanan, Michele C; Mott, Brendon M; Maes, Patrick; Corby-Harris, Vanessa

    2014-12-01

    Honey bee hives are filled with stored pollen, honey, plant resins and wax, all antimicrobial to differing degrees. Stored pollen is the nutritionally rich currency used for colony growth and consists of 40-50% simple sugars. Many studies speculate that prior to consumption by bees, stored pollen undergoes long-term nutrient conversion, becoming more nutritious 'bee bread' as microbes predigest the pollen. We quantified both structural and functional aspects associated with this hypothesis using behavioural assays, bacterial plate counts, microscopy and 454 amplicon sequencing of the 16S rRNA gene from both newly collected and hive-stored pollen. We found that bees preferentially consume fresh pollen stored for <3 days. Newly collected pollen contained few bacteria, values which decreased significantly as pollen were stored >96 h. The estimated microbe to pollen grain surface area ratio was 1:1 000 000 indicating a negligible effect of microbial metabolism on hive-stored pollen. Consistent with these findings, hive-stored pollen grains did not appear compromised according to microscopy. Based on year round 454 amplicon sequencing, bacterial communities of newly collected and hive-stored pollen did not differ, indicating the lack of an emergent microbial community co-evolved to digest stored pollen. In accord with previous culturing and 16S cloning, acid resistant and osmotolerant bacteria like Lactobacillus kunkeei were found in greatest abundance in stored pollen, consistent with the harsh character of this microenvironment. We conclude that stored pollen is not evolved for microbially mediated nutrient conversion, but is a preservative environment due primarily to added honey, nectar, bee secretions and properties of pollen itself. © 2014 John Wiley & Sons Ltd.

  2. An efficient and rapid transgenic pollen screening and detection method using flow cytometry.

    PubMed

    Moon, Hong S; Eda, Shigetoshi; Saxton, Arnold M; Ow, David W; Stewart, C Neal

    2011-01-01

    Assaying for transgenic pollen, a major vector of transgene flow, provides valuable information and essential data for the study of gene flow and assessing the effectiveness of transgene containment. Most studies have employed microscopic screening methods or progeny analyses to estimate the frequency of transgenic pollen. However, these methods are time-consuming and laborious when large numbers of pollen grains must be analyzed to look for rare transgenic pollen grains. Thus, there is an urgent need for the development of a simple, rapid, and high throughput analysis method for transgenic pollen analysis. In this study, our objective was to determine the accuracy of using flow cytometry technology for transgenic pollen quantification in practical application where transgenic pollen is not frequent. A suspension of non-transgenic tobacco pollen was spiked with a known amount of verified transgenic tobacco pollen synthesizing low or high amounts of green fluorescent protein (GFP). The flow cytometric method detected approximately 75% and 100% of pollen grains synthesizing low and high amounts of GFP, respectively. The method is rapid, as it is able to count 5000 pollen grains per minute-long run. Our data indicate that this flow cytometric method is useful to study gene flow and assessment of transgene containment.

  3. It is a matter of timing: asynchrony during pollen development and its consequences on pollen performance in angiosperms-a review.

    PubMed

    Carrizo García, Carolina; Nepi, Massimo; Pacini, Ettore

    2017-01-01

    Functional pollen is needed to successfully complete fertilization. Pollen is formed inside the anthers following a specific sequence of developmental stages, from microsporocyte meiosis to pollen release, that concerns microsporocytes/microspores and anther wall tissues. The processes involved may not be synchronous within a flower, an anther, and even a microsporangium. Asynchrony has been barely analyzed, and its biological consequences have not been yet assessed. In this review, different processes of pollen development and lifetime, stressing on the possible consequences of their differential timing on pollen performance, are summarized. Development is usually synchronized until microsporocyte meiosis I (occasionally until meiosis II). Afterwards, a period of mostly asynchronous events extends up to anther opening as regards: (1) meiosis II (sometimes); (2) microspore vacuolization and later reduction of vacuoles; (3) amylogenesis, amylolysis, and carbohydrate inter-conversion; (4) the first haploid mitosis; and (5) intine formation. Asynchrony would promote metabolic differences among developing microspores and therefore physiologically heterogeneous pollen grains within a single microsporangium. Asynchrony would increase the effect of competition for resources during development and pollen tube growth and also for water during (re)hydration on the stigma. The differences generated by developmental asynchronies may have an adaptive role since more efficient pollen grains would be selected with regard to homeostasis, desiccation tolerance, resilience, speed of (re)hydration, and germination. The performance of each pollen grain which landed onto the stigma will be the result of a series of selective steps determined by its development, physiological state at maturity, and successive environmental constrains.

  4. Pollen structure visualization using high-resolution laboratory-based hard X-ray tomography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Qiong; Gluch, Jürgen; Krüger, Peter

    A laboratory-based X-ray microscope is used to investigate the 3D structure of unstained whole pollen grains. For the first time, high-resolution laboratory-based hard X-ray microscopy is applied to study pollen grains. Based on the efficient acquisition of statistically relevant information-rich images using Zernike phase contrast, both surface- and internal structures of pine pollen - including exine, intine and cellular structures - are clearly visualized. The specific volumes of these structures are calculated from the tomographic data. The systematic three-dimensional study of pollen grains provides morphological and structural information about taxonomic characters that are essential in palynology. Such studies have amore » direct impact on disciplines such as forestry, agriculture, horticulture, plant breeding and biodiversity. - Highlights: • The unstained whole pine pollen was visualized by high-resolution laboratory-based HXRM for the first time. • The comparison study of pollen grains by LM, SEM and high-resolution laboratory-based HXRM. • Phase contrast imaging provides significantly higher contrast of the raw images compared to absorption contrast imaging. • Surface and internal structure of the pine pollen including exine, intine and cellular structures are clearly visualized. • 3D volume data of unstained whole pollen grains are acquired and the specific volumes of the different layer are calculated.« less

  5. Evolution of the incidence of pollen grains and sensitivity to pollen in the city of Elche (Spain).

    PubMed

    Javier, Fernandez; Emilio, Flores; Montserrat, Varea; Victor, Soriano; Purificaci N, Gonzalez

    2015-09-01

    Environment-mediated pollen production varies over time and space, influencing pollen exposure risk and ultimately patient sensitization trends. In order to assess temporal variation of pollen incidence and patient sensitization, we set up a pollen incidence and patient sensitization survey in the city of Elche, Spain, over a 10-years interval. Pollen counts were obtained from a Burkard-type collector located in the city of Elche. We studied consecutive patients attending the outpatient consulting room at the Elche Hospital for suspected pollinosis (276 in 2005), and compared observed trends with cases from 1995 (200). Skin tests were performed for most of the common pollen in our area. The total pollen count increased by 41% from 1995 (13,219) to 2005 (22,854). There were significant counts differences between 1995 and 2005 in Olea europaea (2,018 vs. 4,433), Phoenix dactylifera (3,130 vs. 3,891), and Cupressaceae (1,212 vs. 3,115). The differences between sensitization to pollen in both years were mainly for those in relation to Olea europaea (51.4% vs. 74.9%), Salsola kali (53.7% vs. 71.8%), Parietaria judaica (10.3% vs. 21.5%), Phoenix dactylifera (5.6% vs. 22.3%), Plantago lanceolata (17.8% vs. 38.5%), and Poaceae (47.7% vs. 44.1%). The percentage of monosensitized patients was similar in both years, 16% in 1995 and 17% in 2005. Increased pollen counts in the environment may have led to increased sensitization to pollen. Possible causes may be due to changes in the weather, although the improvements of the extracts used in skin testing, increased air pollution, and/or climate change are factors to consider.

  6. Aerodynamics and pollen ultrastructure in Ephedra.

    PubMed

    Bolinder, Kristina; Niklas, Karl J; Rydin, Catarina

    2015-03-01

    Pollen dispersal is affected by the terminal settling velocity (Ut) of the grains, which is determined by their size, bulk density, and by atmospheric conditions. The likelihood that wind-dispersed pollen is captured by ovulate organs is influenced by the aerodynamic environment created around and by ovulate organs. We investigated pollen ultrastructure and Ut of Ephedra foeminea (purported to be entomophilous), and simulated the capture efficiency of its ovules. Results were compared with those from previously studied anemophilous Ephedra species.• Ut was determined using stroboscopic photography of pollen in free fall. The acceleration field around an "average" ovule was calculated, and inflight behavior of pollen grains was predicted using computer simulations. Pollen morphology and ultrastructure were investigated using SEM and STEM.• Pollen wall ultrastructure was correlated with Ut in Ephedra. The relative proportion and amount of granules in the infratectum determine pollen bulk densities, and (together with overall size) determine Ut and thus dispersal capability. Computer simulations failed to reveal any functional traits favoring anemophilous pollen capture in E. foeminea.• The fast Ut and dense ultrastructure of E. foeminea pollen are consistent with functional traits that distinguish entomophilous species from anemophilous species. In anemophilous Ephedra species, ovulate organs create an aerodynamic microenvironment that directs airborne pollen to the pollination drops. In E. foeminea, no such microenvironment is created. Ephedroid palynomorphs from the Cretaceous share the ultrastructural characteristics of E. foeminea, and at least some may, therefore, have been produced by insect-pollinated plants. © 2015 Botanical Society of America, Inc.

  7. High temperature stress and its effect on pollen development and morphological components of harvest index in the C3 model grass Brachypodium distachyon

    PubMed Central

    Harsant, Jeffrey; Pavlovic, Lazar; Chiu, Greta; Sultmanis, Stefanie; Sage, Tammy L.

    2013-01-01

    The effect of high temperatures on harvest index (HI) and morphological components that contribute to HI was investigated in two lines (Bd21 and Bd21-3) of Brachypodium distachyon, a C3 grass recognized as a tractable plant, to address critical issues associated with enhancing cereal crop yields in the presence of global climate change. The results demonstrated that temperatures ≥32 °C eliminated HI. Reductions in yield at 32 °C were due primarily to declines in pollen viability, retention of pollen in anthers, and pollen germination, while abortion of microspores by the uninucleate stage that was correlated with abnormal tapetal development resulted in yield failure at 36 °C. Increasing temperatures from 24 to 32 °C resulted in reductions in tiller numbers but had no impact on axillary branch numbers per tiller. Grain developed at 24 and 28 °C primarily in tiller spikes, although spikes on axillary branches also formed grain. Grain quantity decreased in tiller spikes but increased in axillary branch spikes as temperatures rose from 24 to 28 °C. Differential patterns of axillary branching and floret development within spikelets between Bd21 and Bd21-3 resulted in higher grain yield in axillary branches of Bd21-3 at 28 °C. The response of male reproductive development and tiller branching patterns in B. distachyon to increasing temperatures mirrors that in other cereal crops, providing support for the use of this C3 grass in assessing the molecular control of HI in the presence of global warming. PMID:23771979

  8. Poaceae Pollen from Southern Brazil: Distinguishing Grasslands (Campos) from Forests by Analyzing a Diverse Range of Poaceae Species

    PubMed Central

    Radaeski, Jefferson N.; Bauermann, Soraia G.; Pereira, Antonio B.

    2016-01-01

    This aim of this study was to distinguish grasslands from forests in southern Brazil by analyzing Poaceae pollen grains. Through light microscopy analysis, we measured the size of the pollen grain, pore, and annulus from 68 species of Rio Grande do Sul. Measurements were recorded of 10 forest species and 58 grassland species, representing all tribes of the Poaceae in Rio Grande do Sul. We measured the polar, equatorial, pore, and annulus diameter. Results of statistical tests showed that arboreous forest species have larger pollen grain sizes than grassland and herbaceous forest species, and in particular there are strongly significant differences between arboreous and grassland species. Discriminant analysis identified three distinct groups representing each vegetation type. Through the pollen measurements we established three pollen types: larger grains (>46 μm), from the Bambuseae pollen type, medium-sized grains (46–22 μm), from herbaceous pollen type, and small grains (<22 μm), from grassland pollen type. The results of our compiled Poaceae pollen dataset may be applied to the fossil pollen of Quaternary sediments. PMID:27999585

  9. A combinatorial morphospace for angiosperm pollen

    NASA Astrophysics Data System (ADS)

    Mander, Luke

    2016-04-01

    The morphology of angiosperm (flowering plant) pollen is extraordinarily diverse. This diversity results from variations in the morphology of discrete anatomical components. These components include the overall shape of a pollen grain, the stratification of the exine, the number and form of any apertures, the type of dispersal unit, and the nature of any surface ornamentation. Different angiosperm pollen morphotypes reflect different combinations of these discrete components. In this talk, I ask the following question: given the anatomical components of angiosperm pollen that are known to exist in the plant kingdom, how many unique biologically plausible combinations of these components are there? I explore this question from the perspective of enumerative combinatorics using an algorithm I have written in the Python programming language. This algorithm (1) calculates the number of combinations of these components; (2) enumerates those combinations; and (3) graphically displays those combinations. The result is a combinatorial morphospace that reflects an underlying notion that the process of morphogenesis in angiosperm pollen can be thought of as an n choose k counting problem. I compare the morphology of extant and fossil angiosperm pollen grains to this morphospace, and suggest that from a combinatorial point of view angiosperm pollen is not as diverse as it could be, which may be a result of developmental constraints.

  10. [Threshold pollen count necessary to evoke allergic symptoms].

    PubMed

    Rapiejko, Piotr; Stanlaewicz, Wanda; Szczygielski, Kornel; Jurkiewicz, Dariusz

    2007-01-01

    The purpose of this study was to analyze the relation between clinical picture of allergic disease and the level of pollen count the patients are exposed to. We analyzed the severity of allergic rhinitis, conjunctivitis and bronchial asthma in a group of 640 subjects from Warsaw area with hypersensitivity to hazel, alder, grass, mugwort, plantain, nettle, Alternaria and Cladosporium allergens. Aerobiological measurements, patients' symptoms score cards and the results of physical examination were analyzed. First symptoms in patients allergic to grass were visible during exposure to the concentration of 20 pollen grains in 1 m3 of air (25% subjects sensitised to grass pollen). Symptoms were noted in all the subjects sensitized to grass pollen at a concentration of approximately 50 grains/m3 of air. During exposure to the concentration of 65 pollen grains per m3 the symptoms were strengthened. Several hours' exposure to grass pollen concentration exceeding 120 grains/m3 cause dyspnoea in some patients. Similar intensive symptoms occurred after exposure to alder, birch and mugwort pollen. Patients with positive skin prick tests to plantain and nettle pollen allergens experienced symptoms of low intensity or even none symptoms during pollination period. Subjects with hypersensitivity to Alternaria allergens experienced symptoms during exposure to the concentration of approximately 80 spores in 1 m3 of air, while patients sensitised to Cladosporium allergens, during exposure to the concentration of over 2800 spores in 1 m3 of air. The dominant symptom occurring in patients sensitized to fungal allergens was loss of nasal patency, and dyspnoea as well as recurring cough at higher concentrations. Clinical symptoms of allergic disease were connected to the concentration and the kind of aeroallergen the subjects were exposed to.

  11. Contribution of pollen to atmospheric ice nuclei concentrations

    NASA Astrophysics Data System (ADS)

    Hader, J. D.; Wright, T. P.; Petters, M. D.

    2014-06-01

    Recent studies have suggested that the ice-nucleating ability of some types of pollen is derived from non-proteinaceous macromolecules. These macromolecules may become dispersed by the rupturing of the pollen grain during wetting and drying cycles in the atmosphere. If true, this mechanism might prove to be a significant source of ice nuclei (IN) concentrations when pollen is present. Here we test this hypothesis by measuring ambient IN concentrations from the beginning to the end of the 2013 pollen season in Raleigh, North Carolina, USA. Air samples were collected using a swirling aerosol collector twice per week and the solutions were analysed for ice nuclei activity using a droplet freezing assay. Rainwater samples were collected at times when pollen grain number concentrations were near their maximum value and analysed with the drop-freezing assay to compare the potentially enhanced IN concentrations measured near the ground with IN concentrations found aloft. Ambient ice nuclei spectra, defined as the number of ice nuclei per volume of air as a function of temperature, are inferred from the aerosol collector solutions. No general trend was observed between ambient pollen grain counts and observed IN concentrations, suggesting that ice nuclei multiplication via pollen grain rupturing and subsequent release of macromolecules was not prevalent for the pollen types and meteorological conditions typically encountered in the southeastern US. A serendipitously sampled collection after a downpour provided evidence for a rain-induced IN burst with an observed IN concentration of approximately 30 per litre, a 30-fold increase over background concentrations at -20 °C. The onset temperature of freezing for these particles was approximately -12 °C, suggesting that the ice-nucleating particles were biological in origin.

  12. COLLAPSED ABNORMAL POLLEN1 Gene Encoding the Arabinokinase-Like Protein Is Involved in Pollen Development in Rice1[C][W][OA

    PubMed Central

    Ueda, Kenji; Yoshimura, Fumiaki; Miyao, Akio; Hirochika, Hirohiko; Nonomura, Ken-Ichi; Wabiko, Hiroetsu

    2013-01-01

    We isolated a pollen-defective mutant, collapsed abnormal pollen1 (cap1), from Tos17 insertional mutant lines of rice (Oryza sativa). The cap1 heterozygous plant produced equal numbers of normal and collapsed abnormal grains. The abnormal pollen grains lacked almost all cytoplasmic materials, nuclei, and intine cell walls and did not germinate. Genetic analysis of crosses revealed that the cap1 mutation did not affect female reproduction or vegetative growth. CAP1 encodes a protein consisting of 996 amino acids that showed high similarity to Arabidopsis (Arabidopsis thaliana) l-arabinokinase, which catalyzes the conversion of l-arabinose to l-arabinose 1-phosphate. A wild-type genomic DNA segment containing CAP1 restored mutants to normal pollen grains. During rice pollen development, CAP1 was preferentially expressed in anthers at the bicellular pollen stage, and the effects of the cap1 mutation were mainly detected at this stage. Based on the metabolic pathway of l-arabinose, cap1 pollen phenotype may have been caused by toxic accumulation of l-arabinose or by inhibition of cell wall metabolism due to the lack of UDP-l-arabinose derived from l-arabinose 1-phosphate. The expression pattern of CAP1 was very similar to that of another Arabidopsis homolog that showed 71% amino acid identity with CAP1. Our results suggested that CAP1 and related genes are critical for pollen development in both monocotyledonous and dicotyledonous plants. PMID:23629836

  13. Impact of common cytostatic drugs on pollen fertility in higher plants.

    PubMed

    Mišík, Miroslav; Kundi, Michael; Pichler, Clemens; Filipic, Metka; Rainer, Bernhard; Mišíková, Katarina; Nersesyan, Armen; Knasmueller, Siegfried

    2016-08-01

    Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4-6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems.

  14. Identification of IgE- binding pollen protein from Cannabis sativa in pollen-hypersensitive patients from north Pakistan.

    PubMed

    Choudhary, Shazia; Murad, Sheeba; Hayat, Muhammad Qasim; Shakoor, Zahid; Arshad, Muhammad

    2017-01-01

    Cannabis sativa (C.sativa) is well-known for its medicinal, industrial and recreational use. However, allergies in relation to Cannabis sativa (C.sativa) are rarely reported. C. sativa is one of the common weeds found in Pakistan and its pollen grains are common in spring and fall season. Although categorized as an aeroallergen, there are limited number of reports regarding allergenic potential in C. sativa. Therefore, the current study is aimed at exploring the IgE- binding potential among the C. sativa pollen in local pollen allergic patients. Initial screening of C. sativa sensitized individuals was carried out by dot blot from the sera of pollen allergic patients. Proteins from the pollen grains were extracted and resolved on 10% gel. Eight bands were visible on gel however only one protein fragment i.e. of 14KDa size was found to bind to IgE as analyzed through protein gel blot analysis. Strong IgE affinity of a 14 kDa protein fragment from C. sativa pollen extract suggests its allergenic potential. Further study is required to find the exact nature of this protein fragment.

  15. A Morphogenetic Model Accounting for Pollen Aperture Pattern in Flowering Plants.

    PubMed

    Ressayre; Godelle; Mignot; Gouyon

    1998-07-21

    Pollen grains are embeddded in an extremely resistant wall. Apertures are well defined places where the pollen wall is reduced or absent that permit pollen tube germination. Pollen grains are produced by meiosis and aperture number definition appears to be linked with the partition that follows meiosis and leads to the formation of a tetrad of four haploid microspores. In dicotyledonous plants, meiosis is simultaneous which means that cytokinesis occurs once the two nuclear divisions are completed. A syncitium with the four nuclei stemming from meiosis is formed and cytokinesis isolates simulataneously the four products of meiosis. We propose a theoretical morphogenetic model which takes into account part of the features of the ontogeny of the pollen grains. The nuclei are considered as attractors acting upon a morphogenetic substance distributed within the cytoplasm of the dividing cell. This leads to a partition of the volume of the cell in four domains that is similar to the observations of cytokinesis in the studied species. The most widespread pattern of aperture distribution in dicotyledonous plants (three apertures equidistributed on the pollen grain equator) can be explained by bipolar interactions between nuclei stemming from the second meiotic division, and observed variations on these patterns by disturbances of these interactions. In numerous plant species, several pollen grains differing in aperture number are produced by a single individual. The distribution of the different morphs within tetrads indicates that the four daughter cells can have different aperture number. The model provides an explanation for the duplication of one of the apertures of a three-aperture pollen grain leading to a four-aperture one and in parallel it gives an explanation for how heterogeneous tetrads can be formed.Copyright 1998 Academic Press

  16. Water status and associated processes mark critical stages in pollen development and functioning.

    PubMed

    Firon, Nurit; Nepi, Massimo; Pacini, Ettore

    2012-06-01

    The male gametophyte developmental programme can be divided into five phases which differ in relation to the environment and pollen hydration state: (1) pollen develops inside the anther immersed in locular fluid, which conveys substances from the mother plant--the microsporogenesis phase; (2) locular fluid disappears by reabsorption and/or evaporation before the anther opens and the maturing pollen grains undergo dehydration--the dehydration phase; (3) the anther opens and pollen may be dispersed immediately, or be held by, for example, pollenkitt (as occurs in almost all entomophilous species) for later dispersion--the presentation phase; (4) pollen is dispersed by different agents, remaining exposed to the environment for different periods--the dispersal phase; and (5) pollen lands on a stigma and, in the case of a compatible stigma and suitable conditions, undergoes rehydration and starts germination--the pollen-stigma interaction phase. This review highlights the issue of pollen water status and indicates the various mechanisms used by pollen grains during their five developmental phases to adjust to changes in water content and maintain internal stability. Pollen water status is co-ordinated through structural, physiological and molecular mechanisms. The structural components participating in regulation of the pollen water level, during both dehydration and rehydration, include the exine (the outer wall of the pollen grain) and the vacuole. Recent data suggest the involvement of water channels in pollen water transport and the existence of several molecular mechanisms for pollen osmoregulation and to protect cellular components (proteins and membranes) under water stress. It is suggested that pollen grains will use these mechanisms, which have a developmental role, to cope with environmental stress conditions.

  17. Gametophytic vs. sporophytic control of pollen aperture number: a generational conflict.

    PubMed

    Till-Bottraud, Irène; Gouyon, Pierre-Henri; Ressayre, Adrienne; Godelle, Bernard

    2012-11-01

    In flowering plants, the haploid phase is reduced to the pollen grain and embryo sac. These reproductive tissues (gametophytes) are actually distinct individuals that have a different genome from the plant (sporophyte), and are more or less independent. The morphology of pollen grains, particularly the openings permitting pollen tube germination (apertures), is crucial for determining the outcome of pollen competition. Many species of flowering plants simultaneously produce pollen grains with different aperture numbers in a single individual (heteromorphism). In this paper, we show that the heteromorphic pollen aperture pattern depends on the genetic control of pollen morphogenesis. This points out a conflict of interest between genes expressed in the sporophyte and genes expressed in the gametophyte. More generally, such a conflict should exist whenever heteromorphism is an ESS resulting from a bet-hedging strategy. For pollen aperture, heteromorphism has been observed in about 40% of angiosperm species, suggesting that conflicting situations are the rule. In this context, the sporo-gametophytic conflict could be one of the factors that led to the reduction of the haploid phase in plants. 2012 Elsevier Inc. All rights reserved

  18. Influence of boundary-layer dynamics on pollen dispersion and viability

    NASA Astrophysics Data System (ADS)

    Arritt, Raymond W.; Viner, Brian J.; Westgate, Mark E.

    2013-04-01

    Adoption of genetically modified (GM) crops has raised concerns that GM traits can accidentally cross into conventional crops or wild relatives through the transport of wind-borne pollen. In order to evaluate this risk it is necessary to account both for dispersion of the pollen grains and environmental influences on pollen viability. The Lagrangian approach is suited to this problem because it allows tracking the environmental temperature and moisture that pollen grains experience as they travel. Taking advantage of this capability we have combined a high-resolution version of the WRF meteorological model with a Lagrangian particle dispersion model to predict maize pollen dispersion and viability. WRF is used to obtain fields of wind, turbulence kinetic energy, temperature, and humidity which are then used as input to the Lagrangian dispersion model. The dispersion model in turn predicts transport of a statistical sample of a pollen cloud from source plants to receptors. We also use the three-dimensional temperature and moisture fields from WRF to diagnose changes in moisture content of the pollen grains and consequent loss of viability. Results show that turbulent motions in the convective boundary layer counteract the large terminal velocity of maize pollen grains and lift them to heights of several hundred meters, so that they can be transported long distances before settling to the ground. We also found that pollen lifted into the upper part of the boundary layer remains more viable than has been inferred using surface observations of temperature and humidity. This is attributed to the thermal and moisture structure that typifies the daytime atmospheric boundary layer, producing an environment of low vapor pressure deficit in the upper boundary layer which helps maintain pollen viability.

  19. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor.

    PubMed

    Dong, Shanshan; Liu, Yan; Yu, Cigang; Zhang, Zhenhua; Chen, Ming; Wang, Changyong

    2016-01-01

    Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow.

  20. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor

    PubMed Central

    Dong, Shanshan; Liu, Yan; Yu, Cigang; Zhang, Zhenhua; Chen, Ming; Wang, Changyong

    2016-01-01

    Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow. PMID:26975052

  1. Rate of dehydration of corn (Zea mays L.) pollen in the air.

    PubMed

    Aylor, Donald E

    2003-10-01

    The water content of corn (Zea mays L.) pollen directly affects its dispersal in the atmosphere through its effect on settling speed and viability. Therefore, the rate of water loss from pollen after being shed from the anther is an important component of a model to predict effective pollen transport distances in the atmosphere. The rate of water loss from corn pollen in air was determined using two methods: (1) by direct weighing of samples containing approximately 5 x 10(4) grains, and (2) by microscopic measurement of the change in size of individual grains. The conductance of the pollen wall to water loss was derived from the time rate of change of pollen mass or pollen grain size. The two methods gave average conductance values of 0.026 and 0.027 cm s-1, respectively. In other experiments, the water potential, psi, of corn pollen was determined at various values of relative water content (dry weight basis), either by using a thermocouple psychrometer or by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -3.218 theta(-1.35) (r2 = 0.94; for -298 < or = psi < or = -1 MPa). This result was incorporated into a model differential equation for the rate of water loss from pollen. The model agreed well (r2 approximately 0.98) with the observed time-course of the decrease of water content of pollen grains exposed to a range of temperature and humidity conditions.

  2. Pollen source and resource limitation to fruit production in the rare species Eremosparton songoricum (Fabaceae)

    USDA-ARS?s Scientific Manuscript database

    Eremosparton songoricum (Litv.) Vass. is a rare, central Asian desert species which shows lower fruit set and seed set (<16%) than most hermaphroditic species. We hypothesized that fruit production was limited by pollen and resources. To evaluate potential fruit abortion due to pollen limitation, su...

  3. Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen

    PubMed Central

    Lora, Jorge; Testillano, Pilar S; Risueño, Maria C; Hormaza, Jose I; Herrero, Maria

    2009-01-01

    Background In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Results Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Conclusion Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer. PMID:19874617

  4. Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen.

    PubMed

    Lora, Jorge; Testillano, Pilar S; Risueño, Maria C; Hormaza, Jose I; Herrero, Maria

    2009-10-29

    In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer.

  5. LONGITUDINAL MONITORING OF TREE AIRBORNE POLLEN IN JAPAN.

    PubMed

    Kishikawa, Reiko; Kotoh, Eiko; Oshikawa, Chie; Soh, Nobuo; Shimoda, Terufumi; Saito, Akemi; Sahashi, Norio; Enomoto, Tadao; Usami, Atsushi; Teranishi, Hidetoyo; Fujisaki, Yohko; Yokoyama, Toshitaka; Murayama, Kohji; Imai, Tohru; Fukutomi, Yuma; Taniguchi, Masami; Iwanaga, Tomoaki

    2017-01-01

    In Japan patients with Japanese Cedar (JC) pollinosis have increased nation widely since the latter of 1970's. The Ministry of Health and Welfare of Japanese Governments has begun to take preventive measures against JC pollinosis and airborne pollen monitoring has begun to investigate as a causative agent since 1986. We have estimated the longitudinal investigation result for successful prevention and treatment against pollinosis in Japan. We have monitored airborne pollen all year around since July 1986 by gravitational pollen sampler, Durham's sampler, at more than 20 locations in the Japanese Islands. Pollen samples were sent to our hospital and counted pollen number per cm 2 after stained by Calberla solution and then classified main pollen grains as a causative agent of pollinosis. JC pollen number was the most of all, more than 40%, next cypress family, about 20%. They were occupied of more than 60% of all and they increased with the remarkable annual fluctuation as the allergen of JC pollinosis. Beech family pollen counting were also increasing and occupied about 10% of all pollen counts. In Hokkaido the prevalence of birch family pollen count was larger than that in other districts. There is cross-reactivity between beech and birch family which related with oral allergic syndrome.Perspective and Conclusion: In future new occurrences of oral allergy syndrome due to increasing allergic tree pollen grains would be appeared. The contentious pollen research should be important for patients with pollinosis in Japan.

  6. Estimates of common ragweed pollen emission and dispersion over Europe using RegCM-pollen model

    NASA Astrophysics Data System (ADS)

    Liu, L.; Solmon, F.; Vautard, R.; Hamaoui-Laguel, L.; Torma, Cs. Zs.; Giorgi, F.

    2015-11-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In the online model environment where climate is integrated with dispersion and vegetation production, pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to ragweed density distribution on pollen emission, a calibration based on airborne pollen observations is used. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger. From these simulations health risks associated common ragweed pollen spread are then evaluated through calculation of exposure time above health

  7. Structural correlates of imbibitional injury in Typha pollen

    NASA Technical Reports Server (NTRS)

    Sack, F. D.; Leopold, A. C.; Hoekstra, F. A.

    1988-01-01

    The ultrastructure of Typha latifolia pollen was examined as a function of pollen moisture content and incubation temperature, in order to identify possible lesions induced by imbibitional chilling. A syndrome of structural traits was found which characterizes damaged grains. Compared to viable grains, the protoplast of damaged pollen has a higher proportion of its volume occupied by vesicles, and less volume occupied by cytoplasm. Damaged grains also tend to have dilated cisternae of endoplasmic reticulum, larger starch grains and lipid bodies, poorly preserved mitochondria and membranes, and, sometimes, numerous electron-dense globules associated with membranes. The percentage of grains exhibiting this damage syndrome correlates closely with the number of ungerminated grains in most samples, regardless of moisture content or incubation temperature. Injury due to rapid imbibition from the dry state or to imbibitional chilling appear to be similar structurally, regardless of whether the stresses are imposed singly or together. The injury is not confined to one cell component (e.g., mitochondria), but may involve a generalized disruption of membranes. These results suggest that similar stress responses are elicited by imbibition from the dry state and by imbibitional chilling.

  8. Pollen embryogenesis to induce, detect, and analyze mutants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Constantin, M.J.

    The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studies, and the selection of mutations. Although pollen embryogenesis has been demonstrated successfully in numerous plant genera, the procedure cannot as yet be used routinely to generate large populations of plants for experiments. Practical results from use of the technology in genetic toxicology research tomore » detect mutations have failed to fully realize the theoretical potential; further developments of the technology could overcome the limitations. Pollen embryogenesis could be used to develop plants from mutant pollen grains to verify that genetic changes are involved. Through either spontaneous or induced chromosome doubling, these plants can be made homozygous and used to analyze genetically the mutants involved. The success of this approach will depend on the mutant frequency relative to the fraction of pollen grains that undergo embryogenesis; these two factors will dictate population size needed for success. Research effort is needed to further develop pollen embryogenesis for use in the detection of genotoxins under both laboratory and in situ conditions.« less

  9. Ultrastructural aspects of pollen ontogeny in an endangered plant species, Pancratium maritimum L. (Amaryllidaceae).

    PubMed

    Tütüncü Konyar, Sevil

    2017-03-01

    Pollen ontogeny in Pancratium maritimum L. was studied from the sporogenous cell to mature pollen grain stages using transmission electron, scanning electron, and light microscopy to determine whether the pollen development in P. maritimum follows the basic scheme in angiosperms or not. In the course of microsporogenesis and microgametogenesis, special attention was given to the considerable ultrastructural changes that are observed in the cytoplasm of microsporocytes, microspores, and mature pollen grains throughout the successive stages of pollen development. Microsporocyte differentiation concerning number and ultrastructure of organelles facilitates the transition of microsporocytes from the sporophytic phase to the gametophytic phase. However, cytoplasmic differentiation of generative and vegetative cells supports their functional distinctness and pollen maturation. Although microsporogenesis and microgametogenesis in P. maritimum generally follow the usual angiosperm pattern, abnormalities such as formation of unreduced gametes were observed. During normal microsporogenesis, meiocytes undergo meiosis and successive cytokinesis, resulting in the formation of isobilateral, decussate, and linear tetrads. Subsequent to the development of free and vacuolated microspores, the first mitotic division occurs and bicellular monosulcate pollen grains are produced. Pollen grains are shed from the anther at binucleate stage. During pollen ontogeny, three periods of vacuolization were observed: in meiocytes, in mononucleate free microspores, and in the generative cell.

  10. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

    PubMed Central

    Toro A., Richard; Córdova J., Alicia; Canales, Mauricio; Morales S., Raul G. E.; Mardones P., Pedro; Leiva G., Manuel A.

    2015-01-01

    Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

  11. Water status and associated processes mark critical stages in pollen development and functioning

    PubMed Central

    Firon, Nurit; Nepi, Massimo; Pacini, Ettore

    2012-01-01

    Background The male gametophyte developmental programme can be divided into five phases which differ in relation to the environment and pollen hydration state: (1) pollen develops inside the anther immersed in locular fluid, which conveys substances from the mother plant – the microsporogenesis phase; (2) locular fluid disappears by reabsorption and/or evaporation before the anther opens and the maturing pollen grains undergo dehydration – the dehydration phase; (3) the anther opens and pollen may be dispersed immediately, or be held by, for example, pollenkitt (as occurs in almost all entomophilous species) for later dispersion – the presentation phase; (4) pollen is dispersed by different agents, remaining exposed to the environment for different periods – the dispersal phase; and (5) pollen lands on a stigma and, in the case of a compatible stigma and suitable conditions, undergoes rehydration and starts germination – the pollen–stigma interaction phase. Scope This review highlights the issue of pollen water status and indicates the various mechanisms used by pollen grains during their five developmental phases to adjust to changes in water content and maintain internal stability. Conclusions Pollen water status is co-ordinated through structural, physiological and molecular mechanisms. The structural components participating in regulation of the pollen water level, during both dehydration and rehydration, include the exine (the outer wall of the pollen grain) and the vacuole. Recent data suggest the involvement of water channels in pollen water transport and the existence of several molecular mechanisms for pollen osmoregulation and to protect cellular components (proteins and membranes) under water stress. It is suggested that pollen grains will use these mechanisms, which have a developmental role, to cope with environmental stress conditions. PMID:22523424

  12. Pollen Characterization in Size Segregated Atmospheric Aerosol

    NASA Astrophysics Data System (ADS)

    Kolpakova, Anna; Hovorka, Jan; Klán, Miroslav

    2017-12-01

    The first stage of a High Volumetric Cascade Impactor - HiVol (BGI-900), used for sampling of aerosol particles larger than 10 micrometres in aerodynamic diameter, was tested for bioaerosol sampling. Low air flow-rate and low pressure-drop at the jets of the first stage and high air volume are advantageous parameters, which would favour the use of the first stage for bioaerosol sampling. The sampling went in urban, rural and background localities, Prague, Brezno and Laz respectively in the Czech Republic, in summer and autumn. Pollen was separated from the impaction substrate, polyurethane foam, into homogeneous deposit on Nylon filter. The homogeneity of the deposit varied within 4%. Representative portion of the deposit was analysed by a scanning electron microscopy - SEM. There were taken 485 SEM images from 12 samples in 3 localities. Pollen grains were identified in 295 SEM images and determined into 9 genus and 4 families. Median pollen grain concentrations/deformities were 9m-3/24%, 3m-3/18%, 8m-3/50% for Prague, Brezno and Láz localities respectively. The pollen grains of the Poaceae family were found with the highest frequency in all localities. Number of pollen increased with total aerosol mass in Prague locality only. There were also identified brochosomes, rather unique insect secretion products, in the samples from the Láz locality.

  13. Airborne pollen survey in Bangkok, Thailand: A 35-year update.

    PubMed

    Songnuan, Wisuwat; Bunnag, Chaweewan; Soontrapa, Kitipong; Pacharn, Punchama; Wangthan, Unchalee; Siriwattanakul, Umaporn; Malainual, Nat

    2015-09-01

    Pollen allergy is a growing global health issue. While airborne pollen counts are reported daily in several countries, such information is lacking in Thailand. This study aimed to survey airborne pollens at five sites in Bangkok, comparing data with the previous study performed 35 years ago in 1980. Sample collection was done using the ROTOROD® sampler by exposing the rods for one hour each day twice a week from May 2012-April 2013. Overall, we found that the average pollen count was relatively high throughout the year, at an average of 242 grains/m3. The highest peak was found in September (700 grains/m3). Interestingly, we found that the pollen count was noticeably lower in 2012-2013 when compared to the 1980 study. We also observed the approximate shift of pollen peaks about one to two months earlier in the 2012-2013 study. However, the major groups of airborne pollens did not change significantly. Grass, sedge, amaranthus pollens and fern spores still dominated. The unidentified pollen group was the only group with a higher pollen count when compared to the previous study.

  14. [Clustering Sugi-pollen dispersal patterns for the past 26 years].

    PubMed

    Ito, Yukiko

    2014-05-01

    Pollinosis caused by the pollen of Sugi (Cryptopmeria japonica) trees is the most significant allergic disease occurring in the spring in Japan. For pollinosis patients and medical staff, it is important to know when the pollen dispersion would reach maximum or when the pollen count would decrease as well as knowing what would the total density of pollen grains be. These sorts of information could be useful for the purpose of disease prevention and deciding on the therapeutic regimen. In this study, we presented the sugi-dispersal patterns and cited several examples of the dispersal pattern. Airborne pollen grains were collected using a Durham sampler. Total annual pollen counts/cm2 were examined. The sugi-dispersal patterns were classified into several groups by cluster analysis using variables of ten days pollen counts distribution from February to April for the past 26 years. (1987-2012). The annual pollen count revealed an alternate rhythm consisting of an "on" year (high pollen count) and an "off" year (low pollen count). The results of the cluster analysis showed eleven off-years classified as one group (group 1), and fifteen on-years classified into three groups (groups 2A, 2B, and 2C). The dispersal pattern in group 1 was almost symmetrical with the pollen count rapidly decreasing until late-March. On the other hand, the patterns in group 2 were asymmetrical. In group 2A and 2B a high rate of dispersion was indicated after maximum dispersion, whereas in group 2C the high rate of dispersion was indicated before maximum dispersion. In group 2A, a major dispersion of almost 3000 grains was noted in late-March, and immediately proceeded to the cypress (Chamaecyparis) pollen season without any decrease seen in pollen dispersion. The periods of dispersion of over 10 pollen grains/cm2 per day were 38, 47, 47 and 51 days in groups 1, 2A, 2B and 2C, respectively. That in group 2 was significantly longer than that in group 1, but there was no significant differences

  15. Spatial variability in the pollen count in Sydney, Australia: can one sampling site accurately reflect the pollen count for a region?

    PubMed

    Katelaris, Constance H; Burke, Therese V; Byth, Karen

    2004-08-01

    There is increasing interest in the daily pollen count, with pollen-sensitive individuals using it to determine medication use and researchers relying on it for commencing clinical drug trials and assessing drug efficacy according to allergen exposure. Counts are often expressed qualitatively as low, medium, and high, and often only 1 pollen trap is used for an entire region. To examine the spatial variability in the pollen count in Sydney, Australia, and to compare discrepancies among low-, medium-, and high-count days at 3 sites separated by a maximum of 30 km. Three sites in western Sydney were sampled using Burkard traps. Data from the 3 sites were used to compare vegetation differences, possible effects of some meteorological parameters, and discrepancies among sites in low-, medium-, and high-count days. Total pollen counts during the spring months were 14,382 grains/m3 at Homebush, 11,584 grains/m3 at Eastern Creek, and 9,269 grains/m3 at Nepean. The only significant correlation between differences in meteorological parameters and differences in pollen counts was the Homebush-Nepean differences in rainfall and pollen counts. Comparison between low- and high-count days among the 3 sites revealed a discordance rate of 8% to 17%. For informing the public about pollen counts, the count from 1 trap is a reasonable estimation in a 30-km region; however, the discrepancies among 3 trap sites would have a significant impact on the performance of a clinical trial where enrollment was determined by a low or high count. Therefore, for clinical studies, data collection must be local and applicable to the study population.

  16. Herbivory in spiders: the importance of pollen for orb-weavers.

    PubMed

    Eggs, Benjamin; Sanders, Dirk

    2013-01-01

    Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders' diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders' diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores.

  17. A pollen-specific RALF from tomato that regulates pollen tube elongation.

    PubMed

    Covey, Paul A; Subbaiah, Chalivendra C; Parsons, Ronald L; Pearce, Gregory; Lay, Fung T; Anderson, Marilyn A; Ryan, Clarence A; Bedinger, Patricia A

    2010-06-01

    Rapid Alkalinization Factors (RALFs) are plant peptides that rapidly increase the pH of plant suspension cell culture medium and inhibit root growth. A pollen-specific tomato (Solanum lycopersicum) RALF (SlPRALF) has been identified. The SlPRALF gene encodes a preproprotein that appears to be processed and released from the pollen tube as an active peptide. A synthetic SlPRALF peptide based on the putative active peptide did not affect pollen hydration or viability but inhibited the elongation of normal pollen tubes in an in vitro growth system. Inhibitory effects of SlPRALF were detectable at concentrations as low as 10 nm, and complete inhibition was observed at 1 mum peptide. At least 10-fold higher levels of alkSlPRALF, which lacks disulfide bonds, were required to see similar effects. A greater effect of peptide was observed in low-pH-buffered medium. Inhibition of pollen tube elongation was reversible if peptide was removed within 15 min of exposure. Addition of 100 nm SlPRALF to actively growing pollen tubes inhibited further elongation until tubes were 40 to 60 mum in length, after which pollen tubes became resistant to the peptide. The onset of resistance correlated with the timing of the exit of the male germ unit from the pollen grain into the tube. Thus, exogenous SlPRALF acts as a negative regulator of pollen tube elongation within a specific developmental window.

  18. Pollen structure visualization using high-resolution laboratory-based hard X-ray tomography.

    PubMed

    Li, Qiong; Gluch, Jürgen; Krüger, Peter; Gall, Martin; Neinhuis, Christoph; Zschech, Ehrenfried

    2016-10-14

    A laboratory-based X-ray microscope is used to investigate the 3D structure of unstained whole pollen grains. For the first time, high-resolution laboratory-based hard X-ray microscopy is applied to study pollen grains. Based on the efficient acquisition of statistically relevant information-rich images using Zernike phase contrast, both surface- and internal structures of pine pollen - including exine, intine and cellular structures - are clearly visualized. The specific volumes of these structures are calculated from the tomographic data. The systematic three-dimensional study of pollen grains provides morphological and structural information about taxonomic characters that are essential in palynology. Such studies have a direct impact on disciplines such as forestry, agriculture, horticulture, plant breeding and biodiversity. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Pollen analysis of natural honeys from the central region of Shanxi, North China.

    PubMed

    Song, Xiao-Yan; Yao, Yi-Feng; Yang, Wu-De

    2012-01-01

    Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010-2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples) included Caprifoliaceae (found in 10 samples), Laminaceae (10), Brassicaceae (12), Rosaceae (12), Moraceae (13), Rhamnaceae (15), Asteraceae (17), and Fabaceae (19). In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples), Robinia pseudoacacia (3), Vitex negundo var. heterophylla (2), Sophora japonica (1), Ailanthus altissima (1), Asteraceae type (1), and Fabaceae type (1). The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample) suggested that 13 samples belonged to Group I (<20,000 pollen grains), 4 to Group II (20,000-100,000), and 2 to Group III (100,000-500,000). The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants) indicated that the honey samples are of good quality and suitable for human consumption.

  20. Identification of caleosin and oleosin in oil bodies of pine pollen.

    PubMed

    Pasaribu, Buntora; Chen, Chii-Shiarng; Liao, Yue Ken; Jiang, Pei-Luen; Tzen, Jason T C

    2017-02-01

    Unique proteins including steroleosin, caleosin, oleosin-L, and oleosin-G have been identified in seed oil bodies of pine (Pinus massoniana). In this study, mature pollen grains with wing-like bladders were collected from pine (Pinus elliottii). Ultrastructural studies showed that oil bodies were present in pollen grains, but not the attached bladders, and the presence of oil bodies was further confirmed by fluorescent staining with BODIPY 493/503. Stable oil bodies were successfully purified from pine pollen grains, and analyzed to be mainly composed of triacylglycerols. Putative oleosin and caleosin in pine pollen oil bodies were detected by immunoassaying with antibodies against sesame seed caleosin and lily pollen oleosin. Complete cDNA fragments encoding these two pollen oil-body proteins were obtained by PCR cloning. Sequence alignment showed that pine pollen caleosin (27 kDa) was highly homologous to pine seed caleosin (28 kDa) except for the lack of an appendix of eight residues at the C-terminus in accord with the 1 kDa difference in their molecular masses. Pine pollen oleosin (15 kDa) was highly homologous to pine seed oleosin-G (14 kDa) except for an insertion of eight residues at the N-terminus in accord with the 1 kDa difference in their molecular masses. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Quantitative DNA Analyses for Airborne Birch Pollen

    PubMed Central

    Müller-Germann, Isabell; Vogel, Bernhard; Vogel, Heike; Pauling, Andreas; Fröhlich-Nowoisky, Janine; Pöschl, Ulrich; Després, Viviane R.

    2015-01-01

    Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR), which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm) and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8) and the other for a multi-copy gene (ITS). The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm), the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future. PMID:26492534

  2. Fur versus feathers: pollen delivery by bats and hummingbirds and consequences for pollen production.

    PubMed

    Muchhala, Nathan; Thomson, James D

    2010-06-01

    One floral characteristic associated with bat pollination (chiropterophily) is copious pollen production, a pattern we confirmed in a local comparison of hummingbird- and bat-adapted flowers from a cloud forest site in Ecuador. Previous authors have suggested that wasteful pollen transfer by bats accounted for the pattern. Here we propose and test a new hypothesis: bats select for increased pollen production because they can efficiently transfer larger amounts of pollen, which leads to a more linear male fitness gain curve for bat-pollinated plants. Flight cage experiments with artificial flowers and flowers of Aphelandra acanthus provide support for this hypothesis; in both instances, the amount of pollen delivered to stigmas by birds is not related to the amount of pollen removed from anthers on the previous visit, while the same function for bats increases linearly. Thus, increased pollen production will be linearly related to increased male reproductive success for bat flowers, while for bird flowers, increased pollen production leads to rapidly diminishing fitness returns. We speculate that fur takes up and holds more pollen than feathers, which seem to readily shed excess grains. Our gain-curve hypothesis may also explain why evolutionary shifts from bird to bat pollination seem more common than shifts in the opposite direction.

  3. Annual and intradiurnal variation of dominant airborne pollen and the effects of meteorological factors in Çeşme (Izmir, Turkey).

    PubMed

    Uguz, Ulas; Guvensen, Aykut; Tort, Nedret Sengonca

    2017-09-30

    In this present study, airborne pollen in Çeşme was investigated between February 17, 2012 and February 17, 2014 using the volumetric method. Çeşme, one of Turkey's most important tourism centers, which attracts numerous local and foreign tourists each year, is a district of Izmir, a province in the western part of Turkey. During the 2-year study, 12,905 pollen grains belonging to 64 taxa (33 arboreal, 31 non-arboreal plants) were detected. However, the 2-year data results revealed that the taxa with the pollen concentration more than 4% in the atmosphere were Cupressaceae/Taxaceae (4268 pollen, 33.07%), Olea europaea (1614 pollen grains, 12.51%), Pinaceae (1085 pollen grains, 8.41%), Quercus spp. (1081 pollen grains, 8.38%), Pistacia spp. (743 pollen grains, 5.76%), and Poaceae (557 pollen grains, 4.32%), all of which comprised 72.44% of the total count. The relationship between the daily pollen counts belonging to these six taxa and the hourly average temperature (°C), daily precipitation (mm), relative humidity (%), and wind speed (km/h) was assessed using the Spearman correlation test, and significant results were determined. During the study, the intradiurnal distribution of the aforementioned pollen varied. The highest pollen concentration was detected between 11:00 a.m. and 6:00 p.m. (first year 30.3%; second year 30.1%).

  4. Pollen morphology and viability in Bromeliaceae.

    PubMed

    Souza, Everton H; Souza, Fernanda V D; Rossi, Mônica L; Packer, Renan M; Cruz-Barros, Maria Amelia V; Martinelli, Adriana P

    2017-01-01

    Pollen morphology characterization is important in taxonomy, conservation and plant breeding, and pollen viability studies can support breeding programs. This study investigated pollen morphology and male fertility in 18 species of Bromeliaceae with ornamental potential. For morphological characterization, pollen grains were acetolyzed and characterization of exine was done using scanning and transmission electron microscopy. Pollen viability was investigated by in vitro germination and histochemical tests. Species belonging to Aechmea and Ananas genera presented medium size pollen, except for Ae. fasciata, with large pollen. Al. nahoumii, P. sagenarius and the Vriesea species analyzed showed large pollen, except for V. carinata, with very large pollen. Pollen of Aechmea, Ananas and P. sagenarius presented bilateral symmetry, diporate, exine varying from tectate to semitectate. Al. nahoumii and Vriesea species presented pollen with bilateral symmetry, monocolpate; exine was semitectate, reticulate and heterobrochate. Germination percentage and tube growth were greater in SM and BKM media. Histochemical tests showed pollen viability above 70% for all species, except for Ananas sp. (40%). Pollen morphology is important for the identification of species, especially in this family, which contains a large number of species. High rates of viability favor fertilization and seed production, essential for efficient hybrid production and conservation.

  5. Pollen morphology and plant taxonomy of white oaks in eastern North America

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Solomon, A.M.

    An evaluation of possible approaches to fossil oak pollen identification utilized scanning electron microscopy to examine exine-surface features of 171 collections, representing 16 Quercus subgenus Lepidobalanus species and varieties of eastern North America. Twenty qualitative pollen morphological characters were defined and tabulated for each of 217 pollen grains. The data were subjected to cluster analysis and cluster diagrams were compared with published white oak taxonomy. Pollen morphology and plant taxonomy compared well in series of the subgenus Lepidobalanus due primarily to consistency of character presence and absence within species and varieties. Pollen morphology of white oaks appears to reflect plantmore » systematics above the species level. Use of routine SEM analysis to identify series of white oaks among fossil pollen grains likely will yield valid results. 38 references.« less

  6. Bioinspired Pollen-Like Hierarchical Surface for Efficient Recognition of Target Cancer Cells.

    PubMed

    Wang, Wenshuo; Yang, Gao; Cui, Haijun; Meng, Jingxin; Wang, Shutao; Jiang, Lei

    2017-08-01

    The efficient recognition and isolation of rare cancer cells holds great promise for cancer diagnosis and prognosis. In nature, pollens exploit spiky structures to realize recognition and adhesion to stigma. Herein, a bioinspired pollen-like hierarchical surface is developed by replicating the assembly of pollen grains, and efficient and specific recognition to target cancer cells is achieved. The pollen-like surface is fabricated by combining filtering-assisted assembly and soft lithography-based replication of pollen grains of wild chrysanthemum. After modification with a capture agent specific to cancer cells, the pollen-like surface enables the capture of target cancer cells with high efficiency and specificity. In addition, the pollen-like surface not only assures high viability of captured cells but also performs well in cell mixture system and at low cell density. This study represents a good example of constructing cell recognition biointerfaces inspired by pollen-stigma adhesion. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Herbivory in Spiders: The Importance of Pollen for Orb-Weavers

    PubMed Central

    Eggs, Benjamin; Sanders, Dirk

    2013-01-01

    Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders’ diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders’ diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores. PMID:24312430

  8. Pollen and stigma morphology of some Phaseoleae species (Leguminosae) with different pollinators.

    PubMed

    Basso-Alves, J P; Agostini, K; Teixeira, S de Pádua

    2011-07-01

    Pollen transport to a receptive stigma can be facilitated through different pollinators, which submits the pollen to different selection pressures. This study aimed to associate pollen and stigma morphology with zoophily in species of the tribe Phaseoleae. Species of the genera Erythrina, Macroptilium and Mucuna with different pollinators were chosen. Pollen grains and stigmas were examined under light microscopy (anatomy), scanning electronic microscopy (surface analyses) and transmission electronic microscopy (ultrastructure). The three genera differ in terms of pollen wall ornamentation, pollen size, pollen aperture, thickness of the pollen wall, amount of pollenkitt, pollen hydration status and dominant reserves within the pollen grain, while species within each genus are very similar in most studied characteristics. Most of these features lack relationships to pollinator type, especially in Erythrina and Mucuna. Pollen reserves are discussed on a broad scale, according to the occurrence of protein in the pollen of invertebrate- or vertebrate-pollinated species. Some pollen characteristics are more associated to semi-dry stigma requirements. This apical, compact, cuticularised and secretory stigma occurs in all species investigated. We conclude that data on pollen and stigma structure should be included together with those on floral morphology and pollinator behaviour for the establishment of functional pollination classes. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Adsorption of air pollutants on the grain surface of Japanese cedar pollen

    NASA Astrophysics Data System (ADS)

    Okuyama, Yuji; Matsumoto, Kiyoshi; Okochi, Hiroshi; Igawa, Manabu

    The contaminants adsorbed on the surface of pollen may affect the development of hay fever, because the patients of the fever are larger in areas with much air pollution than in nonpolluted areas and the fine particles and gases are susceptible to deposit on the nasal cavities and eyes by their transfer on the pollen. Since Japanese cedar pollinosis is the most common hay fever in Japan, we analyzed the air pollutants adsorbed on the surface of dispersed Japanese cedar pollen in the urban and mountainous districts. Fine anthropogenic particles were significantly adsorbed and many elements were concentrated on the surface of the pollen in the urban site of Yokohama, while they were not concentrated on the surface of the pollen collected at a mountainous site. The acid gases are also adsorbed and acidify the surface, and their amounts increase with their concentrations in the ambient air. The high adsorption of nitric acid on the pollen determined by an exposure experiment of nitric acid gas suggests that nitric acid is dissolved in the inner part of the pollen. The adsorption amounts of the gases on the pollen were especially greater than those on other natural particles, humic acid and yellow sand.

  10. Pollen Analysis of Natural Honeys from the Central Region of Shanxi, North China

    PubMed Central

    Song, Xiao-Yan; Yao, Yi-Feng; Yang, Wu-De

    2012-01-01

    Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010–2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples) included Caprifoliaceae (found in 10 samples), Laminaceae (10), Brassicaceae (12), Rosaceae (12), Moraceae (13), Rhamnaceae (15), Asteraceae (17), and Fabaceae (19). In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples), Robinia pseudoacacia (3), Vitex negundo var. heterophylla (2), Sophora japonica (1), Ailanthus altissima (1), Asteraceae type (1), and Fabaceae type (1). The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample) suggested that 13 samples belonged to Group I (<20,000 pollen grains), 4 to Group II (20,000–100,000), and 2 to Group III (100,000–500,000). The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants) indicated that the honey samples are of good quality and suitable for human consumption. PMID:23185358

  11. Evolution of pollen morphology in Loranthaceae

    PubMed Central

    Grímsson, Friðgeir; Grimm, Guido W.; Zetter, Reinhard

    2018-01-01

    Abstract Earlier studies indicate a strong correlation of pollen morphology and ultrastructure with taxonomy in Loranthaceae. Using high-resolution light microscopy and scanning electron microscopy imaging of the same pollen grains, we document pollen types of 35 genera including 15 studied for the first time. Using a molecular phylogenetic framework based on currently available sequence data with good genus-coverage, we reconstruct trends in the evolution of Loranthaceae pollen and pinpoint traits of high diagnostic value, partly confirming earlier intuitive hypotheses based on morphological observations. We find that pollen morphology in Loranthaceae is strongly linked to phylogenetic relationships. Some pollen types are diagnostic for discrete genera or evolutionary lineages, opening the avenue to recruit dispersed fossil pollen as age constraints for dated phylogenies and as independent data for testing biogeographic scenarios; so far based exclusively on modern-day data. Correspondences and discrepancies between palynological and molecular data and current taxonomic/systematic concepts are identified and suggestions made for future palynological and molecular investigations of Loranthaceae. PMID:29386990

  12. Immersion freezing of birch pollen washing water

    NASA Astrophysics Data System (ADS)

    Augustin, S.; Wex, H.; Niedermeier, D.; Pummer, B.; Grothe, H.; Hartmann, S.; Tomsche, L.; Clauss, T.; Voigtländer, J.; Ignatius, K.; Stratmann, F.

    2013-11-01

    Birch pollen grains are known to be ice nucleating active biological particles. The ice nucleating activity has previously been tracked down to biological macromolecules that can be easily extracted from the pollen grains in water. In the present study, we investigated the immersion freezing behavior of these ice nucleating active (INA) macromolecules. Therefore we measured the frozen fractions of particles generated from birch pollen washing water as a function of temperature at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). Two different birch pollen samples were considered, with one originating from Sweden and one from the Czech Republic. For the Czech and Swedish birch pollen samples, freezing was observed to start at -19 and -17 °C, respectively. The fraction of frozen droplets increased for both samples down to -24 °C. Further cooling did not increase the frozen fractions any more. Instead, a plateau formed at frozen fractions below 1. This fact could be used to determine the amount of INA macromolecules in the droplets examined here, which in turn allowed for the determination of nucleation rates for single INA macromolecules. The main differences between the Swedish birch pollen and the Czech birch pollen were obvious in the temperature range between -17 and -24 °C. In this range, a second plateau region could be seen for Swedish birch pollen. As we assume INA macromolecules to be the reason for the ice nucleation, we concluded that birch pollen is able to produce at least two different types of INA macromolecules. We were able to derive parameterizations for the heterogeneous nucleation rates for both INA macromolecule types, using two different methods: a simple exponential fit and the Soccer ball model. With these parameterization methods we were able to describe the ice nucleation behavior of single INA macromolecules from both the Czech and the Swedish birch pollen.

  13. Ultrastructure and pollen morphology of Bromeliaceae species from the Atlantic Rainforest in Southeastern Brazil.

    PubMed

    Silva, Vanessa J D; Ribeiro, Ester M; Luizi-Ponzo, Andrea P; Faria, Ana Paula G

    2016-01-01

    Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L.) Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl.) Schult.f., Billbergia distachia (Vell.) Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb.) Lindl., Portea petropolitana (Wawra) Mez, Pitcairnia flammea Lindl., Quesnelia indecora Mez, Tillandsia polystachia (L.) L., T. stricta Sol., T. gardneri Lindl., T. geminiflora Brongn. and Vriesea grandiflora Leme. Light and scanning electron microscopy were used and the species were grouped into three pollen types, organized according to aperture characteristics: Type I - pantoporate pollen grains observed in P. petropolitana, Type II - 2-porate pollen grains, observed in the genera Ananas, Aechmea and Quesnelia, and Type III - 1-colpate pollen grains, observed in the genera Billbergia, Pitcairnia, Tillandsia and Vriesea. Pollen data led to the construction of an identification key. The results showed that the species analyzed can be distinguished using mainly aperture features and exine ornamentation, and that these characteristics may assist in taxonomic studies of the family.

  14. Airborne pollen and suicide mortality in Tokyo, 2001-2011.

    PubMed

    Stickley, Andrew; Sheng Ng, Chris Fook; Konishi, Shoko; Koyanagi, Ai; Watanabe, Chiho

    2017-05-01

    Prior research has indicated that pollen might be linked to suicide mortality although the few studies that have been undertaken to date have produced conflicting findings and been limited to Western settings. This study examined the association between the level of airborne pollen and suicide mortality in Tokyo, Japan in the period from 2001 to 2011. The daily number of suicide deaths was obtained from the Japanese Ministry of Health, Labour and Welfare, with pollen data being obtained from the Tokyo Metropolitan Institute of Public Health. A time-stratified case-crossover study was performed to examine the association between different levels of pollen concentration and suicide mortality. During the study period there were 5185 male and 2332 female suicides in the pollen season (February to April). For men there was no association between airborne pollen and suicide mortality. For women, compared to when there was no airborne pollen, the same-day (lag 0) pollen level of 30 to <100 grains per cm 2 was associated with an approximately 50% increase in the odds for suicide (e.g. 30 to <50 grains per cm 2 : odds ratio 1.574, 95% confidence interval 1.076-2.303, p=0.020). The estimates remained fairly stable after adjusting for air pollutants and after varying the cut-points that defined the pollen levels. Our results indicate that pollen is associated with female suicide mortality in Tokyo. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Pollen Load and Flower Constancy of Three Species of Stingless Bees (Hymenoptera, Apidae, Meliponinae)

    PubMed Central

    Pangestika, Norita Widya; Atmowidi, Tri; Kahono, Sih

    2017-01-01

    The genera of stingless bees play an important role as pollinators of plants. These bees are actively involved in the pollination of agricultural crops and known to have preferences in selecting flowers to pollinate. The aims of this study were to analyse the pollen load and flower constancy in Tetragonula laeviceps, Lepidotrigona terminata, and Heterotrigona itama. Each individual of species stingless bees collected and was put in a 1.5 mL micro-tube contain 0.5 mL 70% ethanol:glycerol (4:1). Pollen loads on each individual of stingless bees was counted by hemocytometer. Flower constancy of stingless bees was measured based on percentage of pollen type loaded on the body. Results showed that the pollen loads of H. itama was the highest (31392 pollen grains) followed by L. terminata (23017 pollen grains) and T. laeviceps (8015 pollen grains). These species also demonstrated different flower constancy, T. laeviceps on Poaceae flowers (76.49%), L. terminata on Euphorbiaceae flowers (80.46%), and H. itama on Solanaceae flowers (83.33%). PMID:28890769

  16. On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia

    NASA Astrophysics Data System (ADS)

    de Morton, Julian; Bye, John; Pezza, Alexandre; Newbigin, Edward

    2011-07-01

    In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible individuals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m-3) or high (50-100 pollen grains m-3) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low (<20 pollen grains m-3) concentration of grass pollen, winds were of maritime origin. On extreme and high grass pollen days, a peak in APC occurred on average around 1730 hours, probably due to a reduction in surface boundary layer turbulence. The sum of daily APC for each grass pollen season was highly correlated ( r = 0.79) with spring rainfall in Melbourne for that year, with about 60% of a declining linear trend across the study period being attributable to a reduction of meat cattle and sheep (and hence grazing land) in rural areas around Melbourne. Finally, all of the ten extreme pollen events (3 days or more with APC > 100 pollen grains m-3) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems.

  17. On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia.

    PubMed

    de Morton, Julian; Bye, John; Pezza, Alexandre; Newbigin, Edward

    2011-07-01

    In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible individuals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m(-3)) or high (50-100 pollen grains m(-3)) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low (<20 pollen grains m(-3)) concentration of grass pollen, winds were of maritime origin. On extreme and high grass pollen days, a peak in APC occurred on average around 1730 hours, probably due to a reduction in surface boundary layer turbulence. The sum of daily APC for each grass pollen season was highly correlated (r = 0.79) with spring rainfall in Melbourne for that year, with about 60% of a declining linear trend across the study period being attributable to a reduction of meat cattle and sheep (and hence grazing land) in rural areas around Melbourne. Finally, all of the ten extreme pollen events (3 days or more with APC > 100 pollen grains m(-3)) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems.

  18. Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil.

    PubMed

    Barreto, Cintia F; Vilela, Claudia G; Baptista-Neto, José A; Barth, Ortrud M

    2012-09-01

    Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

  19. Airborne pollen of Carya, Celtis, Cupressus, Fraxinus and Pinus in the metropolitan area of Monterrey Nuevo Leon, Mexico.

    PubMed

    Rocha-Estrada, Alejandra; Alvarado-Vázquez, Marco Antonio; Torres-Cepeda, Teresa Elizabeth; Foroughbakhch-Pournavab, Rahim; Hernández-Piñero, Jorge Luis

    2008-01-01

    The concentration of pollen grains in the atmosphere over the metropolitan area of Monterrey, Nuevo Leon, Mexico, was analyzed throughout a year from March 2003-February 2004, focused on the genus Carya, Celtis, Cupressus, Fraxinus and Pinus owing to their interest as etiological pollinosis agents in diverse regions of the world. A 7-day Hirst type volumetric spore and pollen trap was located on a building roof of the city at 15 m from ground level for continuous sampling. The total quantity of pollen recorded for the study period was 21,083 grains/m(3), corresponding to 49.75 % of the taxa of interest. February and March were the months with higher pollen amounts in the air with 7,525 and 2,781 grains/m(3), respectively, and amounted to 49 % of total year through pollen. Fraxinus was the genus which contributed to the largest amount of pollen with 28 % of total grains (5,935 grains/m(3)) followed by Cupressus with 13 % (2,742 grains/ m(3)). Celtis, Pinus and Carya contributed with 5.3 % , 2.7 % , and 0.6 % of total pollen, respectively. These results indicate that Fraxinus and Cupressus are present in the area in sufficient quantity to indicate likely involvement in the origin of allergic disorders in the human population.

  20. Pollen loads and specificity of native pollinators of lowbush blueberry.

    PubMed

    Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

    2014-06-01

    The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem.

  1. An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis

    PubMed Central

    Takikawa, Yoshihiro; Matsuda, Yoshinori; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Toyoda, Hideyoshi

    2017-01-01

    An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica, from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure. PMID:28098835

  2. An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis.

    PubMed

    Takikawa, Yoshihiro; Matsuda, Yoshinori; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Toyoda, Hideyoshi

    2017-01-15

    An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica , from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure.

  3. Neighbourhood density and genetic relatedness interact to determine fruit set and abortion rates in a continuous tropical tree population

    PubMed Central

    Jones, F.A; Comita, L.S

    2008-01-01

    Tropical trees may show positive density dependence in fruit set and maturation due to pollen limitation in low-density populations. However, pollen from closely related individuals in the local neighbourhood might reduce fruit set or increase fruit abortion in self-incompatible tree species. We investigated the role of neighbourhood density and genetic relatedness on individual fruit set and abortion in the neotropical tree Jacaranda copaia in a large forest plot in central Panama. Using nested neighbourhood models, we found a strong positive effect of increased conspecific density on fruit set and maturation. However, high neighbourhood genetic relatedness interacted with density to reduce total fruit set and increase the proportion of aborted fruit. Our results imply a fitness advantage for individuals growing in high densities as measured by fruit set, but realized fruit set is lowered by increased neighbourhood relatedness. We hypothesize that the mechanism involved is increased visitation by density-dependent invertebrate pollinators in high-density populations, which increases pollen quantity and carry-over and increases fruit set and maturation, coupled with self-incompatibility at early and late stages due to biparental inbreeding that lowers fruit set and increases fruit abortion. Implications for the reproductive ecology and conservation of tropical tree communities in continuous and fragmented habitats are discussed. PMID:18713714

  4. Urticaceae pollen concentration in the atmosphere of North Western Spain.

    PubMed

    Vega-Maray, Ana Maria; Valencia-Barrera, Rosa; Fernandez-Gonzalez, Delia; Fraile, Roberto

    2003-01-01

    Plants of the Urticaceae family can develop into a pest on soils enriched with nitrogen. Urticaceae pollen is a biohazard because it elicits severe pollinosis. Pollen grains were sampled by using a Lanzoni seven-day-recording trap from February 1995-December 2000 in the atmosphere of the city of Ponferrada (Leon, North Western Spain). The Spearman test was used to analyse the statistical correlation between Urticaceae pollen and certain meteorological factors in different main pollination periods. Maximum values are reached in June and July, minimum levels are recorded in January and December. The parameters bearing the greatest positive influence on the occurrence of Urticaceae pollen grains are: temperature (maximum, minimum and mean), humidity (absolute, wet-bulb temperature, dew point and mixing ratio) and south western wind direction; negative parameters are: relative humidity, rainfall and period without wind. The highest correlation coefficients were obtained with temperature and wet-bulb. Absolute humidity and wet-bulb temperature yielded better correlation than relative humidity; hence, these two parameters must be included in this type of study. The use of one main pollination period or another in statistical analysis has an influence on the coefficient value. The behaviour of the pollen grains in the atmosphere during the year also influences the results.

  5. The Role of Arabidopsis ABCG9 and ABCG31 ATP Binding Cassette Transporters in Pollen Fitness and the Deposition of Steryl Glycosides on the Pollen Coat[W

    PubMed Central

    Choi, Hyunju; Ohyama, Kiyoshi; Kim, Yu-Young; Jin, Jun-Young; Lee, Saet Buyl; Yamaoka, Yasuyo; Muranaka, Toshiya; Suh, Mi Chung; Fujioka, Shozo; Lee, Youngsook

    2014-01-01

    The pollen coat protects pollen grains from harmful environmental stresses such as drought and cold. Many compounds in the pollen coat are synthesized in the tapetum. However, the pathway by which they are transferred to the pollen surface remains obscure. We found that two Arabidopsis thaliana ATP binding cassette transporters, ABCG9 and ABCG31, were highly expressed in the tapetum and are involved in pollen coat deposition. Upon exposure to dry air, many abcg9 abcg31 pollen grains shriveled up and collapsed, and this phenotype was restored by complementation with ABCG9pro:GFP:ABCG9. GFP-tagged ABCG9 or ABCG31 localized to the plasma membrane. Electron microscopy revealed that the mutant pollen coat resembled the immature coat of the wild type, which contained many electron-lucent structures. Steryl glycosides were reduced to about half of wild-type levels in the abcg9 abcg31 pollen, but no differences in free sterols or steryl esters were observed. A mutant deficient in steryl glycoside biosynthesis, ugt80A2 ugt80B1, exhibited a similar phenotype. Together, these results indicate that steryl glycosides are critical for pollen fitness, by supporting pollen coat maturation, and that ABCG9 and ABCG31 contribute to the accumulation of this sterol on the surface of pollen. PMID:24474628

  6. Pollination of Schisandra henryi (Schisandraceae) by Female, Pollen-eating Megommata Species (Cecidomyiidae, Diptera) in South-central China

    PubMed Central

    Yuan, Liang-Chen; Luo, Yi-Bo; Thien, Leonard B.; Fan, Jian-Hua; Xu, Huan-Li; Chen, Zhi-Duan

    2007-01-01

    Background and Aims The mutualistic interaction between insects and flowers is considered to be a major factor in the early evolution of flowering plants. The Schisandraceae were, until now, the only family in the ANITA group lacking information on pollination biology in natural ecosystems. Thus, the objective of this research was to document the pollination biology and breeding system of Schisandra henryi. Methods Field observations were conducted in three populations of S. henryi and the floral phenology, floral characters and insect activities were recorded. Floral fragrances were sampled in the field and analysed using TCT-GC-MS. Floral thermogenesis was measured with a TR-71U Thermo Recorder. Pollen loads and location of pollen grains on insect bodies (including the gut) were checked with a scanning electron microscope and under a light microscope. Key Results Schisandra henryi is strictly dioecious. Male flowers are similar to female flowers in colour, shape, and size, but more abundant than female flowers. The distance between tepals and the androecium or gynoecium is narrow. Neither male nor female flowers are fragrant or thermogenic. Schisandra henryi is pollinated only by adult female Megommata sp. (Cecidomyiidae, Diptera) that eat the pollen grains as extra nutrition for ovary maturation and ovipositing. Both male and female flowers attract the pollinators using similar visual cues and thus the female flowers use deceit as they offer no food. Conclusions Schisandra henryi exhibits a specialized pollination system, which differs from the generalized pollination system documented in other ANITA members. Pollen is the sole food resource for Megommata sp. and the female flowers of S. henryi attract pollinators by deceit. This is the first report of predacious gall midges utilizing pollen grains as a food source. The lack of floral thermogenesis and floral odours further enforces the visual cues by reducing attractants for other potential pollinators. PMID

  7. Pollen Concentration in the Atmosphere of Abha City, Saudi Arabia and its Relationship with Meteorological Parameters

    NASA Astrophysics Data System (ADS)

    Alwadie, Hussein M.

    A qualitative and quantitative evaluation of pollen concentration in the atmosphere of Abha city, Saudi Arabia with the relation to meteorological parameters is presented. Investigations were undertaken from January to December 2006 using a Burkard 7 day volumetric spore trap. A total of 6,492 pollen grains m-3 belonging to 50 pollen taxa was detected. Poaceae represented 55.1% of total pollen, Leguminosae (11.7%), Compositae (6.1%), Solanaceae (4.6%) and Cupressaceae (4.2%). Pollen grains were found throughout the year. July represented the highest peak of pollen number and also the highest pollen taxa. The monthly variation of pollen taxa and their relationship to meteorological parameters were investigated. It was found that the pollen concentration is positively correlated with temperature and negatively correlated with rainfall, relative humidity and wind velocity. May-September represented the months of highest pollen number (95% of total pollen).

  8. Identification and localization of a caleosin in olive (Olea europaea L.) pollen during in vitro germination

    PubMed Central

    Zienkiewicz, Krzysztof; Castro, Antonio J.; de Dios Alché, Juan; Zienkiewicz, Agnieszka; Suárez, Cynthia; Rodríguez-García, María Isabel

    2010-01-01

    In plant organs and tissues, the neutral storage lipids are confined to discrete spherical organelles called oil bodies. Oil bodies from plant seeds contain 0.6–3% proteins, including oleosins, steroleosins, and caleosins. In this study, a caleosin isoform of ∼30 kDa was identified in the olive pollen grain. The protein was mainly located at the boundaries of the oil bodies in the cytoplasm of the pollen grain and the pollen tube. In addition, caleosins were also visualized in the cytoplasm at the subapical zone, as well as in the tonoplast of vacuoles present in the pollen tube cytoplasm. The cellular behaviour of lipid bodies in the olive pollen was also monitored during in vitro germination. The number of oil bodies decreased 20-fold in the pollen grain during germination, whereas the opposite tendency occurred in the pollen tube, suggesting that oil bodies moved from one to the other. The data suggest that this pollen caleosin might have a role in the mobilization of oil bodies as well as in the reorganization of membrane compartments during pollen in vitro germination. PMID:20164143

  9. Identification and persistence of Pinus pollen DNA on cotton fabrics: A forensic application.

    PubMed

    Schield, Cassandra; Campelli, Cassandra; Sycalik, Jennifer; Randle, Christopher; Hughes-Stamm, Sheree; Gangitano, David

    2016-01-01

    Advances in plant genomics have had an impact on the field of forensic botany. However, the use of pollen DNA profiling in forensic investigations has yet to be applied. Five volunteers wore a jacket with Pinus echinata pollen-containing cotton swatches for a 14-day period. Pollen decay was evaluated at days 0, 3, 6, 9 and 14 by microscopy. Pollen grains were then transferred to slides using a portable forensic vacuum handle. Ten single grains per swatch were isolated for DNA analysis. DNA was extracted using a high throughput extraction method. A nine-locus short tandem repeat (STR) multiplex system, including previously published primers from Pinus taeda, was developed. DNA was amplified by PCR using fluorescent dyes and analyzed by capillary electrophoresis. Pollen counts from cotton swatches in a 14-day period exhibited an exponential decay from 100% to 17%. The success rate of PCR amplification was 81.2%. Complete and partial STR profiles were generated from 250 pollen grains analyzed (44% and 37%, respectively). Due to the limited amount of DNA, drop-in events were observed (1.87%). However, the rate of contamination with pollen from other pine individuals originating from environmental sources was 4.4%. In conclusion, this study has shown that pollen can be a stable source of forensic DNA evidence, as a proof-of-principle, and that may persist on cotton clothing for at least 14 days of wear. This method can be applied in forensic cases where pollen grains larger than 10 μm (e.g., from herbs or trees) may be transferred to clothing (worn by suspect or victim) by primary contact. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    PubMed

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  11. Seasonal and intradiurnal variation of airborne pollen concentrations in Bodrum, SW Turkey.

    PubMed

    Tosunoglu, Aycan; Bicakci, Adem

    2015-04-01

    An aeropalynological study was performed in Bodrum, the famous tourism center in southwestern Turkey with a Hirst-type volumetric 7-day pollen and spore trap for 2 years (2007-2008). In Bodrum, 25,099 pollen grains as a mean value belonging to 41 taxa were recorded annually during the study period, and pollen grains from woody plant taxa had the largest atmospheric contribution of 86.99% and 24 taxa. However, 17 herbaceous plant taxa constituted 12.82% of the annual total pollen count, and 0.19% were unidentified. An average annual pollen index of 22.66% was recorded in March, despite differences from year to year. The highest pollen variability of 34 taxa was recorded in April and May. Predominant pollen types belonged to Cupressaceae/Taxaceae (42.73%), Quercus (15.95%), Pinus (9.78%), Olea europaea (9.04%), Poaceae (5.50%), Betula (1.82%), Pistacia (1.74%), Morus (1.72%), Urticaceae (1.46%), and Plantago (1.28%) and generated 91.03 of the annual total. In total, 32.59% of the mean annual total pollen index was recorded in the morning, and less pollen was recorded in the evening (18.71%). Maximum pollen concentration was recorded between 11:00 and 12:00 a.m.

  12. Lilium spp. pollen in China (Liliaceae): Taxonomic and Phylogenetic Implications and Pollen Evolution Related to Environmental Conditions

    PubMed Central

    Du, Yun-peng; Wei, Chi; Wang, Zhong-xuan; Li, Shuang; He, Heng-bin; Jia, Gui-xia

    2014-01-01

    Recent molecular and karyologic studies have significantly modified delimitation of Lilium. However, despite the importance of pollen evolution in the genus comprehensive studies with electron microscopy and evaluation of pollen evolution are lacking. Therefore, we studied pollen morphology in a sample of 65 individuals from 37 taxa covering all the sections distributed in the world, using scanning electron microscopy. Our collection of 49 individuals from 21 taxa covering all five sections in China was also included in the database. We found pollen tetrads in L. bakerianum. Based on present and previous studies, our results suggest that pollen from L. formosanum should be classified as a new type, Formosanum. Combined with morphological and molecular evidence, pollen sculpture patterns appear to reflect phylogenetic relationships and are useful for species or subsection delimitation. Based on a comprehensive survey and correlation with potential functional implications, we propose the following hypothesis: evolution of an exine sculpture shows pollen type trends from Martagon → Callose → Concolor → Formosanum. The evolutionary trend regarding pollen sculpture and size could be related to selective pressure to adapt to environmental conditions. Pollen size and shape showed a significantly positive correlation with annual precipitation, and smaller pollen grains appear to adapt better in habitats with extreme conditions. Evolution trends in exine sculpture do not appear to be definitively correlated with pollen size and shape. PMID:24498208

  13. Lilium spp. pollen in China (Liliaceae): taxonomic and phylogenetic implications and pollen evolution related to environmental conditions.

    PubMed

    Du, Yun-peng; Wei, Chi; Wang, Zhong-xuan; Li, Shuang; He, Heng-bin; Jia, Gui-xia

    2014-01-01

    Recent molecular and karyologic studies have significantly modified delimitation of Lilium. However, despite the importance of pollen evolution in the genus comprehensive studies with electron microscopy and evaluation of pollen evolution are lacking. Therefore, we studied pollen morphology in a sample of 65 individuals from 37 taxa covering all the sections distributed in the world, using scanning electron microscopy. Our collection of 49 individuals from 21 taxa covering all five sections in China was also included in the database. We found pollen tetrads in L. bakerianum. Based on present and previous studies, our results suggest that pollen from L. formosanum should be classified as a new type, Formosanum. Combined with morphological and molecular evidence, pollen sculpture patterns appear to reflect phylogenetic relationships and are useful for species or subsection delimitation. Based on a comprehensive survey and correlation with potential functional implications, we propose the following hypothesis: evolution of an exine sculpture shows pollen type trends from Martagon → Callose → Concolor → Formosanum. The evolutionary trend regarding pollen sculpture and size could be related to selective pressure to adapt to environmental conditions. Pollen size and shape showed a significantly positive correlation with annual precipitation, and smaller pollen grains appear to adapt better in habitats with extreme conditions. Evolution trends in exine sculpture do not appear to be definitively correlated with pollen size and shape.

  14. Feature Extraction and Machine Learning for the Classification of Brazilian Savannah Pollen Grains

    PubMed Central

    Souza, Junior Silva; da Silva, Gercina Gonçalves

    2016-01-01

    The classification of pollen species and types is an important task in many areas like forensic palynology, archaeological palynology and melissopalynology. This paper presents the first annotated image dataset for the Brazilian Savannah pollen types that can be used to train and test computer vision based automatic pollen classifiers. A first baseline human and computer performance for this dataset has been established using 805 pollen images of 23 pollen types. In order to access the computer performance, a combination of three feature extractors and four machine learning techniques has been implemented, fine tuned and tested. The results of these tests are also presented in this paper. PMID:27276196

  15. The bouquet of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) flowers arises from the biosynthesis of sesquiterpene volatiles in pollen grains

    PubMed Central

    Martin, Diane M.; Toub, Omid; Chiang, Angela; Lo, Bernard C.; Ohse, Sebastian; Lund, Steven T.; Bohlmann, Jörg

    2009-01-01

    Terpenoid volatiles are important information molecules that enable pollinators to locate flowers and may protect reproductive tissues against pathogens or herbivores. Inflorescences of grapevine (Vitis vinifera L.) are composed of tiny green flowers that produce an abundance of sesquiterpenoid volatiles. We demonstrate that male flower parts of grapevines are responsible for sesquiterpenoid floral scent formation. We describe temporal and spatial patterns of biosynthesis and release of floral volatiles throughout the blooming of V. vinifera L. cv. Cabernet Sauvignon. The biosynthesis of sesquiterpene volatiles, which are emitted with a light-dependent diurnal pattern early in the morning at prebloom and bloom, is localized to anthers and, more specifically, within the developing pollen grains. Valencene synthase (VvValCS) enzyme activity, which produces the major sesquiterpene volatiles of grapevine flowers, is present in anthers. VvValCS transcripts are most abundant in flowers at prebloom stages. Western blot analysis identified VvValCS protein in anthers, and in situ immunolabeling located VvValCS protein in pollen grains during bloom. Histochemical staining, as well as immunolabeling analysis by fluorescent microscopy and transmission electron microscopy, indicated that VvValCS localizes close to lipid bodies within the maturing microspore. PMID:19359488

  16. A 10-year climatology of pollen aerosol for the continental United States: implications for aerosol-climate interactions

    NASA Astrophysics Data System (ADS)

    Wozniak, M. C.

    2016-12-01

    Our current understanding of biological particles and their role in the climate system is uncertain. Pollen, a primary biological aerosol particle, has been understudied in the context of climate and atmospheric science because of its coarse size (10-100 µm). Local coarse grain pollen concentrations can reach up to 10,000 grains m-3, and when ruptured by wet or turbulent atmospheric conditions, can produce fine particles (sub-pollen particles, 10-1000 nm) that may increase pollen's lifetime in the atmosphere. Therefore, pollen contributes to both coarse and fine particle loads in the atmosphere that may have climatic impacts. During peak pollen emissions season, what impacts does pollen have on aerosol concentrations in the atmosphere and their indirect forcing? Here we use a model of accurately timed and scaled pollen and sub-pollen particle emissions with climate-dependent phenological dates for four plant functional types (deciduous broadleaf, evergreen needleleaf, grass and ragweed) that dominate emissions across the continental United States. Terrestrial pollen emissions are coupled with the land component of a regional climate model (RegCM4-CLM), and are transported as atmospheric tracers that are allowed interact with radiation and clouds, accounting for the direct and indirect effects of pollen. A ten-year climatology of pollen emissions and climate interactions is calculated for both pollen grains and sub-pollen particles. Its implications for the local and overall radiation budget, aerosol-cloud-precipitation interactions and regional climate are discussed.

  17. Classifying black and white spruce pollen using layered machine learning.

    PubMed

    Punyasena, Surangi W; Tcheng, David K; Wesseln, Cassandra; Mueller, Pietra G

    2012-11-01

    Pollen is among the most ubiquitous of terrestrial fossils, preserving an extended record of vegetation change. However, this temporal continuity comes with a taxonomic tradeoff. Analytical methods that improve the taxonomic precision of pollen identifications would expand the research questions that could be addressed by pollen, in fields such as paleoecology, paleoclimatology, biostratigraphy, melissopalynology, and forensics. We developed a supervised, layered, instance-based machine-learning classification system that uses leave-one-out bias optimization and discriminates among small variations in pollen shape, size, and texture. We tested our system on black and white spruce, two paleoclimatically significant taxa in the North American Quaternary. We achieved > 93% grain-to-grain classification accuracies in a series of experiments with both fossil and reference material. More significantly, when applied to Quaternary samples, the learning system was able to replicate the count proportions of a human expert (R(2) = 0.78, P = 0.007), with one key difference - the machine achieved these ratios by including larger numbers of grains with low-confidence identifications. Our results demonstrate the capability of machine-learning systems to solve the most challenging palynological classification problem, the discrimination of congeneric species, extending the capabilities of the pollen analyst and improving the taxonomic resolution of the palynological record. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  18. Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae).

    PubMed

    D'Ávila, V A; Aguiar-Menezes, E L; Gonçalves-Esteves, V; Mendonça, C B F; Pereira, R N; Santos, T M

    2016-04-19

    Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems.

  19. High temperature exposure did not affect induced 2n pollen viability in Populus.

    PubMed

    Tian, Mengdi; Zhang, Yuan; Liu, Yan; Kang, Xiangyang; Zhang, Pingdong

    2018-02-11

    High temperature exposure is widely used as a physical mutagenic agent to induce 2n gametes in Populus. However, whether high temperature exposure affects induced 2n pollen viability remains unknown. To clarify whether high temperature exposure affected the induced 2n pollen viability, 2n pollen induced by 38 and 41 °C temperatures, pollen morphology, 2n pollen germination in vitro, and crossing induced 2n pollen with normal gametes to produce a triploid was, based on observations of meiosis, conducted in Populus canescens. We found that the dominant meiotic stages (F = 56.6, p < .001) and the treatment duration (F = 21.4, p < .001) significantly affected the occurrence rate of induced 2n pollen. A significant decrease in pollen production and an increase in aborted pollen were observed (p < .001). High temperature sometimes affected in ectexine deposition and some narrow furrows were also analysed via details of ectexine structure. However, no significant difference in 2n pollen germination rate was observed between natural 2n pollen (26.7%) and high-temperature-induced 2n pollen (26.2%), and 42 triploids were created by crossing high-temperature-induced 2n pollen, suggesting that 38 and 41 °C temperatures exposure will not result in dysfunctional induced 2n pollen. © 2018 John Wiley & Sons Ltd.

  20. AtTMEM18 plays important roles in pollen tube and vegetative growth in Arabidopsis

    PubMed Central

    Dou, Xiao‐Ying; Yang, Ke‐Zhen; Ma, Zhao‐Xia; Chen, Li‐Qun; Zhang, Xue‐Qin; Bai, Jin‐Rong

    2016-01-01

    Abstract In flowering plants, pollen tube growth is essential for delivery of male gametes into the female gametophyte or embryo sac for double fertilization. Although many genes have been identified as being involved in the process, the molecular mechanisms of pollen tube growth remains poorly understood. In this study, we identified that the Arabidopsis Transmembrane Protein 18 (AtTMEM18) gene played important roles in pollen tube growth. The AtTMEM18 shares a high similarity with the Transmembrane 18 proteins (TMEM18s) that are conserved in most eukaryotes and may play important roles in obesity in humans. Mutation in the AtTMEM18 by a Ds insertion caused abnormal callose deposition in the pollen grains and had a significant impact on pollen germination and pollen tube growth. AtTMEM18 is expressed in pollen grains, pollen tubes, root tips and other vegetative tissues. The pollen‐rescued assays showed that the mutation in AtTMEM18 also caused defects in roots, stems, leaves and transmitting tracts. AtTMEM18‐GFP was located around the nuclei. Genetic assays demonstrated that the localization of AtTMEM18 around the nuclei in the generative cells of pollen grains was essential for the male fertility. Furthermore, expression of the rice TMEM18‐homologous protein (OsTMEM18) driven by LAT52 promoter could recover the fertility of the Arabidopsis attmem18 mutant. These results suggested that the TMEM18 is important for plant growth in Arabidopsis. PMID:26699939

  1. Trehalase: A New Pollen Enzyme

    PubMed Central

    Gussin, Arnold E. S.; McCormack, Jeffrey H.; Waung, Lucille Yih-Lo; Gluckin, Doreen S.

    1969-01-01

    Pollen from 5 plant species (Lycopersicon pimpinellifolium Mill., Hermerocallis minor Mill., Galtonia condicans Decne., Camellia japonica L., and Lathyrus odoratus L.) representing 4 families germinated well in media containing trehalose as the sole carbon source. Data are presented indicating that pollen metabolized this disaccharide for germination and subsequent pollen-tube growth; the sugar was not merely an osmoregulator. An inhibitor of trehalase activity depressed germination in trehalose but not in sucrose. Phloridzin dihydrate, an inhibitor of glucose transport, depressed germination in both disaccharides. Biochemical tests demonstrated that a pollen extract was capable of hydrolyzing trehalose to its constituent glucose monomers. Heat inactivation experiments confirmed the presence of a distinct trehalase having a rigid specificity for its substrate. By this method, trehalase activity was completely distinguishable from the activities of other α- and β-glucosidases and β-galactosidases. Localization data indicated that the enzyme diffused from intact grains and was probably soluble. The presence of its substrate could not be demonstrated in pollen or in stigmatic or stylar tissues. PMID:5379538

  2. Trehalase: a new pollen enzyme.

    PubMed

    Gussin, A E; McCormack, J H; Waung, L Y; Gluckin, D S

    1969-08-01

    Pollen from 5 plant species (Lycopersicon pimpinellifolium Mill., Hermerocallis minor Mill., Galtonia condicans Decne., Camellia japonica L., and Lathyrus odoratus L.) representing 4 families germinated well in media containing trehalose as the sole carbon source. Data are presented indicating that pollen metabolized this disaccharide for germination and subsequent pollen-tube growth; the sugar was not merely an osmoregulator. An inhibitor of trehalase activity depressed germination in trehalose but not in sucrose. Phloridzin dihydrate, an inhibitor of glucose transport, depressed germination in both disaccharides. Biochemical tests demonstrated that a pollen extract was capable of hydrolyzing trehalose to its constituent glucose monomers. Heat inactivation experiments confirmed the presence of a distinct trehalase having a rigid specificity for its substrate. By this method, trehalase activity was completely distinguishable from the activities of other alpha- and beta-glucosidases and beta-galactosidases. Localization data indicated that the enzyme diffused from intact grains and was probably soluble. The presence of its substrate could not be demonstrated in pollen or in stigmatic or stylar tissues.

  3. Assessing the impact of Cry1Ab-expressing corn pollen on monarch butterfly larvae in field studies

    PubMed Central

    Stanley-Horn, Diane E.; Dively, Galen P.; Hellmich, Richard L.; Mattila, Heather R.; Sears, Mark K.; Rose, Robyn; Jesse, Laura C. H.; Losey, John E.; Obrycki, John J.; Lewis, Les

    2001-01-01

    Survival and growth of monarch larvae, Danaus plexippus (L.), after exposure to either Cry1Ab-expressing pollen from three Bacillus thuringiensis (Bt) corn (Zea mays L.) events differing in toxin expression or to the insecticide, λ-cyhalothrin, were examined in field studies. First instars exposed to low doses (≈22 grains per cm2) of event-176 pollen gained 18% less weight than those exposed to Bt11 or Mon810 pollen after a 5-day exposure period. Larvae exposed to 67 pollen grains per cm2 on milkweed leaves from within an event-176 field exhibited 60% lower survivorship and 42% less weight gain compared with those exposed to leaves from outside the field. In contrast, Bt11 pollen had no effect on growth to adulthood or survival of first or third instars exposed for 5 days to ≈55 and 97 pollen grains per cm2, respectively. Similarly, no differences in larval survivorship were observed after a 4-day exposure period to leaves with 504–586 (within fields) or 18–22 (outside the field) pollen grains per cm2 collected from Bt11 and non-Bt sweet-corn fields. However, survivorship and weight gain were drastically reduced in non-Bt fields treated with λ-cyhalothrin. The effects of Bt11 and Mon810 pollen on the survivorship of larvae feeding 14 to 22 days on milkweeds in fields were negligible. Further studies should examine the lifetime and reproductive impact of Bt11 and Mon810 pollen on monarchs after long-term exposure to naturally deposited pollen. PMID:11559839

  4. Taphonomic bias in pollen and spore record: a review

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fisk, L.H.

    The high dispersibility and ease of pollen and spore transport have led researchers to conclude erroneously that fossil pollen and spore floras are relatively complete and record unbiased representations of the regional vegetation extant at the time of sediment deposition. That such conclusions are unjustified is obvious when the authors remember that polynomorphs are merely organic sedimentary particles and undergo hydraulic sorting not unlike clastic sedimentary particles. Prior to deposition in the fossil record, pollen and spores can be hydraulically sorted by size, shape, and weight, subtly biasing relative frequencies in fossil assemblages. Sorting during transport results in palynofloras whosemore » composition is environmentally dependent. Therefore, depositional environment is an important consideration to make correct inferences on the source vegetation. Sediment particle size of original rock samples may contain important information on the probability of a taphonomically biased pollen and spore assemblage. In addition, a reasonable test of hydraulic sorting is the distribution of pollen grain sizes and shapes in each assemblage. Any assemblage containing a wide spectrum of grain sizes and shapes has obviously not undergone significant sorting. If unrecognized, taphonomic bias can lead to paleoecologic, paleoclimatic, and even biostratigraphic misinterpretations.« less

  5. Characterization of the maize pollen transcriptome: Validation of microarray results using quantitative real-time PCR

    EPA Science Inventory

    Pollen is the primary means of gene flow between plants and plant populations and plays a critical role in seed production. Pollen fitness can be defined as the ability of a particular pollen grain to outcompete other pollen present on the stigma and complete fertilization, thus ...

  6. Urbanity as a determinant of exposure to grass pollen in Helsinki Metropolitan area, Finland.

    PubMed

    Hugg, Timo T; Hjort, Jan; Antikainen, Harri; Rusanen, Jarmo; Tuokila, Mirkka; Korkonen, Sanna; Weckström, Jan; Jaakkola, Maritta S; Jaakkola, Jouni J K

    2017-01-01

    Little is known about the levels of exposure to grass pollen in urban environments. We assessed the spatio-temporal variation of grass pollen concentrations and the role of urbanity as a determinant of grass pollen exposure in the Helsinki Metropolitan area. We monitored grass pollen concentrations in 2013 at 16 sites during the peak pollen season by using rotorod-type samplers at the breathing height. The sites were in the cities of Helsinki and Espoo, Finland, and formed city-specific lines that represented urban-rural gradient. The monitoring sites were both visually and based on land use data ranked as high to low (graded 1 to 8) pollen area. The lowest grass pollen concentrations were observed in the most urban sites compared to the least urban sites (mean 3.6 vs. 6.8 grains/m3 in Helsinki; P<0.0001, and 5.2 vs. 87.5 grains/m3 in Espoo; P<0.0001). Significant differences were observed between concentrations measured in morning periods compared to afternoon periods (4.9 vs. 5.4 in Helsinki, P = 0.0186, and 21.8 vs. 67.1 in Espoo, P = 0.0004). The mean pollen concentration increased with decreasing urbanity both in Helsinki (0.59 grains/m3 per urbanity rank, 95% CI 0.25-0.93) and Espoo (8.42, 6.23-10.61). Pollen concentrations were highest in the afternoons and they were related to the ambient temperature. Urbanity was a strong and significant determinant of pollen exposure in two Finnish cities. Pollen exposure can periodically reach such high levels even in the most urban environments that can cause allergic reactions among individuals with allergies.

  7. Urbanity as a determinant of exposure to grass pollen in Helsinki Metropolitan area, Finland

    PubMed Central

    Hugg, Timo T.; Hjort, Jan; Antikainen, Harri; Rusanen, Jarmo; Tuokila, Mirkka; Korkonen, Sanna; Weckström, Jan; Jaakkola, Maritta S.

    2017-01-01

    Little is known about the levels of exposure to grass pollen in urban environments. We assessed the spatio-temporal variation of grass pollen concentrations and the role of urbanity as a determinant of grass pollen exposure in the Helsinki Metropolitan area. We monitored grass pollen concentrations in 2013 at 16 sites during the peak pollen season by using rotorod-type samplers at the breathing height. The sites were in the cities of Helsinki and Espoo, Finland, and formed city-specific lines that represented urban-rural gradient. The monitoring sites were both visually and based on land use data ranked as high to low (graded 1 to 8) pollen area. The lowest grass pollen concentrations were observed in the most urban sites compared to the least urban sites (mean 3.6 vs. 6.8 grains/m3 in Helsinki; P<0.0001, and 5.2 vs. 87.5 grains/m3 in Espoo; P<0.0001). Significant differences were observed between concentrations measured in morning periods compared to afternoon periods (4.9 vs. 5.4 in Helsinki, P = 0.0186, and 21.8 vs. 67.1 in Espoo, P = 0.0004). The mean pollen concentration increased with decreasing urbanity both in Helsinki (0.59 grains/m3 per urbanity rank, 95% CI 0.25–0.93) and Espoo (8.42, 6.23–10.61). Pollen concentrations were highest in the afternoons and they were related to the ambient temperature. Urbanity was a strong and significant determinant of pollen exposure in two Finnish cities. Pollen exposure can periodically reach such high levels even in the most urban environments that can cause allergic reactions among individuals with allergies. PMID:29023565

  8. A New Secondary Pollen Presentation Mechanism from a Wild Ginger (Zingiber densissimum) and Its Functional Roles in Pollination Process

    PubMed Central

    Fan, Yong-Li; Kress, W. John; Li, Qing-Jun

    2015-01-01

    Background and Aims Secondary pollen presentation (SPP), a floral mechanism of reproductive adaptation, has been described for more than 200 years, with nine types SPP recorded. However, few studies have been done experimentally to link the floral mechanism of SPP to its functional roles in pollination process. This study aims to describe a new SPP mechanism from a wild ginger (Zingiber densissimum, Zingiberaceae) and explore how the pollen arrangement of SPP affects pollen removal during the interaction with different pollinators. Methodology/Principal Findings Field observations and experiments revealed that flowers lasted for less than one day. The breeding system was partially self-incompatible. Two bee species, Macropis hedini (which carried pollen dorsally) and Amegilla zonata (which carried pollen ventrally) were the primary pollinators. About a third of pollen grains were relocated from the anther to the labellum staminode of flowers through the adherence of aggregated pollen chains, while other grains were presented on the anther. In a single visit, each bee species removed pollen grains from both the labellum staminode and the anther. Macropis hedini was more effective than Amegilla zonata. Conclusions/Significance Our study describes a new SPP mechanism in angiosperms. The new SPP mode enables pollen grains presented on the anther and the labellum staminode simultaneously via the adherence of aggregated pollen chains, thus promoting pollen to be taken away by different pollinators. This SPP mechanism plays a key role during pollen removal and may have evolved under the pressure to improve male fitness. PMID:26637125

  9. Dynamic morphologies of pollen plastids visualised by vegetative-specific FtsZ1-GFP in Arabidopsis thaliana.

    PubMed

    Fujiwara, Makoto T; Hashimoto, Haruki; Kazama, Yusuke; Hirano, Tomonari; Yoshioka, Yasushi; Aoki, Seishiro; Sato, Naoki; Itoh, Ryuuichi D; Abe, Tomoko

    2010-06-01

    The behaviour and multiplication of pollen plastids have remained elusive despite their crucial involvement in cytoplasmic inheritance. Here, we present live images of plastids in pollen grains and growing tubes from transgenic Arabidopsis thaliana lines expressing stroma-localised FtsZ1-green-fluorescent protein fusion in a vegetative cell-specific manner. Vegetative cells in mature pollen contained a morphologically heterogeneous population of round to ellipsoidal plastids, whilst those in late-developing (maturing) pollen included plastids that could have one or two constriction sites. Furthermore, plastids in pollen tubes exhibited remarkable tubulation, stromule (stroma-filled tubule) extension, and back-and-forth movement along the direction of tube growth. Plastid division, which involves the FtsZ1 ring, was rarely observed in mature pollen grains.

  10. The Effect of Heat Stress on Tomato Pollen Characteristics is Associated with Changes in Carbohydrate Concentration in the Developing Anthers

    PubMed Central

    PRESSMAN, ETAN; PEET, MARY M.; PHARR, D. MASON

    2002-01-01

    Continuous exposure of tomato ‘Trust’ to high temperatures (day/night temperatures of 32/26 °C) markedly reduced the number of pollen grains per flower and decreased viability. The effect of heat stress on pollen viability was associated with alterations in carbohydrate metabolism in various parts of the anther during its development. Under control, favourable temperature conditions (28/22 °C), starch accumulated in the pollen grains, where it reached a maximum value 3 d before anthesis; it then diminished towards anthesis. During anther development, the concentration of total soluble sugars gradually increased in the anther walls and in the pollen grains (but not in the locular fluid), reaching a maximum at anthesis. Continuous exposure of the plants to high temperatures (32/26 °C) prevented the transient increase in starch concentration and led to decreases in the concentrations of soluble sugars in the anther walls and the pollen grains. In the locular fluid, however, a higher soluble sugar concentration was detected under the high‐temperature regime throughout anther development. These results suggest that a major effect of heat stress on pollen development is a decrease in starch concentration 3 d before anthesis, which results in a decreased sugar concentration in the mature pollen grains. These events possibly contribute to the decreased pollen viability in tomato. PMID:12466104

  11. Reconstructing Earth's Past Climates: The Hidden Secrets of Pollen

    ERIC Educational Resources Information Center

    Steele, Adrienne; Warny, Sophie

    2013-01-01

    "Palynology" is the study of fossil pollen and spores, and these tiny grains can provide fundamental information about past climates on Earth. Among their many unique and useful properties, pollen and spores are composed of some of the most chemically resistant organic compounds found in nature. They are also produced in vast quantities…

  12. Anther development of maize (Zea mays) and longstamen rice (Oryza longistaminata) revealed by cryo-SEM, with foci on locular dehydration and pollen arrangement.

    PubMed

    Tsou, Chih-Hua; Cheng, Ping-Chin; Tseng, Chiung-Maan; Yen, Hsiao-Jung; Fu, Yu-Lan; You, Tien-Rong; Walden, David B

    2015-03-01

    Key message: Pollen maturation in Poaceae. Another development has been extensively examined by various imaging tools, including transmission electron microscopy, scanning electron microscopy, and light microscopy, but none is capable of identifying liquid water. Cryo-scanning electron microscopy with high-pressure rapid freeze fixation is excellent in preserving structures at cellular level and differentiating gas- versus liquid-filled space, but rarely used in anther study. We applied this technique to examine anther development of Poaceae because of its economic importance and unusual peripheral arrangement of pollen. Maize and longstamen rice were focused on. Here, we report for the first time that anthers of Poaceae lose the locular free liquid during late-microspore to early pollen stages; the majority of pollen grains arranged in a tight peripheral whorl develops normally and reaches maturity in the gas-filled loculus. Occasionally, pollen grains are found situated in the locular cavity, but they remain immature or become shrunk at anthesis. At pollen stage, microchannels and cytoplasmic strands are densely distributed in the entire pollen exine and intine, respectively, suggesting that nutrients are transported into the pollen from the entire surface. We propose that in Poaceae, the specialized peripheral arrangement of pollen grains is crucial for pollen maturation in the gas-filled loculus, which enables pollen achieving large surface contact area with the tapetum and neighboring grains to maintain sufficient nutrient flow. This report also shows that the single aperture of pollen in Poaceae usually faces the tapetum, but other orientation is also common; pollen grains with different aperture orientations show no morphological differences.

  13. Privet pollen (Ligustrum sp.) as potential cause of pollinosis in the city of Cordoba, south-west Spain.

    PubMed

    Cariñanos, P; Alcázar, P; Galán, C; Domínguez, E

    2002-02-01

    Privet pollen rarely accounts for more than 1% of the annual total of daily pollen concentrations measured in a city; however in areas where these trees are widely used as ornamentals the amounts collected may be high enough to cause allergy symptoms. Air samples taken with volumetric particle samplers Lanzoni VPPS 1000 (Lanzoni s.r.l., Bologna, Italy) show that there are differences in privet pollen concentrations measured in neighbourhoods with a high incidence of privet trees and in those taken at some distance from the source of emission. The results suggest that differences are due to the short dispersal range of the pollen grains once released from the plant, resulting from both the entomophilous nature of the plant and the large size of the pollen grains. Urban design, moreover, may play an important role in impeding pollen grain dispersion if the air cannot flow freely through long, narrow avenues. Another important consideration is that the last stages of the flowering period of privet overlaps with the flowering period of olive trees, the main allergen in the area. The fact that the two pollen types share common allergens means that there may be a cross-reaction between olive tree pollen and privet pollen. Privet pollen should be considered as a potential causative agent of local allergy problems in areas where its presence is extensive and is in combination with other allergens.

  14. PsPMEP, a pollen-specific pectin methylesterase of pea (Pisum sativum L.).

    PubMed

    Gómez, María Dolores; Renau-Morata, Begoña; Roque, Edelín; Polaina, Julio; Beltrán, José Pío; Cañas, Luis A

    2013-09-01

    Pectin methylesterases (PMEs) are a family of enzymes involved in plant reproductive processes such as pollen development and pollen tube growth. We have isolated and characterized PsPMEP, a pea (Pisum sativum L.) pollen-specific gene that encodes a protein with homology to PMEs. Sequence analysis showed that PsPMEP belongs to group 2 PMEs, which are characterized by the presence of a processable amino-terminal PME inhibitor domain followed by the catalytic PME domain. Moreover, PsPMEP contains several motifs highly conserved among PMEs with the essential amino acid residues involved in enzyme substrate binding and catalysis. Northern blot and in situ hybridization analyses showed that PsPMEP is expressed in pollen grains from 4 days before anthesis till anther dehiscence and in pollinated carpels. In the PsPMEP promoter region, we have identified several conserved cis-regulatory elements that have been associated with gene pollen-specific expression. Expression analysis of PsPMEP promoter fused to the uidA reporter gene in Arabidopsis thaliana plants showed a similar expression pattern when compared with pea, indicating that this promoter is also functional in a non-leguminous plant. GUS expression was detected in mature pollen grains, during pollen germination, during pollen tube elongation along the transmitting tract, and when the pollen tube reaches the embryo sac in the ovule.

  15. Natural variation in PTB1 regulates rice seed setting rate by controlling pollen tube growth.

    PubMed

    Li, Shuangcheng; Li, Wenbo; Huang, Bin; Cao, Xuemei; Zhou, Xingyu; Ye, Shumei; Li, Chengbo; Gao, Fengyan; Zou, Ting; Xie, Kailong; Ren, Yun; Ai, Peng; Tang, Yangfan; Li, Xuemei; Deng, Qiming; Wang, Shiquan; Zheng, Aiping; Zhu, Jun; Liu, Huainian; Wang, Lingxia; Li, Ping

    2013-01-01

    Grain number, panicle seed setting rate, panicle number and grain weight are the most important components of rice grain yield. To date, several genes related to grain weight, grain number and panicle number have been described in rice. However, no genes regulating the panicle seed setting rate have been functionally characterized. Here we show that the domestication-related POLLEN TUBE BLOCKED 1 (PTB1), a RING-type E3 ubiquitin ligase, positively regulates the rice panicle seed setting rate by promoting pollen tube growth. The natural variation in expression of PTB1 which is affected by the promoter haplotype and the environmental temperature, correlates with the rice panicle seed setting rate. Our results support the hypothesis that PTB1 is an important maternal sporophytic factor of pollen tube growth and a key modulator of the rice panicle seed setting rate. This finding has implications for the improvement of rice yield.

  16. Effects of acidity on tree pollen germination and tube growth

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.

    Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollenmore » germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.« less

  17. A new image-based tool for the high throughput phenotyping of pollen viability: evaluation of inter- and intra-cultivar diversity in grapevine.

    PubMed

    Tello, Javier; Montemayor, María Ignacia; Forneck, Astrid; Ibáñez, Javier

    2018-01-01

    Low pollen viability may limit grapevine yield under certain conditions, causing relevant economic losses to grape-growers. It is usually evaluated by the quantification of the number of viable and non-viable pollen grains that are present in a sample after an adequate pollen grain staining procedure. Although the manual counting of both types of grains is the simplest and most sensitive approach, it is a laborious and time-demanding process. In this regard, novel image-based approaches can assist in the objective, accurate and cost-effective phenotyping of this trait. Here, we introduce PollenCounter, an open-source macro implemented as a customizable Fiji tool for the high-throughput phenotyping of pollen viability. This tool splits RGB images of stained pollen grains into its primary channels, retaining red and green color fractionated images (which contain information on total and only viable pollen grains, respectively) for the subsequent isolation and counting of the regions of interest (pollen grains). This framework was successfully used for the analysis of pollen viability of a high number of samples collected in a large collection of grapevine cultivars. Results revealed a great genetic variability, from cultivars having very low pollen viability (like Corinto Bianco; viability: 14.1 ± 1.3%) to others with a very low presence of sterile pollen grains (Cuelga; viability: 98.2 ± 0.5%). A wide range of variability was also observed among several clones of cv. Tempranillo Tinto (from 97.9 ± 0.9 to 60.6 ± 5.9%, in the first season). Interestingly, the evaluation of this trait in a second season revealed differential genotype-specific sensitivity to environment. The use of PollenCounter is expected to aid in different areas, including genetics research studies, crop improvement and breeding strategies that need of fast, precise and accurate results. Considering its flexibility, it can be used not only in grapevine, but also in other species showing

  18. Pollination biology of northern red and black oak

    Treesearch

    Robert A. Cecich; William W. Haenchen

    1995-01-01

    Pistillate flower abortion in northern red oak and black oak was evaluated in relation to pollination and fertilization. The presence, position, and characteristics of the pollen grains, pollen tubes, and ovules were determined with bright field and fluorescence microscopy. Flower survival counts were made weekly, from late April to mid- September. Both species have...

  19. Forest tree pollen dispersal via the water cycle.

    PubMed

    Williams, Claire G

    2013-06-01

    Pine pollen (Pinus spp.), along with other atmospheric particles, is dispersed by the water cycle, but this mode of dispersal requires cloud-pollen interactions that depend on taxon-specific biological properties. In the simplest form of this dispersal, pine pollen ascends vertically to altitudes of 2 to 6 km, where a fraction is captured by mixed-phase cloud formation. Captured pollen accretes into frozen droplets, which ultimately descend as rain, snow, or hail. Whether Pinus pollen can still germinate after its exposure to high-altitude freezing is pertinent to (1) how forests adapt to climate change and (2) potential gene flow between genetically modified plantation species and their conspecific relatives. • To address this question, pollen from four Old World and two New World Pinus species were subjected to immersion freezing, a common cloud formation mode, under laboratory conditions. • Some pollen grains immersed at -20°C for 15, 60, or 120 min in either a dehydrated or a water-saturated state were still capable of germination. After exposure, dehydrated pine pollen had higher germination (43.3%) than water-saturated pollen (7.6%). • Pine pollen exposed to freezing during cloud formation can still germinate, raising the question of whether rain-delivered live pollen might be linked to rain-facilitated pollination. Dispersal of live pine pollen via cloud formation and the water cycle itself deserves closer study.

  20. Pollen density on the stigma affects endogenous gibberellin metabolism, seed and fruit set, and fruit quality in Pyrus pyrifolia.

    PubMed

    Zhang, Caixi; Tateishi, Naoya; Tanabe, Kenji

    2010-10-01

    To clarify the relationship between pollen density and gametophytic competition in Pyrus pyrifolia, gametophytic performance, gibberellin metabolism, fruit set, and fruit quality were investigated by modifying P. pyrifolia pollen grain number and density with Lycopodium spores. Higher levels of pollen density improved seed viability, fruit set, and fruit quality. Treatments with the highest pollen density showed a significantly increased fruit growth rate and larger fruit at harvest. High pollen density increased germination rate and gave a faster pollen tube growth, both in vivo and in vitro. Endogenous gibberellin (GA) concentrations increased in pollen tubes soon after germination and the concentration of two growth-active GAs, GA(3), and GA(4), was positively correlated to final fruit size, cell numbers in the mesocarp, and pollen tube growth rate. These two GAs appear to be biosynthesized de novo in pollen tube and are the main pollen-derived bioactive GAs found after pollen germination. GA(1) levels in the pollen tube appear to be related to a pollen-style interaction that occurred after the pollen grains landed on the stigma.

  1. A combinatorial approach to angiosperm pollen morphology.

    PubMed

    Mander, Luke

    2016-11-30

    Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters. © 2016 The Author(s).

  2. A combinatorial approach to angiosperm pollen morphology

    PubMed Central

    2016-01-01

    Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters. PMID:27881756

  3. Effects of fluoride on pollen germination, pollen tube growth, and fruit development in tomato and cucumber

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sulzbach, C.W.; Pack, M.R.

    Tomato and cucumber pollen germination in vitro was significantly inhibited at 10.5 and 2.6 mM NaF, respectively, or higher, in media containing 1.25 mM Ca. Germination was not inhibited provided the Ca was at least chemically equivalent to the F in the media. Long-term, continuous HF fumigations of tomato plants at 7.9 and 13.0 ..mu..g F/m/sup 3/ reduced pollen germination in vitro when the plants were grown with low Ca (1 mM) nutrient solution. No reduction was found at 13.0 ..mu..g F/m/sup 3/ when tomato plants were grown with 4 mM Ca. Regardless of Ca nutrition, HF fumigations of cucumbermore » plants at 10.2 ..mu..g F/m/sup 3/ or less did not inhibit pollen germination. Fluorescent staining of pistils from manually pollinated tomato flowers showed reductions in the number of pollen grains retained on the stigma, pollen germination, and pollen tubes reaching ovules when the maternal parent plants were grown in HF treatments averaging as low as 4.2 ..mu..g F/m/sup 3/. Similar effects were found when pollen parents grown with 1 mM Ca were subjected to 7.9 ..mu..g F/m/sup 3/, but not when pollen parents grown with 5 mM Ca were subjected to 4.4 ..mu..g F/m/sup 3/. Early tomato fruit and seed development were inhibited by treatments similar to those that caused the pollen responses. 11 references, 1 figure, 5 tables.« less

  4. Relationships between airborne pollen grains, wind direction and land cover using GIS and circular statistics.

    PubMed

    Maya-Manzano, J M; Sadyś, M; Tormo-Molina, R; Fernández-Rodríguez, S; Oteros, J; Silva-Palacios, I; Gonzalo-Garijo, A

    2017-04-15

    Airborne bio-aerosol content (mainly pollen and spores) depends on the surrounding vegetation and weather conditions, particularly wind direction. In order to understand this issue, maps of the main land cover in influence areas of 10km in radius surrounding pollen traps were created. Atmospheric content of the most abundant 14 pollen types was analysed in relation to the predominant wind directions measured in three localities of SW of Iberian Peninsula, from March 2011 to March 2014. Three Hirst type traps were used for aerobiological monitoring. The surface area for each land cover category was calculated and wind direction analysis was approached by using circular statistics. This method could be helpful for estimating the potential risk of exposure to various pollen types. Thus, the main land cover was different for each monitoring location, being irrigated crops, pastures and hardwood forests the main categories among 11 types described. Comparison of the pollen content with the predominant winds and land cover shows that the atmospheric pollen concentration is related to some source areas identified in the inventory. The study found that some pollen types (e.g. Plantago, Fraxinus-Phillyrea, Alnus) come from local sources but other pollen types (e.g. Quercus) are mostly coming from longer distances. As main conclusions, airborne particle concentrations can be effectively split by addressing wind with circular statistics. By combining circular statistics and GIS method with aerobiological data, we have created a useful tool for understanding pollen origin. Some pollen loads can be explained by immediate surrounding landscape and observed wind patterns for most of the time. However, other factors like medium or long-distance transport or even pollen trap location within a city, may occasionally affect the pollen load recorded using an air sampler. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Flavonoids, alkali earth and rare earth elements affect germination of pecan pollen

    USDA-ARS?s Scientific Manuscript database

    The factors regulating pecan [Carya illinoinensis (Wangenh.) K. Koch] pollen grain germination on receptive stigmatic flower surfaces in vivo or in vitro in pollen viability assays are poorly understood. While there are many potential regulating factors, there is evidence for involvement of flavonol...

  6. HOTHEAD-Like HTH1 is Involved in Anther Cutin Biosynthesis and is Required for Pollen Fertility in Rice.

    PubMed

    Xu, Ya; Liu, Shasha; Liu, Yaqin; Ling, Sheng; Chen, Caisheng; Yao, Jialing

    2017-07-01

    The cuticle covering the outer surface of anthers is essential for male reproductive development in plants. However, the mechanism underlying the synthesis of these lipidic polymers remains unclear. HOTHEAD (HTH) in Arabidopsis thaliana is a presumptive glucose-methanol-choline (GMC) oxidoreductase involved in the biosynthesis of long-chain α-,ω-dicarboxylic fatty acids. In this study, we characterized the function of an anther-specific gene HTH1 in rice. HTH1 contains a conserved GMC oxidoreductase-like domain, and the sequence of HTH1 was highly similar to that of HTH in A. thaliana. Quantitative real-time PCR (qRT-PCR) and in situ hybridization analyses showed that HTH1 was highly expressed in epidermal cells of anthers. Rice plants with HTH1 suppression through CRISPR (clustered regularly interspaced short palindromic repeats) and RNA interference (RNAi) displayed defective anther wall and aborted pollen. Disorganized cuticle layers in anthers and shriveled pollen grains were observed in HTH1-RNAi lines. The total amounts of long-chain fatty acids and cutin monomers in anthers of HTH1-RNAi lines were significantly reduced compared with the wild type. Our results suggested that HTH1 is involved in cutin biosynthesis and is required for anther development and pollen fertility in rice. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. The role of seasonal grass pollen on childhood asthma emergency department presentations.

    PubMed

    Erbas, B; Akram, M; Dharmage, S C; Tham, R; Dennekamp, M; Newbigin, E; Taylor, P; Tang, M L K; Abramson, M J

    2012-05-01

    Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations. To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season. A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma. A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m(3) , the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001). This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m(3) , independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy. © 2012 Blackwell Publishing Ltd.

  8. The Beauty and Biology of Pollen.

    ERIC Educational Resources Information Center

    Clay-Poole, Scott T.; Slesnick, Irwin L.

    1983-01-01

    Describes: basic features of pollen grains (shapes, apertures, layering of wall, exine sculpturing); strategies for pollination (anemophily--wind transported, zoophily--animal transported); and the structures specialized for each process. Gives instructions for using scanning electron microscope photographs and for collecting, identifying, and…

  9. Forecasting models for sugi (Cryptomeria japonica D. Don) pollen count showing an alternate dispersal rhythm.

    PubMed

    Ito, Yukiko; Hattori, Reiko; Mase, Hiroki; Watanabe, Masako; Shiotani, Itaru

    2008-12-01

    Pollen information is indispensable for allergic individuals and clinicians. This study aimed to develop forecasting models for the total annual count of airborne pollen grains based on data monitored over the last 20 years at the Mie Chuo Medical Center, Tsu, Mie, Japan. Airborne pollen grains were collected using a Durham sampler. Total annual pollen count and pollen count from October to December (OD pollen count) of the previous year were transformed to logarithms. Regression analysis of the total pollen count was performed using variables such as the OD pollen count and the maximum temperature for mid-July of the previous year. Time series analysis revealed an alternate rhythm of the series of total pollen count. The alternate rhythm consisted of a cyclic alternation of an "on" year (high pollen count) and an "off" year (low pollen count). This rhythm was used as a dummy variable in regression equations. Of the three models involving the OD pollen count, a multiple regression equation that included the alternate rhythm variable and the interaction of this rhythm with OD pollen count showed a high coefficient of determination (0.844). Of the three models involving the maximum temperature for mid-July, those including the alternate rhythm variable and the interaction of this rhythm with maximum temperature had the highest coefficient of determination (0.925). An alternate pollen dispersal rhythm represented by a dummy variable in the multiple regression analysis plays a key role in improving forecasting models for the total annual sugi pollen count.

  10. Suicide risk in relation to air pollen counts: a study based on data from Danish registers

    PubMed Central

    Qin, Ping; Waltoft, Berit L; Mortensen, Preben B; Postolache, Teodor T

    2013-01-01

    Objectives Since the well-observed spring peak of suicide incidents coincides with the peak of seasonal aeroallergens as tree-pollen, we want to document an association between suicide and pollen exposure with empirical data from Denmark. Design Ecological time series study. Setting Data on suicide incidents, air pollen counts and meteorological status were retrieved from Danish registries. Participants 13 700 suicide incidents over 1304 consecutive weeks were obtained from two large areas covering 2.86 million residents. Primary and secondary outcome measures Risk of suicide associated with pollen concentration was assessed using a time series Poisson-generalised additive model. Results We noted a significant association between suicide risk and air pollen counts. A change of pollen counts levels from 0 to ‘10–<30’ grains/m3 air was associated with a relative risk of 1.064, that is, a 6.4% increase in weekly number of suicides in the population, and from 0 to ‘30–100’ grains, a relative risk of 1.132. The observed association remained significant after controlling for effects of region, calendar time, temperature, cloud cover and humidity. Meanwhile, we observed a significant sex difference that suicide risk in men started to rise when there was a small increase of air pollen, while the risk in women started to rise until pollen grains reached a certain level. High levels of pollen had slightly stronger effect on risk of suicide in individuals with mood disorder than those without the disorder. Conclusions The observed association between suicide risk and air pollen counts supports the hypothesis that aeroallergens, acting as immune triggers, may precipitate suicide. PMID:23793651

  11. Intra- and extracellular lipid composition and associated gene expression patterns during pollen development in Brassica napus.

    PubMed

    Piffanelli, P; Ross, J H; Murphy, D J

    1997-03-01

    Pollen development in angiosperms is regulated by the interaction of products contributed by both the gametophytic (haploid) and sporophytic (diploid) genomes. In entomophilous species, lipids are major products of both sporophytic and gametophytic metabolism during pollen development. Mature pollen grains of Brassica napus are shown to contain three major acyl lipid pools as follows: (i) the extracellular tryphine mainly consisting of medium-chain neutral esters; (ii) the intracellular membranes, particularly endoplasmic reticulum, mainly containing phospholipids; and (iii) the intracellular storage lipids, which are mostly triacylglycerols. This paper reports on the kinetics of accumulation of these lipid classes during pollen maturation and the expression patterns of several lipid biosynthetic genes and their protein products that are differentially regulated in developing microspores/ pollen grains (gametophyte) and tapetal cells (sporophyte) of B. napus. Detailed analysis of three members of the stearoyl-ACP desaturase (sad) gene family by Northern blotting, in situ hybridization and RT-PCR showed that the same individual genes were expressed both in gametophytic and sporophytic tissues, although under different temporal regulation. In the tapetum, maximal expression of two marker genes for lipid biosynthesis (sad and ear) occurred at a bud length of 2-3 mm, and the corresponding gene products SAD and EAR were detected by Western blotting in 3-4 mm buds, coinciding with the maximal rates of tapetal lipid accumulation. These lipids are released following tapetal cell disintegration and are relocated to form the major structural component of the extracellular tryphine layer that coats the mature pollen grain. In contrast, in developing microspores/pollen grains, maximal expression of the lipid marker genes sad, ear, acp and cyb5 was at the 3-5 mm bud stages, with the SAD and EAR gene products detected in 4-7 mm buds. This pattern of expression coincided with

  12. Co-occurrence of Artemisia and Ambrosia pollen seasons against the background of the synoptic situations in Poland.

    PubMed

    Stępalska, Danuta; Myszkowska, Dorota; Katarzyna, Leśkiewicz; Katarzyna, Piotrowicz; Katarzyna, Borycka; Kazimiera, Chłopek; Łukasz, Grewling; Idalia, Kasprzyk; Barbara, Majkowska-Wojciechowska; Małgorzata, Malkiewicz; Małgorzata, Nowak; Krystyna, Piotrowska-Weryszko; Małgorzata, Puc; Elżbieta, Weryszko-Chmielewska

    2017-04-01

    The Asteraceae family is one of the largest families, comprising 67 genera and 264 species in Poland. However, only a few genera, including Artemisia and Ambrosia are potential allergenic sources. The aim of the study was to estimate how often and to what degree Artemisia and Ambrosia pollen seasons co-occur intensifying human health risk, and how synoptic situations influence frequency of days with high pollen concentrations of both taxa. Artemisia and Ambrosia pollen data were collected, using the volumetric method, at 8 sites in Poland. Daily concentrations of Artemisia pollen equal to 30 grains or more and Ambrosia pollen equal to 10 grains or more were accepted as high values. Concentrations of more than 10 pollen grains were defined as high in the case of Ambrosia because its allergenicity is considered higher. High concentrations were confronted with synoptic situations. Analysis was performed on the basis of two calendars on circulation types of atmosphere in Poland (Niedźwiedź, 2006, 2015). Co-occurrence of Artemisia and Ambrosia pollen seasons is being found most often, when Ambrosia pollen season starts in the first half of August. If it happens in the last 10 days of August high pollen concentrations of Artemisia and Ambrosia do not occur at the same days. At three sites (Sosnowiec, Rzeszów, Lublin) high Ambrosia pollen concentrations during the Artemisia pollen season appear more often than in other sites under question. The high Artemisia pollen concentrations occur, when continental or polar maritime old air masses inflow into Poland. The impact of air masses on high Ambrosia pollen concentrations depends on site localizations. It is likely, that in the south-eastern part of Poland high Ambrosia pollen concentrations result from the pollen transport from east-south-south-westerly directions and the local sources. Co-occurrence of both taxa pollen seasons depends on the air masses inflow and appears more often in a south-eastern part of Poland.

  13. Co-occurrence of Artemisia and Ambrosia pollen seasons against the background of the synoptic situations in Poland

    NASA Astrophysics Data System (ADS)

    Stępalska, Danuta; Myszkowska, Dorota; Katarzyna, Leśkiewicz; Katarzyna, Piotrowicz; Katarzyna, Borycka; Kazimiera, Chłopek; Łukasz, Grewling; Idalia, Kasprzyk; Barbara, Majkowska-Wojciechowska; Małgorzata, Malkiewicz; Małgorzata, Nowak; Krystyna, Piotrowska-Weryszko; Małgorzata, Puc; Elżbieta, Weryszko-Chmielewska

    2017-04-01

    The Asteraceae family is one of the largest families, comprising 67 genera and 264 species in Poland. However, only a few genera, including Artemisia and Ambrosia are potential allergenic sources. The aim of the study was to estimate how often and to what degree Artemisia and Ambrosia pollen seasons co-occur intensifying human health risk, and how synoptic situations influence frequency of days with high pollen concentrations of both taxa. Artemisia and Ambrosia pollen data were collected, using the volumetric method, at 8 sites in Poland. Daily concentrations of Artemisia pollen equal to 30 grains or more and Ambrosia pollen equal to 10 grains or more were accepted as high values. Concentrations of more than 10 pollen grains were defined as high in the case of Ambrosia because its allergenicity is considered higher. High concentrations were confronted with synoptic situations. Analysis was performed on the basis of two calendars on circulation types of atmosphere in Poland (Niedźwiedź, 2006, 2015). Co-occurrence of Artemisia and Ambrosia pollen seasons is being found most often, when Ambrosia pollen season starts in the first half of August. If it happens in the last 10 days of August high pollen concentrations of Artemisia and Ambrosia do not occur at the same days. At three sites (Sosnowiec, Rzeszów, Lublin) high Ambrosia pollen concentrations during the Artemisia pollen season appear more often than in other sites under question. The high Artemisia pollen concentrations occur, when continental or polar maritime old air masses inflow into Poland. The impact of air masses on high Ambrosia pollen concentrations depends on site localizations. It is likely, that in the south-eastern part of Poland high Ambrosia pollen concentrations result from the pollen transport from east-south-south-westerly directions and the local sources. Co-occurrence of both taxa pollen seasons depends on the air masses inflow and appears more often in a south-eastern part of Poland.

  14. Grass Pollen Affects Survival and Development of Larval Anopheles arabiensis (Diptera: Culicidae).

    PubMed

    Asmare, Yelfwagash; Hopkins, Richard J; Tekie, Habte; Hill, Sharon R; Ignell, Rickard

    2017-09-01

    Nutrients in breeding sites are critical for the survival and development of malaria mosquitoes, having a direct impact on vectorial capacity. Yet, there is a limited understanding about the natural larval diet and its impact on the individual fitness of mosquitoes. Recent studies have shown that gravid Anopheles arabiensis Patton (Diptera: Culicidae) are attracted by and oviposit in grass-associated habitats. The pollen provided by these grasses is a potential source of nutrients for the larvae. Here, we assess the effect of Typha latifolia L. (Poales: Typhaceae), Echinochloa pyramidalis Lamarck, Pennisetum setaceum Forsskål, and Zea mays L. pollen on larval survival and rate of development in An. arabiensis under laboratory conditions. In addition, we characterize the carbon to nitrogen ratio and the size of pollen grains as a measure of diet quality. Carbon-rich pollen with a small grain size (T. latifolia and P. setaceum; 9.7 ± 0.3 × 103 and 5.5 ± 0.2 × 104 µm3, respectively) resulted in enhanced rates of development of An. arabiensis. In contrast, the larva fed on the nitrogen-rich control diet (TetraMin) was slower to develop, but demonstrated the highest larval survival. Larvae fed on carbon-rich and large-grained Z. mays pollen (4.1 ± 0.2 × 105 µm3) survived at similar levels as those fed on the control diet and also took a longer time to develop compared with larvae fed on the other pollens. While males and females did not appear to develop differently on the different pollen diets, males consistently emerged faster than their female counterparts. These results are discussed in relation to integrated vector management. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  15. Self-pollen interference is absent in wild radish (Raphanus raphanistrum, Brassicaceae), a species with sporophytic self-incompatibility.

    PubMed

    Koelling, Vanessa A; Karoly, Keith

    2007-05-01

    Explaining the diversity of mating systems and floral forms in flowering plants is a long-standing concern of evolutionary biologists. One topic of interest is the conditions under which self-pollination can interfere with seed set for flowering plants with a self-incompatibility system. We investigated the effect of self-pollen interference for wild radish, Raphanus raphanistrum, which has sporophytic self-incompatibility. We performed pollinations and determined seed set for plants grown in the greenhouse, using pollen mixtures representing either self- with outcross-pollen or outcross-pollen alone. Stigmas were collected for a subset of pollinated flowers to determine the number of pollen grains applied. Average seed set for the self/cross (5.13 seeds/pollination) and cross treatments (5.09 seeds/pollination) did not differ significantly. Stigmatic pollen loads averaged around 700 grains, an amount close to observed natural pollen loads on R. raphanistrum. We concluded that for R. raphanistrum in natural populations, self-pollen is unlikely to interfere with outcross-pollen success. This study is the first to investigate effects of self-pollen interference on seed set for a homomorphic species with sporophytic self-incompatibility where rejection occurs at the stigmatic surface.

  16. Pollen sensitivity to ultraviolet-B (UV-B) suggests floral structure evolution in alpine plants.

    PubMed

    Zhang, Chan; Yang, Yong-Ping; Duan, Yuan-Wen

    2014-03-31

    Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants.

  17. 219 The Revised Edition of Korean Calendar for Allergenic Pollens

    PubMed Central

    Oh, Jae-won; Kim, Joo-Hwa; Kim, Seong-Won; Kang, Im-Joo; Kim, Bong-Seong; Kook, Myung-Hee; Park, Kang-Seo; Lee, Ha-Baik; Kim, Kyu Rang; Choi, Young-Jean

    2012-01-01

    Background The old version of pollen calendar was used until this year in South Korea. That calendar did not reflect current pollen distribution and concentrations that can be influenced by changes in weather and environment. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in 8 regions nationwide between 1997 and 2009 in South Korea. Methods The distribution of pollen grains was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) nationwide for 12 years between July 1, 1997 and June 30, 2009. Pollen were collected by using Burkard 7-day sampler (Burkard manufacturing Co Ltd, Hertfordshire, UK), and the collected pollens were sent every week to Hanyang Guri Hospital. Then pollens were strained with Calberla's fuchsin staining solution and were identified. The number of pollen grains per m3 was calculated. Results Alder, birch and Japanese cedar started to appear in February. Japanese cedar showed a highest pollen concentration in Jeju. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Common ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. Birch appeared earlier in Kangneung, and pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja, alder and juniper produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than common ragweed. In Busan where is the southeast city, the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among

  18. Glutathione synthesis is essential for pollen germination in vitro

    PubMed Central

    2011-01-01

    Background The antioxidant glutathione fulfills many important roles during plant development, growth and defense in the sporophyte, however the role of this important molecule in the gametophyte generation is largely unclear. Bioinformatic data indicate that critical control enzymes are negligibly transcribed in pollen and sperm cells. Therefore, we decided to investigate the role of glutathione synthesis for pollen germination in vitro in Arabidopsis thaliana accession Col-0 and in the glutathione deficient mutant pad2-1 and link it with glutathione status on the subcellular level. Results The depletion of glutathione by buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, reduced pollen germination rates to 2-5% compared to 71% germination in wildtype controls. The application of reduced glutathione (GSH), together with BSO, restored pollen germination and glutathione contents to control values, demonstrating that inhibition of glutathione synthesis is responsible for the decrease of pollen germination in vitro. The addition of indole-3-acetic acid (IAA) to media containing BSO restored pollen germination to control values, which demonstrated that glutathione depletion in pollen grains triggered disturbances in auxin metabolism which led to inhibition of pollen germination. Conclusions This study demonstrates that glutathione synthesis is essential for pollen germination in vitro and that glutathione depletion and auxin metabolism are linked in pollen germination and early elongation of the pollen tube, as IAA addition rescues glutathione deficient pollen. PMID:21439079

  19. Anther response to high-temperature stress during development and pollen thermotolerance heterosis as revealed by pollen tube growth and in vitro pollen vigor analysis in upland cotton.

    PubMed

    Song, Guicheng; Wang, Miaomiao; Zeng, Bin; Zhang, Jing; Jiang, Chenliang; Hu, Qirui; Geng, Guangtao; Tang, Canming

    2015-05-01

    Pollen tube growth in styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the adverse effect of high temperatures during square development. High-temperature stress during flowering influences the square development of upland cotton (Gossypium hirsutum L.) and cotton yield. Although it is well known that square development is sensitive to high temperature, high-temperature sensitive stages of square development and the effects of high temperature on pollen tube growth in the styles are unknown. The effect of high temperature on anther development corresponding to pollen vigor is unknown during anther development. The objectives of this study were to identify the stages of square development that are sensitive to high temperatures (37/30 and 40/34 °C), to determine whether the abnormal development of squares influenced by high temperature is responsible for the variation in the in vitro germination percent of pollen grains at anthesis, to identify the effect of high temperature on pollen germination in the styles, and to determine pollen thermotolerance heterosis. Our results show that the stages from the sporogenous cell to tetrad stage (square length <6.0 mm) were the most sensitive to high temperature, and the corresponding pollen viability at anthesis was consistent with the changes in the square development stage. Pollen tube growth in the styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the effect of high temperature during square development. The thermotolerance of hybrid F1 pollen showed heterosis, and pollen viability could be used as a criterion for screening for high-temperature tolerance cultivars. These results can be used in breeding to develop new cotton cultivars that can withstand high-temperature conditions, particularly in a future warmer climate.

  20. Effects of shading on spike differentiation and grain yield formation of summer maize in the field

    NASA Astrophysics Data System (ADS)

    Cui, Haiyan; Camberato, James J.; Jin, Libin; Zhang, Jiwang

    2015-09-01

    A field experiment was conducted to study the effects of shading on tassel and ear development and yield formation of three summer maize hybrids Zhenjie 2 (ZJ2), Denghai 605 (DH605), and Zhengdan 958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth stages from silking stage (R1) to physiological maturity stage (R6) (treatment S1), from the sixth extended leaf stage (V6) to R1 (treatment S2) and from seeding to R6 (treatment S3). Shading had no significant effect on the time from seeding to shoot emergence (VE); however, subsequent growth and development were delayed with shading beyond this point. The differentiation time of both tassel and ear delayed, and female spike (tassel) floret differentiation, sexual organ formation time, and anthesis-silking interval (ASI) were lengthened. After shading, the total number of floret, silk, and fertilization floret reduced significantly; the number of abortive seeds increased, and the total setting percentage among different treatments showed that CK>S2>S1>S3; and the total setting percentages in S1, S2, and S3 of ZD958 were 44, 72, and 15 % respectively. The total floret number of tassel primordium differentiation, fertility rate, and seed setting rate of florets in S3 treatment was the minimum; kernels per ear decreased seriously and single ear setting percentage was only 16 %; although floret degeneration number of S2 during ear differentiation stages increased and floret fertility rate reduced than that of CK, fertilization flower seed production increased and abortive seed decreased after canceling shading. Aborted kernel of S1 increased and kernel dry weight reduced, resulting in a significant decrease of kernel number per ear and kernel weight, and the grain abortive rate of 40-62 %. In conclusion, shading changed the growth and development process and caused infertility of tassel and ear; tassel branches decreased

  1. Variation of the group 5 grass pollen allergen content of airborne pollen in relation to geographic location and time in season.

    PubMed

    Buters, Jeroen; Prank, Marje; Sofiev, Mikhail; Pusch, Gudrun; Albertini, Roberto; Annesi-Maesano, Isabella; Antunes, Celia; Behrendt, Heidrun; Berger, Uwe; Brandao, Rui; Celenk, Sevcan; Galan, Carmen; Grewling, Łukasz; Jackowiak, Bogdan; Kennedy, Roy; Rantio-Lehtimäki, Auli; Reese, Gerald; Sauliene, Ingrida; Smith, Matt; Thibaudon, Michel; Weber, Bernhard; Cecchi, Lorenzo

    2015-07-01

    Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergen from pollen. We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-volume cascade impactor at 10 sites across Europe for 3 consecutive years. Group 5 allergen levels were determined with a Phl p 5-specific ELISA in 2 fractions of ambient air: particulate matter of greater than 10 μm in diameter and particulate matter greater than 2.5 μm and less than 10 μm in diameter. Mediator release by ambient air was determined in FcεRI-humanized basophils. The origin of pollen was modeled and condensed to pollen potency maps. On average, grass pollen released 2.3 pg of Phl p 5 per pollen. Allergen release per pollen (potency) varied substantially, ranging from less than 1 to 9 pg of Phl p 5 per pollen (5% to 95% percentile). The main variation was locally day to day. Average potency maps across Europe varied between years. Mediator release from basophilic granulocytes correlated better with allergen levels per cubic meter (r(2) = 0.80, P < .001) than with pollen grains per cubic meter (r(2) = 0.61, P < .001). In addition, pollen released different amounts of allergen in the non-pollen-bearing fraction of ambient air, depending on humidity. Across Europe, the same amount of pollen released substantially different amounts of group 5 grass pollen allergen. This variation in allergen release is in addition to variations in pollen counts. Molecular aerobiology (ie, determining allergen in ambient air) might be a valuable addition to pollen counting. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  2. Poaceae, Secale spp. and Artemisia spp. pollen in the air at two sites of different degrees of urbanisation.

    PubMed

    Kruczek, Aleksandra; Puc, Małgorzata; Wolski, Tomasz

    2017-03-21

    Among herbal plants, most cases of allergic reactions, like seasonal inflammation of nasal mucosa, conjunctivitis and pollen asthma, are related to the allergens from grass pollen. As the blossoming and pollination of rye is known to start the pollen season of grasses, information about the airborne rye pollen count permits alerting the people allergic to certain allergens contained in rye pollen. An important cause of allergy is also the pollen from wormwood, blossoming in late summer, as its two main allergens produce cross-reactions with many other plant allergens. The aim of the study was to evaluate the risk of allergic reactions in persons with pollinosis on the basis of the pollen calendar, analysis of concentrations of pollen grains of grass and rye, and comparison of diurnal pattern of airborne pollen grain concentrations at two sites with different degrees of urbanisation (Gudowo in the country and the city of Szczecin) in 2012-2014. The concentration of pollen was measured by the volume method. Length of the pollination season was determined by the method of 98%, assuming that the beginning and the end of the pollen season are the days on which 1% and 99% of the annual sum of pollen appeared. The first pollen grains to appear in the air are those produced by rye, followed by those produced by grass and wormwood. The pollen seasons of grasses and wormwood started about one week earlier in Gudowo than in Szczecin, while the pollen season of rye started at almost the same time in the country and in the city. Airborne pollen counts of grasses, rye and wormwood were much higher in the country than in the city. The differences most probably result from the different floristic composition at these two sites and reflect the local contribution of the taxa studied in the country. The risk of allergy caused by the pollen of the taxa analysed was much higher in Gudowo (in the country), than in Szczecin city.

  3. ROPES reveals past land cover and pollen productivity estimates from single pollen records

    NASA Astrophysics Data System (ADS)

    Theuerkauf, Martin; Couwenberg, John

    2018-04-01

    Quantitative reconstructions of past vegetation cover commonly require pollen productivity estimates (PPEs). PPEs are calibrated in extensive and rather cumbersome surface-sample studies, and are so far only available for selected regions. Moreover, it may be questioned whether present-day pollen-landcover relationships are valid for palaeo-situations. We here introduce the ROPES approach that simultaneously derives PPEs and mean plant abundances from single pollen records. ROPES requires pollen counts and pollen accumulation rates (PARs, grains cm-2 year-1). Pollen counts are used to reconstruct plant abundances following the REVEALS approach. The principle of ROPES is that changes in plant abundance are linearly represented in observed PAR values. For example, if the PAR of pine doubles, so should the REVEALS reconstructed abundance of pine. Consequently, if a REVEALS reconstruction is ‘correct’ (i.e. ‘correct’ PPEs are used) the ratio ‘PAR over REVEALS’ is constant for each taxon along all samples of a record. With incorrect PPEs, the ratio will instead vary. ROPES starts from random (likely incorrect) PPEs, but then adjusts them using an optimization algorithm with the aim to minimize variation in the ‘PAR over REVEALS’ ratio across the record. ROPES thus simultaneously calculates mean plant abundances and PPEs. We illustrate the approach with test applications on nine synthetic pollen records. The results show that good performance of ROPES requires data sets with high underlying variation, many samples and low noise in the PAR data. ROPES can deliver first landcover reconstructions in regions for which PPEs are not yet available. The PPEs provided by ROPES may then allow for further REVEALS-based reconstructions. Similarly, ROPES can provide insight in pollen productivity during distinct periods of the past such as the Lateglacial. We see a potential to study spatial and temporal variation in pollen productivity for example in relation to site

  4. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

    NASA Astrophysics Data System (ADS)

    Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

    2017-08-01

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

  5. Efficiency of a new bioaerosol sampler in sampling Betula pollen for antigen analyses.

    PubMed

    Rantio-Lehtimäki, A; Kauppinen, E; Koivikko, A

    1987-01-01

    A new bioaerosol sampler consisting of Liu-type atmospheric aerosol sampling inlet, coarse particle inertial impactor, two-stage high-efficiency virtual impactor (aerodynamic particle sizes respectively in diameter: greater than or equal to 8 microns, 8-2.5 microns, and 2.5 microns; sampling on filters) and a liquid-cooled condenser was designed, fabricated and field-tested in sampling birch (Betula) pollen grains and smaller particles containing Betula antigens. Both microscopical (pollen counts) and immunochemical (enzyme-linked immunosorbent assay) analyses of each stage were carried out. The new sampler was significantly more efficient than Burkard trap e.g. in sampling particles of Betula pollen size (ca. 25 microns in diameter). This was prominent during pollen peak periods (e.g. May 19th, 1985, in the virtual impactor 9482 and in the Burkard trap 2540 Betula p.g. X m-3 of air). Betula antigens were detected also in filter stages where no intact pollen grains were found; in the condenser unit the antigen concentrations instead were very low.

  6. More than sixty origins of pantoporate pollen in angiosperms.

    PubMed

    Prieu, Charlotte; Sauquet, Hervé; Gouyon, Pierre-Henri; Albert, Béatrice

    2017-12-01

    Apertures in pollen grains are key structures of the wall, involved in pollen tube germination and exchanges with the environment. Aperture types in angiosperms are diverse, but pollen with one and three apertures (including monosulcate and tricolpate, respectively) are the two most common types. Here, we investigate the phylogenetic distribution in angiosperms of pollen with many round, scattered apertures called pantoporate pollen. We constructed a morphological data set with species producing pantoporate pollen and representative angiosperm species with other pollen types, sampled from every angiosperm order, with a total of 1260 species distributed in 330 families. This data set was analyzed with parsimony to characterize the phylogenetic distribution of pantoporate pollen in angiosperms. We show that pantoporate pollen is distributed throughout most of the angiosperm tree, including early diverging angiosperms, monocots, and eudicots. However, this pollen type is usually restricted to a few species in a given group, and is seldom fixed at large taxonomical scales, with a few notable exceptions. Pantoporate pollen evolved many times during angiosperm history, but the persistence of this morphology in the long term is infrequent. This distribution pattern could indicate conflicting short-term and long-term selective pressures, pantoporate pollen being selected in the short run, but eliminated in the long run. Biological hypotheses supporting this scenario are discussed, in the context of both theoretical and empirical data on pollen biology. © 2017 Botanical Society of America.

  7. Gibberellins Are Required for Seed Development and Pollen Tube Growth in Arabidopsis

    PubMed Central

    Singh, Davinder P.; Jermakow, Angelica M.; Swain, Stephen M.

    2002-01-01

    Gibberellins (GAs) are tetracyclic diterpenoids that are essential endogenous regulators of plant growth and development. GA levels within the plant are regulated by a homeostatic mechanism that includes changes in the expression of a family of GA-inactivating enzymes known as GA 2-oxidases. Ectopic expression of a pea GA 2-oxidase2 cDNA caused seed abortion in Arabidopsis, extending and confirming previous observations obtained with GA-deficient mutants of pea, suggesting that GAs have an essential role in seed development. A new physiological role for GAs in pollen tube growth in vivo also has been identified. The growth of pollen tubes carrying the 35S:2ox2 transgene was reduced relative to that of nontransgenic pollen, and this phenotype could be reversed partially by GA application in vitro or by combining with spy-5, a mutation that increases GA response. Treatment of wild-type pollen tubes with an inhibitor of GA biosynthesis in vitro also suggested that GAs are required for normal pollen tube growth. These results extend the known physiological roles of GAs in Arabidopsis development and suggest that GAs are required for normal pollen tube growth, a physiological role for GAs that has not been established previously. PMID:12468732

  8. Modern pollen deposition in Long Island Sound

    USGS Publications Warehouse

    Beuning, Kristina R.M.; Fransen, Lindsey; Nakityo, Berna; Mecray, Ellen L.; Buchholtz ten Brink, Marilyn R.

    2000-01-01

    Palynological analyses of 20 surface sediment samples collected from Long Island Sound show a pollen assemblage dominated by Carya, Betula, Pinus, Quercus, Tsuga, and Ambrosia, as is consistent with the regional vegetation. No trends in relative abundance of these pollen types occur either from west to east or associated with modern riverine inputs throughout the basin. Despite the large-scale, long-term removal of fine-grained sediment from winnowed portions of the eastern Sound, the composition of the pollen and spore component of the sedimentary matrix conforms to a basin-wide homogeneous signal. These results strongly support the use of select regional palynological boundaries as chronostratigraphic tools to provide a framework for interpretation of the late glacial and Holocene history of the Long Island Sound basin sediments.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Underbrink, A.G.; Sparrow, A.H.; Pond, V.

    The effects of x or gamma rays and 0.43-MeV neutrons on pollen abortion, as measured by cotton blue staining, were studied in fifteen rnembers of four genera (Floscopa, Gibasis, Tradescantia, and Tripogandra) of the family Commelinaceae. The roles of interphase chromosome volume (ICV), nuclear volume (NV), and ploidy on the degree of pollen abortion induced by radiation were investigated. For each species, the maximum percentage of aborted grains was determined over a postirradiation period equivalent to an entire period of microsporogenesis. Dose-response curves were constructed for each species and these were found to vary in slope. From these curves, RBEmore » values were determined for two species of Tradescantia and for a diploid and tetraploid species of Gibasis. Within the dose range investigated, highest RBEs at 10% pollen abortion ranged from about 23 for Gibasis karwinskyana (4x) to about 9.4 for the diploid Gibasis. Ploidy was not found to influence the radiation response to an appreciable extent when ICVs were similar. High polyploids with small ICVs were found to be more radioresistant, but this response appears to be a function of ICV and not the degree of ploidy. Correlations were sought between 50% pollen abortion and ICV or NV. No correlations were found using NV. However, following low LET radiation an inverse relationship (-1 slope) was obtained between 50% pollen abortion and ICV. The same relation appears to hold for neutrons, but since only four species were available for comparison this relationship is still inconclusive. (auth)« less

  10. The mature anther-preferentially expressed genes are associated with pollen fertility, pollen germination and anther dehiscence in rice.

    PubMed

    Ling, Sheng; Chen, Caisheng; Wang, Yang; Sun, Xiaocong; Lu, Zhanhua; Ouyang, Yidan; Yao, Jialing

    2015-02-19

    The anthers and pollen grains are critical for male fertility and hybrid rice breeding. The development of rice mature anther and pollen consists of multiple continuous stages. However, molecular mechanisms regulating mature anther development were poorly understood. In this study, we have identified 291 mature anther-preferentially expressed genes (OsSTA) in rice based on Affymetrix microarray data. Gene Ontology (GO) analysis indicated that OsSTA genes mainly participated in metabolic and cellular processes that are likely important for rice anther and pollen development. The expression patterns of OsSTA genes were validated using real-time PCR and mRNA in situ hybridizations. Cis-element identification showed that most of the OsSTA genes had the cis-elements responsive to phytohormone regulation. Co-expression analysis of OsSTA genes showed that genes annotated with pectinesterase and calcium ion binding activities were rich in the network, suggesting that OsSTA genes could be involved in pollen germination and anther dehiscence. Furthermore, OsSTA RNAi transgenic lines showed male-sterility and pollen germination defects. The results suggested that OsSTA genes function in rice male fertility, pollen germination and anther dehiscence and established molecular regulating networks that lay the foundation for further functional studies.

  11. Pollen Processing Behavior of Heliconius Butterflies: A Derived Grooming Behavior

    PubMed Central

    Hikl, Anna-Laetitia; Krenn, Harald W.

    2011-01-01

    Pollen feeding behaviors Heliconius and Laparus (Lepidoptera: Nymphalidae) represent a key innovation that has shaped other life history traits of these neotropical butterflies. Although all flower visiting Lepidoptera regularly come in contact with pollen, only Heliconius and Laparus butterflies actively collect pollen with the proboscis and subsequently take up nutrients from the pollen grains. This study focused on the behavior of pollen processing and compared the movement patterns with proboscis grooming behavior in various nymphalid butterflies using video analysis. The proboscis movements of pollen processing behavior consisted of a lengthy series of repeated coiling and uncoiling movements in a loosely coiled proboscis position combined with up and down movements and the release of saliva. The proboscis-grooming behavior was triggered by contamination of the proboscis in both pollen feeding and non-pollen feeding nymphalid butterflies. Proboscis grooming movements included interrupted series of coiling and uncoiling movements, characteristic sideways movements, proboscis lifting, and occasionally full extension of the proboscis. Discharge of saliva was more pronounced in pollen feeding species than in non-pollen feeding butterfly species. We conclude that the pollen processing behavior of Heliconius and Laparus is a modified proboscis grooming behavior that originally served to clean the proboscis after contamination with particles. PMID:22208893

  12. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice.

    PubMed

    Wu, Jinwen; Shahid, Muhammad Qasim; Chen, Lin; Chen, Zhixiong; Wang, Lan; Liu, Xiangdong; Lu, Yonggen

    2015-12-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (S(i)S(j)) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. © 2015 American Society of Plant Biologists. All Rights Reserved.

  13. Wind tunnel and field assessment of pollen dispersal in soybean [Glycine max (L.) Merr.].

    PubMed

    Yoshimura, Yasuyuki

    2011-01-01

    Although genetically modified (GM) soybean has never been cultivated commercially in Japan, it is essential to set up the isolation distance required to prevent out-crossing between GM and conventional soybean in preparation for any future possibility of pollen transfer. The airborne soybean pollen was sampled using some Durham pollen samplers located in the range of 20 m from the field edge. In addition, the dispersal distance was assessed in a wind tunnel under constant air flow and then it was compared with the anticipated distances based on the pollen diameter. In the field, the maximum pollen density per day observed was 1.235 grains cm(-2) day(-1) at three observation points within 2.5 m from the field and inside the field the mean density did not reach the rate of 1 grain cm(-2 )day(-1) during 19 flowering days. The results of the wind tunnel experiment also showed that the plants had almost no airborne release of pollen and the dispersal distance was shorter than theoretical value due to clustered dispersal. This study showed little airborne pollen in and around the soybean field and the dispersal is restricted to a small area. Therefore, wind-mediated pollination appears to be negligible.

  14. The occurrence of Ambrosia pollen in the atmosphere of Northwest Turkey: investigation of possible source regions

    NASA Astrophysics Data System (ADS)

    Celenk, Sevcan; Malyer, Hulusi

    2017-08-01

    Ambrosia pollen was first reported as an important allergen in North America at the end of the nineteenth century, and many European countries have recently reported its increasing significance for pollen allergy. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the studied period could be the result of long-distance transport (LDT) and to identify the potential sources of Ambrosia pollen grains. The study investigates Ambrosia pollen episodes during the peak term of six yearly periods between 2010 and 2015 by examining source regions in Ambrosia pollen in Bursa, Turkey. A volumetric trap was used for collecting the pollen samples, and the back-trajectory model was used to identify a potential source of atmospheric Ambrosia pollen. The days when pollen levels exceeded 30 P m-3 were computed, and clusters were shown on the figures. The study indicates that the Ambrosia pollen grains recorded during the episode in Bursa were not produced by local sources but transported long distances from potential source regions around the Azov Sea in Russia and Ukraine, Black Sea region of Turkey, Romania, and Bulgaria. Note that atmospheric concentrations of Ambrosia pollen exceeded the clinical threshold during 28 days during the investigation period. Taking into consideration the high allergenicity of Ambrosia pollen, the present findings suggest that the number of ragweed-sensitized individuals might increase in the near future in the region.

  15. Behavior of profilins in the atmosphere and in vitro, and their relationship with the performance of airborne pollen

    NASA Astrophysics Data System (ADS)

    Aloisi, Iris; Del Duca, Stefano; De Nuntiis, Paola; Vega Maray, Ana M.; Mandrioli, Paolo; Gutiérrez, Pablo; Fernández-González, Delia

    2018-04-01

    Most pollen allergens in the air are carried by pollen grains, but the presence of airborne smaller respirable particles containing pollen allergens has also been demonstrated. Meteorological factors drastically affect the occurrence of pollen, allergen release in the air and diffusion of the latest. In order to shed light on this phenomenon, the dynamics of pollen and the pollen panallergen profilin in the air of two European cities (León, Spain and Bologna, Italy) having different weather conditions, were analyzed. Pollen sampling was performed continuously from March to June 2015 using two seven-day recording volumetric trap of Hirst-type, while the particles for aeroallergen quantification were sampled with a Burkard Cyclone sampler and the profilin content in aerosol samples was quantified using an indirect double-antibody sandwich ELISA. In both cities, pollen and profilin concentrations followed a similar trend and showed a significant correlation; however, peaks were often misaligned, with the profilin peaks following those of pollen. Several meteorological parameters, such as relative humidity, significantly influenced pollen and allergen dispersion. In vitro pollen tests were thus performed in order to mimic pollen rehydration, occurring in natural conditions and a massive protein release from allergenic pollen was detected during the early stages of pollen rehydration when profilin was also extruded from the grains. The different timing and protein amounts released from different pollen during hydration might explain, at least in part, the non-synchronous pollen and profilin peaks detected in the atmosphere.

  16. Identification of novel superoxide dismutase isoenzymes in the olive (Olea europaea L.) pollen.

    PubMed

    Zafra, Adoración; Castro, Antonio Jesús; Alché, Juan de Dios

    2018-06-08

    Among antioxidant enzymes, the superoxide dismutase (SOD) family is a major actor in catalysing the disproportionation of superoxide. Apart from its role as antioxidant, these enzymes have a role in cell signalling, and Cu,Zn-SOD proteins are also major pollen allergens. In order to deepen our understanding of the SOD isoenzymes present in olive pollen and to analyse the molecular variability of the pollen Cu,Zn-SOD family, we carried out biochemical, transcriptomic and localization studies of pollen grains from different olive cultivars and other allergenic species. Olive pollen showed a high rate of total SOD activity in all cultivars assayed, which did not correlate with pollen viability. Mass spectrometry analysis together with activity assays and Western blotting experiments enabled us to identify new forms of Cu,Zn-SOD enzyme (including chloroplastidic and peroxisomal forms) as well as differentially expressed Mn-, Fe- and Cu,Zn-SOD isoenzymes among the pollen of different olive cultivars and allergenic species. Ultrastructural localization of Cu,Zn-SOD revealed its plastidial localization in the pollen grain. We also identified the occurrence of a shorter form of one of the cytosolic Cu,Zn-SOD enzymes, likely as the result of alternative splicing. This shorter enzyme showed lower SOD activity as compared to the full length form. The presence of multiple SOD isoenzymes in the olive pollen could be related to the need of finely tuning the ROS metabolism during the transition from its quiescent condition at maturity to a highly metabolically active state at germination.

  17. Expression of Foreign Genes Demonstrates the Effectiveness of Pollen-Mediated Transformation in Zea mays.

    PubMed

    Yang, Liyan; Cui, Guimei; Wang, Yixue; Hao, Yaoshan; Du, Jianzhong; Zhang, Hongmei; Wang, Changbiao; Zhang, Huanhuan; Wu, Shu-Biao; Sun, Yi

    2017-01-01

    Plant genetic transformation has arguably been the core of plant improvement in recent decades. Efforts have been made to develop in planta transformation systems due to the limitations present in the tissue-culture-based methods. Herein, we report an improved in planta transformation system, and provide the evidence of reporter gene expression in pollen tube, embryos and stable transgenicity of the plants following pollen-mediated plant transformation with optimized sonication treatment of pollen. The results showed that the aeration at 4°C treatment of pollen grains in sucrose prior to sonication significantly improved the pollen viability leading to improved kernel set and transformation efficiency. Scanning electron microscopy observation revealed that the removal of operculum covering pollen pore by ultrasonication might be one of the reasons for the pollen grains to become competent for transformation. Evidences have shown that the eGfp gene was expressed in the pollen tube and embryos, and the Cry1Ac gene was detected in the subsequent T 1 and T 2 progenies, suggesting the successful transfer of the foreign genes to the recipient plants. The Southern blot analysis of Cry1Ac gene in T 2 progenies and PCR-identified Apr gene segregation in T 2 seedlings confirmed the stable inheritance of the transgene. The outcome illustrated that the pollen-mediated genetic transformation system can be widely applied in the plant improvement programs with apparent advantages over tissue-culture-based transformation methods.

  18. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice1[OPEN

    PubMed Central

    Wu, Jinwen; Chen, Lin; Chen, Zhixiong; Wang, Lan; Lu, Yonggen

    2015-01-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (SiSj) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. PMID:26511913

  19. Inheritance of Hetero-Diploid Pollen S-Haplotype in Self-Compatible Tetraploid Chinese Cherry (Prunus pseudocerasus Lindl)

    PubMed Central

    Gu, Chao; Liu, Qing-Zhong; Yang, Ya-Nan; Zhang, Shu-Jun; Khan, Muhammad Awais; Wu, Jun; Zhang, Shao-Ling

    2013-01-01

    The breakdown of self-incompatibility, which could result from the accumulation of non-functional S-haplotypes or competitive interaction between two different functional S-haplotypes, has been studied extensively at the molecular level in tetraploid Rosaceae species. In this study, two tetraploid Chinese cherry (Prunus pseudocerasus) cultivars and one diploid sweet cherry (Prunus avium) cultivar were used to investigate the ploidy of pollen grains and inheritance of pollen-S alleles. Genetic analysis of the S-genotypes of two intercross-pollinated progenies showed that the pollen grains derived from Chinese cherry cultivars were hetero-diploid, and that the two S-haplotypes were made up of every combination of two of the four possible S-haplotypes. Moreover, the distributions of single S-haplotypes expressed in self- and intercross-pollinated progenies were in disequilibrium. The number of individuals of the two different S-haplotypes was unequal in two self-pollinated and two intercross-pollinated progenies. Notably, the number of individuals containing two different S-haplotypes (S1- and S5-, S5- and S8-, S1- and S4-haplotype) was larger than that of other individuals in the two self-pollinated progenies, indicating that some of these hetero-diploid pollen grains may have the capability to inactivate stylar S-RNase inside the pollen tube and grow better into the ovaries. PMID:23596519

  20. Classification and phylogenetic analysis of Chinese hawthorn assessed by plant and pollen morphology.

    PubMed

    Ma, S L Y; Lu, Y M

    2016-09-19

    The Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) is uniquely originated in northern China. The ecological and horticultural importance of Chinese hawthorn is considerable and some varieties are valued for their fruit or medicine extracts. Its taxonomy and phylogeny remain poorly understood. Apart from general plant morphological traits, pollen is an important trait for the classification of plants and their evolutionary origin. However, few studies have investigated the pollen of Chinese hawthorn. Here, an analysis of plant and pollen morphological characteristics was conducted in 57 cultivars from the Shenyang region. Thirty plant morphological characters and nine pollen grain characters were investigated. The plant morphological analysis revealed that the coefficient of variation for 13 traits was >20%, which indicates a high degree of variability. We also found that the pollen grains varied greatly in size, shape (from prolate to perprolate), and exine pattern (striate-perforate predominantly). The number of apertures was typically three. Based on these findings, we suggest that pollen morphology associated with plant morphological traits can be used for classification and phylogenetic analysis of Chinese hawthorn cultivars. In sum, our results provide new insights and constitute a scientific basis for future studies on the classification and evolution of Chinese hawthorn.

  1. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

    DOE PAGES

    Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

    2017-03-29

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua’i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near themore » island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni’ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. As a result, they demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.« less

  2. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua’i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near themore » island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni’ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. As a result, they demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.« less

  3. Pollen Lipidomics: Lipid Profiling Exposes a Notable Diversity in 22 Allergenic Pollen and Potential Biomarkers of the Allergic Immune Response

    PubMed Central

    Bashir, Mohamed Elfatih H.; Lui, Jan Hsi; Palnivelu, Ravishankar; Naclerio, Robert M.; Preuss, Daphne

    2013-01-01

    Background/Aim Pollen grains are the male gametophytes that deliver sperm cells to female gametophytes during sexual reproduction of higher plants. Pollen is a major source of aeroallergens and environmental antigens. The pollen coat harbors a plethora of lipids that are required for pollen hydration, germination, and penetration of the stigma by pollen tubes. In addition to proteins, pollen displays a wide array of lipids that interact with the human immune system. Prior searches for pollen allergens have focused on the identification of intracellular allergenic proteins, but have largely overlooked much of the extracellular pollen matrix, a region where the majority of lipid molecules reside. Lipid antigens have attracted attention for their potent immunoregulatory effects. By being in close proximity to allergenic proteins on the pollen surface when they interact with host cells, lipids could modify the antigenic properties of proteins. Methodology/Principal Findings We performed a comparative pollen lipid profiling of 22 commonly allergenic plant species by the use of gas chromatography-mass spectroscopy, followed by detailed data mining and statistical analysis. Three experiments compared pollen lipid profiles. We built a database library of the pollen lipids by matching acquired pollen-lipid mass spectra and retention times with the NIST/EPA/NIH mass-spectral library. We detected, identified, and relatively quantified more than 106 lipid molecular species including fatty acids, n-alkanes, fatty alcohols, and sterols. Pollen-derived lipids stimulation up-regulate cytokines expression of dendritic and natural killer T cells co-culture. Conclusions/Significance Here we report on a lipidomic analysis of pollen lipids that can serve as a database for identifying potential lipid antigens and/or novel candidate molecules involved in allergy. The database provides a resource that facilitates studies on the role of lipids in the immunopathogenesis of allergy. Pollen

  4. A pollen-specific calmodulin-binding protein, NPG1, interacts with putative pectate lyases.

    PubMed

    Shin, Sung-Bong; Golovkin, Maxim; Reddy, Anireddy S N

    2014-06-12

    Previous genetic studies have revealed that a pollen-specific calmodulin-binding protein, No Pollen Germination 1 (NPG1), is required for pollen germination. However, its mode of action is unknown. Here we report direct interaction of NPG1 with pectate lyase-like proteins (PLLs). A truncated form of AtNPG1 lacking the N-terminal tetratricopeptide repeat 1 (TPR1) failed to interact with PLLs, suggesting that it is essential for NPG1 interaction with PLLs. Localization studies with AtNPG1 fused to a fluorescent reporter driven by its native promoter revealed its presence in the cytosol and cell wall of the pollen grain and the growing pollen tube of plasmolyzed pollen. Together, our data suggest that the function of NPG1 in regulating pollen germination is mediated through its interaction with PLLs, which may modify the pollen cell wall and regulate pollen tube emergence and growth.

  5. Distribution of pectins in the pollen apertures of Oenothera hookeri.velans ster/+ster.

    PubMed

    Noher de Halac, I; Cismondi, I A; Rodriguez-Garcia, M I; Famá, G

    2003-04-01

    Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7 directed against pectin epitopes in fertile pollen grains of Oenothera hookeri.velans ster/+ster. The same region was also analyzed by classical cytochemistry for polysaccharide detection. Immunogold labelling at the JIM7 epitope showed only in mature pollen labelling mainly located at the intine endo-aperture region. Cytoplasmic structures near the plasma membrane of the vegetative cell showed no labelling gold grains. In the same pollen stge the labelling at the JIM5 epitope was mostly confined to a layer located in the limit between the endexine and the ektexine at the level of the border of the oncus. Some tubuli at the base of the ektexine showed also an accumulation of gold particles. No JIM5 label was demonstrated in the aperture chamber and either in any cytoplasmic structure of the pollen grains. The immunocytochemical technique, when compared with the traditional methods for non-cellulose polysaccharide cytochemistry is fare more sensitive and allows the univocal determination of temporal and spatial location of pectins recognized by the JIM7 and JIM5 MAbs.

  6. Juniper Pollen Hotspots in the Southwest

    NASA Technical Reports Server (NTRS)

    Bunderson, L. D.; VandeWater, P.; Luvall, J.; Levetin, E.

    2013-01-01

    Rationale: Juniperus pollen is a major allergen in Texas, Oklahoma, and New Mexico. While the bulk of pollen may be released in rural areas, large amounts of pollen can be transported to urban areas. Major juniper species in the region include: Juniperus ashei, J. virginiana, J. pinchotii, and J. monosperma. Pollen release is virtually continuous beginning in late September with J. pinchotii and ending in May with J. monosperma. Urban areas in the region were evaluated for the potential of overlapping seasons in order to inform sensitive individuals. Methods: Burkard volumetric pollen traps were established for two consecutive spring seasons at 6 sites in northern New Mexico and 6 sites for two consecutive winter and fall seasons in Texas and Oklahoma Standard methods were used in the preparation and analysis of slides. Results: The Dallas-Fort Worth Metroplex is home to over 6 million people. It is adjacent to populations of J. pinchotii, J. virginiana, and J. ashei. Peak concentration near Dallas for J. ashei in 2011 was 5891 pollen grains/m3 in January 7th. The peak date for J. pinchotii at an upwind sampling location in San Marcos, TX was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was February 20, 2011. Amarillo, TX is adjacent to J. pinchotii, J. ashei, and J. monosperma populations and may be subject to juniper pollen from September through May. Conclusions: Considering the overlapping distributions of juniper trees and the overlapping temporal release of pollen, sensitive patients may benefit from avoiding hotspots.

  7. [Allergic responses to date palm and pecan pollen in Israel].

    PubMed

    Waisel, Y; Keynan, N; Gil, T; Tayar, D; Bezerano, A; Goldberg, A; Geller-Bernstein, C; Dolev, Z; Tamir, R; Levy, I

    1994-03-15

    Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.

  8. Transport and radiative impacts of atmospheric pollen using online, observation-based emissions

    NASA Astrophysics Data System (ADS)

    Wozniak, M. C.; Steiner, A. L.; Solmon, F.; Li, Y.

    2015-12-01

    Atmospheric pollen emitted from trees and grasses exhibits both a high temporal variability and a highly localized spatial distribution that has been difficult to quantify in the atmosphere. Pollen's radiative impact is also not quantified because it is neglected in climate modeling studies. Here we couple an online, meteorological active pollen emissions model guided by observations of airborne pollen to understand the role of pollen in the atmosphere. We use existing pollen counts from 2003-2008 across the continental U.S. in conjunction with a tree database and historical meteorological data to create an observation-based phenological model that produces accurately scaled and timed emissions. These emissions are emitted and transported within the regional climate model (RegCM4) and the direct radiative effect is calculated. Additionally, we simulate the rupture of coarse pollen grains into finer particles by adding a second size mode for pollen emissions, which contributes to the shortwave radiative forcing and also has an indirect effect on climate.

  9. Nasal filters in prevention of seasonal rhinitis induced by allergenic pollen grains. Open clinical study.

    PubMed

    D'Amato, G; Liccardi, G; Salzillo, A; Russo, M; Narciso, P; Allegra, L

    2012-04-01

    Nasal filters (Sanispira) might represent a novel approach in preventing exacerbations of symptoms of seasonal allergic rhinitis by reducing pollen access to nasal cavities. Female and male voluntary patients between the ages of 18 and 64 years living in Naples area and affected by allergic rhinitis were recruited in an open clinical study. All were allergic to Parietaria pollen as assessed by skin-prick and/or RAST test with or without associated sensitization to other pollens such as Gramineae and Olea europaea. A pollen count was also carried out from 10th April until 30th of June 2011. The results of our study show positive statistical differences between the scores of common nasal symptoms and the reduced use of antihistaminic drugs in patients using nasal filters in comparison to non users. Nasal filters constitute a useful mean to reduce symptoms of seasonal allergic rhinitis in patients suffering from pollen allergy.

  10. Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for "omics" analysis.

    PubMed

    Lu, Yunlong; Wei, Liqin; Wang, Tai

    2015-01-01

    The development of sperm cells (SCs) from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput "omics" approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs), from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative cell nuclei (VN) from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants.

  11. Pollen tube reuses intracellular components of nucellar cells undergoing programmed cell death in Pinus densiflora.

    PubMed

    Hiratsuka, Rie; Terasaka, Osamu

    2011-04-01

    Through the process known as programmed cell death (PCD), nucelli of Pinus densiflora serve as the transmitting tissue for growth of the pollen tube. We sought to clarify the processes of degradation of nucellar cell components and their transport to the pollen tube during PCD in response to pollen tube penetration of such nucelli. Stimulated by pollination, synthesis of large amounts of starch grains occurred in cells in a wide region of the nucellus, but as the pollen tube penetrated the nucellus, starch grains were degraded in amyloplasts of nucellar cells. In cells undergoing PCD, electron-dense vacuoles with high membrane contrast appeared, assumed a variety of autophagic structures, expanded, and ultimately collapsed and disappeared. Vesicles and electron-dense amorphous materials were released inside the thickened walls of cells undergoing PCD, and those vesicles and materials reaching the pollen tube after passing through the extracellular matrix were taken into the tube by endocytosis. These results show that in PCD of nucellar cells, intracellular materials are degraded in amyloplasts and vacuoles, and some of the degraded material is supplied to the pollen tube by vesicular transport to support tube growth.

  12. Wind-mediated horseweed (Conyza canadensis) gene flow: pollen emission, dispersion, and deposition.

    PubMed

    Huang, Haiyan; Ye, Rongjian; Qi, Meilan; Li, Xiangzhen; Miller, David R; Stewart, Charles Neal; DuBois, David W; Wang, Junming

    2015-07-01

    Horseweed (Conyza canadensis) is a problem weed in crop production because of its evolved resistance to glyphosate and other herbicides. Although horseweed is mainly self-pollinating, glyphosate-resistant (GR) horseweed can pollinate glyphosate-susceptible (GS) horseweed. To the best of our knowledge, however, there are no available data on horseweed pollen production, dispersion, and deposition relative to gene flow and the evolution of resistance. To help fill this knowledge gap, a 43-day field study was performed in Champaign, Illinois, USA in 2013 to characterize horseweed atmospheric pollen emission, dispersion, and deposition. Pollen concentration and deposition, coupled with atmospheric data, were measured in a source field (180 m by 46 m) and its surrounding areas up to 1 km downwind horizontally and up to 100 m vertically. The source strength (emission rate) ranged from 0 to 140 pollen grains per plant per second (1170 to 2.1×10(6) per plant per day). For the life of the study, the estimated number of pollen grains generated from this source field was 10.5×10(10) (2.3×10(6) per plant). The release of horseweed pollen was not strongly correlated to meteorological data and may be mainly determined by horseweed physiology. Horseweed pollen reached heights of 80 to100 m, making long-distance transport possible. Normalized (by source data) pollen deposition with distance followed a negative-power exponential curve. Normalized pollen deposition was 2.5% even at 480 m downwind from the source edge. Correlation analysis showed that close to or inside the source field at lower heights (≤3 m) vertical transport was related to vertical wind speed, while horizontal pollen transport was related to horizontal wind speed. High relative humidity prevented pollen transport at greater heights (3-100 m) and longer distances (0-1000 m) from the source. This study can contribute to the understanding of how herbicide-resistance weeds or invasive plants affect ecology

  13. An occupational respiratory allergy caused by Sinapis alba pollen in olive farmers.

    PubMed

    Anguita, J L; Palacios, L; Ruiz-Valenzuela, L; Bartolomé, B; López-Urbano, M J; Sáenz de San Pedro, B; Cano, E; Quiralte, J

    2007-04-01

    Sinapis alba (white mustard) is a entomophilic species included in the Brassicaceae family. To date it has not been related to allergic sensitization or clinical respiratory disease. Twelve olive orchard workers had a history of rhinitis and/or bronchial asthma that occurred during control weed management and/or harvest, from January to March. They underwent skin prick tests (SPT) with S. alba pollen extract and a standard battery of aeroallergens. Sinapis alba pollen extract was prepared for performing quantitative skin tests, enzyme allergosorbent test and nasal challenge test (NCT). A portable monitoring station and an urban volumetric Hirst-type spore trap were used for the aerobiological study. Eleven patients suffered from rhinitis and bronchial asthma and one had only from rhinitis. All patients were sensitized to S. alba pollen extract, and they showed a positive NCT response. In the urban aerobiologic monitoring station the amount of S. alba pollen only exceptionally reached peaks of 21 grains/m(3), whereas in the work environment peaks of 1801 grains/m(3) were detected between 15 February and 7 April. We demonstrate the existence of a new occupational allergen for olive farmers: S. alba pollen. We point out the importance of perform aerobiological sampling within the occupational environment for the detection and quantification of the allergenic source.

  14. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae).

    PubMed

    Timerman, David; Greene, David F; Urzay, Javier; Ackerman, Josef D

    2014-12-06

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind-stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  15. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

    PubMed Central

    Timerman, David; Greene, David F.; Urzay, Javier; Ackerman, Josef D.

    2014-01-01

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind–stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. PMID:25297315

  16. Analysis of Peroxisome Biogenesis in Pollen by Confocal Microscopy and Transmission Electron Microscopy.

    PubMed

    Jia, Peng-Fei; Li, Hong-Ju; Yang, Wei-Cai

    2017-01-01

    Peroxisome is an essential single-membrane bound organelle in most eukaryotic cells and functions in diverse cellular processes. De novo formation, division, and turnover of peroxisomes contribute to its biogenesis, morphology, and population regulation. In plants, peroxisome plays multiple roles, including metabolism, development, and stress response. Defective peroxisome biogenesis and development retard plant growth, adaption, and reproduction. Through tracing the subcellular localization of fluorescent reporter tagged matrix protein of peroxisome, fluorescence microscopy is a reliable and fast way to detect peroxisome biogenesis. Further fine-structural observation of peroxisome by TEM enables researchers to observe the detailed ultrastructure of its morphology and spatial contact with other organelles. Pollen grain is a specialized structure where two small sperm cells are enclosed in the cytoplasm of a large vegetative cell. Two features make pollen grain a good system to study peroxisome biogenesis: indispensable requirement of peroxisome for germination on the stigma and homogeneity. Here, we describe the methods of studying peroxisome biogenesis in Arabidopsis pollen grains by fluorescent live-imaging with confocal laser scanning microscopy (CLSM) and by DAB-staining based transmission electron microscopy (TEM).

  17. Cytochrome P450 family member CYP704B2 catalyzes the {omega}-hydroxylation of fatty acids and is required for anther cutin biosynthesis and pollen exine formation in rice.

    PubMed

    Li, Hui; Pinot, Franck; Sauveplane, Vincent; Werck-Reichhart, Danièle; Diehl, Patrik; Schreiber, Lukas; Franke, Rochus; Zhang, Ping; Chen, Liang; Gao, Yawei; Liang, Wanqi; Zhang, Dabing

    2010-01-01

    The anther cuticle and microspore exine act as protective barriers for the male gametophyte and pollen grain, but relatively little is known about the mechanisms underlying the biosynthesis of the monomers of which they are composed. We report here the isolation and characterization of a rice (Oryza sativa) male sterile mutant, cyp704B2, which exhibits a swollen sporophytic tapetal layer, aborted pollen grains without detectable exine, and undeveloped anther cuticle. In addition, chemical composition analysis indicated that cutin monomers were hardly detectable in the cyp704B2 anthers. These defects are caused by a mutation in a cytochrome P450 family gene, CYP704B2. The CYP704B2 transcript is specifically detected in the tapetum and the microspore from stage 8 of anther development to stage 10. Heterologous expression of CYP704B2 in yeast demonstrated that CYP704B2 catalyzes the production of omega -hydroxylated fatty acids with 16 and 18 carbon chains. Our results provide insights into the biosynthesis of the two biopolymers sporopollenin and cutin. Specifically, our study indicates that the omega -hydroxylation pathway of fatty acids relying on this ancient CYP704B family, conserved from moss to angiosperms, is essential for the formation of both cuticle and exine during plant male reproductive and spore development.

  18. Variations and trends of Fagaceae pollen in Northern Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Canu, Annalisa; Pellizzaro, Grazia; Arca, Bachisio; Vargiu, Arnoldo

    2016-04-01

    The aim of this study is to analyze variations in the start and the end dates of pollen season, date of maximum concentration peak, pollen season duration, pollen concentration value and Seasonal Pollen Index of airborne Fagaceae pollen series recorded in Sassari, Northern Italy, and to evaluate their relation to meteorological data. Daily pollen concentration data were measured from 1986 to 2008 in a urban area of northern Sardinia (Italy) using a Burkard seven-day recording volumetric spore trap. The date of the peak occurrence was defined as the day when the cumulated daily pollen values reached the 50 % of the total annual pollen concentration. Meteorological data were recorded during the same period by an automatic weather station. Cumulative Degree days were calculated, for each year, from different starting dates using the daily averaging method. The correlation between meteorological variables and the different characteristics of pollen seasons was analyzed using Spearman's correlation tests. In the city of Sassari the Fagaceae airborne pollen content was mainly due to Quercus. The main pollen season took place from April to June. The longest pollen season appeared in the year 2002. The cumulative counts varied over the years, with a mean value of 5,336 pollen grains, a lowest total of 550 in 1986 and a highest total of 8,678 in 2001. Daily pollen concentrations presented positive correlation with temperature, and negative with relative humidity (p<0,0001) and with rainfall. In addition, Cumulative Degree days were significantly correlated with the dates of maximum concentration peak (p<0,0001).

  19. Arabidopsis ACA7, encoding a putative auto-regulated Ca(2+)-ATPase, is required for normal pollen development.

    PubMed

    Lucca, Noel; León, Gabriel

    2012-04-01

    Microgametogenesis is a complex process that involves numerous well-coordinated cell activities, ending with the production of pollen grains. Pollen development has been studied at the cytological level in Arabidopsis and other plant species, where its temporal time course has been defined. However, the molecular mechanism underlying this process is still unclear, since a relative small number of genes and/or processes have been identified as essential for pollen development. We have designed a methodology to select candidate genes for functional analysis, based on transcriptomic data obtained from different stages of pollen development. From our analyses, we selected At2g22950 as a candidate gene; this gene encodes a protein belonging to the auto-regulated Ca(2+)-ATPase family, ACA7. Microarray data indicate that ACA7 is expressed exclusively in developing pollen grains, with the highest level of mRNA at the time of the second pollen mitosis. Our RT-PCR experiments showed that ACA7 mRNA is detected exclusively in developing flowers. Confocal microscopy experiments showed a plasma membrane localization for the recombinant GFP:ACA7 protein. We identified two different insertional mutant lines, aca7-1 and aca7-2; plants from both mutant lines displayed a normal vegetative development but showed large amounts of dead pollen grains in mature flowers assayed by Alexander's staining. Histological analysis indicated that abnormalities are detected after the first pollen mitosis and we found a strong correlation between ACA7 mRNA accumulation and the severity of the phenotype. Our results indicate that ACA7 is a plasma membrane protein that has an important role during pollen development, possibly through regulation of Ca(2+) homeostasis. © Springer-Verlag 2011

  20. Isolation and characterization of a novel pollen-specific promoter in maize (Zea mays L.).

    PubMed

    Wang, He; Fan, Mingxia; Wang, Guohong; Zhang, Chunyu; Shi, Lei; Wei, Zhengyi; Ma, Wenjuan; Chang, Jing; Huang, Senxin; Lin, Feng

    2017-06-01

    ZmSTK2_USP, located on the long arm of chromosome 4, belongs to the serine/threonine kinase gene in maize. The sequence analysis of 2100 bp upstream from the start codon ATG has shown that it contains cis-element motifs and two types of anther/pollen-specific promoter elements (GTGA and AGAAA), suggesting that it is the pollen-specific promoter. To investigate the function of ZmSTK2_USP promoter, the GUS gene fusion system was employed. In proZmSTK2_USP-GUS genetically modified plants, GUS activity was detected in mature pollen grains and pollen tubes but not found in other floral and vegetative tissues. These results show that proZmSTK2_USP is the pollen-specific promoter and drives pollen-specific activity during the middle stage of pollen development until pollen maturation.

  1. The weak effects of climatic change on Plantago pollen concentration: 17 years of monitoring in Northwestern Spain.

    PubMed

    González-Parrado, Zulima; Valencia-Barrera, Rosa Ma; Vega-Maray, Ana Ma; Fuertes-Rodríguez, Carmen Reyes; Fernández-González, Delia

    2014-09-01

    Plantago L. species are very common in nitrified areas such as roadsides and their pollen is a major cause of pollinosis in temperate regions. In this study, we sampled airborne pollen grains in the city of León (NW, Spain) from January 1995 to December 2011, by using a Burkard® 7-day-recording trap. The percentage of Plantago pollen compared to the total pollen count ranged from 11% (1997) to 3% (2006) in the period under study. Peak pollen concentrations were recorded in May and June. Our 17-year analysis failed to disclose significant changes in the seasonal trend of plantain pollen concentration. In addition, there were no important changes in the start dates of pollen release and the meteorological parameters analyzed did not show significant variations in their usual trends. We analyzed the influence of several meteorological parameters on Plantago pollen concentration to explain the differences in pollen concentration trends during the study. Our results show that temperature, sun hours, evaporation, and relative humidity are the meteorological parameters best correlated to the behavior of Plantago pollen grains. In general, the years with low pollen concentrations correspond to the years with less precipitation or higher temperatures. We calculated the approximate Plantago flowering dates using the cumulative sum of daily maximum temperatures and compared them with the real bloom dates. The differences obtained were 4 days in 2009, 3 days in 2010, and 1 day in 2011 considering the complete period of pollination.

  2. The weak effects of climatic change on Plantago pollen concentration: 17 years of monitoring in Northwestern Spain

    NASA Astrophysics Data System (ADS)

    González-Parrado, Zulima; Valencia-Barrera, Rosa Ma.; Vega-Maray, Ana Ma.; Fuertes-Rodríguez, Carmen Reyes; Fernández-González, Delia

    2014-09-01

    Plantago L. species are very common in nitrified areas such as roadsides and their pollen is a major cause of pollinosis in temperate regions. In this study, we sampled airborne pollen grains in the city of León (NW, Spain) from January 1995 to December 2011, by using a Burkard® 7-day-recording trap. The percentage of Plantago pollen compared to the total pollen count ranged from 11 % (1997) to 3 % (2006) in the period under study. Peak pollen concentrations were recorded in May and June. Our 17-year analysis failed to disclose significant changes in the seasonal trend of plantain pollen concentration. In addition, there were no important changes in the start dates of pollen release and the meteorological parameters analyzed did not show significant variations in their usual trends. We analyzed the influence of several meteorological parameters on Plantago pollen concentration to explain the differences in pollen concentration trends during the study. Our results show that temperature, sun hours, evaporation, and relative humidity are the meteorological parameters best correlated to the behavior of Plantago pollen grains. In general, the years with low pollen concentrations correspond to the years with less precipitation or higher temperatures. We calculated the approximate Plantago flowering dates using the cumulative sum of daily maximum temperatures and compared them with the real bloom dates. The differences obtained were 4 days in 2009, 3 days in 2010, and 1 day in 2011 considering the complete period of pollination.

  3. The dangerous liaison between pollens and pollution in respiratory allergy.

    PubMed

    Schiavoni, Giovanna; D'Amato, Gennaro; Afferni, Claudia

    2017-03-01

    To recapitulate the more recent epidemiologic studies on the association of air pollution with respiratory allergic diseases prevalence and to discuss the main limitations of current approaches used to establish a link between pollinosis and pollution. Through the use of PubMed, we conducted a broad literature review in the following areas: epidemiology of respiratory allergic diseases, effect of pollution and climate changes on pollen grains, and immunomodulatory properties of pollen substances. Studies on short- and long-term exposure to air pollutants, such as gaseous and particulate materials, on allergic sensitization, and on exacerbation of asthma symptoms were considered. Trend in respiratory allergic disease prevalence has increased worldwide during the last 3 decades. Although recent epidemiologic studies on a possible association of this phenomenon with increasing pollution are controversial, botanic studies suggest a clear effect of several pollutants combined to climatic changes on the increased expression of allergenic proteins in several pollen grains. The current literature suggests the need for considering both pollen allergen and pollutant contents for epidemiologic evaluation of environmental determinants in respiratory allergies. We propose that a measure of allergenic potential of pollens, indicative of the increase in allergenicity of a polluted pollen, may be considered as a new risk indicator for respiratory health in urban areas. Because public greens are located in strict proximity to the anthropogenic sources of pollution, the identification of novel more reliable parameters for risk assessment in respiratory allergic diseases is an essential need for public health management and primary prevention area. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  4. Bee Pollen Flavonoids as a Therapeutic Agent in Allergic and Immunological Disorders.

    PubMed

    Jannesar, Masoomeh; Sharif Shoushtari, Maryam; Majd, Ahmad; Pourpak, Zahra

    2017-06-01

    Bee pollen grains, as the male reproductive part of seed-bearing plants contain considerable concentrations of various phytochemicals and nutrients. Since antiquity, people throughout the world used pollens to cure colds, flu, ulcers, premature aging, anemia and colitis. It is now well-documented that some bee pollen secondary metabolites (e.g. flavonoid) may have positive health effects. In recent years, the flavonoids have attracted much interest because of their wide range of biological properties and their beneficial effects on human health. The current review, points out potential therapeutic effects of bee pollen flavonoids as one of the main bee pollen bioactive compounds in allergic and immunological diseases. Due to the fact that some types of flavonoid components in bee pollen have anti-allergic, anti-oxidant and anti-inflammatory properties, bee pollen flavonoids can be excellent candidates for future studies including phytotherapy, molecular pharmacology and substitutes for chemicals used in treating allergic and immunological disorders.

  5. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo; Hialine Working Group

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different

  6. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    The HIALINE working Group; Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network).Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient.Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration.Although Bet v 1 is a mixture of different

  7. Analysis of Airborne Betula Pollen in Finland; a 31-Year Perspective

    PubMed Central

    Yli-Panula, Eija; Fekedulegn, Desta Bey; Green, Brett James; Ranta, Hanna

    2009-01-01

    In this 31-year retrospective study, we examined the influence of meteorology on airborne Betula spp. (birch) pollen concentrations in Turku, Finland. The seasonal incidence of airborne birch pollen in Turku occurred over a brief period each year during spring (April 30 – May 31). Mean peak concentrations were restricted to May (May 5 to 13). Statistically significant increases in the annual accumulated birch pollen sum and daily maximum values were observed over the study period. Birch pollen counts collected in April were retrospectively shown to increase over the duration of the study. Increases in April temperature values were also significantly associated with the earlier onset of the birch pollen season. Furthermore, the number of days where daily birch pollen concentrations exceeded 10 and 1,000 grains/m3 also increased throughout the study period. These data demonstrate that increases in temperature, especially during months preceding the onset of the birch pollen season, favor preseason phenological development and pollen dispersal. Birch pollen derived from other geographical locations may also contribute to the aerospora of Turku, Finland. To date, the public health burden associated with personal exposure to elevated birch pollen loads remains unclear and is the focus of future epidemiological research. PMID:19578456

  8. Pollen loads and allergic rhinitis in Darwin, Australia: a potential health outcome of the grass-fire cycle.

    PubMed

    Johnston, Fay H; Hanigan, Ivan C; Bowman, David M J S

    2009-03-01

    Although the prevalence of asthma and allergic rhinitis has been increasing in tropical regions, little is known about the allergenicity of pollens from tropical plant families or the importance of ongoing environmental changes. We investigated associations between daily average pollen counts of several tropical plant families and sales of medications for the treatment of allergic rhinitis in Darwin, Australia-a tropical setting in which grass abundance has increased due to increased fire frequencies and the introduction of African pasture grasses. Daily pollen counts with detailed identification of plant species were undertaken in conjunction with a weekly survey of flowering plant species from April 2004 to November 2005. Five pharmacies provided daily sales data of selected medications commonly used to treat allergic rhinitis. We used generalized linear modeling to examine outcomes. All analyses accounted for the potential confounding effects of time trends, holidays, respiratory viral illnesses, meteorological conditions, and air pollution. The peak total pollen count was 94 grains/m(3). Despite the low levels of Poaceae (grass) pollen (maximum daily count, 24 grains/m(3)), there was a clear association with daily sales of anti-allergic medications greatest at a lag of 1 day. Sales increased by 5% with an interquartile range rise (3 grain/m(3)) in Poaceae pollen (5.07%, 95%CI 1.04%, 9.25%). No associations were observed with pollen from other plant families. Although further testing is required, we suggest that an overlooked aspect of the "grass-fire cycle" that is degrading many tropical landscapes, could be an increase in the prevalence of allergic rhinitis.

  9. Visual Recognition Software for Binary Classification and its Application to Pollen Identification

    NASA Astrophysics Data System (ADS)

    Punyasena, S. W.; Tcheng, D. K.; Nayak, A.

    2014-12-01

    An underappreciated source of uncertainty in paleoecology is the uncertainty of palynological identifications. The confidence of any given identification is not regularly reported in published results, so cannot be incorporated into subsequent meta-analyses. Automated identifications systems potentially provide a means of objectively measuring the confidence of a given count or single identification, as well as a mechanism for increasing sample sizes and throughput. We developed the software ARLO (Automated Recognition with Layered Optimization) to tackle difficult visual classification problems such as pollen identification. ARLO applies pattern recognition and machine learning to the analysis of pollen images. The features that the system discovers are not the traditional features of pollen morphology. Instead, general purpose image features, such as pixel lines and grids of different dimensions, size, spacing, and resolution, are used. ARLO adapts to a given problem by searching for the most effective combination of feature representation and learning strategy. We present a two phase approach which uses our machine learning process to first segment pollen grains from the background and then classify pollen pixels and report species ratios. We conducted two separate experiments that utilized two distinct sets of algorithms and optimization procedures. The first analysis focused on reconstructing black and white spruce pollen ratios, training and testing our classification model at the slide level. This allowed us to directly compare our automated counts and expert counts to slides of known spruce ratios. Our second analysis focused on maximizing classification accuracy at the individual pollen grain level. Instead of predicting ratios of given slides, we predicted the species represented in a given image window. The resulting analysis was more scalable, as we were able to adapt the most efficient parts of the methodology from our first analysis. ARLO was able to

  10. Pollen and stomata morphometrics and polyploidy in Eriotheca (Malvaceae-Bombacoideae).

    PubMed

    Marinho, R C; Mendes-Rodrigues, C; Bonetti, A M; Oliveira, P E

    2014-03-01

    Approximately 70% of the angiosperm species are polyploid, an important phenomenon in the evolution of those plants. But ploidy estimates have often been hindered because of the small size and large number of chromosomes in many tropical groups. Since polyploidy affects cell size, morphometric analyses of pollen grains and stomata have been used to infer ploidy level. Polyploidy is present in many species of the Cerrado, the Neotropical savanna region in Central Brazil, and has been linked to apomixis in some taxa. Eriotheca gracilipes and Eriotheca pubescens are common tree species in this region, and present cytotypes that form reproductive mosaics. Hexaploid individuals (2n = 6x = 276) are polyembryonic and apomictic, while tetraploid and diploid individuals (2n = 2x = 92, 2n = 4x = 184) are sexual and monoembryonic. We tested whether morphometric analysis can be used to estimate ploidy levels in E. gracilipes and E. pubescens individuals. Pollen material from diploid and hexaploid individuals of E. gracilipes, and tetraploid and hexaploid individuals of E. pubescens, were fixed in 50% FAA, and expanded leaves were dried in silica gel. Pollen grains and stomata of at least five individuals from each population were measured. The results demonstrate that all measures were significantly different among cytotypes. Individuals with higher levels of ploidy (hexaploid) all presented measurements that were higher than those with lower levels (diploid and tetraploid). There was no overlap between ploidy levels in each species at 95% confidence interval. Thus, the size of the pollen grains and stomata are effective parameters for analysis of ploidy levels in E. gracilipes and E. pubescens. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. 222 Aerobiological and Immunological Studies on Coconut Pollen Allergy

    PubMed Central

    Saha, Bodhisattwa; Bhattacharya, Swati Gupta

    2012-01-01

    Background Pollen grains constitute a significant portion of the aerobiological flora. The plant Coccos nucifera (commonly known as coconut) is found in huge quantities in the tropical coastal areas of the world and is very common in Kolkata, India. A 2 years aerobiological survey was carried out using Burkard Volumetric Sampler to know the seasonal variation of Cocos nucifera pollen. The plant flower through out the year but maximum concentration was found in the month of August. Allergenicity of Cocos nucifera pollen has been reported from the Skin Prick Test, Lung function test, ELISA from a 400 susceptible patients in and around West Bengal in India. An immunobiological study was conducted to identify major allergens from Coccos nucifera pollen causing hay fever, skin allergy and allergic asthma in Kolkata population. Methods Proteins from pollen grains were obtained by initially defatting and then extracted with sodium phosphate buffer with 10 mM PMSF. Total protein was divided into 4 fractions by ammonium sulfate at 25%, 50 %, 75% and 100% respectively. SDS PAGE was done with the 25% fraction (result obtained from dot blotting) and subsequently western blotting was performed. Two dimensional gel electrophoresis and immunoblotting was also done from the crude protein. Results The total protein was separated on a SDS PAGE gel showed 21 prominent bands by Coomassie Blue staining. Dot -blotting the different fractions from ammonium sulfate cut, showed a positive result in the 25% fraction. Western blot with patient specific sera gave 3 bands out of which a major band was obtained at 60Kd. This result was obtained in more than 65% of the patients from whom Sera was isolated. 2D gel electrophoresis of the crude protein sample was performed which showed 120 protein spots in the PI range of 3 to 10 and molecular weight 14Kd to 97Kd. Immunoblotting the 2D gel with pooled patient specific sera showed 20 spots thus implying IgE reactivity. Conclusions It can thus be

  12. Cytochrome P450 Family Member CYP704B2 Catalyzes the ω -Hydroxylation of Fatty Acids and Is Required for Anther Cutin Biosynthesis and Pollen Exine Formation in Rice[W][OA

    PubMed Central

    Li, Hui; Pinot, Franck; Sauveplane, Vincent; Werck-Reichhart, Danièle; Diehl, Patrik; Schreiber, Lukas; Franke, Rochus; Zhang, Ping; Chen, Liang; Gao, Yawei; Liang, Wanqi; Zhang, Dabing

    2010-01-01

    The anther cuticle and microspore exine act as protective barriers for the male gametophyte and pollen grain, but relatively little is known about the mechanisms underlying the biosynthesis of the monomers of which they are composed. We report here the isolation and characterization of a rice (Oryza sativa) male sterile mutant, cyp704B2, which exhibits a swollen sporophytic tapetal layer, aborted pollen grains without detectable exine, and undeveloped anther cuticle. In addition, chemical composition analysis indicated that cutin monomers were hardly detectable in the cyp704B2 anthers. These defects are caused by a mutation in a cytochrome P450 family gene, CYP704B2. The CYP704B2 transcript is specifically detected in the tapetum and the microspore from stage 8 of anther development to stage 10. Heterologous expression of CYP704B2 in yeast demonstrated that CYP704B2 catalyzes the production of ω -hydroxylated fatty acids with 16 and 18 carbon chains. Our results provide insights into the biosynthesis of the two biopolymers sporopollenin and cutin. Specifically, our study indicates that the ω -hydroxylation pathway of fatty acids relying on this ancient CYP704B family, conserved from moss to angiosperms, is essential for the formation of both cuticle and exine during plant male reproductive and spore development. PMID:20086189

  13. BcMF8, a putative arabinogalactan protein-encoding gene, contributes to pollen wall development, aperture formation and pollen tube growth in Brassica campestris

    PubMed Central

    Lin, Sue; Dong, Heng; Zhang, Fang; Qiu, Lin; Wang, Fangzhan; Cao, Jiashu; Huang, Li

    2014-01-01

    Background and Aims The arabinogalactan protein (AGP) gene family is involved in plant reproduction. However, little is known about the function of individual AGP genes in pollen development and pollen tube growth. In this study, Brassica campestris male fertility 8 (BcMF8), a putative AGP-encoding gene previously found to be pollen specific in Chinese cabbage (B. campestris ssp. chinensis), was investigated. Methods Real-time reverse transcription–PCR and in situ hybridization were used to analyse the expression pattern of BcMF8 in pistils. Prokaryotic expression and western blots were used to ensure that BcMF8 could encode a protein. Antisense RNA technology was applied to silence gene expression, and morphological and cytological approaches (e.g. scanning electron microscopy and transmission electron microscopy) were used to reveal abnormal phenotypes caused by gene silencing. Key Results The BcMF8 gene encoded a putative AGP protein that was located in the cell wall, and was expressed in pollen grains and pollen tubes. The functional interruption of BcMF8 by antisense RNA technology resulted in slipper-shaped and bilaterally sunken pollen with abnormal intine development and aperture formation. The inhibition of BcMF8 led to a decrease in the percentage of in vitro pollen germination. In pollen that did germinate, the pollen tubes were unstable, abnormally shaped and burst more frequently relative to controls, which corresponded to an in vivo arrest of pollen germination at the stigma surface and retarded pollen tube growth in the stylar transmitting tissues. Conclusions The phenotypic defects of antisense BcMF8 RNA lines (bcmf8) suggest a crucial function of BcMF8 in modulating the physical nature of the pollen wall and in helping in maintaining the integrity of the pollen tube wall matrix. PMID:24489019

  14. Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

    PubMed Central

    Kim, Joo-Hwa; Lee, Ha-Baik; Kim, Seong-Won; Kang, Im-Joo; Kook, Myung-Hee; Kim, Bong-Seong; Park, Kang-Seo; Baek, Hey-Sung; Kim, Kyu-Rang; Choi, Young-Jean

    2012-01-01

    The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop. PMID:22468096

  15. Changes in sensitization rate to weed allergens in children with increased weeds pollen counts in Seoul metropolitan area.

    PubMed

    Kim, Joo-Hwa; Oh, Jae-Won; Lee, Ha-Baik; Kim, Seong-Won; Kang, Im-Joo; Kook, Myung-Hee; Kim, Bong-Seong; Park, Kang-Seo; Baek, Hey-Sung; Kim, Kyu-Rang; Choi, Young-Jean

    2012-04-01

    The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m(3)/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m(3)/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.

  16. Determination of allergenic load and pollen count of Cupressus arizonica pollen by flow cytometry using Cup a1 polyclonal antibody.

    PubMed

    Benítez, Francisco Moreno; Camacho, Antonio Letrán; Del Cuvillo Bernal, Alfonso; de Medina, Pedro Lobatón Sánchez; Cózar, Francisco J García; Romeu, Ma Luisa Espinazo

    2013-07-10

    Background: There is an increase in the incidence of pollen related allergy, thus information on pollen schedules would be a great asset for physicians to improve the clinical care of patients. Like cypress pollen sensitization shows a high prevalence among the causes of allergic rhinitis, and therefore it is of interest to use it like a model of study, distinguishing cypress pollen, pollen count and allergenic load level. In this work, we use a flow cytometry based technique to obtain both Cupressus arizonica pollen count and allergenic load, using specific rabbit polyclonal antibody Cup a1 and its comparison with optical microscopy technique measurement. Methods: Airborne samples were collected from Burkard Spore-Trap and Burkard Cyclone Cupressus arizonica pollen was studied using specific rabbit polyclonal antibody Cup a1, labelled with AlexaFluor ® 488 or 750 and analysed by Flow Cytometry in both an EPICS XL and Cyan ADP cytometers (Beckman Coulter ® ). Optical microscopy study was realized with a Leica optical microscope. Bland & Altman was used to determine agreement between both techniques measured. Results: We can identify three different populations based on rabbit polyclonal antibody Cup a1 staining. The main region (44.5%) had 97.3% recognition, a second region (25%) with 28% and a third region (30.5%) with 68% respectively. Immunofluorescence and confocal microscopy showed that main region corresponds to whole pollen grains, the second region are pollen without exine and the third region is constituted by smaller particles with allergenic properties. Pollen schedule shows a higher correlation measured by optical microscopy and flow cytometry in the pollen count with a p-value: 0.0008E -2 and 0.0002 with regard to smaller particles, so the Bland & Altman measurement showed a good correlation between them, p-value: 0,0003. Conclusion: Determination of pollen count and allergenic load by flow cytometry represents an important tool in the determination

  17. Determination of allergenic load and pollen count of Cupressus arizonica pollen by flow cytometry using Cup a1 polyclonal antibody.

    PubMed

    Benítez, Francisco Moreno; Camacho, Antonio Letrán; del Cuvillo Bernal, Alfonso; de Medina, Pedro Lobatón Sánchez; García Cózar, Francisco J; Romeu, Marisa Espinazo

    2014-01-01

    There is an increase in the incidence of pollen related allergy, thus information on pollen schedules would be a great asset for physicians to improve the clinical care of patients. Like cypress pollen sensitization shows a high prevalence among the causes of allergic rhinitis, and therefore it is of interest to use it like a model of study, distinguishing cypress pollen, pollen count, and allergenic load level. In this work, we use a flow cytometry based technique to obtain both Cupressus arizonica pollen count and allergenic load, using specific rabbit polyclonal antibody Cup a1 and its comparison with optical microscopy technique measurement. Airborne samples were collected from Burkard Spore-Trap and Burkard Cyclone Cupressus arizonica pollen was studied using specific rabbit polyclonal antibody Cup a1, labeled with AlexaFluor(®) 488 or 750 and analysed by Flow Cytometry in both an EPICS XL and Cyan ADP cytometers (Beckman Coulter(®) ). Optical microscopy study was realized with a Leica optical microscope. Bland and Altman was used to determine agreement between both techniques measured. We can identify three different populations based on rabbit polyclonal antibody Cup a1 staining. The main region (44.5%) had 97.3% recognition, a second region (25%) with 28% and a third region (30.5%) with 68% respectively. Immunofluorescence and confocal microscopy showed that main region corresponds to whole pollen grains, the second region are pollen without exine and the third region is constituted by smaller particles with allergenic properties. Pollen schedule shows a higher correlation measured by optical microscopy and flow cytometry in the pollen count with a P-value: 0.0008 E(-2) and 0.0002 with regard to smaller particles, so the Bland and Altman measurement showed a good correlation between them, P-value: 0.0003. Determination of pollen count and allergenic load by flow cytometry represents an important tool in the determination of airborne respiratory allergens

  18. Dynamics of storage reserve deposition during Brassica rapa L. pollen and seed development in microgravity

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Popova, A.; McClure, G.; Musgrave, M. E.

    2005-01-01

    Pollen and seeds share a developmental sequence characterized by intense metabolic activity during reserve deposition before drying to a cryptobiotic form. Neither pollen nor seed development has been well studied in the absence of gravity, despite the importance of these structures in supporting future long-duration manned habitation away from Earth. Using immature seeds (3-15 d postpollination) of Brassica rapa L. cv. Astroplants produced on the STS-87 flight of the space shuttle Columbia, we compared the progress of storage reserve deposition in cotyledon cells during early stages of seed development. Brassica pollen development was studied in flowers produced on plants grown entirely in microgravity on the Mir space station and fixed while on orbit. Cytochemical localization of storage reserves showed differences in starch accumulation between spaceflight and ground control plants in interior layers of the developing seed coat as early as 9 d after pollination. At this age, the embryo is in the cotyledon elongation stage, and there are numerous starch grains in the cotyledon cells in both flight and ground control seeds. In the spaceflight seeds, starch was retained after this stage, while starch grains decreased in size in the ground control seeds. Large and well-developed protein bodies were observed in cotyledon cells of ground control seeds at 15 d postpollination, but their development was delayed in the seeds produced during spaceflight. Like the developing cotyledonary tissues, cells of the anther wall and filaments from the spaceflight plants contained numerous large starch grains, while these were rarely seen in the ground controls. The tapetum remained swollen and persisted to a later developmental stage in the spaceflight plants than in the ground controls, even though most pollen grains appeared normal. These developmental markers indicate that Brassica seeds and pollen produced in microgravity were physiologically younger than those produced in 1 g

  19. Cloning and characterisation of a putative pollen-specific polygalacturonase gene (CpPG1) differentially regulated during pollen development in zucchini (Cucurbita pepo L.).

    PubMed

    Carvajal, F; Garrido, D; Jamilena, M; Rosales, R

    2014-03-01

    Studies in zucchini (Cucurbita pepo L. spp. pepo) pollen have been limited to the viability and morphology of the mature pollen grain. The enzyme polygalacturonase (PG) is involved in pollen development and pollination in many species. In this work, we study anther and pollen development of C. pepo and present the cloning and characterisation of a putative PG CpPG1 (Accession no. HQ232488) from pollen cDNA in C. pepo. The predicted protein for CpPG1 has 416 amino acids, with a high homology to other pollen PGs, such as P22 from Oenothera organensis (76%) and PGA3 from Arabidopsis thaliana (73%). CpPG1 belongs to clade C, which comprises PGs expressed in pollen, and presents a 34 amino acid signal peptide for secretion towards the cell wall. DNA-blot analysis revealed that there are at least another two genes that code for PGs in C. pepo. The spatial and temporal accumulation of CpPG1 was studied by semi-quantitative- and qRT-PCR. In addition, mRNA was detected only in anthers, pollen and the rudimentary anthers of bisexual flowers (only present in some zucchini cultivars under certain environmental conditions that trigger anther development in the third whorl of female flowers). However, no expression was detected in cotyledons, stem or fruit. Furthermore, CpPG1 mRNA was accumulated throughout anther development, with the highest expression found in mature pollen. Similarly, exo-PG activity increased from immature anther stages to mature anthers and mature pollen. Overall, these data support the pollen specificity of this gene and suggest an involvement of CpPG1 in pollen development in C. pepo. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Implementation of pre-seasonal sublingual immunotherapy with a five-grass pollen tablet during optimal dosage assessment.

    PubMed

    Horak, F; Jaeger, S; Worm, M; Melac, M; Didier, A

    2009-03-01

    The optimal dose (300IR) of a five-grass pollen sublingual immunotherapy tablet in terms of efficacy was previously demonstrated from the first pollen season. Here, we aim to confirm whether this dose remained optimal during the peak of the pollen season by assessing the efficacy and quality of life data. A total of 628 subjects with grass pollen rhinoconjunctivitis were randomized in a double-blind, placebo-controlled, multi-centre, pan-European trial. Subjects received once-daily tablets (Stallergenes, Antony, France) of 100IR, 300IR, 500IR or placebo, starting 4 months before and throughout the 2005 grass pollen season. The pollen season was defined as the first day of 3 consecutive days with a grass pollen count above 30 grains/m(3) of air, recorded using Hirst-type volumetric pollen traps, to the last day before 3 consecutive days with a pollen count below 30 grains/m(3). The grass pollen season lasted an average of 30 days, with a peak of 12 days. The mean treatment duration before the grass pollen season was similar in the four treatment groups (121.4+/-31.1 to 128.6+/-15.4 days in the safety population). Both the 300IR and 500IR groups had highly significant improvements in Rhinoconjunctivitis Total Symptom Score (RTSS) vs. placebo at the peak pollen season (P=0.0005 and 0.0014, respectively), which agreed with improvements in RTSS in the primary evaluations. The average RTSS scores were slightly elevated during the peak pollen season in all treatment groups. The overall Rhinoconjunctivitis Quality of Life Questionnaire score confirmed the optimal dosage 300IR at peak (P<0.0001) and at the end (P< or =0.0031) of the pollen season. All doses were well tolerated. At the peak pollen season, the efficacy and quality of life data for both 300IR and 500IR groups was significantly improved vs. the placebo group. These results confirm the conclusions of the primary evaluations and validate the use of 300IR tablets for clinical practice.

  1. Room-temperature fabrication of core-shell nano-ZnO/pollen grain biocomposite for adsorptive removal of organic dye from water

    NASA Astrophysics Data System (ADS)

    Tzvetkov, George; Kaneva, Nina; Spassov, Tony

    2017-04-01

    A new core-shell nano-ZnO/pollen grain (n-ZnO/PG) biocomposite has been successfully synthesized via simple and low-temperature two-step liquid precipitation method. The synthetic strategy consists of grafting the surface of pine pollen grains (PG) with Zn2+-organic complexes followed by a treatment in Zn(CH3COO)2/NaOH solution, thus producing a closed n-ZnO shell around the organic core, with a thickness of ∼450 nm. Scanning electron microscopy, X-ray diffraction, FTIR, XPS and UV-vis spectroscopy measurements along with N2 adsorption/desorption were used to characterize the resulting n-ZnO/PG biocomposite. The as-prepared core-shell microparticles are meso-/macro-porous with BET surface area of 25 m2 g-1 and total pore volume of 0.26 cm3 g-1. The adsorption properties of n-ZnO/PG were evaluated through adsorption of Malachite Green (MG) from aqueous medium at room temperature (25 °C). For the sake of comparison, the physico-chemical and adsorptive properties of the raw PG and pure n-ZnO were also examined. Results indicate that n-ZnO/PG is the most favorable for the adsorption of MG under the conditions used in this study. The adsorption kinetic data for PG, n-ZnO and n-ZnO/PG follow the pseudo-second order equation and the maximum adsorption capacity follows an order of n-ZnO/PG > n-ZnO > PG. For n-ZnO/PG an adsorption uptake up to 145.9 mg g-1 is observed. The as-prepared core-shell biocomposite material is a promising cost-effective and environmentally friendly adsorbent due to its textural properties, surface chemistry, adsorption capacity and recyclability.

  2. Molecular identification of tuliposide B-converting enzyme: a lactone-forming carboxylesterase from the pollen of tulip.

    PubMed

    Nomura, Taiji; Murase, Tatsunori; Ogita, Shinjiro; Kato, Yasuo

    2015-07-01

    6-Tuliposides A (PosA) and B (PosB), which are the major secondary metabolites in tulip (Tulipa gesneriana), are enzymatically converted to the antimicrobial lactonized aglycons, tulipalins A (PaA) and B (PaB), respectively. We recently identified a PosA-converting enzyme (TCEA) as the first reported member of the lactone-forming carboxylesterases. Herein, we describe the identification of another lactone-forming carboxylesterase, PosB-converting enzyme (TCEB), which preferentially reacts with PosB to give PaB. This enzyme was isolated from tulip pollen, which showed high PosB-converting activity. Purified TCEB exhibited greater activity towards PosB than PosA, which was contrary to that of the TCEA. Novel cDNA (TgTCEB1) encoding the TCEB was isolated from tulip pollen. TgTCEB1 belonged to the carboxylesterase family and was approximately 50% identical to the TgTCEA polypeptides. Functional characterization of the recombinant enzyme verified that TgTCEB1 catalyzed the conversion of PosB to PaB with an activity comparable with the native TCEB. RT-qPCR analysis of each part of plant revealed that TgTCEB1 transcripts were limited almost exclusively to the pollen. Furthermore, the immunostaining of the anther cross-section using anti-TgTCEB1 polyclonal antibody verified that TgTCEB1 was specifically expressed in the pollen grains, but not in the anther cells. N-terminal transit peptide of TgTCEB1 was shown to function as plastid-targeted signal. Taken together, these results indicate that mature TgTCEB1 is specifically localized in plastids of pollen grains. Interestingly, PosB, the substrate of TgTCEB1, accumulated on the pollen surface, but not in the intracellular spaces of pollen grains. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  3. Seasonal variation of birch and grass pollen loads and allergen release at two sites in the German Alps

    NASA Astrophysics Data System (ADS)

    Jochner, Susanne; Lüpke, Marvin; Laube, Julia; Weichenmeier, Ingrid; Pusch, Gudrun; Traidl-Hoffmann, Claudia; Schmidt-Weber, Carsten; Buters, Jeroen T. M.; Menzel, Annette

    2015-12-01

    Less vegetated mountainous areas may provide better conditions for allergy sufferers. However, atmospheric transport can result in medically relevant pollen loads in such regions. The majority of investigations has focused on the pollen load, expressed as daily averages of pollen per cubic meter of air (pollen grains/m³); however, the severity of allergic symptoms is also determined by the actual allergen content of this pollen, its pollen potency, which may differ between high and low altitudes. We analysed airborne birch and grass pollen concentrations along with allergen content (birch: Bet v 1, grass: Phl p 5) at two different altitudes (734 and 2650 m a.s.l.) in the Zugspitze region (2009-2010). Back-trajectories were calculated for the high altitude site and for specific days with abrupt increases in pollen potency. We observed several days with medically relevant pollen concentrations at the highest site. In addition, a few days with pollen were not associated with allergens and vice versa. The calculated seasonal mean allergen release per pollen grain was 1.8-3.3 pg Bet v 1 and 5.7 pg Phl p 5 in the valley and 1.1-3.7 pg Bet v 1 and 0.7-1.5 pg Phl p 5 at the high altitude site. Back-trajectories revealed that high pollen potency at the higher site was generally associated with south-westerly to south-easterly (birch), or northerly (grass) wind directions. By investigating days with sudden increases in pollen potency, however, it was difficult to draw definitive conclusions on long- or short-range transport. Our findings suggest that people allergic to pollen might suffer less at higher altitudes and further indicate that a risk assessment relying on the actual concentration of airborne pollen does not necessarily reflect the actual allergy exposure of individuals.

  4. RNA Silencing of Exocyst Genes in the Stigma Impairs the Acceptance of Compatible Pollen in Arabidopsis1[OPEN

    PubMed Central

    Safavian, Darya; Indriolo, Emily; Chapman, Laura; Ahmed, Abdalla

    2015-01-01

    Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNA-silencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance. PMID:26443677

  5. Honey bee hairs and pollenkitt are essential for pollen capture and removal.

    PubMed

    Amador, Guillermo J; Matherne, Marguerite; Waller, D'Andre; Mathews, Megha; Gorb, Stanislav N; Hu, David L

    2017-03-23

    While insect grooming has been observed and documented for over one hundred years, we present the first quantitative analysis of this highly dynamic process. Pollinating insects, like honey bees, purposely cover themselves with millions of pollen particles that, if left ungroomed, would make sensing and controlled flight difficult. How do they get clean? We show that the hairs on insect eyes are tuned to the pollen they collect; namely, the hairs are spaced so that they suspend pollen above the body for easy removal by the forelegs. In turn, hair spacing on the foreleg dictates the leg's ability to store the pollen removed during each swipe. In tests with wax-covered honey bees, we show that hairy forelegs are necessary for pollen removal. Moreover, the viscous fluid found on the surface of pollen grains, or pollenkitt, greatly enhances adhesion. We find that bees accumulate twice as much pollen if pollenkitt is present. This study may help further understand pollination, as well as inform designs for mechanically-sensitive functional surfaces with micro- and nano-structures that are easier to keep clean.

  6. Pollen and ovule development in Arabidopsis thaliana under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Musgrave, M. E.; Matthews, S. W.; Cummins, D. B.; Tucker, S. C.

    1995-01-01

    The development of pollen and ovules in Arabidopsis thaliana on the space shuttle 'Endeavour' (STS-54) was investigated. Plants were grown on nutrient agar for 14 days prior to loading into closed plant growth chambers that received light and temperature control inside the Plant Growth Unit flight hardware on the shuttle middeck. After 6 days in spaceflight the plants were retrieved and immediately dissected and processed for light and electron microscope observation. Reproductive development aborted at an early stage. Pistils were collapsed and ovules inside were seen to he empty. No viable pollen was observed from STS-54 plants; young microspores were deformed and empty. At a late stage, the cytoplasm of the pollen contracted and became disorganized, but the pollen wall developed and the exine appeared normal. The tapetum in the flight flowers degenerated at early stages. Ovules from STS-54 flight plants stopped growing and the integuments and nucellus collapsed and degenerated. The megasporocytes appeared abnormal and rarely underwent meiosis. Apparently they enlarged, or occasionally produced a dyad or tetrad, to assume the form of a female gametophyte with the single nucleus located in an egglike cell that lacks a cell wall. Synergids, polar nuclei, and antipodals were not observed. The results demonstrate the types of lesions occurring in plant reproductive material under spaceflight conditions.

  7. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen

    PubMed Central

    Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-01-01

    Pollen–stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen–stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen–stigma interactions during pollination. PMID:27472382

  8. Dynamics of sulfate and nitrate dry deposition associated with pollen

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khalili, E.K.

    A field study of pollen dispersion and deposition from a remote forested area in Northern Wisconsin has been undertaken. Although the experiments constitute a case study in Wisconsin, the experimental site was chosen, which represents much of the Eastern US and Europe where acid rain is considered an important environmental problem. Measurements of dry deposition of pollen were made during the pollination season (May and June, 1987). Deposited particles were weighted to determine mass fluxes, then washed and subjected to ion chromatographic analysis for sulfate and nitrate. Ambient concentration of pollen were measured by a coarse particle sampler (Noll Inertialmore » Rotary Impact) during the same time period. The chemical analysis of pollen species collected around the sampling site as well as commercially available pollen demonstrated that sulfate and nitrate were present on all pollen samples. Many trace metals such as Fe, Al, Zn, Cu, Mn, Cd, Pb, Ca, and Si and organic acids were quantified. It was hypothesized that pollen accumulate extraneous amounts of non-essential, as well as essential elements from the soil supplying nutrient. Therefore, pollen can be used as a fingerprint for the availability and the level of contamination of a particular element in the forest soil environment. A model developed for measurement of coarse particle dry deposition was utilized to measure the pollen dry deposition velocity. It was shown that depositional velocity of pollen exceeds the settling velocity by a factor of 3 to 4, and both V{sub d} and fluxes of pollen grains increase with wind speed. Finally, the role of pollen dispersion and deposition has been discussed and emphasized for modeling of lake acidification in forested region.« less

  9. Pollen analysis of honey and pollen collected by Apis mellifera linnaeus, 1758 (Hymenoptera, Apidae), in a mixed environment of Eucalyptus plantation and native cerrado in Southeastern Brazil.

    PubMed

    Simeão, C M G; Silveira, F A; Sampaio, I B M; Bastos, E M A F

    2015-11-01

    Eucalyptus plantations are frequently used for the establishment of bee yards. This study was carried on at Fazenda Brejão, northwestern region of the State of Minas Gerais, Brazil. This farm is covered both with native Cerrado vegetation (Brazilian savanna) and eucalyptus plantations. This paper reports on the botanic origin of pollen pellets and honey collected from honeybee (Apis mellifera) hives along a thirteen-month period (January 2004 to January 2005). The most frequent pollen types found in the pollen pellets during the rainy season were Trema micrantha (Ulmaceae), Copaifera langsdorffii (Fabaceae), an unidentified Poaceae, unidentified Asteraceae-2, Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae); during the dry season the most frequent pollen types were Acosmium dasycarpum (Fabaceae), Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae). Pollen grains of Baccharis sp. (Asteraceae), Cecropia sp. 1 (Cecropiaceae), Copaifera langsdorffii (Fabaceae), Mimosa nuda (Fabaceae), Eucalyptus spp. (Myrtaceae) and Trema micrantha (Ulmaceae) were present in the honey samples throughout the study period.

  10. Pollen Forecast and Dispersion Modelling

    NASA Astrophysics Data System (ADS)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  11. Genomic Conflicts that Cause Pollen Mortality and Raise Reproductive Barriers in Arabidopsis thaliana

    PubMed Central

    Simon, Matthieu; Durand, Stéphanie; Pluta, Natacha; Gobron, Nicolas; Botran, Lucy; Ricou, Anthony; Camilleri, Christine; Budar, Françoise

    2016-01-01

    Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in the offspring of two distant natural strains of Arabidopsis thaliana, Shahdara and Mr-0, with Shahdara as the female parent. Using both classical and quantitative genetic approaches as well as cytological observation of pollen viability, we demonstrate that this particular hybrid sterility results from two causes of pollen mortality. First, the Shahdara cytoplasm induces gametophytic cytoplasmic male sterility (CMS) controlled by several nuclear loci. Second, several segregation distorters leading to allele-specific pollen abortion (pollen killers) operate in hybrids with either cytoplasm. The complete sterility of the hybrid with the Shahdara cytoplasm results from the genetic linkage of the two causes of pollen mortality, i.e., CMS nuclear determinants and pollen killers. Furthermore, natural variation at these loci in A. thaliana is associated with different male-sterility phenotypes in intraspecific hybrids. Our results suggest that the genomic conflicts that underlie segregation distorters and CMS can concurrently lead to reproductive barriers between distant strains within a species. This study provides a new framework for identifying molecular mechanisms and the evolutionary history of loci that contribute to reproductive isolation, and possibly to speciation. It also suggests that two types of genomic conflicts, CMS and segregation distorters, may coevolve in natural populations. PMID:27182945

  12. Airborne pollen and spores of León (Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-González, Delia; Suarez-Cervera, María; Díaz-González, Tomás; Valencia-Barrera, Rosa María

    1993-06-01

    A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter, Pinus and Quercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores ( Penicillium, Aspergillus and Cladosporium) as well as Dictyospores ( Alternaria) were the most abundant; Puccinia was common in the air in August. Fluctuations in the total pollen and spores m3 of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.

  13. Pollen Morphology of Caesalpinia pulcherrima (L.) Swartz in Highland and Lowland West Sumatra

    NASA Astrophysics Data System (ADS)

    Fitri, R.; Des, M.

    2018-04-01

    Determine the morphology structure of pollen on some variation colour of corolla Caesalpinia pulcherrima L. (Swartz) in highland and lowland West Sumatra has been conducted. The result reveals that topography and variation colour of corolla C. pulcherrima L. (Swartz) affects the shape of pollen. Pollen of C. pulcherrima L. (Swartz) has single grains or monad, isopolar polarity, radial symmetry, and size categories large. The length of polar axis (P) 58.16 to 74.11 μm, the length of the equatorial diameter (E) 59.86 to 75.97 μm, so that pollen can be classified into sub-spheroidal sub-oblate, spheriodal sub-spheroidal oblate, and sub-spheroidal prolate. Ornamentation of C. pulcherrima (L.) Swartz was reticulate. The pollen has aperture 3, the type pore and located in equatorial. From these data can be concluded that pollen from varying colour of corolla C. pulcherrima (L.) Swartz has same in terms of unit, polarity, symmetry, size, and type aperture, but it different in terms of shape.

  14. Impacts of air pollution exposure on the allergenic properties of Arizona cypress pollens

    NASA Astrophysics Data System (ADS)

    Shahali, Y.; Pourpak, Z.; Moin, M.; Zare, A.; Majd, A.

    2009-02-01

    Epidemiological studies have demonstrated that urbanization and high levels of vehicle emissions correlated with the increasing trend of pollen-induced respiratory allergies. Numerous works have investigated the role of pollutants in the pathogenesis of respiratory diseases but impacts of anthropogenic pollution on pollen allergenic properties are still poorly understood. The objective of this survey was to evaluate impacts of the traffic-related pollution on the structure and allergenic protein content of Arizona cypress (Cupressus arizonica, CA) pollens, recognized as a rising cause of seasonal allergy in various regions worldwide. According to our results, traffic-related air pollution by its direct effects on the elemental composition of pollens considerably increased the fragility of the pollen exine, causing numerous cracks in its surface and facilitating pollen content liberation. Pollen grains were also covered by numerous submicronic orbicules which may act as effective vectors for pollen-released components into the lower regions of respiratory organs. On the other hand, this study provides us reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the Arizona cypress pollen allergy in Tehran. Although traffic related pollution affects the allergenic components of CA pollens, the repercussions on the respiratory health of urban populations have yet to be clarified and need further investigations.

  15. Platanus pollen allergen, Pla a 1: quantification in the atmosphere and influence on a sensitizing population.

    PubMed

    Fernández-González, D; González-Parrado, Z; Vega-Maray, A M; Valencia-Barrera, R M; Camazón-Izquierdo, B; De Nuntiis, P; Mandrioli, P

    2010-11-01

    The allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. The prevalence of allergy to Platanus is currently moderate, although the percentage of monosensitized patients is low. This hinders accurate interpretation of the relationship between the amount of pollen inhaled and the patient's symptoms. This study aims to investigate the relationship between the atmospheric concentration pattern of Pla a 1 aeroallergen and the Platanus pollen. The pollen sampling was carried out using a Hirst-type volumetric trap (Burkard(©) ) for pollen grains and a Burkard Cyclone sampler (Burkard(©) ) for Pla a 1 allergen. Serum-specific IgE levels to Acer sp., Artemisia vulgaris, Betula alba, Chenopodium album, Cupressus arizonica, Cynodon dactylon, Fraxinus excelsior, Lolium perenne, Pinus sp., Plantago lanceolata, Platanus acerifolia, Populus sp., Quercus ilex and Taraxacum officinale allergens were determined using the EAST System (Hytec specific IgE EIA kit; Hycor Biomedical, Kassel, Germany). The aerobiological dynamics of Platanus pollen grains and Pla a 1 differed considerably, particularly during the Platanus pollination period. Of the 118 subjects tested, sera from 34 contained specific IgE to Platanus pollen and all of them had specific IgE to other pollen types. The presence of the aeroallergen Pla a 1 in the atmosphere appears to be independent of Platanus pollen counts over the same period, which may be contributing to allergic symptoms and sensitization. The number of polysensitized patients displaying allergy to Platanus suggested that allergic symptoms were caused by co-sensitization or cross-reactivity involving a number of allergenic particles. © 2010 Blackwell Publishing Ltd.

  16. Functional role of long-lived flowers in preventing pollen limitation in a high elevation outcrossing species

    PubMed Central

    Pacheco, Diego Andrés; Dudley, Leah S

    2017-01-01

    Abstract Low pollinator visitation in harsh environments may lead to pollen limitation which can threaten population persistence. Consequently, avoidance of pollen limitation is expected in outcrossing species subjected to habitually low pollinator service. The elevational decline in visitation rates on many high mountains provides an outstanding opportunity for addressing this question. According to a recent meta-analysis, levels of pollen limitation in alpine and lowland species do not differ. If parallel trends are manifested among populations of alpine species with wide elevational ranges, how do their uppermost populations contend with lower visitation? We investigated visitation rates and pollen limitation in high Andean Rhodolirium montanum. We test the hypothesis that lower visitation rates at high elevations are compensated for by the possession of long-lived flowers. Visitation rates decreased markedly over elevation as temperature decreased. Pollen limitation was absent at the low elevation site but did occur at the high elevation site. While initiation of stigmatic pollen deposition at high elevations was not delayed, rates of pollen arrival were lower, and cessation of pollination, as reflected by realized flower longevity, occurred later in the flower lifespan. Comparison of the elevational visitation decline and levels of pollen limitation indicates that flower longevity partially compensates for the lower visitation rates at high elevation. The functional role of flower longevity, however, was strongly masked by qualitative pollen limitation arising from higher abortion levels attributable to transference of genetically low-quality pollen in large clones. Stronger clonal growth at high elevations could counterbalance the negative fitness consequences of residual pollen limitation due to low visitation rates and/or difficult establishment under colder conditions. Visitation rates on the lower part of the elevational range greatly exceeded community

  17. Effects of simulated acid rain on pollen physiology and ultrastructure in the apple.

    PubMed

    Bellani, L M; Rinallo, C; Muccifora, S; Gori, P

    1997-01-01

    Viability, germination and tube length were investigated in pollen grains of field-grown 'Summerred' apple trees (Malus domestica Borkh) exposed to deionized water, rainfall or simulated acid rain at pH 5.6, 4.0 and 3.0. Pollen viability and germination significantly decreased with lower values of pH and with increasing number of treatments. The effects of pH 5.6 and natural rainfall were not significant. Electron microscope investigation of vegetative pollen cells of plants exposed to acid rain at pH 4.0 and 3.0 showed modified features in mitochondria, plastids and endoplasmic reticulum.

  18. New insights into the early steps of oil body mobilization during pollen germination

    PubMed Central

    Castro, Antonio Jesús

    2013-01-01

    In some plants, pollen grains accumulate storage lipids that serve as energy supply during germination. Here, three enzymes involved in early steps of oil body mobilization in the male gametophyte were functionally characterized for the first time. The effect of extracellular sugars on pollen performance and oil body dynamics was also analysed. Olive pollen oil bodies showed phospholipase A, lipase, and lipoxygenase activities on their surface. Enzyme activity levels increased during germination with a maximum after 3h. Removal of extracellular sugars from the germination medium did not affect pollen performance but increased enzyme activity rates and sped up oil body mobilization. Inhibitors seriously hampered pollen germination and pollen tube growth, leading to a characteristic accumulation of oil bodies in the germinative aperture. It can be concluded that storage lipids are sufficient for proper olive pollen germination. A lipase and a lipoxygenase are likely involved in oil body mobilization. Extracellular sugars may modulate their function, while a phospholipase A may promote their access to the storage lipids. PMID:23132905

  19. Atmospheric solids analysis probe mass spectrometry for the rapid identification of pollens and semi-quantification of flavonoid fingerprints

    DOE PAGES

    Xiao, Xiaoyin; Miller, Lance L.; Parchert, Kylea J.; ...

    2016-06-08

    From allergies to plant reproduction, pollens have important impacts on the health of human and plant populations, yet identification of pollen grains remains difficult and time-consuming. Low-volatility flavonoids generated from pollens cannot be easily characterized and quantified with current analytical techniques. Here we demonstrate the novel use of atmospheric solids analysis probe mass spectrometry (ASAP-MS) for the characterization of flavonoids in pollens. Flavonoid patterns were generated for pollens collected from different plant types (trees and bushes) in addition to bee pollens from distinct geographic regions. Standard flavonoids (kaempferol and rhamnazin) and those produced from pollens were compared and assessed withmore » ASAP-MS using low-energy collision MS/MS. Results for a semi-quantitative method for assessing the amount of a flavonoid in pollens are also presented.« less

  20. Atmospheric solids analysis probe mass spectrometry for the rapid identification of pollens and semi-quantification of flavonoid fingerprints

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xiao, Xiaoyin; Miller, Lance L.; Parchert, Kylea J.

    From allergies to plant reproduction, pollens have important impacts on the health of human and plant populations, yet identification of pollen grains remains difficult and time-consuming. Low-volatility flavonoids generated from pollens cannot be easily characterized and quantified with current analytical techniques. Here we demonstrate the novel use of atmospheric solids analysis probe mass spectrometry (ASAP-MS) for the characterization of flavonoids in pollens. Flavonoid patterns were generated for pollens collected from different plant types (trees and bushes) in addition to bee pollens from distinct geographic regions. Standard flavonoids (kaempferol and rhamnazin) and those produced from pollens were compared and assessed withmore » ASAP-MS using low-energy collision MS/MS. Results for a semi-quantitative method for assessing the amount of a flavonoid in pollens are also presented.« less

  1. Pollen morphology and plant taxonomy of red oaks in eastern North America

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Solomon, A.M.

    Identification of Quercus (oak) pollen taxa could enhance Quaternary palynological interpretations from eastern North America. A first step is to determine a morphological and taxonomic basis for such identifications. Scanning electron microscopy was utilized to examine exine-surface features of 266 specimens representing 21 red oak (subgen. Erythrobalanus) species from eastern North America, and two intermediate oak (subgen. Protobalanus) species from the desert southwest. Twenty pollen morphological characteristics defined previously were tabulated for each of 324 pollen grains. The data were subjected to cluster analyses. Cluster diagrams were compared with traditional oak systematics. Pollen morphology and plant taxonomy compared poorly withmore » respect to series and species relationships among the red oaks, apparently due as much to high intraspecific and low interspecific variability in pollen-morphological characters as to the uncertain taxonomy of red oaks. Pollen morphology, however, does support the hypothesis of subgeneric oak evolution from intermediate oaks to the series Virentes of white oaks, and from more advanced white oaks to the red oak species. 19 references, 25 figures, 1 table.« less

  2. Relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts.

    PubMed

    Yamamoto, Naomichi; Matsuki, Yuuki; Yokoyama, Hiromichi; Matsuki, Hideaki

    2015-01-01

    Japanese cedar pollinosis (JCP) is an important illness caused by the inhalation of airborne allergenic cedar pollens, which are dispersed in the early spring throughout the Japanese islands. However, associations between pollen exposures and the prevalence or severity of allergic symptoms are largely unknown, due to a lack of understanding regarding personal pollen exposures in relation to indoor and outdoor concentrations. This study aims to examine the relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts. We conducted a 4-year monitoring campaign to quantify indoor, outdoor, and personal airborne cedar pollen counts, where the personal passive settling sampler that has been previously validated against a volumetric sampler was used to count airborne pollen grains. A total of 256 sets of indoor, outdoor, and personal samples (768 samples) were collected from 9 subjects. Medians of the seasonally-integrated indoor-to-outdoor, personal-to-outdoor, and personal-to-indoor ratios of airborne pollen counts measured for 9 subjects were 0.08, 0.10, and 1.19, respectively. A greater correlation was observed between the personal and indoor counts (r = 0.89) than between the personal and outdoor counts (r = 0.71), suggesting a potential inaccuracy in the use of outdoor counts as a basis for estimating personal exposures. The personal pollen counts differed substantially among the human subjects (49% geometric coefficient of variation), in part due to the variability in the indoor counts that have been found as major determinants of the personal pollen counts. The findings of this study highlight the need for pollen monitoring in proximity to human subjects to better understand the relationships between pollen exposures and the prevalence or severity of pollen allergy.

  3. The long distance transport of airborne Ambrosia pollen to the UK and the Netherlands from Central and south Europe

    NASA Astrophysics Data System (ADS)

    de Weger, Letty A.; Pashley, Catherine H.; Šikoparija, Branko; Skjøth, Carsten A.; Kasprzyk, Idalia; Grewling, Łukasz; Thibaudon, Michel; Magyar, Donat; Smith, Matt

    2016-12-01

    The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport. Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500 m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rhône Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rhône Valley to reach the higher levels and enter the airstream moving to northwest Europe where they were deposited at ground level and recorded by monitoring sites. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France.

  4. PIV Measurements of Atmospheric Turbulence and Pollen Dispersal Above a Corn Canopy

    NASA Astrophysics Data System (ADS)

    Zhu, W.; van Hout, R.; Luznik, L.; Katz, J.

    2003-12-01

    Dispersal of pollen grains by wind and gravity (Anemophilous) is one of the oldest means of plant fertilization available in nature. Recently, the growth of genetically modified foods has raised questions on the range of pollen dispersal in order to limit cross-fertilization between organically grown and transgenic crops. The distance that a pollen grain can travel once released from the anther is determined, among others, by the aerodynamic parameters of the pollen and the characteristics of turbulence in the atmosphere in which it is released. Turbulence characteristics of the flow above a pollinating corn field were measured using Particle Image Velocimetry (PIV). The measurements were performed on the eastern shore of the Chesapeake Bay, in Maryland, during July 2003. Two PIV systems were used simultaneously, each with an overall sample area of 18x18 cm. The spacing between samples was about equal to the field of view. The PIV instrumentation, including CCD cameras, power supply and laser sheets forming optics were mounted on a measurement platform, consisting of a hydraulic telescopic arm that could be extended up to 10m. The whole system could be rotated in order to align it with the flow. The flow was seeded with smoke generated about 30m upstream of the sample areas. Measurements were carried out at several elevations, from just below canopy height up to 1m above canopy. The local meteorological conditions around the test site were monitored by other sensors including sonic anemometers, Rotorod pollen counters and temperature sensors. Each processed PIV image provides an instantaneous velocity distribution containing 64x64 vectors with a vector spacing of ~3mm. The pollen grains (~100mm) can be clearly distinguished from the smoke particles (~1mm) based on their size difference. The acquired PIV data enables calculation of the mean flow and turbulence characteristics including Reynolds stresses, spectra, turbulent kinetic energy and dissipation rate. Data

  5. Capturing the Surface Texture and Shape of Pollen: A Comparison of Microscopy Techniques

    PubMed Central

    Sivaguru, Mayandi; Mander, Luke; Fried, Glenn; Punyasena, Surangi W.

    2012-01-01

    Research on the comparative morphology of pollen grains depends crucially on the application of appropriate microscopy techniques. Information on the performance of microscopy techniques can be used to inform that choice. We compared the ability of several microscopy techniques to provide information on the shape and surface texture of three pollen types with differing morphologies. These techniques are: widefield, apotome, confocal and two-photon microscopy (reflected light techniques), and brightfield and differential interference contrast microscopy (DIC) (transmitted light techniques). We also provide a first view of pollen using super-resolution microscopy. The three pollen types used to contrast the performance of each technique are: Croton hirtus (Euphorbiaceae), Mabea occidentalis (Euphorbiaceae) and Agropyron repens (Poaceae). No single microscopy technique provided an adequate picture of both the shape and surface texture of any of the three pollen types investigated here. The wavelength of incident light, photon-collection ability of the optical technique, signal-to-noise ratio, and the thickness and light absorption characteristics of the exine profoundly affect the recovery of morphological information by a given optical microscopy technique. Reflected light techniques, particularly confocal and two-photon microscopy, best capture pollen shape but provide limited information on very fine surface texture. In contrast, transmitted light techniques, particularly differential interference contrast microscopy, can resolve very fine surface texture but provide limited information on shape. Texture comprising sculptural elements that are spaced near the diffraction limit of light (∼250 nm; NDL) presents an acute challenge to optical microscopy. Super-resolution structured illumination microscopy provides data on the NDL texture of A. repens that is more comparable to textural data from scanning electron microscopy than any other optical microscopy technique

  6. Molecular evidence that rough endoplasmic reticulum is the site of calreticulin translation in Petunia pollen tubes growing in vitro.

    PubMed

    Suwińska, Anna; Lenartowski, Robert; Smoliński, Dariusz Jan; Lenartowska, Marta

    2015-07-01

    In germinating pollen grains and growing pollen tubes, CRT is translated on ER membrane-bound ribosomes in the regions where its activity is required for stabilization of tip-focused Ca (2+) gradient. Pollen tube growth requires coordination of signaling, exocytosis, and actin cytoskeletal organization. Many of these processes are thought to be controlled by finely tuned regulation of cytoplasmic Ca(2+) in discrete regions of the tube cytoplasm. Most notably, a mechanism must function to maintain a steep gradient of Ca(2+) that exists at the tip of growing pollen tube. Several pieces of evidence point to calreticulin (CRT) as a key Ca(2+)-binding/-buffering protein involved in pollen germination and pollen tube growth. We previously hypothesized that in germinating pollen and growing tubes, CRT is translated on the ribosomes associated with endoplasmic reticulum (ER) in the regions where its activity might be required. In this report, we have addressed this idea by identifying the sites where CRT mRNA, CRT protein, 18S rRNA, and rough ER are localized in Petunia pollen tubes. We observed all four components in the germinal aperture of pollen grains and in subapical regions of elongating tubes. These results seem to support our idea that CRT is translated on ER membrane-bound ribosomes during pollen germination and pollen tube growth. In elongated pollen tubes, we found CRT mainly localized in the subapical zone, where ER and Golgi stacks are abundant. In eukaryotic cells, these organelles serve as mobile intracellular stores of easily releasable Ca(2+), which can be buffered by proteins such as CRT. Therefore, we postulate that subapical-localized CRT is involved in pollen tube growth by maintaining the stable tip-focused Ca(2+) gradient and thus modulating local Ca(2+) concentration within the tube cytoplasm.

  7. Palynology after Y2K--Understanding the Source Area of Pollen in Sediments

    NASA Astrophysics Data System (ADS)

    Davis, M. B.

    Pollen grains preserved in lake and bog sediment provide a record of past vegetation that has been an important source of information about climate and land cover during the Quaternary Period. Yet from the beginning, questions have been raised about the source area of pollen in sediment. Interpretation has been hampered by the lack of well-developed theory treating the relationship between the spatial distribution of trees on the landscape and the percentages of pollen in sediment. Within the past decade, however, new theory, models, and empirical data show how heterogeneous vegetation is represented by pollen. The distinction between "local" and "regional" pollen is explained by the Prentice-Sugita dispersal/deposition models, which predict how the ratio of regional to local pollen changes with lake size. Sugita's model simulating a landscape with heterogeneous vegetation predicts the size of the relevant source area-the area of vegetation reflected in between-lake variations in pollen loading-while demonstrating that regional pollen from beyond this distance is homogeneous at all lakes of similar size. By predicting the way landscape patterns will be reflected in pollen records, simulation models can improve research design and lead to more detailed and spatially precise records of past vegetation, enhancing continental-scale climate reconstructions.

  8. Intercellular communication in Arabidopsis thaliana pollen discovered via AHG3 transcript movement from the vegetative cell to sperm

    USDA-ARS?s Scientific Manuscript database

    An Arabidopsis pollen grain (male gametophyte) consists of three cells: the vegetative cell, which forms the pollen tube, and two sperm cells enclosed within the vegetative cell. It is still unclear if there is intercellular communication between the vegetative cell and the sperm cells. Here we show...

  9. Genomic Conflicts that Cause Pollen Mortality and Raise Reproductive Barriers in Arabidopsis thaliana.

    PubMed

    Simon, Matthieu; Durand, Stéphanie; Pluta, Natacha; Gobron, Nicolas; Botran, Lucy; Ricou, Anthony; Camilleri, Christine; Budar, Françoise

    2016-07-01

    Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in the offspring of two distant natural strains of Arabidopsis thaliana, Shahdara and Mr-0, with Shahdara as the female parent. Using both classical and quantitative genetic approaches as well as cytological observation of pollen viability, we demonstrate that this particular hybrid sterility results from two causes of pollen mortality. First, the Shahdara cytoplasm induces gametophytic cytoplasmic male sterility (CMS) controlled by several nuclear loci. Second, several segregation distorters leading to allele-specific pollen abortion (pollen killers) operate in hybrids with either cytoplasm. The complete sterility of the hybrid with the Shahdara cytoplasm results from the genetic linkage of the two causes of pollen mortality, i.e., CMS nuclear determinants and pollen killers. Furthermore, natural variation at these loci in A. thaliana is associated with different male-sterility phenotypes in intraspecific hybrids. Our results suggest that the genomic conflicts that underlie segregation distorters and CMS can concurrently lead to reproductive barriers between distant strains within a species. This study provides a new framework for identifying molecular mechanisms and the evolutionary history of loci that contribute to reproductive isolation, and possibly to speciation. It also suggests that two types of genomic conflicts, CMS and segregation distorters, may coevolve in natural populations. Copyright © 2016 by the Genetics Society of America.

  10. The miRNAs and their regulatory networks responsible for pollen abortion in Ogura-CMS Chinese cabbage revealed by high-throughput sequencing of miRNAs, degradomes, and transcriptomes

    PubMed Central

    Wei, Xiaochun; Zhang, Xiaohui; Yao, Qiuju; Yuan, Yuxiang; Li, Xixiang; Wei, Fang; Zhao, Yanyan; Zhang, Qiang; Wang, Zhiyong; Jiang, Wusheng; Zhang, Xiaowei

    2015-01-01

    Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables in Asia and is cultivated across the world. Ogura-type cytoplasmic male sterility (Ogura-CMS) has been widely used in the hybrid breeding industry for Chinese cabbage and many other cruciferous vegetables. Although, the cause of Ogura-CMS has been localized to the orf138 locus in the mitochondrial genome, however, the mechanism by which nuclear genes respond to the mutation of the mitochondrial orf138 locus is unclear. In this study, a series of whole genome small RNA, degradome and transcriptome analyses were performed on both Ogura-CMS and its maintainer Chinese cabbage buds using deep sequencing technology. A total of 289 known miRNAs derived from 69 families (including 23 new families first reported in B. rapa) and 426 novel miRNAs were identified. Among these novel miRNAs, both 3-p and 5-p miRNAs were detected on the hairpin arms of 138 precursors. Ten known and 49 novel miRNAs were down-regulated, while one known and 27 novel miRNAs were up-regulated in Ogura-CMS buds compared to the fertile plants. Using degradome analysis, a total of 376 mRNAs were identified as targets of 30 known miRNA families and 100 novel miRNAs. A large fraction of the targets were annotated as reproductive development related. Our transcriptome profiling revealed that the expression of the targets was finely tuned by the miRNAs. Two novel miRNAs were identified that were specifically highly expressed in Ogura-CMS buds and sufficiently suppressed two pollen development essential genes: sucrose transporter SUC1 and H+-ATPase 6. These findings provide clues for the contribution of a potential miRNA regulatory network to bud development and pollen engenderation. This study contributes new insights to the communication between the mitochondria and chromosome and takes one step toward filling the gap in the regulatory network from the orf138 locus to pollen abortion in Ogura-CMS plants from a mi

  11. The miRNAs and their regulatory networks responsible for pollen abortion in Ogura-CMS Chinese cabbage revealed by high-throughput sequencing of miRNAs, degradomes, and transcriptomes.

    PubMed

    Wei, Xiaochun; Zhang, Xiaohui; Yao, Qiuju; Yuan, Yuxiang; Li, Xixiang; Wei, Fang; Zhao, Yanyan; Zhang, Qiang; Wang, Zhiyong; Jiang, Wusheng; Zhang, Xiaowei

    2015-01-01

    Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables in Asia and is cultivated across the world. Ogura-type cytoplasmic male sterility (Ogura-CMS) has been widely used in the hybrid breeding industry for Chinese cabbage and many other cruciferous vegetables. Although, the cause of Ogura-CMS has been localized to the orf138 locus in the mitochondrial genome, however, the mechanism by which nuclear genes respond to the mutation of the mitochondrial orf138 locus is unclear. In this study, a series of whole genome small RNA, degradome and transcriptome analyses were performed on both Ogura-CMS and its maintainer Chinese cabbage buds using deep sequencing technology. A total of 289 known miRNAs derived from 69 families (including 23 new families first reported in B. rapa) and 426 novel miRNAs were identified. Among these novel miRNAs, both 3-p and 5-p miRNAs were detected on the hairpin arms of 138 precursors. Ten known and 49 novel miRNAs were down-regulated, while one known and 27 novel miRNAs were up-regulated in Ogura-CMS buds compared to the fertile plants. Using degradome analysis, a total of 376 mRNAs were identified as targets of 30 known miRNA families and 100 novel miRNAs. A large fraction of the targets were annotated as reproductive development related. Our transcriptome profiling revealed that the expression of the targets was finely tuned by the miRNAs. Two novel miRNAs were identified that were specifically highly expressed in Ogura-CMS buds and sufficiently suppressed two pollen development essential genes: sucrose transporter SUC1 and H (+) -ATPase 6. These findings provide clues for the contribution of a potential miRNA regulatory network to bud development and pollen engenderation. This study contributes new insights to the communication between the mitochondria and chromosome and takes one step toward filling the gap in the regulatory network from the orf138 locus to pollen abortion in Ogura-CMS plants from a mi

  12. Pollen developmental defects in ZD-CMS rice line explored by cytological, molecular and proteomic approaches.

    PubMed

    Yan, Junjie; Tian, Han; Wang, Shuzhen; Shao, Jinzhen; Zheng, Yinzhen; Zhang, Hongyuan; Guo, Lin; Ding, Yi

    2014-08-28

    Cytoplasmic male sterility (CMS) is a widely observed phenomenon, which is especially useful in hybrid seed production. Meixiang A (MxA) is a new rice CMS line derived from a pollen-free sterile line named Yunnan ZidaoA (ZD-CMS). In this study, a homologous WA352 gene with variation in two nucleotides was identified in MxA. Cytological analysis revealed that MxA was aborted in the early uninucleate stage. The protein expression profiles of MxA and its maintainer line MeixiangB (MxB) were systematically compared using iTRAQ-based quantitative proteomics technology using young florets at the early uninucleate stage. A total of 688 proteins were quantified in both rice lines, and 45 of these proteins were found to be differentially expressed. Bioinformatics analysis indicated a large number of the proteins involved in carbohydrate metabolism or the stress response were downregulated in MxA, suggesting that these metabolic processes had been hindered during pollen development in MxA. The ROS (reactive oxygen species) level was increased in the mitochondrion of MxA, and further ultrastructural analysis showed the mitochondria with disrupted cristae in the rice CMS line MxA. These findings substantially contribute to our knowledge of pollen developmental defects in ZD-CMS rice line. MeixiangA (MxA) is a new type of rice CMS line, which is derived from pollen-free sterile line Yunnan ZidaoA. In this study, the cytological, molecular and proteomic approaches were used to study the characteristics of this new CMS line. Cytological study indicates the CMS line is aborted at the early uninucleate stage. A potential sterile gene ZD352 is identified in MxA, the protein product of which is mainly accumulated at the MMC/Meiotic stage. iTRAQ based proteomic analysis is performed to study the relevant proteins involved in the CMS occurance, 45 proteins are found to be significant differentially expressed and these proteins are involved in many cellular processes such as

  13. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohd-Arrabe', A. B.; Noraini, Talip Noraini

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidalmore » based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat.« less

  14. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Mohd-Arrabe', A. B.; Noraini, Talip Noraini

    2013-11-01

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidal based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat.

  15. Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Musgrave, M. E.

    1996-01-01

    Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

  16. Effect of Bt-176 maize pollen on first instar larvae of the Peacock butterfly (Inachis io) (Lepidoptera; Nymphalidae).

    PubMed

    Felke, Martin; Langenbruch, Gustav-Adolf; Feiertag, Simon; Kassa, Adane

    2010-01-01

    More than 10 years after registration of the first Bt maize cultivar in Europe, there still exists a remarkable lack of data on effects on Lepidoptera which would be necessary for a complete and comprehensive environmental risk assessment. So far only very few European butterfly species have been tested in this aspect. In our study the effect of transgenic Bacillus thuringiensis (Bt) maize pollen (event Bt-176) on the development and survival of neonate larvae of the Peacock butterfly, Inachis io (L.) was for the first time shown. The results of our study suggest that the Peacock butterfly may serve as a model organism for assessing potential side effects of new developed transgenic Bt crops on non-target butterflies in a GMO environmental risk assessment. The study was done under laboratory conditions by exposing larvae of the Peacock butterfly to various pollen doses of transgenic maize event Bt-176 (cv. PACTOL CB) or the conventional isogenic maize (cv. PACTOL) using a no-choice test. Larvae feeding for 48 h on nettle plants (Urtica dioica) that were contaminated with higher pollen concentrations from Bt-176 maize (205 and 388 applied pollen.cm⁻²) suffered a significantly higher mortality rate (68 and 85% respectively) compared to larvae feeding on leaves with no pollen (11%), or feeding on leaves with pollen from conventional maize (6 to 25%). At lower Bt maize pollen doses (23-104 applied pollen.cm⁻²),mortality ranged from 11-25% and there were no apparent differences among treatments. The corresponding LC₅₀-and LC₉₀-values for neonate larvae of the Peacock butterfly were 187 and 448 applied pollen grains.cm⁻² of Bt-176, respectively.Weight of larvae surviving consumption of Bt-176 maize pollen declined between 10 and 81% with increased pollen doses (r = -0.95). The highest weight reduction (81%) corresponded to the highest pollen concentration (388 pollen grains applied.cm⁻²). Ingestion of pollen from the conventional maize hybrid did not

  17. Mapping allergenic pollen vegetation in UK to study environmental exposure and human health.

    PubMed

    McInnes, Rachel N; Hemming, Deborah; Burgess, Peter; Lyndsay, Donna; Osborne, Nicholas J; Skjøth, Carsten Ambelas; Thomas, Sam; Vardoulakis, Sotiris

    2017-12-01

    Allergenic pollen is produced by the flowers of a number of trees, grasses and weeds found throughout the UK. Exposure to such pollen grains can exacerbate pollen-related asthma and allergenic conditions such as allergic rhinitis (hay fever). Maps showing the location of these allergenic taxa have many applications: they can be used to provide advice on risk assessments; combined with health data to inform research on health impacts such as respiratory hospital admissions; combined with weather data to improve pollen forecasting systems; or as inputs to pollen emission models. In this study we present 1km resolution maps of 12 taxa of trees, grass and weeds found in the UK. We have selected the main species recorded by the UK pollen network. The taxa mapped in this study were: Alnus (alder), Fraxinus (ash), Betula (birch), Corylus (hazel), Quercus (oak), Pinus (pine) and Salix (willow), Poaceae (grass), Artemisia (mugwort), Plantago (plantain), Rumex (dock, sorrels) and Urtica (nettle). We also focus on one high population centre and present maps showing local level detail around the city of London. Our results show the different geographical distributions of the 12 taxa of trees, weeds and grass, which can be used to study plants in the UK associated with allergy and allergic asthma. These maps have been produced in order to study environmental exposure and human health, although there are many possible applications. This novel method not only provides maps of many different plant types, but also at high resolution across regions of the UK, and we uniquely present 12 key plant taxa using a consistent methodology. To consider the impact on human health due to exposure of the pollen grains, it is important to consider the timing of pollen release, and its dispersal, as well as the effect on air quality, which is also discussed here. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  18. [Association between airborne pollen distribution and allergic diseases in Beijing urban area].

    PubMed

    Wang, X Y; Tian, Z M; Ning, H Y; Wang, X Y

    2017-05-20

    Objective: The aim of this study is to investigate the impact of airborne pollen in urban Beijing area on the consultation rate of allergic diseases. Method: A modified pollen sampler was used to monitor the distribution of main airborne pollen during Jan 1st 2015 to Dec 31 2015.The consultation rate of allergic rhinitis and asthma was obtained meanwhile among allergy, ENT and pneumology department. Relationship between pollen and consultation rate was analyzed by Pearson index. Result: ①Through the whole year of 2015 the total quantity of pollens amounted to 76164 grains. Two pollen peaks were observed which happened in spring (March 29.7%, April 34.8%) and autumn (August 9.9%, September 10.5%). The main airborne pollens in spring were cypress, sycamore, and poplar, while in autumn were artemisia, Chenopodiaceae, and Humulus. ②The peak consultation season of allergic rhinitis was presented in March to April and August to September with a positive correlation between allergy and ENT department ( r =0.625, P <0.05). Consultation peak of asthma was observed in allergy department but not pneumology department. ③Allergic rhinitis and asthma consultation rate was higher in autumn than spring while the pollen distribution was the opposite. No correlation was found between consultation rate and pollen distribution P >0.05. Conclusion: The airborne pollen distribution was in accordance with consultation rate in allergy department. The pollen count in spring was higher than autumn in Beijing urban area with a consultation peak in autumn inversely. This indicates a higher sensitization ability of autumn pollen compared with spring pollen. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

  19. Detection of chaos: New approach to atmospheric pollen time-series analysis

    NASA Astrophysics Data System (ADS)

    Bianchi, M. M.; Arizmendi, C. M.; Sanchez, J. R.

    1992-09-01

    Pollen and spores are biological particles that are ubiquitous to the atmosphere and are pathologically significant, causing plant diseases and inhalant allergies. One of the main objectives of aerobiological surveys is forecasting. Prediction models are required in order to apply aerobiological knowledge to medical or agricultural practice; a necessary condition of these models is not to be chaotic. The existence of chaos is detected through the analysis of a time series. The time series comprises hourly counts of atmospheric pollen grains obtained using a Burkard spore trap from 1987 to 1989 at Mar del Plata. Abraham's method to obtain the correlation dimension was applied. A low and fractal dimension shows chaotic dynamics. The predictability of models for atomspheric pollen forecasting is discussed.

  20. A high-resolution angiosperm pollen reference record covering Albian mid-latitude coastal deposits (Lusitanian Basin, Portugal)

    NASA Astrophysics Data System (ADS)

    Horikx, Maurits; Dinis, Jorge L.; Heimhofer, Ulrich

    2013-04-01

    The Lusitanian Basin in Portugal is one of the most important areas to investigate the rise and radiation of early angiosperms. Here, important micro-, macro- and mesofossil remains including pollen, reproductive organs, fruits and seeds have been found. In this study, a high-resolution Early to Late Albian pollen record from a thick (~160m) coastal succession in the Lusitanian Basin containing mixed carbonate-siliciclastic near-shore deposits is generated. The outcrop is located near the town of Ericeira (São Julião) and exhibits some important new features compared to existing records from the Lusitanian basin. The comparatively proximal depositional setting and high sedimentation rate of the São Julião outcrop is well suited for high-resolution palynological sampling compared to previously studied, more distal outcrops. In addition, the succession covers almost the entire Albian including a thick interval representing Late Albian strata. Dating of the succession was obtained using dinoflagellate cyst biostratigraphy, bulk C-isotope analysis and strontium isotope analysis of low-Mg oysters and rudist shells. The high-resolution pollen record shows a distinct radiation pattern of early angiosperm pollen as well as significant changes in the accompanying palynoflora. During most of the section gymnosperm pollen types such as Classopollis spp., Inaperturopollenites spp. and Exesipollenites spp. are dominant. Angiosperm pollen abundances do not exceed 20%, although angiosperms increase slightly from the Early Albian onwards. Monoaperturate grains of magnoliid or monocot affinity remain the most dominant angiosperm pollen type, both in abundances and diversity. Tricolpate and zonoaperturate pollen grains are also present. In addition, the occurrence of several odd-shaped Dichastopollenites-type pollen types is intriguing. The palynological results indicate a warm and dry climate during most of the Albian, although a rise in the spores over pollen ratio in the

  1. Pollen recognition and rejection during the sporophytic self-incompatibility response: Brassica and beyond.

    PubMed

    Hiscock, Simon J; McInnis, Stephanie M

    2003-12-01

    Many hermaphrodite flowering plants avoid self-fertilization through genetic systems of self-incompatibility (SI). SI allows a plant to recognize and to reject self or self-related pollen, thereby preserving its ovules for outcrossing. Genes situated at the S-locus encode the 'male' (pollen) and 'female' (pistil) recognition determinants of SI. In sporophytic SI (SSI) the male determinant is expressed in the diploid anther, therefore haploid pollen grains behave with a diploid S phenotype. In Brassica, the male and the female determinants of SSI have been identified as a peptide ligand and its cognate receptor, respectively, and recent studies have identified downstream signalling molecules involved in pollen rejection. It now needs to be established whether the Brassica mechanism is universal in species with SSI, or unique to the Brassicaceae.

  2. Digestibility and nutritional value of fresh and stored pollen for honey bees (Apis mellifera scutellata).

    PubMed

    Nicolson, Susan W; Da Silva Das Neves, Susana; Human, Hannelie; Pirk, Christian W W

    Pollen, the main protein source for honey bees, is mixed with regurgitated nectar or honey during collection and then stored as 'bee bread' before its consumption, mainly by young nurse workers. It has been suggested that storage of pollen improves its nutritional value and digestibility, but there is little evidence for such changes. We fed two fresh pollen types of different protein content (aloe and sunflower), and two stored pollen types (sunflower and a mixed pollen), to young caged worker bees. We measured daily consumption of pollen and sucrose solution, and survival after 14 days. At day 14 we recorded ovarian activation and extraction efficiency, by counting empty pollen grains in the rectal contents. Extraction efficiency is a measure of pollen digestibility. Contrary to our predictions, bees did not consume more fresh sunflower pollen than fresh aloe pollen to compensate for the lower protein content of sunflower pollen. In addition, they did not consume less sucrose solution when fed stored pollen diets that are already enriched in sugar. Consumption of stored sunflower pollen resulted in a low protein to carbohydrate (P:C) intake. Survival and ovarian activation were higher on diets giving higher P:C intakes. Extraction efficiency was high (up to 99%) for all pollen diets, and comparison of fresh and stored sunflower pollen showed that storage did not make it easier to digest. Changes to pollen during storage do not confer obvious benefits to honey bees. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Relationships among Indoor, Outdoor, and Personal Airborne Japanese Cedar Pollen Counts

    PubMed Central

    Yamamoto, Naomichi; Matsuki, Yuuki; Yokoyama, Hiromichi; Matsuki, Hideaki

    2015-01-01

    Japanese cedar pollinosis (JCP) is an important illness caused by the inhalation of airborne allergenic cedar pollens, which are dispersed in the early spring throughout the Japanese islands. However, associations between pollen exposures and the prevalence or severity of allergic symptoms are largely unknown, due to a lack of understanding regarding personal pollen exposures in relation to indoor and outdoor concentrations. This study aims to examine the relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts. We conducted a 4-year monitoring campaign to quantify indoor, outdoor, and personal airborne cedar pollen counts, where the personal passive settling sampler that has been previously validated against a volumetric sampler was used to count airborne pollen grains. A total of 256 sets of indoor, outdoor, and personal samples (768 samples) were collected from 9 subjects. Medians of the seasonally-integrated indoor-to-outdoor, personal-to-outdoor, and personal-to-indoor ratios of airborne pollen counts measured for 9 subjects were 0.08, 0.10, and 1.19, respectively. A greater correlation was observed between the personal and indoor counts (r = 0.89) than between the personal and outdoor counts (r = 0.71), suggesting a potential inaccuracy in the use of outdoor counts as a basis for estimating personal exposures. The personal pollen counts differed substantially among the human subjects (49% geometric coefficient of variation), in part due to the variability in the indoor counts that have been found as major determinants of the personal pollen counts. The findings of this study highlight the need for pollen monitoring in proximity to human subjects to better understand the relationships between pollen exposures and the prevalence or severity of pollen allergy. PMID:26110813

  4. Environmental behaviour of airborne Amaranthaceae pollen in the southern part of the Iberian Peninsula, and its role in future climate scenarios.

    PubMed

    Cariñanos, Paloma; Alcázar, Purificación; Galán, Carmen; Domínguez, Eugenio

    2014-02-01

    The Amaranthaceae family includes a number of species which, through a series of specific adaptations, thrive in salty soils, arid environments and altered human settlements. Their ability to tolerate high temperatures favours summer flowering, giving rise to the widespread involvement of Amaranthaceae pollen grains in summer allergies, both in Mediterranean Europe and in areas with arid climates. This study analysed a 21-year set of historical airborne Amaranthaceae pollen records for an area located in the southern part of the Iberian Peninsula, in order to chart species' environmental reaction to changing climate conditions which occurred in the last decades. Airborne pollen data were collected from January 1991 to December 2011 using a Hirst-type volumetric impact sampler. Results showed that Amaranthaceae pollen remained in the atmosphere for over 6 months along the year, from early spring until early autumn. The annual Pollen Index ranged from barely 200 grains to almost 2000 grains, and was strongly influenced by rainfall during the flowering period, which prompted the development of new individuals and thus an increase in pollen production. A trend was noted towards increasingly early pollen peak dates; peaks were recorded in August-September in years with summer rainfall, but as early as May-June in years when over 50% of annual rainfall was recorded in the months prior to flowering. The gradual decline in the annual Pollen Index over later years is attributable not only to growing urbanisation of the area but also to a change in rainfall distribution pattern. High maximum temperatures in spring were also directly related to the peak date and the Pollen Index. This ability to adapt to changeable and occasionally stressful and restrictive, environmental conditions places Amaranthaceae at a competitive advantage with respect to other species sharing the same ecological niche. An increased presence of Amaranthaceae is likely to have a greater impact on future

  5. Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe

    NASA Astrophysics Data System (ADS)

    Liu, Li; Solmon, Fabien; Vautard, Robert; Hamaoui-Laguel, Lynda; Zsolt Torma, Csaba; Giorgi, Filippo

    2016-05-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hay fever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In this online approach pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used. Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger and the model is better constrained. From these simulations health risks associated to common ragweed pollen

  6. Small RNA Sequencing Reveals Differential miRNA Expression in the Early Development of Broccoli (Brassica oleracea var. italica) Pollen

    PubMed Central

    Li, Hui; Wang, Yu; Wu, Mei; Li, Lihong; Jin, Chuan; Zhang, Qingli; Chen, Chengbin; Song, Wenqin; Wang, Chunguo

    2017-01-01

    Pollen development is an important and complex biological process in the sexual reproduction of flowering plants. Although the cytological characteristics of pollen development are well defined, the regulation of its early stages remains largely unknown. In the present study, miRNAs were explored in the early development of broccoli (Brassica oleracea var. italica) pollen. A total of 333 known miRNAs that originated from 235 miRNA families were detected. Fifty-five novel miRNA candidates were identified. Sixty of the 333 known miRNAs and 49 of the 55 predicted novel miRNAs exhibited significantly differential expression profiling in the three distinct developmental stages of broccoli pollen. Among these differentially expressed miRNAs, miRNAs that would be involved in the developmental phase transition from uninucleate microspores to binucleate pollen grains or from binucleate to trinucleate pollen grains were identified. miRNAs that showed significantly enriched expression in a specific early stage of broccoli pollen development were also observed. In addition, 552 targets for 127 known miRNAs and 69 targets for 40 predicted novel miRNAs were bioinformatically identified. Functional annotation and GO (Gene Ontology) analysis indicated that the putative miRNA targets showed significant enrichment in GO terms that were related to plant organ formation and morphogenesis. Some of enriched GO terms were detected for the targets directly involved in plant male reproduction development. These findings provided new insights into the functions of miRNA-mediated regulatory networks in broccoli pollen development. PMID:28392797

  7. Small RNA Sequencing Reveals Differential miRNA Expression in the Early Development of Broccoli (Brassica oleracea var. italica) Pollen.

    PubMed

    Li, Hui; Wang, Yu; Wu, Mei; Li, Lihong; Jin, Chuan; Zhang, Qingli; Chen, Chengbin; Song, Wenqin; Wang, Chunguo

    2017-01-01

    Pollen development is an important and complex biological process in the sexual reproduction of flowering plants. Although the cytological characteristics of pollen development are well defined, the regulation of its early stages remains largely unknown. In the present study, miRNAs were explored in the early development of broccoli ( Brassica oleracea var. italica ) pollen. A total of 333 known miRNAs that originated from 235 miRNA families were detected. Fifty-five novel miRNA candidates were identified. Sixty of the 333 known miRNAs and 49 of the 55 predicted novel miRNAs exhibited significantly differential expression profiling in the three distinct developmental stages of broccoli pollen. Among these differentially expressed miRNAs, miRNAs that would be involved in the developmental phase transition from uninucleate microspores to binucleate pollen grains or from binucleate to trinucleate pollen grains were identified. miRNAs that showed significantly enriched expression in a specific early stage of broccoli pollen development were also observed. In addition, 552 targets for 127 known miRNAs and 69 targets for 40 predicted novel miRNAs were bioinformatically identified. Functional annotation and GO (Gene Ontology) analysis indicated that the putative miRNA targets showed significant enrichment in GO terms that were related to plant organ formation and morphogenesis. Some of enriched GO terms were detected for the targets directly involved in plant male reproduction development. These findings provided new insights into the functions of miRNA-mediated regulatory networks in broccoli pollen development.

  8. Alternative statistical methods for interpreting airborne Alder (Alnus glutimosa (L.) Gaertner) pollen concentrations.

    PubMed

    González Parrado, Zulima; Valencia Barrera, Rosa M; Fuertes Rodríguez, Carmen R; Vega Maray, Ana M; Pérez Romero, Rafael; Fraile, Roberto; Fernández González, Delia

    2009-01-01

    This paper reports on the behaviour of Alnus glutinosa (alder) pollen grains in the atmosphere of Ponferrada (León, NW Spain) from 1995 to 2006. The study, which sought to determine the effects of various weather-related parameters on Alnus pollen counts, was performed using a volumetric method. The main pollination period for this taxon is January-February. Alder pollen is one of the eight major airborne pollen allergens found in the study area. An analysis was made of the correlation between pollen counts and major weather-related parameters over each period. In general, the strongest positive correlation was with temperature, particularly maximum temperature. During each period, peak pollen counts occurred when the maximum temperature fell within the range 9 degrees C-14 degrees C. Finally, multivariate analysis showed that the parameter exerting the greatest influence was temperature, a finding confirmed by Spearman correlation tests. Principal components analysis suggested that periods with high pollen counts were characterised by high maximum temperature, low rainfall and an absolute humidity of around 6 g m(-3). Use of this type of analysis in conjunction with other methods is essential for obtaining an accurate record of pollen-count variations over a given period.

  9. Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

    NASA Astrophysics Data System (ADS)

    Aboulaich, Nadia; Achmakh, Lamiaa; Bouziane, Hassan; Trigo, M. Mar; Recio, Marta; Kadiri, Mohamed; Cabezudo, Baltasar; Riadi, Hassane; Kazzaz, Mohamed

    2013-03-01

    Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008-2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114-173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m3. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2-78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33-42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.

  10. Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco).

    PubMed

    Aboulaich, Nadia; Achmakh, Lamiaa; Bouziane, Hassan; Trigo, M Mar; Recio, Marta; Kadiri, Mohamed; Cabezudo, Baltasar; Riadi, Hassane; Kazzaz, Mohamed

    2013-03-01

    Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008-2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114-173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m(3). Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2-78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33-42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.

  11. Cost of abortions in Zambia: A comparison of safe abortion and post abortion care.

    PubMed

    Parmar, Divya; Leone, Tiziana; Coast, Ernestina; Murray, Susan Fairley; Hukin, Eleanor; Vwalika, Bellington

    2017-02-01

    Unsafe abortion is a significant but preventable cause of maternal mortality. Although induced abortion has been legal in Zambia since 1972, many women still face logistical, financial, social, and legal obstacles to access safe abortion services, and undergo unsafe abortion instead. This study provides the first estimates of costs of post abortion care (PAC) after an unsafe abortion and the cost of safe abortion in Zambia. In the absence of routinely collected data on abortions, we used multiple data sources: key informant interviews, medical records and hospital logbooks. We estimated the costs of providing safe abortion and PAC services at the University Teaching Hospital, Lusaka and then projected these costs to generate indicative cost estimates for Zambia. Due to unavailability of data on the actual number of safe abortions and PAC cases in Zambia, we used estimates from previous studies and from other similar countries, and checked the robustness of our estimates with sensitivity analyses. We found that PAC following an unsafe abortion can cost 2.5 times more than safe abortion care. The Zambian health system could save as much as US$0.4 million annually if those women currently treated for an unsafe abortion instead had a safe abortion.

  12. Bee Pollen

    MedlinePlus

    ... confuse bee pollen with bee venom, honey, or royal jelly. People take bee pollen for nutrition; as an ... menstrual cycles. This product contains 6 mg of royal jelly, 36 mg of bee pollen extract, bee pollen, ...

  13. Pollen specific expression of maize genes encoding actin depolymerizing factor-like proteins.

    PubMed Central

    Lopez, I; Anthony, R G; Maciver, S K; Jiang, C J; Khan, S; Weeds, A G; Hussey, P J

    1996-01-01

    In pollen development, a dramatic reorganization of the actin cytoskeleton takes place during the passage of the pollen grain into dormancy and on activation of pollen tube growth. A role for actin-binding proteins is implicated and we report here the identification of a small gene family in maize that encodes actin depolymerizing factor (ADF)-like proteins. The ADF group of proteins are believed to control actin polymerization and depolymerization in response to both intracellular and extracellular signals. Two of the maize genes ZmABP1 and ZmABP2 are expressed specifically in pollen and germinating pollen suggesting that the protein products may be involved in pollen actin reorganization. A third gene, ZmABP3, encodes a protein only 56% and 58% identical to ZmABP1 and ZmABP2, respectively, and its expression is suppressed in pollen and germinated pollen. The fundamental biochemical characteristics of the ZmABP proteins has been elucidated using bacterially expressed ZmABP3 protein. This has the ability to bind monomeric actin (G-actin) and filamentous actin (F-actin). Moreover, it decreases the viscosity of polymerized actin solutions consistent with an ability to depolymerize filaments. These biochemical characteristics, taken together with the sequence comparisons, support the inclusion of the ZmABP proteins in the ADF group. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8693008

  14. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks

    PubMed Central

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  15. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination

    PubMed Central

    Rejón, Juan D.; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J.

    2012-01-01

    Background and Aims A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. Methods The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Key Results Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. Conclusions In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of

  16. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

    PubMed

    Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

    2012-10-01

    A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

  17. Pollen--tiny and ephemeral but not forgotten: New ideas on their ecology and evolution.

    PubMed

    Williams, Joseph H; Mazer, Susan J

    2016-03-01

    Ecologists and evolutionary biologists have been interested in the functional biology of pollen since the discovery in the 1800s that pollen grains encompass tiny plants (male gametophytes) that develop and produce sperm cells. After the discovery of double fertilization in flowering plants, botanists in the early 1900s were quick to explore the effects of temperature and maternal nutrients on pollen performance, while evolutionary biologists began studying the nature of haploid selection and pollen competition. A series of technical and theoretic developments have subsequently, but usually separately, expanded our knowledge of the nature of pollen performance and how it evolves. Today, there is a tremendous diversity of interests that touch on pollen performance, ranging from the ecological setting on the stigma, structural and physiological aspects of pollen germination and tube growth, the form of pollen competition and its role in sexual selection in plants, virus transmission, mating system evolution, and inbreeding depression. Given the explosion of technical knowledge of pollen cell biology, computer modeling, and new methods to deal with diversity in a phylogenetic context, we are now more than ever poised for a new era of research that includes complex functional traits that limit or enhance the evolution of these deceptively simple organisms. © 2016 Botanical Society of America.

  18. Abortion patients' perceptions of abortion regulation.

    PubMed

    Cockrill, Kate; Weitz, Tracy A

    2010-01-01

    Most states regulate abortion differently than other health care services. Examples of these regulations include mandating waiting periods and the provision of state-authored information, and prohibiting private and public insurance coverage for abortion. The primary purpose of this paper is to explore abortion patients' perspectives on these regulations. We recruited 20 participants from three abortion providing facilities located in two states in the U.S. South and Midwest. Using a survey and semistructured interview, we collected information about women's knowledge of abortion regulation and policy preferences. During the interviews, women weighed the pros and cons of abortion regulations. We used grounded theory analytical techniques and matrix analysis to organize and interpret the data. We discovered five themes in these women's considerations of regulation: responsibility, empathy, safe and accessible health care, privacy, and equity. Women in the study generally supported policies that they felt protected women or informed decisions. However, most women also opposed laws mandating two-day abortion appointments for women who were traveling long distances. Women tended to favor financial coverage of abortion, arguing that it could help poor women afford abortion or reduce state expenditures. Overall the study participants' opinions on abortion policy reflect key values for advocates and policy makers to consider: responsibility, empathy, safe and accessible health care, privacy, and equity. Future work should examine abortion regulations in light of these shared values. Laws that promote misinformation or prohibit accommodations of unique circumstances are not consistent the positions articulated by the subjects in our study. Copyright 2010 Jacobs Institute of Women

  19. Pollen spectrum, a cornerstone for tracing the evolution of the eastern Central Asian desert

    NASA Astrophysics Data System (ADS)

    Lu, Kai-Qing; Xie, Gan; Li, Min; Li, Jin-Feng; Trivedi, Anjali; Ferguson, David K.; Yao, Yi-Feng; Wang, Yu-Fei

    2018-04-01

    The temperate desert in arid Central Asia (ACA) has acted as a thoroughfare for the ancient Silk Road and today's Belt and Road, linking economic and cultural exchanges between East and West. The interaction between human sustainable development and the dynamic change in the desert ecosystem in this region is an area of concern for governments and scientific communities. Nevertheless, the lack of a pollen spectrum of the dominant taxa within the temperate desert vegetation and a corresponding relation between pollen assemblages and specific desert vegetation types is an obstacle to further understanding the formation and maintenance of this desert ecosystem. In this work, we link pollen assemblages to specific desert vegetation types with a new pollen spectrum with specific pollen grains, specific plant taxa and related habitats, providing a solid foundation for further tracing the evolution of the desert ecosystem in eastern arid Central Asia.

  20. Pollen viability, physiology, and production of maize plants exposed to pyraclostrobin+epoxiconazole.

    PubMed

    Junqueira, Verônica Barbosa; Costa, Alan Carlos; Boff, Tatiana; Müller, Caroline; Mendonça, Maria Andréia Corrêa; Batista, Priscila Ferreira

    2017-04-01

    The use of fungicides in maize has been more frequent due to an increase in the incidence of diseases and also the possible physiological benefits that some of these products may cause. However, some of these products (e.g., strobilurins and triazoles) may interfere with physiological processes and the formation of reproductive organs. Therefore, the effect of these products on plants at different developmental stages needs to be better understood to reduce losses and maximize production. The effect of the fungicide pyraclostrobin+epoxiconazole (P+E) was evaluated at different growth stages in meiosis, pollen grain viability and germination, physiology, and production of maize plants in the absence of disease. An experiment was carried out with the hybrid DKB390 PROII and the application of pyraclostrobin+epoxiconazole at the recommended dose and an untreated control at 3 different timings (S1 - V10; S2 - V14; S3 - R1) with 5 replications. Gas exchange, chlorophyll fluorescence, pollen viability and germination, as well as the hundred-grain weight were evaluated. Anthers were collected from plants of S1 for cytogenetic analysis. The fungicide pyraclostrobin+epoxiconazole reduced the viability of pollen grains (1.4%), but this was not enough to reduce production. Moreover, no differences were observed in any of the other parameters analyzed, suggesting that P+E at the recommended dose and the tested stages does not cause toxic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Has pollination mode shaped the evolution of ficus pollen?

    PubMed

    Wang, Gang; Chen, Jin; Li, Zong-Bo; Zhang, Feng-Ping; Yang, Da-Rong

    2014-01-01

    The extent to which co-evolutionary processes shape morphological traits is one of the most fascinating topics in evolutionary biology. Both passive and active pollination modes coexist in the fig tree (Ficus, Moraceae) and fig wasp (Agaonidae, Hymenoptera) mutualism. This classic obligate relationship that is about 75 million years old provides an ideal system to consider the role of pollination mode shifts on pollen evolution. Twenty-five fig species, which cover all six Ficus subgenera, and are native to the Xishuangbanna region of southwest China, were used to investigate pollen morphology with scanning electron microscope (SEM). Pollination mode was identified by the Anther/Ovule ratio in each species. Phylogenetic free regression and a correlated evolution test between binary traits were conducted based on a strong phylogenetic tree. Seventeen of the 25 fig species were actively pollinated and eight species were passively pollinated. Three pollen shape types and three kinds of exine ornamentation were recognized among these species. Pollen grains with ellipsoid shape and rugulate ornamentation were dominant. Ellipsoid pollen occurred in all 17 species of actively pollinated figs, while for the passively pollinated species, two obtuse end shapes were identified: cylinder and sphere shapes were identified in six of the eight species. All passively pollinated figs presented rugulate ornamentation, while for actively pollinated species, the smoother types - psilate and granulate-rugulate ornamentations - accounted for just five and two among the 17 species, respectively. The relationship between pollen shape and pollination mode was shown by both the phylogenetic free regression and the correlated evolution tests. Three pollen shape and ornamentation types were found in Ficus, which show characteristics related to passive or active pollination mode. Thus, the pollen shape is very likely shaped by pollination mode in this unique obligate mutualism.

  2. Has Pollination Mode Shaped the Evolution of Ficus Pollen?

    PubMed Central

    Wang, Gang; Chen, Jin; Li, Zong-Bo; Zhang, Feng-Ping; Yang, Da-Rong

    2014-01-01

    Background The extent to which co-evolutionary processes shape morphological traits is one of the most fascinating topics in evolutionary biology. Both passive and active pollination modes coexist in the fig tree (Ficus, Moraceae) and fig wasp (Agaonidae, Hymenoptera) mutualism. This classic obligate relationship that is about 75 million years old provides an ideal system to consider the role of pollination mode shifts on pollen evolution. Methods and Main Findings Twenty-five fig species, which cover all six Ficus subgenera, and are native to the Xishuangbanna region of southwest China, were used to investigate pollen morphology with scanning electron microscope (SEM). Pollination mode was identified by the Anther/Ovule ratio in each species. Phylogenetic free regression and a correlated evolution test between binary traits were conducted based on a strong phylogenetic tree. Seventeen of the 25 fig species were actively pollinated and eight species were passively pollinated. Three pollen shape types and three kinds of exine ornamentation were recognized among these species. Pollen grains with ellipsoid shape and rugulate ornamentation were dominant. Ellipsoid pollen occurred in all 17 species of actively pollinated figs, while for the passively pollinated species, two obtuse end shapes were identified: cylinder and sphere shapes were identified in six of the eight species. All passively pollinated figs presented rugulate ornamentation, while for actively pollinated species, the smoother types - psilate and granulate-rugulate ornamentations - accounted for just five and two among the 17 species, respectively. The relationship between pollen shape and pollination mode was shown by both the phylogenetic free regression and the correlated evolution tests. Conclusions Three pollen shape and ornamentation types were found in Ficus, which show characteristics related to passive or active pollination mode. Thus, the pollen shape is very likely shaped by pollination mode

  3. [Sensitization to Castanea sativa pollen and pollinosis in northern Extremadura (Spain)].

    PubMed

    Cosmes Martín, P M; Moreno Ancillo, A; Domínguez Noche, C; Gutiérrez Vivas, A; Belmonte Soler, J; Roure Nolla, J M

    2005-01-01

    Castanea sativa pollen allergy has generally been considered to be uncommon and clinically insignificant. In our geographical area (Plasencia, Cáceres, Spain) Castanea sativa pollen is a major pollen. To determine the atmospheric fluctuations and prevalence of patients sensitized to Castanea pollen in our region and to compare this sensitization with sensitizations to other pollens. Patients with respiratory symptoms attending our outpatient clinic for the first time in 2003 were studied. The patients underwent skin prick tests with commercial extracts of a battery of inhalants including Castanea sativa pollen. Serologic specific IgE to Castanea sativa pollen was determined using the CAP system (Pharmacia and Upjohn, Uppsala, Sweden). Airborne pollen counts in our city were obtained using Cour collection apparatus over a 4-year period (2000 to 2003). The most predominant pollens detected were (mean of the maximal weekly concentrations over 4 years in pollen grains/m3): Quercus 968, Poacea 660, Olea 325, Platanus 229, Pinus 126, Cupresaceae 117, Plantago 109, Alnus 41, Populus 40, Castanea 32. We studied 346 patients (mean age: 24.1 years). In 210 patients with a diagnosis of pollinosis, the percentages of sensitization were: Dactylis glomerata 80.4%, Olea europea 71.9%, Fraxinus excelsior 68%, Plantago lanceolata 62.8%, Chenopodium album 60.9%, Robinia pseudoacacia 49%, Artemisia vulgaris 43.8%, Platanus acerifolia 36.6%, Parietaria judaica 36.1%, Populus nigra 32.3%, Betula alba 27.6%, Quercus ilex 21.4%, Alnus glutinosa 20.9%, Cupressus arizonica 7.6% and Castanea sativa 7.1%. Fifteen patients were sensitized to Castanea sativa and 14 had seasonal rhinoconjunctivitis and asthma. Ten patients had serum specific IgE to Castanea pollen (maximum value: 17.4 Ku/l). Castanea pollen is present in our area in large amounts from the 23rd to the 28th weeks of the year, with a peak pollen count in the 25th week. The most important allergenic pollens in northern Extremadura

  4. Abortion.

    PubMed

    1993-05-01

    The Alan Guttmacher Institute's State Reproductive Health Monitor "Legislative Proposals and Actions" provides US legislative information on abortion. The listing contains information on pending bills: the state, the identifying legislative number, the sponsor, the committee, the date the bill was introduced, a description of the bill, and when available the bill's status. The bills cover: 1) clinic licensing, e.g., requiring outpatient health care facilities in which abortions are performed, to have malpractice liability insurance; 2) comprehensive statues, which require parental notification before minor may obtain abortions, mandate abortion counseling to all women 24 hours before the abortion can be performed and prohibit disciplining or discharging a state employee for refusing to provide abortion counseling; 3) fetal personhood and rights, e.g. providing that life is vested in each person at fertilization; 4) fetal research and remains; 5) gender of fetus, which regulate abortions relative to sex selection in pregnancies; 6) harassment regulation; 7) informed consent and waiting periods detailing the risks and alternatives to abortion, and the 24-hour waiting period; 8) insurance coverage, e.g., eliminating language banning the coverage of abortions for state workers, and prohibiting disclosure by a health insurance carrier to the employer of a claimant that the claimant had a surgical abortion; 9) legality of abortion, urging Congress to reject he Freedom of Choice Act; 10) parental consent and notification; 11) postviability requirements; 12) public funding; 13) reporting requirements; 14) reproductive rights, and 15) spousal and paternal consent and notification.

  5. [Abortion and rights. Legal thinking about abortion].

    PubMed

    Perez Duarte, A E

    1991-01-01

    Analysis of abortion in Mexico from a juridical perspective requires recognition that Mexico as a national community participates in a double system of values. Politically it is defined as a liberal, democratic, and secular state, but culturally the Judeo-Christian ideology is dominant in all social strata. This duality complicates all juridical-penal decisions regarding abortion. Public opinion on abortion is influenced on the 1 hand by extremely conservative groups who condemn abortion as homicide, and on the other hand by groups who demand legislative reform in congruence with characteristics that define the state: an attitude of tolerance toward the different ideological-moral positions that coexist in the country. The discussion concerns the rights of women to voluntary maternity, protection of health, and to making their own decisions regarding their bodies vs. the rights of the fetus to life. The type of analysis is not objective, and conclusions depend on the ideology of the analyst. Other elements must be examined for an objective consideration of the social problem of abortion. For example, aspects related to maternal morbidity and mortality and the demographic, economic, and physical and mental health of the population would all seem to support the democratic juridical doctrine that sees the clandestine nature of abortion as the principal problem. It is also observed that the illegality of abortion does not guarantee its elimination. Desperate women will seek abortion under any circumstances. The illegality of abortion also impedes health and educational policies that would lower abortion mortality. There are various problems from a strictly juridical perspective. A correct definition of the term abortion is needed that would coincide with the medical definition. The discussion must be clearly centered on the protected juridical right and the definition of reproductive and health rights and rights to their own bodies of women. The experiences of other

  6. Consumption of Bt Rice Pollen Containing Cry1C or Cry2A Protein Poses a Low to Negligible Risk to the Silkworm Bombyx mori (Lepidoptera: Bombyxidae)

    PubMed Central

    Yang, Yan; Liu, Yue; Cao, Fengqin; Chen, Xiuping; Cheng, Lisheng; Romeis, Jörg; Li, Yunhe; Peng, Yufa

    2014-01-01

    By consuming mulberry leaves covered with pollen from nearby genetically engineered, insect-resistant rice lines producing Cry proteins derived from Bacillus thuringiensis (Bt), larvae of the domestic silkworm, Bombyx mori (Linnaeus) (Lepidoptera: Bombyxidae), could be exposed to insecticidal proteins. Laboratory experiments were conducted to assess the potential effects of Cry1C- or Cry2A-producing transgenic rice (T1C-19, T2A-1) pollen on B. mori fitness. In a short-term assay, B. mori larvae were fed mulberry leaves covered with different densities of pollen from Bt rice lines or their corresponding near isoline (control) for the first 3 d and then were fed mulberry leaves without pollen. No effect was detected on any life table parameter, even at 1800 pollen grains/cm2 leaf, which is much higher than the mean natural density of rice pollen on leaves of mulberry trees near paddy fields. In a long-term assay, the larvae were fed Bt and control pollen in the same way but for their entire larval stage (approximately 27 d). Bt pollen densities ≥150 grains/cm2 leaf reduced 14-d larval weight, increased larval development time, and reduced adult eclosion rate. ELISA analyses showed that 72.6% of the Cry protein was still detected in the pollen grains excreted with the feces. The low exposure of silkworm larvae to Cry proteins when feeding Bt rice pollen may be the explanation for the relatively low toxicity detected in the current study. Although the results demonstrate that B. mori larvae are sensitive to Cry1C and Cry2A proteins, the exposure levels that harmed the larvae in the current study are far greater than natural exposure levels. We therefore conclude that consumption of Bt rice pollen will pose a low to negligible risk to B. mori. PMID:25014054

  7. Pollen tube energetics: respiration, fermentation and the race to the ovule

    PubMed Central

    Rounds, Caleb M.; Winship, Lawrence J.; Hepler, Peter K.

    2011-01-01

    Background Pollen tubes grow by transferring chemical energy from stored cellular starch and newly assimilated sugars into ATP. This drives myriad processes essential for cell elongation, directly or through the creation of ion gradients. Respiration plays a central role in generating and regulating this energy flow and thus in the success of plant reproduction. Pollen tubes are easily grown in vitro and have become an excellent model for investigating the contributions of respiration to plant cellular growth and morphogenesis at the molecular, biochemical and physiological levels. Scope In recent decades, pollen tube research has become increasingly focused on the molecular mechanisms involved in cellular processes. Yet, effective growth and development requires an intact, integrated set of cellular processes, all supplied with a constant flow of energy. Here we bring together information from the current and historical literature concerning respiration, fermentation and mitochondrial physiology in pollen tubes, and assess the significance of more recent molecular and genetic investigations in a physiological context. Conclusions The rapid growth of the pollen tube down the style has led to the evolution of high rates of pollen tube respiration. Respiration rates in lily predict a total energy turnover of 40–50 fmol ATP s−1 per pollen grain. Within this context we examine the energetic requirements of cell wall synthesis, osmoregulation, actin dynamics and cyclosis. At present, we can only estimate the amount of energy required, because data from growing pollen tubes are not available. In addition to respiration, we discuss fermentation and mitochondrial localization. We argue that the molecular pathways need to be examined within the physiological context to understand better the mechanisms that control tip growth in pollen tubes. PMID:22476489

  8. Grass pollen counts, air pollution levels and allergic rhinitis severity.

    PubMed

    Annesi-Maesano, Isabella; Rouve, Sarah; Desqueyroux, Hélène; Jankovski, Roger; Klossek, Jean-Michel; Thibaudon, Michel; Demoly, Pascal; Didier, Alain

    2012-01-01

    Little is known about the relation between allergic rhinitis severity and airborne pollen in combination with air pollutants. To model the risk of suffering from severe seasonal allergic rhinitis (SAR) as a function of both pollen count and air pollution levels in a large nationwide sample of patients whose SAR was diagnosed by a physician and confirmed by skin prick test positivity or specific immunolglobulin E to common aeroallergens. The severity of SAR symptoms was estimated with the Symptomatic Global Score (SGS) among 36,397 patients suffering from an untreated and uncomplicated SAR between May and August 2004 in metropolitan France. Patients who had an SGS in the upper third quartile were classified as suffering from severe SAR. A multilevel model relating SAR severity, pollen and air pollution was used to take into account the hierarchical data structure. 18.9% of the 17,567 urban patients retained for the analysis suffered from severe rhinitis. At the Lag0 (day of the visit), a rise of 60 grass pollen grains/m(3) increased the risk of suffering from a severe SAR form by 8% in the multileveled model after adjusting for potential confounders and air pollution levels. Results were also confirmed in the subsample of individuals with documented sensitization to grass pollen. Grass pollen count aggravated SAR in terms of symptoms in our nationwide sample. These findings confirm the need for proper treatment and preventive measures in SAR patients sensitized to grass pollen. Copyright © 2012 S. Karger AG, Basel.

  9. Osmoregulation in Lilium Pollen Grains Occurs via Modulation of the Plasma Membrane H+ ATPase Activity by 14-3-3 Proteins1[C][W][OA

    PubMed Central

    Pertl, Heidi; Pöckl, Magdalena; Blaschke, Christian; Obermeyer, Gerhard

    2010-01-01

    To allow successful germination and growth of a pollen tube, mature and dehydrated pollen grains (PGs) take up water and have to adjust their turgor pressure according to the water potential of the surrounding stigma surface. The turgor pressure of PGs of lily (Lilium longiflorum) was measured with a modified pressure probe for simultaneous recordings of turgor pressure and membrane potential to investigate the relation between water and electrogenic ion transport in osmoregulation. Upon hyperosmolar shock, the turgor pressure decreased, and the plasma membrane (PM) hyperpolarizes in parallel, whereas depolarization of the PM was observed with hypoosmolar treatment. An acidification and alkalinization of the external medium was monitored after hyper- and hypoosmotic treatments, respectively, and pH changes were blocked by vanadate, indicating a putative role of the PM H+ ATPase. Indeed, an increase in PM-associated 14-3-3 proteins and an increase in PM H+ ATPase activity were detected in PGs challenged by hyperosmolar medium. We therefore suggest that in PGs the PM H+ ATPase via modulation of its activity by 14-3-3 proteins is involved in the regulation of turgor pressure. PMID:20974894

  10. Does the increase in ambient CO2 concentration elevate allergy risks posed by oak pollen?

    NASA Astrophysics Data System (ADS)

    Kim, Kyu Rang; Oh, Jae-Won; Woo, Su-Young; Seo, Yun Am; Choi, Young-Jin; Kim, Hyun Seok; Lee, Wi Young; Kim, Baek-Jo

    2018-05-01

    Oak pollen is a major respiratory allergen in Korea, and the distribution of oak trees is expected to increase by ecological succession and climate change. One of the drivers of climate change is increasing CO2, which is also known to amplify the allergy risk of weed pollen by inducing elevated allergenic protein content. However, the impact of CO2 concentration on tree pollen is not clearly understood due to the experimental difficulties in carrying out extended CO2 treatment. To study the response of pollen production of sawtooth oak trees (Quercus acutissima) to elevated levels of ambient CO2, three open-top chambers at the National Institute of Forest Science in Suwon, Korea were utilized with daytime (8 am-6 pm) CO2 concentrations of ambient (× 1.0, 400 ppm), × 1.4 ( 560 ppm), and × 1.8 ( 720 ppm) treatments. Each chamber had three sawtooth oak trees planted in September 2009. One or two trees per chamber matured to bloom in 2016. Five to six catkins were selected per tree and polyethylene bags were attached to collect pollen grains. The total number of catkins per tree was counted and the number and weight of pollen grains per catkin were measured. Oak allergen—Que a 1 (Allergon Co., Uppsala, Sweden)—was extracted and purified to make an ELISA kit by which the antigen levels in the pollen samples were quantified. Total pollen counts per tree of the × 1.4 and × 1.8 treatments showed significant increase of 353 and 1299%, respectively, from the × 1.0 treatment (p < 0.001). Allergenic protein contents at the × 1.4 and × 1.8 treatments also showed significant increase of 12 and 11%, respectively (p = 0.011). The × 1.8 treatment induced significant difference from the × 1.0 treatment in terms of pollen production and allergenic protein content, whereas the × 1.4 treatment showed mixed significance. In summary, the oak trees under the elevated CO2 levels, which are expected in the changing climate, produced significantly higher amount of pollen and

  11. Classification of grass pollen through the quantitative analysis of surface ornamentation and texture.

    PubMed

    Mander, Luke; Li, Mao; Mio, Washington; Fowlkes, Charless C; Punyasena, Surangi W

    2013-11-07

    Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material.

  12. Airborne pollen in Funchal city, (Madeira Island, Portugal) - First pollinic calendar and allergic risk assessment.

    PubMed

    Camacho, Irene Câmara

    2015-01-01

    Nowadays, pollen calendars are useful tools for clinical guidance intended for allergy sufferers, because they can be used to prevent and manage allergic respiratory diseases, thus improving the quality of life. An aeropalinological study was performed in the city of Funchal with the purpose of establishing a pollen calendar and determining allergic risk, based on a seven year study (2003-2009). The airborne pollen monitoring was carried out with a Hirst type volumetric spore trap, following well-established guidelines. The mean annual pollen index was 1,635.09 and comprised 42 different pollen types. Airborne pollen levels were higher between March - June, accounting for 57.9% of the annual counts. Arboreal pollen grains (52.72%) prevailed in the atmosphere together with herbs and grasses (44.64%), while fern spores (2.29%) and unidentified pollen (0.35%) were scarce. The main pollen types were Urticaceae (20.64%), Poaceae (16.02%), Cupressaceae (13.61%), Pinaceae (9.07%), Myrtaceae (5.93%) and Ericaceae (5.02%). The pollen calendar comprised a total of 14 taxa and is similar to Mediterranean regions, with the exception of Olea europaea, Quercus sp., Betula sp. and Alnus sp. pollen types which are rare or absent. The main pollen season of major pollen taxa is significantly longer in Funchal (on average 239 days) than other European sites, especially for Urticaceae and Poaceae, but the pollen peaks were substantially lower. The pollen calendar for Funchal is the first ever created for Madeira region. Taking into account the low pollen index and number of allergy-risk days recorded (39 days in 7 years), the air quality of Funchal can be considered good.

  13. Successful expression in pollen of various plant species of in vitro synthesized mRNA introduced by particle bombardment.

    PubMed

    Tanaka, T; Nishihara, M; Seki, M; Sakamoto, A; Tanaka, K; Irifune, K; Morikawa, H

    1995-05-01

    Gold particles coated with beta-glucuronidase (GUS) mRNA with a 5' cap structure that had been synthesized in vitro were introduced, by use of a pneumatic particle gun, into pollen grains of lily (Lilium longiflorum), freesia (Freesia refracta) and tulip (Tulipa gesneriana). A fluorometric assay for the GUS activity indicated that in vitro synthesized GUS mRNA introduced into these pollen cells by particle bombardment was successfully expressed. GUS activity in extracts of the bombarded lily pollen became detectable fluorometrically within 30 min after bombardment, peaked at 6 h, then gradually decreased. This activity changed as a function of the developmental stage of the pollen cell of lily.

  14. Pollen counts and their relationship to meteorological factors in Ankara, Turkey during 2005-2008

    NASA Astrophysics Data System (ADS)

    Kizilpinar, Ilginc; Civelek, Ersoy; Tuncer, Ayfer; Dogan, Cahit; Karabulut, Erdem; Sahiner, Umit M.; Yavuz, S. Tolga; Sackesen, Cansin

    2011-07-01

    Pollen plays an important role in the development and exacerbation of allergic diseases. We aimed to investigate the days with highest counts of the most allergenic pollens and to identify the meteorological factors affecting pollen counts in the atmosphere of Ankara, Turkey. Airborne pollen measurements were carried out from 2005 to 2008 with a Burkard volumetric 7-day spore trap. Microscope counts were converted into atmospheric concentrations and expressed as pollen grains/m3. Meteorological parameters were obtained from the State Meteorological Service. All statistical analyses were done with pollen counts obtained from March to October for each year. The percentages of tree, grass and weed pollens were 72.1% ( n = 24,923), 12.8% ( n = 4,433) and 15.1% ( n = 5,219), respectively. The Pinaceae family from tree taxa (39% to 57%) and the Chenopodiaceae/Amaranthaceae family from weed taxa, contributed the highest percentage of pollen (25% to 43%), while from the grass taxa, only the Poaceae family was detected from 2005 to 2008. Poaceae and Chenopodiaceae/Amaranthaceae families, which are the most allergenic pollens, were found in high numbers from May to August in Ankara. In multiple logistic regression analysis, wind speed (OR = 1.18, CI95% = 1.02-1.36, P = 0.023) for tree pollen, daily mean temperature (OR = 1.10, CI95% = 1.04-1.17, P = 0.001) and sunshine hours (OR = 1.15, CI95% = 1.01-1.30, P = 0.033) for grass pollen, and sunshine hours (OR = 3.79, CI95% = 1.03-13.92, P = 0.044) for weed pollen were found as significant risk factors for high pollen count. The pollen calendar and its association with meteorological factors depend mainly on daily temperature, sunshine hours and wind speed, which may help draw the attention of physicians and allergic patients to days with high pollen counts.

  15. Selective seed abortion affects the performance of the offspring in Bauhinia ungulata.

    PubMed

    Mena-Alí, Jorge I; Rocha, Oscar J

    2005-05-01

    Under the microgametophytic competition hypothesis, a non-random pattern of seed abortion is expected, in which only the most vigorous seeds reach maturity. In a previous study, it was found that Bauhinia ungulata (Fabaceae) exhibits a pattern of seed abortion dependent on the position of the ovule within the ovary; ovules located in the stylar half of the fruit, close to the point of entry of pollen tubes to the ovary, have a low probability of seed abortion, whereas ovules in the basal half of the fruit are aborted with a high probability. A series of experimental fruits was generated, in which ovules from either the stylar (treatments 1 and 2) or the basal (treatments 3 and 4) half of fruits were destroyed, to evaluate whether these patterns of selective seed abortion have an effect on the vigour of the offspring in B. ungulata. Only 53 % of the seed from control fruits germinated. Seed set in fruits from treatments 1 and 2 showed a significantly lower (33-43 %) percentage of germination; the germination of seeds from fruits in treatments 3 and 4 (49-51 %) did not differ from control seeds. In addition, it was found that the differences in vigour of the offspring are not random with respect to the position of the ovule in the pod. The overall performance of the seeds correlated with their likelihood of maturation. Seeds located at the basal half of the treatment fruits showed lower values of vigour than seeds located on the stylar half. The differences were more marked for early measures of fitness.

  16. First evidence for Wollemi Pine-type pollen (Dilwynites: Araucariaceae) in South America.

    PubMed

    Macphail, Mike; Carpenter, Raymond J; Iglesias, Ari; Wilf, Peter

    2013-01-01

    We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America.

  17. Simulated environmental criticalities affect transglutaminase of Malus and Corylus pollens having different allergenic potential.

    PubMed

    Iorio, Rosa Anna; Di Sandro, Alessia; Paris, Roberta; Pagliarani, Giulia; Tartarini, Stefano; Ricci, Giampaolo; Serafini-Fracassini, Donatella; Verderio, Elisabetta; Del Duca, Stefano

    2012-02-01

    Increases in temperature and air pollution influence pollen allergenicity, which is responsible for the dramatic raise in respiratory allergies. To clarify possible underlying mechanisms, an anemophilous pollen (hazel, Corylus avellana), known to be allergenic, and an entomophilous one (apple, Malus domestica), the allergenicity of which was not known, were analysed. The presence also in apple pollen of known fruit allergens and their immunorecognition by serum of an allergic patient were preliminary ascertained, resulting also apple pollen potentially allergenic. Pollens were subjected to simulated stressful conditions, provided by changes in temperature, humidity, and copper and acid rain pollution. In the two pollens exposed to environmental criticalities, viability and germination were negatively affected and different transglutaminase (TGase) gel bands were differently immunodetected with the polyclonal antibody AtPng1p. The enzyme activity increased under stressful treatments and, along with its products, was found to be released outside the pollen with externalisation of TGase being predominant in C. avellana, whose grain presents a different cell wall composition with respect to that of M. domestica. A recombinant plant TGase (AtPng1p) stimulated the secreted phospholipase A(2) (sPLA(2)) activity, that in vivo is present in human mucosa and is involved in inflammation. Similarly, stressed pollen, hazel pollen being the most efficient, stimulated to very different extent sPLA(2) activity and putrescine conjugation to sPLA(2). We propose that externalised pollen TGase could be one of the mediators of pollen allergenicity, especially under environmental stress induced by climate changes.

  18. The long range transport of birch (Betula) pollen from Poland and Germany causes significant pre-season concentrations in Denmark

    NASA Astrophysics Data System (ADS)

    Ambelas Skjoth, C.; Sommer, J.; Stach, A.; Smith, M.; Brandt, J.; Christensen, J. H.; Frohn, L. M.; Geels, C.; Hansen, K. M.; Hedegaard, G. B.

    2009-04-01

    In Denmark, where birch pollen is considered to be among the most important allergenic pollen, about one million people suffer from seasonal allergic rhinitis. In Denmark, the official reported pollen forecast is based on the daily weather forecast, the pollen calendar and local 24-h measurements. Birch pollen has the potential for long-range transport but the present Danish pollen forecast does not account for birch pollen being transported into the country from distant sources.. Long-range transport episodes are intermittent and often out of the main pollen season, where individuals in general will be medically unprotected. Here we use an integrated approach to investigate whether or not Denmark receives significant quantities of birch pollen from Poland and Germany before local trees start to flower. In 2006 we used a combination of phenological observations and pollen measurements in Poland (Poznań) and Denmark (Copenhagen). Seasonal and diurnal variations in birch pollen measurement from Copenhagen (2000-2006) were examined with the aim of identifying pre-seasonal episodes originating from long-range transport. The 2.5% accumulation method was used for identifying start of season. If daily pollen counts exceeded 30 grains/m3 either before the local flowering season began or on the actual start day, the episode was chosen for investigation with back trajectory analysis. A birch forest inventory for Northern Europe was produced and implemented in DEHM-Pollen along with a simple unified pollen release model SUPREME to investigate the 2006 campaign in detail. In 2006, full flowering took place in Poznan between 20th and 28th of April and daily concentrations varied between 739 and 2169 grains/m3. In Copenhagen phenological observations showed that local flowering was initiated the 2nd of May. In Copenhagen several episodes with pollen concentrations at 108, 244 and 41 grains/m3 were recorded the 23rd, 26th and 27th of April, respectively. Back-trajectory analysis

  19. Seasonal and Spatial Variations of Indoor Pollen in a Hospital

    PubMed Central

    Tormo-Molina, Rafael; Gonzalo-Garijo, Ángela; Silva-Palacios, Inmaculada; Fernández-Rodríguez, Santiago

    2009-01-01

    The airborne indoor pollen in a hospital of Badajoz (Spain) was monitored over two years using a personal Burkard sampler. The air was sampled in four places indoors—one closed room and one open ward on each of the ground and the third floors—and one place outdoors at the entrance to the hospital. The results were compared with data from a continuous volumetric sampler. While 32 pollen types were identified, nearly 75% of the total counts were represented by just five of them. These were: Quercus, Cupressaceae, Poaceae, Olea, and Plantago. The average indoor concentration was 25.2 grains/m3, and the average indoor/outdoor ratio was 0.27. A strong seasonal pattern was found, with the highest levels in spring and winter, and the indoor concentrations were correlated with the outdoor one. Indoor air movement led to great homogeneity in the airborne pollen presence: the indoor results were not influenced by whether or not the room was isolated, the floor level, or the number of people in or transiting the site during sampling. The presence of ornamental vegetation in the area surrounding the building affected the indoor counts directly as sources of the pollen. PMID:20049254

  20. Demand for abortion and post abortion care in Ibadan, Nigeria

    PubMed Central

    2014-01-01

    Background While induced abortion is considered to be illegal and socially unacceptable in Nigeria, it is still practiced by many women in the country. Poor family planning and unsafe abortion practices have daunting effects on maternal health. For instance, Nigeria is on the verge of not meeting the Millennium development goals on maternal health due to high maternal mortality ratio, estimated to be about 630 maternal deaths per 100,000 live births. Recent evidences have shown that a major factor in this trend is the high incidence of abortion in the country. The objective of this paper is, therefore, to investigate the factors determining the demand for abortion and post-abortion care in Ibadan city of Nigeria. Methods The study employed data from a hospital-based/exploratory survey carried out between March to September 2010. Closed ended questionnaires were administered to a sample of 384 women of reproductive age from three hospitals within the Ibadan metropolis in South West Nigeria. However, only 308 valid responses were received and analysed. A probit model was fitted to determine the socioeconomic factors that influence demand for abortion and post-abortion care. Results The results showed that 62% of respondents demanded for abortion while 52.3% of those that demanded for abortion received post-abortion care. The findings again showed that income was a significant determinant of abortion and post-abortion care demand. Women with higher income were more likely to demand abortion and post-abortion care. Married women were found to be less likely to demand for abortion and post-abortion care. Older women were significantly less likely to demand for abortion and post-abortion care. Mothers’ education was only statistically significant in determining abortion demand but not post-abortion care demand. Conclusion The findings suggest that while abortion is illegal in Nigeria, some women in the Ibadan city do abort unwanted pregnancies. The consequence of this

  1. Demand for abortion and post abortion care in Ibadan, Nigeria.

    PubMed

    Awoyemi, Bosede O; Novignon, Jacob

    2014-01-01

    While induced abortion is considered to be illegal and socially unacceptable in Nigeria, it is still practiced by many women in the country. Poor family planning and unsafe abortion practices have daunting effects on maternal health. For instance, Nigeria is on the verge of not meeting the Millennium development goals on maternal health due to high maternal mortality ratio, estimated to be about 630 maternal deaths per 100,000 live births. Recent evidences have shown that a major factor in this trend is the high incidence of abortion in the country. The objective of this paper is, therefore, to investigate the factors determining the demand for abortion and post-abortion care in Ibadan city of Nigeria. The study employed data from a hospital-based/exploratory survey carried out between March to September 2010. Closed ended questionnaires were administered to a sample of 384 women of reproductive age from three hospitals within the Ibadan metropolis in South West Nigeria. However, only 308 valid responses were received and analysed. A probit model was fitted to determine the socioeconomic factors that influence demand for abortion and post-abortion care. The results showed that 62% of respondents demanded for abortion while 52.3% of those that demanded for abortion received post-abortion care. The findings again showed that income was a significant determinant of abortion and post-abortion care demand. Women with higher income were more likely to demand abortion and post-abortion care. Married women were found to be less likely to demand for abortion and post-abortion care. Older women were significantly less likely to demand for abortion and post-abortion care. Mothers' education was only statistically significant in determining abortion demand but not post-abortion care demand. The findings suggest that while abortion is illegal in Nigeria, some women in the Ibadan city do abort unwanted pregnancies. The consequence of this in the absence of proper post-abortion

  2. Combination of reversible male sterility and doubled haploid production by targeted inactivation of cytoplasmic glutamine synthetase in developing anthers and pollen.

    PubMed

    Ribarits, Alexandra; Mamun, A N K; Li, Shipeng; Resch, Tatiana; Fiers, Martijn; Heberle-Bors, Erwin; Liu, Chun-Ming; Touraev, Alisher

    2007-07-01

    Reversible male sterility and doubled haploid plant production are two valuable technologies in F(1)-hybrid breeding. F(1)-hybrids combine uniformity with high yield and improved agronomic traits, and provide self-acting intellectual property protection. We have developed an F(1)-hybrid seed technology based on the metabolic engineering of glutamine in developing tobacco anthers and pollen. Cytosolic glutamine synthetase (GS1) was inactivated in tobacco by introducing mutated tobacco GS genes fused to the tapetum-specific TA29 and microspore-specific NTM19 promoters. Pollen in primary transformants aborted close to the first pollen mitosis, resulting in male sterility. A non-segregating population of homozygous doubled haploid male-sterile plants was generated through microspore embryogenesis. Fertility restoration was achieved by spraying plants with glutamine, or by pollination with pollen matured in vitro in glutamine-containing medium. The combination of reversible male sterility with doubled haploid production results in an innovative environmentally friendly breeding technology. Tapetum-mediated sporophytic male sterility is of use in foliage crops, whereas microspore-specific gametophytic male sterility can be applied to any field crop. Both types of sterility preclude the release of transgenic pollen into the environment.

  3. Abortion - surgical

    MedlinePlus

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  4. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stairs, G. R.

    The production of pollen under conditions of chronic gamma irradiation was investigated for three oak species. Two chronically irradiated areas were studied: a low level (1 to 15r/day) area where trees had received varying amounts of radiation over a period of 11 years, and a second area receiving gamma radiation for about five months previous to the investigation. In the latter study dose levels ranged from lethal (45r/day) to a region of no detectable effect. In both areas pollen abortion showed a significant increase with increasing radiation exposure, although germinable pollen was produced at all survival levels examined. The germinatingmore » pollen tube length did not show a significant decrease in the irradiated material examined. In addition to cytological effects there was a marked deiny in floral phenology for both areas. Acute irradiation of male flower buds at different stages of meiosis, and of mature pollen were reported. The radiosensitivity of microsporogenesis was evaluated by cytological scoring at anaphase I, and by pollen abortion, germination, and tube lengih. Both the number of chromosome fragments/100 cells scored at anaphase I and pollen abortion showed a linear increase with an increase in radiation exposure. Pollen germination and tube length were less effected by radiation (based on a percent of unaborted grains). It was suggested that a range of 1 kr to 4 kr will be appropriate for irradiating male flower buds of oak to be utilized in a mutation breeding program. Contingent upon additional studies the range of radiation recommended for flower buds is also suggested for the induction of mutations in pollen. Pollen was found to be highly resistant to radiation when evaluated by germination and tube growth studies. No effect was found with irradiation of 100 kr; at 300 kr both germination and tube lengths were depressed. At these levels it is probable that germination is an expression of cytoplasmic growth and not of nuclear viability

  5. Induced abortion.

    PubMed

    2017-06-01

    Abortion is common. Data on abortion rates are inexact but can be used to explore trends. Globally, the estimated rate in the period 2010-2014 was 35 abortions per 1000 women (aged 15-44 years), five points less than the rate of 40 for the period 1990-1994. Abortion laws vary around the world but are generally more restrictive in developing countries. Restrictive laws do not necessarily deter women from seeking abortion but often lead to unsafe practice with significant mortality and morbidity. While a legal framework for abortion is a prerequisite for availability, many laws, which are not evidence based, restrict availability and delay access. Abortion should be available in the interests of public health and any legal framework should be as permissive as possible in order to promote access. In the absence of legal access, harm reduction strategies are needed to reduce abortion-related mortality and morbidity. Abortion can be performed surgically (in the first trimester, by manual or electric vacuum aspiration) or with medication: both are safe and effective. Cervical priming facilitates surgery and reduces the risk of incomplete abortion. Diagnosis of incomplete abortion should be made on clinical grounds, not by ultrasound. Septic abortion is a common cause of maternal death almost always following unsafe abortion and thus largely preventable. While routine follow-up after abortion is unnecessary, all women should be offered a contraceptive method immediately after the abortion. This, together with improved education and other interventions, may succeed in reducing unintended pregnancy. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Profiles of women presenting for abortions in Singapore: focus on teenage abortions and late abortions.

    PubMed

    Lim, Limin; Wong, Hungchew; Yong, Euleong; Singh, Kuldip

    2012-02-01

    Teenage abortions predispose women to adverse pregnancy outcomes in subsequent pregnancies such as anemia, stillbirths, preterm deliveries and low birth weight babies. We aim to profile the women presenting for abortions in our institution and determine risk factors for late presentation for abortions. In this retrospective cohort study, all women who underwent an abortion at the National University Hospital, Singapore, from 2005 to 2009 were recruited. Data was obtained from a prepared questionnaire during the mandatory pre-abortion counseling sessions. Profiles of women aged <20 years were compared with those ≥ 20 years old using Chi-square test if the assumptions for Chi-square test were met; otherwise, Fisher's exact test was carried out. Logistic regression was used to investigate the risk factors for second trimester termination of pregnancy. 2109 women presented for induced abortions, of which 1998 had single abortion throughout the course of the study. The mean age of women with single abortion was 29.1 years (sd 7). In the group of women with single abortion, 182 (9.1%) were teenage abortions. In contrast to women ≥ 20 years of age, pregnant teenagers were more likely not to have used any contraception (51.1% vs. 25.2%) and more likely to present late for abortions (39.6% vs. 15.9%). Other risk factors for late presentation for abortions include Malay ethnicity, singlehood, nulliparity and lack of prior usage of contraception. Teenagers are more likely to have no prior contraceptive usage and to present late for abortions. Lack of proper sexual education and awareness of contraceptive measures may have a major contributory factor to such a trend in teenage abortions. Recommendations have been made in order to curb this societal problem. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. AtSRP1, SMALL RUBBER PARTICLE PROTEIN HOMOLOG, functions in pollen growth and development in Arabidopsis.

    PubMed

    Chi, Yong Hun; Kim, Sun Young; Lee, Eun Seon; Jung, Young Jun; Park, Joung Hun; Paeng, Seol Ki; Oh, Hun Taek; Melencion, Sarah Mae Boyles; Alinapon, Cresilda Vergara; Lee, Sang Yeol

    2016-06-24

    To identify novel roles of SMALL RUBBER PARTICLE PROTEIN Homolog in the non-rubber-producing plant Arabidopsis (AtSRP1), we isolated a T-DNA-insertion knock-out mutant (FLAG_543A05) and investigated its functional characteristics. AtSRP1 is predominantly expressed in reproductive organs and is localized to lipid droplets and ER. Compared to wild-type (WT) Arabidopsis, atsrp1 plants contain small siliques with a reduced number of heterogeneously shaped seeds. The size of anther and pollen grains in atsrp1 is highly irregular, with a lower grain number than WT. Therefore, AtSRP1 plays a novel role related to pollen growth and development in a non-rubber-producing plant. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Pollen-Stigma Adhesion in Kale Is Not Dependent on the Self-(In)Compatibility Genotype.

    PubMed Central

    Luu, D. T.; Heizmann, P.; Dumas, C.

    1997-01-01

    The adhesion of pollen on the stigmas of flowering plants is a critical step for the success of reproduction in angiosperms, long considered to present some specificity in terms of self-incompatibility. We carried out quantitative measurements of the pollen-stigma adhesion (expressed in Newtons) in kale (Brassica oleracea), using the flotation force of Archimedes exerted by dense sucrose solutions (50%, w/v) to release pollen grains fixed on the surface of stigmas. We demonstrate that pollen adhesion varies with the genotypes of the plants used as partners, but increases with time in all cases for about 30 to 60 min after pollination. There is no correlation with the self- or cross-status of the pollinations, nor with the self-compatible or -incompatible genotypes of the parents. Only late events of pollination, after the germination or arrest of the pollen tube, depend on compatibility type. Biochemical and physiological dissection of pollen-stigma adhesion points to major components of this interaction: among male components, the pollen coating, eliminated by delipidation (or modified by mutation in the case of the cer mutants of the related species Arabidopsis thaliana), plays a major role in adhesion; the genetic background of the pollen parent is also of some importance. On the female side, the developmental stage of the stigma and the protein constituents of the stigmatic pellicle are critical for pollen capture. The SLG and SLR1 proteins are not involved in the initial stages of pollen adhesion on the stigma but one or both may be involved in the later stages. PMID:12223868

  9. Airborne grass (Poaceae) pollen in southern Spain. Results of a 10-year study (1987-96).

    PubMed

    González Minero, F J; Candau, P; Tomás, C; Morales, J

    1998-03-01

    This work reports an exhaustive study of the aerobiology of the Gramineae in Seville, Spain, which is typical of coastal Mediterranean areas. Sampling was done with a Cour trap installed on the roof terrace of the School of Pharmacy, Seville, from 1987 to 1996, both inclusive. The climatic pattern of that period was characterized by two exceptionally wet years (1989 and 1996), between which were 5 consecutive years of drought (1990-5). This typically Mediterranean climate affects grass aerobiology. The annual amounts of total grass pollen are low, never exceeding 2500 grains/m3. The start, length, and intensity of the pollen season are significantly correlated with preseasonal meteorologic factors (precipitation and temperature), but intraseasonal meteorologic conditions have no effect on the three variables. The relationships are stated by three equations that, while further years of observations are anticipated, can be considered models to forecast the characteristics of the pollen season: the starting date depends on the mean temperatures of January and February, and the length and intensity of the season depend on the rainfall between the beginning of January and the starting date of the season. For the study period, the weekly concentrations (pollen curves) throughout the year showed no typical pattern of variation over the years, so that it was impossible to make mid- and long-term forecasts of the variation in weekly concentration. The most noteworthy aspects of grass pollen curves are a long pollen season, which starts in February or March and lasts until September or October; peaks of higher concentration (> 100 grains/m3) in May and June, associated with increases in temperature and absence of precipitation; and other peaks in the summer months that may be as high as the spring peaks.

  10. Formation and function of a new pollen aperture pattern in angiosperms: The proximal sulcus of Tillandsia leiboldiana (Bromeliaceae).

    PubMed

    Albert, Béatrice; Matamoro-Vidal, Alexis; Raquin, Christian; Nadot, Sophie

    2010-02-01

    Pollen grains are generally surrounded by an extremely resistant wall interrupted in places by apertures that play a key role in reproduction; pollen tube growth is initiated at these sites. The shift from a proximal to distal aperture location is a striking innovation in seed plant reproduction. Reversals to proximal aperture position have only very rarely been described in angiosperms. The genus Tillandsia belongs to the Bromeliaceae family, and its aperture pattern has been described as distal monosulcate, the most widespread aperture patterns recorded in monocots and basal angiosperms. Here we report developmental and functional elements to demonstrate that the sulcate aperture in Tillandsia leiboldiana is not distal as previously described but proximal. Postmeitotic tetrad observation indicates unambiguously the proximal position of the sulcus, and in vitro germination of pollen grains confirms that the aperture is functional. This is the first report of a sulcate proximal aperture with proximal germination. The observation of microsporogenesis reveals specific features in the patterns of callose thickenings in postmeiotic tetrads.

  11. First Evidence for Wollemi Pine-type Pollen (Dilwynites: Araucariaceae) in South America

    PubMed Central

    Macphail, Mike; Carpenter, Raymond J.; Iglesias, Ari; Wilf, Peter

    2013-01-01

    We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America. PMID:23894439

  12. Misperceptions about the risks of abortion in women presenting for abortion.

    PubMed

    Wiebe, Ellen R; Littman, Lisa; Kaczorowski, Janusz; Moshier, Erin L

    2014-03-01

    Misinformation about the risks and sequelae of abortion is widespread. The purpose of this study was to examine whether women having an abortion who believe that there should be restrictions to abortion (i.e., that some other women should not be allowed to have an abortion) also believe this misinformation about the health risks associated with abortion. We carried out a cross-sectional survey of women presenting consecutively for an abortion at an urban abortion clinic in Vancouver, British Columbia, between February and September 2012. Of 1008 women presenting for abortion, 978 completed questionnaires (97% response rate), and 333 of these (34%) favoured abortion restrictions. More women who favoured restrictions believed that the health risk of an abortion was the same as or greater than the health risk of childbirth (84.2% vs. 65.6%, P < 0.001), that abortion caused mental health problems (39.1% vs. 28.3%, P < 0.001), and that abortion caused infertility (41.7% vs. 21.9%, P < 0.001). Using multivariate logistic regression analyses, believing that abortion should not be restricted was found to be a significantly correlated with correct answers about health risks, mental health problems, and infertility. Misinformed beliefs about the risks of abortion are common among women having an abortion. Women presenting for abortion who favoured restrictions to abortion have more misperceptions about abortion risks than women who favour no restrictions.

  13. Selective Seed Abortion Affects the Performance of the Offspring in Bauhinia ungulata

    PubMed Central

    MENA-ALÍ, JORGE I.; ROCHA, OSCAR J.

    2005-01-01

    • Background and Aims Under the microgametophytic competition hypothesis, a non-random pattern of seed abortion is expected, in which only the most vigorous seeds reach maturity. In a previous study, it was found that Bauhinia ungulata (Fabaceae) exhibits a pattern of seed abortion dependent on the position of the ovule within the ovary; ovules located in the stylar half of the fruit, close to the point of entry of pollen tubes to the ovary, have a low probability of seed abortion, whereas ovules in the basal half of the fruit are aborted with a high probability. • Methods A series of experimental fruits was generated, in which ovules from either the stylar (treatments 1 and 2) or the basal (treatments 3 and 4) half of fruits were destroyed, to evaluate whether these patterns of selective seed abortion have an effect on the vigour of the offspring in B. ungulata. • Key Results Only 53 % of the seed from control fruits germinated. Seed set in fruits from treatments 1 and 2 showed a significantly lower (33–43 %) percentage of germination; the germination of seeds from fruits in treatments 3 and 4 (49–51 %) did not differ from control seeds. In addition, it was found that the differences in vigour of the offspring are not random with respect to the position of the ovule in the pod. • Conclusions The overall performance of the seeds correlated with their likelihood of maturation. Seeds located at the basal half of the treatment fruits showed lower values of vigour than seeds located on the stylar half. The differences were more marked for early measures of fitness. PMID:15749749

  14. Loss of the Arabidopsis thaliana P4-ATPases ALA6 and ALA7 impairs pollen fitness and alters the pollen tube plasma membrane.

    PubMed

    McDowell, Stephen C; López-Marqués, Rosa L; Cohen, Taylor; Brown, Elizabeth; Rosenberg, Alexa; Palmgren, Michael G; Harper, Jeffrey F

    2015-01-01

    Members of the P4 subfamily of P-type ATPases are thought to create and maintain lipid asymmetry in biological membranes by flipping specific lipids between membrane leaflets. In Arabidopsis, 7 of the 12 Aminophospholipid ATPase (ALA) family members are expressed in pollen. Here we show that double knockout of ALA6 and ALA7 (ala6/7) results in siliques with a ~2-fold reduction in seed set with a high frequency of empty seed positions near the bottom. Seed set was reduced to near zero when plants were grown under a hot/cold temperature stress. Reciprocal crosses indicate that the ala6/7 reproductive deficiencies are due to a defect related to pollen transmission. In-vitro growth assays provide evidence that ala6/7 pollen tubes are short and slow, with ~2-fold reductions in both maximal growth rate and overall length relative to wild-type. Outcrosses show that when ala6/7 pollen are in competition with wild-type pollen, they have a near 0% success rate in fertilizing ovules near the bottom of the pistil, consistent with ala6/7 pollen having short and slow growth defects. The ala6/7 phenotypes were rescued by the expression of either an ALA6-YFP or GFP-ALA6 fusion protein, which showed localization to both the plasma membrane and highly-mobile endomembrane structures. A mass spectrometry analysis of mature pollen grains revealed significant differences between ala6/7 and wild-type, both in the relative abundance of lipid classes and in the average number of double bonds present in acyl side chains. A change in the properties of the ala6/7 plasma membrane was also indicated by a ~10-fold reduction of labeling by lipophilic FM-dyes relative to wild-type. Together, these results indicate that ALA6 and ALA7 provide redundant activities that function to directly or indirectly change the distribution and abundance of lipids in pollen, and support a model in which ALA6 and ALA7 are critical for pollen fitness under normal and temperature-stress conditions.

  15. Loss of the Arabidopsis thaliana P4-ATPases ALA6 and ALA7 impairs pollen fitness and alters the pollen tube plasma membrane

    PubMed Central

    McDowell, Stephen C.; López-Marqués, Rosa L.; Cohen, Taylor; Brown, Elizabeth; Rosenberg, Alexa; Palmgren, Michael G.; Harper, Jeffrey F.

    2015-01-01

    Members of the P4 subfamily of P-type ATPases are thought to create and maintain lipid asymmetry in biological membranes by flipping specific lipids between membrane leaflets. In Arabidopsis, 7 of the 12 Aminophospholipid ATPase (ALA) family members are expressed in pollen. Here we show that double knockout of ALA6 and ALA7 (ala6/7) results in siliques with a ~2-fold reduction in seed set with a high frequency of empty seed positions near the bottom. Seed set was reduced to near zero when plants were grown under a hot/cold temperature stress. Reciprocal crosses indicate that the ala6/7 reproductive deficiencies are due to a defect related to pollen transmission. In-vitro growth assays provide evidence that ala6/7 pollen tubes are short and slow, with ~2-fold reductions in both maximal growth rate and overall length relative to wild-type. Outcrosses show that when ala6/7 pollen are in competition with wild-type pollen, they have a near 0% success rate in fertilizing ovules near the bottom of the pistil, consistent with ala6/7 pollen having short and slow growth defects. The ala6/7 phenotypes were rescued by the expression of either an ALA6-YFP or GFP-ALA6 fusion protein, which showed localization to both the plasma membrane and highly-mobile endomembrane structures. A mass spectrometry analysis of mature pollen grains revealed significant differences between ala6/7 and wild-type, both in the relative abundance of lipid classes and in the average number of double bonds present in acyl side chains. A change in the properties of the ala6/7 plasma membrane was also indicated by a ~10-fold reduction of labeling by lipophilic FM-dyes relative to wild-type. Together, these results indicate that ALA6 and ALA7 provide redundant activities that function to directly or indirectly change the distribution and abundance of lipids in pollen, and support a model in which ALA6 and ALA7 are critical for pollen fitness under normal and temperature-stress conditions. PMID:25954280

  16. Effect of micro-scale wind on the measurement of airborne pollen concentrations using volumetric methods on a building rooftop

    NASA Astrophysics Data System (ADS)

    Miki, Kenji; Kawashima, Shigeto; Fujita, Toshio; Nakamura, Kimihito; Clot, Bernard

    2017-06-01

    Evaluating airborne pollen concentrations is important for the understanding of the spatiotemporal dispersion of pollen grains. Using two identical pollen monitors in parallel, we performed two experiments in order to study the influences of a) the physical characteristics (orientation) of the air inlet and b) the presence of obstacles in proximity to the monitors on airborne pollen concentration data. The first experiment consisted of an evaluation of airborne pollen concentrations using two different types of orifices; 1) a vertically oriented inlet and 2) a wind vane intake, both attached to the same type of automatic pollen sampler. The second experiment investigated the relationship between vertical wind speed and horizontal wind direction around an obstacle with the goal of studying the impact of micro-scale wind on pollen sampling efficiency. The results of the two experiments suggest that the wind path near an obstacle might be redirected in a vertical direction before or after the wind flows over the obstacle, which causes measurement errors of airborne pollen concentrations that are proportional to the vertical wind speed, especially when a vertically oriented inlet is used.

  17. Pollen counts and their relationship to meteorological factors in Ankara, Turkey during 2005-2008.

    PubMed

    Kizilpinar, Ilginc; Civelek, Ersoy; Tuncer, Ayfer; Dogan, Cahit; Karabulut, Erdem; Sahiner, Umit M; Yavuz, S Tolga; Sackesen, Cansin

    2011-07-01

    Pollen plays an important role in the development and exacerbation of allergic diseases. We aimed to investigate the days with highest counts of the most allergenic pollens and to identify the meteorological factors affecting pollen counts in the atmosphere of Ankara, Turkey. Airborne pollen measurements were carried out from 2005 to 2008 with a Burkard volumetric 7-day spore trap. Microscope counts were converted into atmospheric concentrations and expressed as pollen grains/m(3). Meteorological parameters were obtained from the State Meteorological Service. All statistical analyses were done with pollen counts obtained from March to October for each year. The percentages of tree, grass and weed pollens were 72.1% (n = 24,923), 12.8% (n = 4,433) and 15.1% (n = 5,219), respectively. The Pinaceae family from tree taxa (39% to 57%) and the Chenopodiaceae/Amaranthaceae family from weed taxa, contributed the highest percentage of pollen (25% to 43%), while from the grass taxa, only the Poaceae family was detected from 2005 to 2008. Poaceae and Chenopodiaceae/Amaranthaceae families, which are the most allergenic pollens, were found in high numbers from May to August in Ankara. In multiple logistic regression analysis, wind speed (OR = 1.18, CI95% = 1.02-1.36, P = 0.023) for tree pollen, daily mean temperature (OR = 1.10, CI95% = 1.04-1.17, P = 0.001) and sunshine hours (OR = 1.15, CI95% = 1.01-1.30, P = 0.033) for grass pollen, and sunshine hours (OR = 3.79, CI95% = 1.03-13.92, P = 0.044) for weed pollen were found as significant risk factors for high pollen count. The pollen calendar and its association with meteorological factors depend mainly on daily temperature, sunshine hours and wind speed, which may help draw the attention of physicians and allergic patients to days with high pollen counts.

  18. RNA-Seq of Arabidopsis Pollen Uncovers Novel Transcription and Alternative Splicing1[C][W][OA

    PubMed Central

    Loraine, Ann E.; McCormick, Sheila; Estrada, April; Patel, Ketan; Qin, Peng

    2013-01-01

    Pollen grains of Arabidopsis (Arabidopsis thaliana) contain two haploid sperm cells enclosed in a haploid vegetative cell. Upon germination, the vegetative cell extrudes a pollen tube that carries the sperm to an ovule for fertilization. Knowing the identity, relative abundance, and splicing patterns of pollen transcripts will improve our understanding of pollen and allow investigation of tissue-specific splicing in plants. Most Arabidopsis pollen transcriptome studies have used the ATH1 microarray, which does not assay splice variants and lacks specific probe sets for many genes. To investigate the pollen transcriptome, we performed high-throughput sequencing (RNA-Seq) of Arabidopsis pollen and seedlings for comparison. Gene expression was more diverse in seedling, and genes involved in cell wall biogenesis were highly expressed in pollen. RNA-Seq detected at least 4,172 protein-coding genes expressed in pollen, including 289 assayed only by nonspecific probe sets. Additional exons and previously unannotated 5′ and 3′ untranslated regions for pollen-expressed genes were revealed. We detected regions in the genome not previously annotated as expressed; 14 were tested and 12 were confirmed by polymerase chain reaction. Gapped read alignments revealed 1,908 high-confidence new splicing events supported by 10 or more spliced read alignments. Alternative splicing patterns in pollen and seedling were highly correlated. For most alternatively spliced genes, the ratio of variants in pollen and seedling was similar, except for some encoding proteins involved in RNA splicing. This study highlights the robustness of splicing patterns in plants and the importance of ongoing annotation and visualization of RNA-Seq data using interactive tools such as Integrated Genome Browser. PMID:23590974

  19. Access to abortion: what women want from abortion services.

    PubMed

    Wiebe, Ellen R; Sandhu, Supna

    2008-04-01

    Whether Canadian physicians can refuse to refer women for abortion and whether private clinics can charge for abortions are matters of controversy. We sought to identify barriers to access for women seeking therapeutic abortion and to have them identify what they considered to be most important about access to abortion services. Women presenting for abortion over a two-month period at two free-standing abortion clinics, one publicly funded and the other private, were invited to participate in the study. Phase I of the study involved administration of a questionnaire seeking information about demographics, perceived barriers to access to abortion, and what the women wanted from abortion services. Phase II involved semi-structured interviews of a convenience sample of women to record their responses to questions about access. Responses from Phase I questionnaires were compared between the two clinics, and qualitative analysis was performed on the interview responses. Of 423 eligible women, 402 completed questionnaires, and of 45 women approached, 39 completed interviews satisfactorily. Women received information about abortion services from their physicians (60.0%), the Internet (14.8%), a telephone directory (7.8%), friends or family (5.3%), or other sources (12.3%). Many had negative experiences in gaining access. The most important issue regarding access was the long wait time; the second most important issue was difficulty in making appointments. In the private clinic, 85% of the women said they were willing to pay for shorter wait times, compared with 43.5% in the public clinic. Physicians who failed to refer patients for abortion or provide information about obtaining an abortion caused distress and impeded access for a significant minority of women requesting an abortion. Management of abortion services should be prioritized to reflect what women want: particularly decreased wait times for abortion and greater ease and convenience in booking appointments

  20. Incidence of Induced Abortion and Post-Abortion Care in Tanzania

    PubMed Central

    Keogh, Sarah C.; Kimaro, Godfather; Muganyizi, Projestine; Philbin, Jesse; Kahwa, Amos; Ngadaya, Esther; Bankole, Akinrinola

    2015-01-01

    Background Tanzania has one of the highest maternal mortality ratios in the world, and unsafe abortion is one of its leading causes. Yet little is known about its incidence. Objectives To provide the first ever estimates of the incidence of unsafe abortion in Tanzania, at the national level and for each of the 8 geopolitical zones (7 in Mainland plus Zanzibar). Methods A nationally representative survey of health facilities was conducted to determine the number of induced abortion complications treated in facilities. A survey of experts on abortion was conducted to estimate the likelihood of women experiencing complications and obtaining treatment. These surveys were complemented with population and fertility data to obtain abortion numbers, rates and ratios, using the Abortion Incidence Complications Methodology. Results In Tanzania, women obtained just over 405,000 induced abortions in 2013, for a national rate of 36 abortions per 1,000 women age 15–49 and a ratio of 21 abortions per 100 live births. For each woman treated in a facility for induced abortion complications, 6 times as many women had an abortion but did not receive care. Abortion rates vary widely by zone, from 10.7 in Zanzibar to 50.7 in the Lake zone. Conclusions The abortion rate is similar to that of other countries in the region. Variations by zone are explained mainly by differences in fertility and contraceptive prevalence. Measures to reduce the incidence of unsafe abortion and associated maternal mortality include expanding access to post-abortion care and contraceptive services to prevent unintended pregnancies. PMID:26361246

  1. Incidence of Induced Abortion and Post-Abortion Care in Tanzania.

    PubMed

    Keogh, Sarah C; Kimaro, Godfather; Muganyizi, Projestine; Philbin, Jesse; Kahwa, Amos; Ngadaya, Esther; Bankole, Akinrinola

    2015-01-01

    Tanzania has one of the highest maternal mortality ratios in the world, and unsafe abortion is one of its leading causes. Yet little is known about its incidence. To provide the first ever estimates of the incidence of unsafe abortion in Tanzania, at the national level and for each of the 8 geopolitical zones (7 in Mainland plus Zanzibar). A nationally representative survey of health facilities was conducted to determine the number of induced abortion complications treated in facilities. A survey of experts on abortion was conducted to estimate the likelihood of women experiencing complications and obtaining treatment. These surveys were complemented with population and fertility data to obtain abortion numbers, rates and ratios, using the Abortion Incidence Complications Methodology. In Tanzania, women obtained just over 405,000 induced abortions in 2013, for a national rate of 36 abortions per 1,000 women age 15-49 and a ratio of 21 abortions per 100 live births. For each woman treated in a facility for induced abortion complications, 6 times as many women had an abortion but did not receive care. Abortion rates vary widely by zone, from 10.7 in Zanzibar to 50.7 in the Lake zone. The abortion rate is similar to that of other countries in the region. Variations by zone are explained mainly by differences in fertility and contraceptive prevalence. Measures to reduce the incidence of unsafe abortion and associated maternal mortality include expanding access to post-abortion care and contraceptive services to prevent unintended pregnancies.

  2. The long pollen tube journey and in vitro pollen germination of Phalaenopsis orchids.

    PubMed

    Chen, Jhun-Chen; Fang, Su-Chiung

    2016-06-01

    Pollen biology in P. aphrodite. Orchids have a distinct reproductive program. Pollination triggers ovule development and differentiation within flowers, and fertilization occurs days to months after pollination. It is unclear how pollen tubes travel through the developing ovaries during ovule development and when pollen tubes arrive at the mature embryo sac to achieve fertilization. Here, we report a robust staining protocol to image and record the timing of pollen germination, progressive growth of pollen tubes in ovaries, and arrival of pollen tubes at embryo sacs in Phalaenopsis aphrodite. The pollen germinated and pollen tubes entered the ovary 3 days after pollination. Pollen tubes continued to grow and filled the entire cavity of the ovary as the ovary elongated and ovules developed. Pollen tubes were found to enter the matured embryo sacs at approximately 60-65 days after pollination in an acropetal manner. Moreover, these temporal changes in developmental events such as growth of pollen tubes and fertilization were associated with expression of molecular markers. In addition, we developed an in vitro pollen germination protocol, which is valuable to enable studies on pollen tube guidance and tip growth regulation in Phalaenopsis orchids and possibly in other orchid species.

  3. Synchronicity of pollination and inoculation with Claviceps africana and its effects on pollen-pistil compatibility and seed production in sorghum.

    PubMed

    Cisneros-López, Ma Eugenia; Mendoza-Onofre, Leopoldo E; González-Hernández, Víctor A; Zavaleta-Mancera, H Araceli; Mora-Aguilera, Gustavo; Hernández-Martínez, Miguel; Córdova-Téllez, Leobigildo

    2010-04-01

    Sorghum ergot (caused by Claviceps africana) is a disease that affects sorghum seed development and yield. The interaction between pollen tube growth and hyphal development determines whether ovaries will be fertilized or colonized. Thus their respective deposition times on the stigma are critical. The effect of the time interval between pollination and inoculation on stigma receptivity and seed production was measured under field conditions in the male-sterile line A9 at Montecillo, State of México (2240m altitude). Pollination and inoculation treatments, from simultaneous application to 2 and 4h difference, were imposed when all stigmas on the panicle had emerged. Control panicles were either only pollinated or only inoculated. Eighteen hours later, pollen grains that adhered to, and germinated within the stigma, pollen tubes in the style and ovary, and fertilized pistils were counted. Pistils showing some disease expression (germinated spores, mycelium growth, or tissue necrosis) at 18, 48, and 72h were recorded. The number of diseased florets was registered at the dough growth stage, while number of seeds, grain yield and 100-seeds weight was measured at the physiological maturity. The pathogen applied in a water suspension of macro and secondary conidia caused a decrease in stigma receptivity; the greatest decrease (40-60%) occurred when the pollen and the inoculum were deposited almost simultaneously, regardless of which was deposited first. The route of the pollen tube was also the route for fungal infection. On average, treatments first inoculated had 60% more diseased florets and 36% less grain yield, 30% fewer seeds and seed size decreased 8%, than those first pollinated. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Aerobiological study in east-central Iberian Peninsula: pollen diversity and dynamics for major taxa.

    PubMed

    Pérez-Badia, Rosa; Rapp, Ana; Vaquero, Consolación; Fernández-González, Federico

    2011-01-01

    A study was made of airborne pollen counts in Cuenca (east-central Iberian Peninsula, Spain), using data obtained over a 3-year period (2008-2010). This is the first such study carried out in the World Heritage city of Cuenca, situated in the large region of Castilla-La Mancha. Air monitoring was performed using the sampling and analysis procedures recommended by the Spanish Aerobiology Network. Sampling commenced in mid- 2007, and provided the first recorded pollen-spectrum for the area. The greatest pollen-type diversity was recorded in spring, whilst the highest pollen counts (over 80 percent of the annual total) were observed between February and June. The lowest counts were found in September, November and December. The 10 leading taxa, in order of abundance, were: Cupressaceae, Quercus, Urticaceae, Pinus, Olea, Poaceae, Populus, Platanus, Chenopodiaceae-Amaranthaceae and Plantago. The pollen calendar was thus typically Mediterrean, and comprised the 27 pollen types reaching 10-day mean counts of over 1 grain/m(3) of air. Maximum concentration values during the day were recorded between 12:00-20:00, coinciding with the highest temperatures and lowest humidity levels. The pollen types responsible for most allergies in the city of Cuenca, ordered by the number of days on which risk levels were reached, were: Poaceae, Urticaceae, Cupressaceae, Olea, Platanus and Chenopodiaceae-Amaranthaceae.

  5. Among-species differences in pollen quality and quantity limitation: implications for endemics in biodiverse hotspots.

    PubMed

    Alonso, Conchita; Navarro-Fernández, Carmen M; Arceo-Gómez, Gerardo; Meindl, George A; Parra-Tabla, Víctor; Ashman, Tia-Lynn

    2013-11-01

    Insufficient pollination is a function of quantity and quality of pollen receipt, and the relative contribution of each to pollen limitation may vary with intrinsic plant traits and extrinsic ecological properties. Community-level studies are essential to evaluate variation across species in quality limitation under common ecological conditions. This study examined whether endemic species are more limited by pollen quantity or quality than non-endemic co-flowering species in three endemic-rich plant communities located in biodiversity hotspots of different continents (Andalusia, California and Yucatan). Natural variations in pollen receipt and pollen tube formation were analysed for 20 insect-pollinated plants. Endemic and non-endemic species that co-flowered were paired in order to estimate and compare the quantity and quality components of pre-zygotic pollination success, obtained through piecewise regression analysis of the relationship between pollen grains and pollen tubes of naturally pollinated wilted flowers. Pollen tubes did not frequently exceed the number of ovules per flower. Only the combination of abundant and good quality pollen and a low number of ovules per flower conferred relief from pre-zygotic pollen limitation in the three stochastic pollination environments studied. Quality of pollen receipt was found to be as variable as quantity among study species. The relative pollination success of endemic and non-endemic species, and its quantity and quality components, was community dependent. Assessing both quality and quantity of pollen receipt is key to determining the ovule fertilization potential of both endemic and widespread plants in biodiverse hotspot regions. Large natural variation among flowers of the same species in the two components and pollen tube formation deserves further analysis in order to estimate the environmental, phenotypic and intraindividual sources of variation that may affect how plants evolve to overcome this limitation in

  6. Analysis of morphological and molecular composition changes in allergenic Artemisia vulgaris L. pollen under traffic pollution using SEM and FTIR spectroscopy.

    PubMed

    Depciuch, J; Kasprzyk, I; Roga, E; Parlinska-Wojtan, M

    2016-11-01

    Nowadays, pollen allergy becomes an increasing problem for human population. Common mugwort (Artemisia vulgaris L.) is one of the major allergenic plants in Europe. In this study, the influence of air pollution caused by traffic on the structure and chemical composition of common mugwort pollen was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and curve-fitting analysis of amide I profile was applied to assess the morphological and structural changes of mugwort pollen grains collected from sites with different vehicle pollution levels. Microscopic observations support the conclusion, that the higher the car traffic, the smaller the pollen grains. The obtained results clearly show that air pollution had an impact on different maximum absorbance values of individual functional groups composing the chemical structure of pollen. Moreover, air pollution induced structural changes in macromolecules of mugwort pollen. In pollen collected from the unpolluted site, the content of sporopollenin (850 cm -1 ) was the highest, whereas polysaccharide concentration (1032 cm -1 ) was the lowest. Significant differences were observed in lipids. Pollen collected from the site with heavy traffic had the lowest content of lipids at 1709, 2071, and 2930 cm -1 . The largest differences were observed in the spectra regions corresponding to proteins. In pollen collected from unpolluted site, the highest level of β-sheet (1600 cm -1 ) and α-helix (1650 cm -1 ) was detected. The structural changes in proteins, observed in the second derivative of the FTIR spectrum and in the curve-fitting analysis of amide I profile, could be caused inter alia by air pollutants. Alterations in protein structure and in their content in the pollen may increase the sensitization and subsequent risk of allergy in predisposed people. The obtained results suggest that the changes in chemical composition of pollen may be a good indicator of air quality and

  7. Genome-wide analyses of late pollen-preferred genes conserved in various rice cultivars and functional identification of a gene involved in the key processes of late pollen development.

    PubMed

    Moon, Sunok; Oo, Moe Moe; Kim, Backki; Koh, Hee-Jong; Oh, Sung Aeong; Yi, Gihwan; An, Gynheung; Park, Soon Ki; Jung, Ki-Hong

    2018-04-23

    Understanding late pollen development, including the maturation and pollination process, is a key component in maintaining crop yields. Transcriptome data obtained through microarray or RNA-seq technologies can provide useful insight into those developmental processes. Six series of microarray data from a public transcriptome database, the Gene Expression Omnibus of the National Center for Biotechnology Information, are related to anther and pollen development. We performed a systematic and functional study across the rice genome of genes that are preferentially expressed in the late stages of pollen development, including maturation and germination. By comparing the transcriptomes of sporophytes and male gametes over time, we identified 627 late pollen-preferred genes that are conserved among japonica and indica rice cultivars. Functional classification analysis with a MapMan tool kit revealed a significant association between cell wall organization/metabolism and mature pollen grains. Comparative analysis of rice and Arabidopsis demonstrated that genes involved in cell wall modifications and the metabolism of major carbohydrates are unique to rice. We used the GUS reporter system to monitor the expression of eight of those genes. In addition, we evaluated the significance of our candidate genes, using T-DNA insertional mutant population and the CRISPR/Cas9 system. Mutants from T-DNA insertion and CRISPR/Cas9 systems of a rice gene encoding glycerophosphoryl diester phosphodiesterase are defective in their male gamete transfer. Through the global analyses of the late pollen-preferred genes from rice, we found several biological features of these genes. First, biological process related to cell wall organization and modification is over-represented in these genes to support rapid tube growth. Second, comparative analysis of late pollen preferred genes between rice and Arabidopsis provide a significant insight on the evolutional disparateness in cell wall biogenesis

  8. Are the birch trees in Southern England a source of Betula pollen for North London?

    PubMed

    Skjøth, C A; Smith, M; Brandt, J; Emberlin, J

    2009-01-01

    Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts>80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts (n=60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200-0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

  9. Amyloplast Membrane Protein SUBSTANDARD STARCH GRAIN6 Controls Starch Grain Size in Rice Endosperm1

    PubMed Central

    Matsushima, Ryo; Maekawa, Masahiko; Kusano, Miyako; Tomita, Katsura; Kondo, Hideki; Nishimura, Hideki; Crofts, Naoko; Fujita, Naoko; Sakamoto, Wataru

    2016-01-01

    Starch is a biologically and commercially important polymer of glucose. Starch is organized into starch grains (SGs) inside amyloplasts. The SG size differs depending on the plant species and is one of the most important factors for industrial applications of starch. There is limited information on genetic factors regulating SG sizes. In this study, we report the rice (Oryza sativa) mutant substandard starch grain6 (ssg6), which develops enlarged SGs in endosperm. Enlarged SGs are observed starting at 3 d after flowering. During endosperm development, a number of smaller SGs appear and coexist with enlarged SGs in the same cells. The ssg6 mutation also affects SG morphologies in pollen. The SSG6 gene was identified by map-based cloning and microarray analysis. SSG6 encodes a protein homologous to aminotransferase. SSG6 differs from other rice homologs in that it has a transmembrane domain. SSG6-green fluorescent protein is localized in the amyloplast membrane surrounding SGs in rice endosperm, pollen, and pericarp. The results of this study suggest that SSG6 is a novel protein that controls SG size. SSG6 will be a useful molecular tool for future starch breeding and applications. PMID:26792122

  10. Effect of enhanced UV-B radiation on pollen quantity, quality, and seed yield in Brassica rapa (Brassicaceae)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Demchik, S.M.; Day, T.A.

    Three experiments examined the influence of ultraviolet-B radiation (UV-B; 280-320 nm) exposure on reproduction in Brassica rapa (Brassicacaeae). Plants were grown in a greenhouse under three biologically effective UV-B levels that stimulated either an ambient stratospheric ozone level (control), 16% ({open_quotes}low enhanced{close_quotes}), or 32% ({open_quotes}high enhanced{close_quotes}) ozone depletion levels at Morgantown, WV, USA in mid-March. In the first experiment,pollen production and viability per flower were reduced by {approx}50% under both enhanced UV-B levels relative to ambient controls. While plants under high-enhanced UV-B produced over 40% more flowers than plants under the two lower UV-B treatments, whole-plant production of viable pollenmore » was reduced under low-enhanced UV-B to 34% of ambient controls. In the second experiment, the influence of source-plant UV-B exposure on in vitro pollen from plants was examined and whether source-plant UV-B exposure influenced in vitro pollen germination and viability. Pollen from plants under both enhanced-UV-B was reduced from 65 to 18%. Viability of the pollen from plants grown under both enhanced UV-B treatments was reduced to a much lesser extent: only from {approx}43 to 22%. Thus, ambient source-plant pollen was more sensitive to enhanced UV-B levels to fertilize plants growing under ambient-UV-B levels, and assessed subsequent seed production and germination. Seed abortion rates were higher in plants pollinated with pollen from the enhanced UV-B treatments, than from ambient UV-B. Despite this, seed yield (number and mass) per plant was similar, regardless of the UV-B exposure of their pollen source. Our findings demonstrate that enhanced UV-B levels associated with springtime ozone depletion events have the capacity to substantially reduce viable pollen production, and could ultimately reduce reproductive success of B. rapa. 37 refs., 4 figs., 2 tabs.« less

  11. Mental health consequences of abortion and refused abortion.

    PubMed

    Watter, W W

    1980-02-01

    There is no scientific evidence to support the hypothesis put forth by Dr. Philip Ney in a recent article published in the Canadian Journal of Psychiatry that induced abortion is associated with an increase in child abuse. There are, however, numerous studies which support the contention that mandatory motherhood adversely affects the mental health of both the mother and the offspring. Studies conducted in Sweden, Scotland, and Czechoslovakia revealed that women who were refused abortions frequently experienced serious psychosocial difficulties for long periods of time following abortion refusal. Case controlled follow-up studies, conducted in Sweden and Czechoslovakia, of offspring born to women who were refused abortions demonstrated that a higher proportion of the unwanted children required psychiatric services, engaged in criminal behavior, and did less well in school than the controlled children. These studies have implications for the current Canadian law which permits a woman to obtain an abortion if pregnancy continuation will endanger her health. In view of the above statistical evidence, and the fact that mortality and morbidity are known to be lower for abortion than for childbirth, any person who denies a woman the right to have an abortion is increasing the risk that the health of the woman will be endangered. By law, therefore, all abortion requests should be honored.

  12. Using flow cytometry to estimate pollen DNA content: improved methodology and applications

    PubMed Central

    Kron, Paul; Husband, Brian C.

    2012-01-01

    Background and Aims Flow cytometry has been used to measure nuclear DNA content in pollen, mostly to understand pollen development and detect unreduced gametes. Published data have not always met the high-quality standards required for some applications, in part due to difficulties inherent in the extraction of nuclei. Here we describe a simple and relatively novel method for extracting pollen nuclei, involving the bursting of pollen through a nylon mesh, compare it with other methods and demonstrate its broad applicability and utility. Methods The method was tested across 80 species, 64 genera and 33 families, and the data were evaluated using established criteria for estimating genome size and analysing cell cycle. Filter bursting was directly compared with chopping in five species, yields were compared with published values for sonicated samples, and the method was applied by comparing genome size estimates for leaf and pollen nuclei in six species. Key Results Data quality met generally applied standards for estimating genome size in 81 % of species and the higher best practice standards for cell cycle analysis in 51 %. In 41 % of species we met the most stringent criterion of screening 10 000 pollen grains per sample. In direct comparison with two chopping techniques, our method produced better quality histograms with consistently higher nuclei yields, and yields were higher than previously published results for sonication. In three binucleate and three trinucleate species we found that pollen-based genome size estimates differed from leaf tissue estimates by 1·5 % or less when 1C pollen nuclei were used, while estimates from 2C generative nuclei differed from leaf estimates by up to 2·5 %. Conclusions The high success rate, ease of use and wide applicability of the filter bursting method show that this method can facilitate the use of pollen for estimating genome size and dramatically improve unreduced pollen production estimation with flow cytometry. PMID

  13. Effect of sporophytic PIRL9 genotype on post-meiotic expression of the Arabidopsis pirl1;pirl9 mutant pollen phenotype.

    PubMed

    Forsthoefel, Nancy R; Vernon, Daniel M

    2011-02-01

    Plant intracellular ras-group-related leucine-rich repeat proteins (PIRLs) are a novel class of plant leucine-rich repeat (LRR) proteins structurally related to animal ras-group LRRs involved in cell signaling and gene regulation. Gene knockout analysis has shown that two members of the Arabidopsis thaliana PIRL gene family, PIRL1 and PIRL9, are redundant and essential for pollen development and viability: pirl1;pirl9 microspores produced by pirl1/PIRL1;pirl9 plants consistently abort just before pollen mitosis I. qrt1 tetrad analysis demonstrated that the genes become essential after meiosis, during anther stage 10. In this study, we characterized the phenotype of pirl1;pirl9 pollen produced by plants heterozygous for pirl9 (pirl1;pirl9/PIRL9). Alexander's staining, scanning electron microscopy, and fluorescence microscopy indicated that pirl1;pirl9 double mutants produced by pirl9 heterozygotes have a less severe phenotype and more variable morphology than pirl1;pirl9 pollen from pirl1/PIRL1;pirl9 plants. Mutant pollen underwent developmental arrest with variable timing, often progressing beyond pollen mitosis I and arresting at the binucleate stage. Thus, although the pirl1 and pirl9 mutations act post-meiosis, the timing and expressivity of the pirl1;pirl9 pollen phenotype depends on the pirl9 genotype of the parent plant. These results suggest a continued requirement for PIRL1 and PIRL9 beyond the initiation of pollen mitosis. Furthermore, they reveal a modest but novel sporophytic effect in which parent plant genotype influences a mutant phenotype expressed in the haploid generation.

  14. Husbands' attitudes towards abortion and Canadian abortion law.

    PubMed

    Osborn, R W; Silkey, B

    1980-01-01

    In a 1975 study of attitudes toward abortion among a stratified sample of 601 men residing in Toronto and married to women of reproductive age, non-Catholic men and men who had weak religious beliefs had significantly more permissive attitudes toward abortion than Catholic men and men who had strong religious beliefs. Each respondent received a scale score based on his acceptance of abortion under 7 different conditions. The 7 conditions were: 1) threat to maternal life; 2) pregnancy due to rape; 3) predicted birth of a mentally or physically handicapped child; 4) threat to maternal mental health; 5) unmarried mother; 6) marriage breakdown; and 7) inability to financially support the child. A high score indicated a permissive attitude toward abortion. High scores were associated with high income and educational levels, non-Catholic affiliation, weak religious beliefs, and being Canadian by birth. When religious factors were controlled, the effect of the other factors was markedly reduced. No association was observed between scale scores and the variables of age and expected family size. A majority of the men approved of abortion for 5 or more of the above listed situations. Men with high scores were more likely to use effective methods of contraception, to be married to women who had abortions, and to favor less restrictive abortion laws. Non-Catholic men and men with weaker religious beliefs were more likely to favor easing the abortion law than Catholic men and men who had strong religious beliefs. Those with higher income and educational levels within each religious group were also more likely to favor easing the law. Tables show: 1) the % distribution of respondents approving abortion by reason for the abortion; and 2) the results of the analyses using various measures of association.

  15. A Study of Incomplete Abortion Following Medical Method of Abortion (MMA).

    PubMed

    Pawde, Anuya A; Ambadkar, Arun; Chauhan, Anahita R

    2016-08-01

    Medical method of abortion (MMA) is a safe, efficient, and affordable method of abortion. However, incomplete abortion is a known side effect. To study incomplete abortion due to medication abortion and compare to spontaneous incomplete abortion and to study referral practices and prescriptions in cases of incomplete abortion following MMA. Prospective observational study of 100 women with first trimester incomplete abortion, divided into two groups (spontaneous or following MMA), was administered a questionnaire which included information regarding onset of bleeding, treatment received, use of medications for abortion, its prescription, and administration. Comparison of two groups was done using Fisher exact test (SPSS 21.0 software). Thirty percent of incomplete abortions were seen following MMA; possible reasons being self-administration or prescription by unregistered practitioners, lack of examination, incorrect dosage and drugs, and lack of follow-up. Complications such as collapse, blood requirement, and fever were significantly higher in these patients compared to spontaneous abortion group. The side effects of incomplete abortions following MMA can be avoided by the following standard guidelines. Self medication, over- the-counter use, and prescription by unregistered doctors should be discouraged and reported, and need of follow-up should be emphasized.

  16. Pollen resistance to water in 80 angiosperm species: flower structures protect rain-susceptible pollen.

    PubMed

    Mao, Yun-Yun; Huang, Shuang-Quan

    2009-08-01

    Flowers exhibit adaptive responses to biotic and abiotic factors. It remains unclear whether pollen susceptibility to rain damage plays a role in the evolution of floral form. We investigated flower performance in rain and compared pollen longevity in dry conditions, pure water and solutions with different sucrose concentrations in 80 flowering species from 46 families with diverse floral shapes and pollination modes. A pollen viability test showed that pollen longevity in all studied species was greatly reduced by wetting. We found that pollen of species with complete protection by flower structures was susceptible to water damage and a high proportion of resistant pollen occurred in unprotected species. Flowers whose structures expose pollen to rain may also reduce rain damage through temporal patterns of pollen presentation. This prediction was supported by our direct measurement of pollen presentation duration on rainy days. Our observations showed that variation in pollen performance in water was associated with differences in floral forms. Water-resistant pollen and extended pollen presentation duration were favored by selection via rain contact in species in which pollen was not protected from rain. These findings support the functional hypothesis that flower structures protect susceptible pollen from rain, demonstrating that rain acts as a force shaping floral form.

  17. The pollen complex from postglacial sediments of the Laptev Sea as a bioindicator

    NASA Astrophysics Data System (ADS)

    Naidina, O. D.

    2014-05-01

    The first results of comparison of palynological analysis (pollen of terrestrial plants), SEM analysis of pollen morphology, and radiocarbon age dating (AMS14C) of sediments of the eastern shelf of the Laptev Sea show that the diverse taxonomic composition of pollen spectra provides an integrated idea of the vegetation and climate of the region over 11.2 calendar kiloyears. It is found that phases of the tree and shrub vegetation development (maxima of pollen of Betula sect. Nanae and Pinus s/g Haploxylon) correspond to the warm epochs in the Holocene. It is obvious that birch phytocoenoses first settled in the southern tundra subzone with increasing temperature, and then coniferous communities of forest tundra. An occurrence of pollen of shrubby birches (Nanae) suggests compliance of permafrost landscapes with cold climate conditions, i.e., with an annual average temperature of -2°C and amount of precipitation of less than 500 mm. Owing to a progressive increase in summer temperatures, dwarf cedar and pine communities advanced toward the seashore. The SEM analysis results show that a significant proportion of regional coniferous pollen belongs to representatives of Pinus pumila (Pall.) and P. sylvestris L. In addition, the SEM study of the exine of Pinus sylvestris L. and P. pumila (Pall.) Regel pollen grains confirmed polymorphism in coniferous pollen. According to the inverse relationship between climate and vegetation, frequent climate fluctuations that are typical of progressive and differential postglacial transgression were revealed. An increase in arboreal pollen transfer onto the shelf later than 9.1 cal. ka coincides with the time of forest boundary migration to the north due to the warming of the Earth's climate. At that time, the tundra vegetation was replaced by forest-tundra vegetation, the maximum stage of sea transgression began, and there appeared a trend of increasing temperature and moisture.

  18. Airborne Quercus pollen in SW Spain: Identifying favourable conditions for atmospheric transport and potential source areas.

    PubMed

    Maya-Manzano, José María; Fernández-Rodríguez, Santiago; Smith, Matt; Tormo-Molina, Rafael; Reynolds, Andrew M; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela; Sadyś, Magdalena

    2016-11-15

    The pollen grains of Quercus spp. (oak trees) are allergenic. This study investigates airborne Quercus pollen in SW Spain with the aim identifying favourable conditions for atmospheric transport and potential sources areas. Two types of Quercus distribution maps were produced. Airborne Quercus pollen concentrations were measured at three sites located in the Extremadura region (SW Spain) for 3 consecutive years. The seasonal occurrence of Quercus pollen in the air was investigated, as well as days with pollen concentrations ≥80Pm(-3). The distance that Quercus pollen can be transported in appreciable numbers was calculated using clusters of back trajectories representing the air mass movement above the source areas (oak woodlands), and by using a state-of-the-art dispersion model. The two main potential sources of Quercus airborne pollen captured in SW Spain are Q. ilex subsp. ballota and Q. suber. The minimum distances between aerobiological stations and Quercus woodlands have been estimated as: 40km (Plasencia), 66km (Don Benito), 62km (Zafra) from the context of this study. Daily mean Quercus pollen concentration can exceed 1,700Pm(-3), levels reached not less than 24 days in a single year. High Quercus pollen concentration were mostly associated with moderate wind speed events (6-10ms(-1)), whereas that a high wind speed (16-20ms(-1)) seems to be associated with low concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Comprehensive analysis of tobacco pollen transcriptome unveils common pathways in polar cell expansion and underlying heterochronic shift during spermatogenesis

    PubMed Central

    2012-01-01

    Background Many flowering plants produce bicellular pollen. The two cells of the pollen grain are destined for separate fates in the male gametophyte, which provides a unique opportunity to study genetic interactions that govern guided single-cell polar expansion of the growing pollen tube and the coordinated control of germ cell division and sperm cell fate specification. We applied the Agilent 44 K tobacco gene chip to conduct the first transcriptomic analysis of the tobacco male gametophyte. In addition, we performed a comparative study of the Arabidopsis root-hair trichoblast transcriptome to evaluate genetic factors and common pathways involved in polarized cell-tip expansion. Results Progression of pollen grains from freshly dehisced anthers to pollen tubes 4 h after germination is accompanied with > 5,161 (14.9%) gametophyte-specific expressed probes active in at least one of the developmental stages. In contrast, > 18,821 (54.4%) probes were preferentially expressed in the sporophyte. Our comparative approach identified a subset of 104 pollen tube-expressed genes that overlap with root-hair trichoblasts. Reverse genetic analysis of selected candidates demonstrated that Cu/Zn superoxide dismutase 1 (CSD1), a WD-40 containing protein (BP130384), and Replication factor C1 (NtRFC1) are among the central regulators of pollen-tube tip growth. Extension of our analysis beyond the second haploid mitosis enabled identification of an opposing-dynamic accumulation of core regulators of cell proliferation and cell fate determinants in accordance with the progression of the germ cell cycle. Conclusions The current study provides a foundation to isolate conserved regulators of cell tip expansion and those that are unique for pollen tube growth to the female gametophyte. A transcriptomic data set is presented as a benchmark for future functional studies using developing pollen as a model. Our results demonstrated previously unknown functions of certain genes in pollen

  20. Static and elevated pollen traps do not provide an accurate assessment of personal pollen exposure.

    PubMed

    Penel, V; Calleja, M; Pichot, C; Charpin, D

    2017-03-01

    Background. Volumetric pollen traps are commonly used to assess pollen exposure. These traps are well suited for estimating the regional mean airborne pollen concentration but are likely not to provide an accurate index of personal exposure. In this study, we tested the hypothesis that hair sampling may provide different pollen counts from those from pollen traps, especially when the pollen exposure is diverse. Methods. We compared pollen counts in hair washes to counts provided by stationary volumetric and gravimetric pollen traps in 2 different settings: urban with volunteers living in short distance from one another and from the static trap and suburban in which volunteers live in a scattered environment, quite far from the static trap. Results. Pollen counts in hair washes are in full agreement with trap counts for uniform pollen exposure. In contrast, for diverse pollen exposure, .individual pollen counts in hair washes vary strongly in quantity and taxa composition between individuals and dates. These results demonstrate that the pollen counts method (hair washes vs. stationary pollen traps) may lead to different absolute and relative contributions of taxa to the total pollen count. Conclusions. In a geographic area with a high diversity of environmental exposure to pollen, static pollen traps, in contrast to hair washes, do not provide a reliable estimate of this higher diversity.

  1. Abortion in Indonesia.

    PubMed

    Sedgh, Gilda; Ball, Haley

    2008-09-01

    Each year in Indonesia, millions of women become pregnant unintentionally, and many choose to end their pregnancies, despite the fact that abortion is generally illegal. Like their counterparts in many developing countries where abortion is stigmatized and highly restricted, Indonesian women often seek clandestine procedures performed by untrained providers, and resort to methods that include ingesting unsafe substances and undergoing harmful abortive massage. Though reliable evidence does not exist, researchers estimate that about two million induced abortions occur each year in the country and that deaths from unsafe abortion represent 14-16% of all maternal deaths in Southeast Asia. Preventing unsafe abortion is imperative if Indonesia is to achieve the fifth Millennium Development Goal of improving maternal health and reducing maternal mortality. Current Indonesian abortion law is based on a national health bill passed in 1992. Though the language on abortion was vague, it is generally accepted that the law allows abortion only if the woman provides confirmation from a doctor that her pregnancy is life-threatening, a letter of consent from her husband or a family member, a positive pregnancy test result and a statement guaranteeing that she will practice contraception afterwards. This report presents what is currently known about abortion in Indonesia. The findings are derived primarily from small-scale, urban, clinic-based studies of women's experiences with abortion. Some studies included women in rural areas and those who sought abortions outside of clinics, but none were nationally representative. Although these studies do not give a full picture of who is obtaining abortions in Indonesia or what their experiences are, the evidence suggests that abortion is a common occurrence in the country and that the conditions under which abortion takes place are often unsafe.

  2. Maize pollen coat xylanase facilitates pollen tube penetration into silk during sexual reproduction.

    PubMed

    Suen, Der Fen; Huang, Anthony H C

    2007-01-05

    Cell wall hydrolases are well documented to be present on pollen, but their roles on the stigma during sexual reproduction have not been previously demonstrated. We explored the function of the tapetum-synthesized xylanase, ZmXYN1, on maize (Zea mays L.) pollen. Transgenic lines (xyl-less) containing little or no xylanase in the pollen coat were generated with use of an antisense construct of the xylanase gene-coding region driven by the XYN1 gene promoter. Xyl-less and wild-type plants had similar vegetative growth. Electron microscopy revealed no appreciable morphological difference in anther cells and pollen between xyl-less lines and the wild type, whereas immunofluorescence microscopy and biochemical analyses indicated an absence of xylanase on xyl-less pollen. Xyl-less pollen germinated as efficiently as wild-type pollen in vitro in a liquid medium but less so on gel media of increasing solidity or on silk, which is indicative of partial impaired water uptake. Once germinated in vitro or on silk, the xyl-less and wild-type pollen tubes elongated at comparable rates. Tubes of germinated xyl-less pollen on silk did not penetrate into the silk as efficiently as tubes of wild-type pollen, and this lower efficiency could be overcome by the addition of xylanase to the silk. For wild-type pollen, coat xylanase activity on oat spelled xylan in vitro and tube penetration into silk were inhibited by xylose but not glucose. The overall findings indicate that maize pollen coat xylanase facilitates pollen tube penetration into silk via enzymatic xylan hydrolysis.

  3. Abortion rights down under.

    PubMed

    Kirkby, M

    1994-08-01

    State and federal governments in Australia fear actively trying to ensure access to abortion. No federal abortion law in Australia exists. Abortion is a state matter. The federal government's health care system does reimburse women for abortion services, however. State laws prohibit unlawful abortions but they do not define what they mean by unlawful abortion. Victoria, New South Wales, and Queensland have had common law interpretations of their Crimes Acts, which allow greater access to abortion. Tasmania and Western Australia have not had common law interpretations. Thus, even though abortion is available, women and providers are not secure. Abortion reform in South Australia and the Northern Territory has made access to abortion more difficult. A woman must be a resident in South Australia for 2 months before she can obtain an abortion. Abortions are allowed only in a clinic or a hospital. Women in metropolitan Melbourne and Sydney have good access to abortion services, while those in the country or in an isolated part of NSW or Victoria may have an antiabortion physician serving their area. Women in Queensland, Tasmania, and Western Australia pay a lot for an abortion because they also have to pay for airfare to a large city. Only a gynecologist can perform abortions in the Northern Territory. Social workers often coerce Aboriginal women into an abortion. The few antiabortion physicians have a big impact on whether women receive abortion information or not. Research at Adelaide and Flinders Universities show that abortion-related trauma is linked to obtaining information and access to abortion services. Physicians are nervous about performing abortions because abortion is still in the Crimes Acts and Criminal Codes, making it difficult to recruit high quality and empathetic practitioners. Antiabortion groups are small and tend not to adopt extreme tactics. The Abortion Rights Network of Australia has recently been formed.

  4. A Six-Year Study on the Changes in Airborne Pollen Counts and Skin Positivity Rates in Korea: 2008-2013.

    PubMed

    Park, Hye Jung; Lee, Jae-Hyun; Park, Kyung Hee; Kim, Kyu Rang; Han, Mae Ja; Choe, Hosoeng; Oh, Jae-Won; Hong, Chein-Soo

    2016-05-01

    The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of 4442 skin-prick tests conducted at the Severance Hospital Allergy-Asthma Clinic from January 1, 2008 to December 31, 2013. For 6 years, the mean monthly total pollen count showed two peaks, one in May and the other in September. Pollen count for grasses also showed the same trend. The pollen counts for trees, grasses, and weeds changed annually, but the changes were not significant. The annual skin positivity rates in response to pollen from grasses and weeds increased significantly over the 6 years. Among trees, the skin positivity rates in response to pollen from walnut, popular, elm, and alder significantly increased over the 6 years. Further, there was a significant correlation between the annual rate of change in pollen count and the rate of change in skin positivity rate for oak and hop Japanese. The pollen counts and skin positivity rates should be monitored, as they have changed annually. Oak and hop Japanese, which showed a significant correlation with the annual rate of change in pollen count and the rate of change in skin positivity rate over the 6 years may be considered the major allergens in Korea.

  5. Phosphoproteomics Profiling of Tobacco Mature Pollen and Pollen Activated in vitro *

    PubMed Central

    Fíla, Jan; Radau, Sonja; Matros, Andrea; Hartmann, Anja; Scholz, Uwe; Feciková, Jana; Mock, Hans-Peter; Čapková, Věra; Zahedi, René Peiman; Honys, David

    2016-01-01

    Tobacco mature pollen has extremely desiccated cytoplasm, and is metabolically quiescent. Upon re-hydration it becomes metabolically active and that results in later emergence of rapidly growing pollen tube. These changes in cytoplasm hydration and metabolic activity are accompanied by protein phosphorylation. In this study, we subjected mature pollen, 5-min-activated pollen, and 30-min-activated pollen to TCA/acetone protein extraction, trypsin digestion and phosphopeptide enrichment by titanium dioxide. The enriched fraction was subjected to nLC-MS/MS. We identified 471 phosphopeptides that carried 432 phosphorylation sites, position of which was exactly matched by mass spectrometry. These 471 phosphopeptides were assigned to 301 phosphoproteins, because some proteins carried more phosphorylation sites. Of the 13 functional groups, the majority of proteins were put into these categories: transcription, protein synthesis, protein destination and storage, and signal transduction. Many proteins were of unknown function, reflecting the fact that male gametophyte contains many specific proteins that have not been fully functionally annotated. The quantitative data highlighted the dynamics of protein phosphorylation during pollen activation; the identified phosphopeptides were divided into seven groups based on the regulatory trends. The major group comprised mature pollen-specific phosphopeptides that were dephosphorylated during pollen activation. Several phosphopeptides representing the same phosphoprotein had different regulation, which pinpointed the complexity of protein phosphorylation and its clear functional context. Collectively, we showed the first phosphoproteomics data on activated pollen where the position of phosphorylation sites was clearly demonstrated and regulatory kinetics was resolved. PMID:26792808

  6. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    PubMed Central

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  7. Phleum pratense pollen starch granules induce humoral and cell-mediated immune responses in a rat model of allergy.

    PubMed

    Motta, A; Peltre, G; Dormans, J A M A; Withagen, C E T; Lacroix, G; Bois, F; Steerenberg, P A

    2004-02-01

    Timothy grass (Phleum pratense) pollen allergens are an important cause of allergic symptoms. However, pollen grains are too large to penetrate the deeper airways. Grass pollen is known to release allergen-bearing starch granules (SG) upon contact with water. These granules can create an inhalable allergenic aerosol capable of triggering an early asthmatic response and are implicated in thunderstorm-associated asthma. We studied the humoral (IgE) and bronchial lymph node cells reactivities to SG from timothy grass pollen in pollen-sensitized rats. Brown-Norway rats were sensitized (day 0) and challenged (day 21) intratracheally with intact pollen and kept immunized by pollen intranasal instillation by 4 weeks intervals during 3 months. Blood and bronchial lymph nodes were collected 7 days after the last intranasal challenge. SG were purified from fresh timothy grass pollen using 5 microm mesh filters. To determine the humoral response (IgE) to SG, we developed an original ELISA inhibition test, based on competition between pollen allergens and purified SG. The cell-mediated response to SG in the bronchial lymph node cells was determined by measuring the uptake of [3H]thymidine in a proliferation assay. An antibody response to SG was induced, and purified SG were able to inhibit the IgE ELISA absorbance by 45%. Pollen extract and intact pollen gave inhibitions of 55% and 52%, respectively. A cell-mediated response was also found, as pollen extract, intact pollen and SG triggered proliferation of bronchial lymph node cells. It was confirmed that timothy grass pollen contains allergen-loaded SG, which are released upon contact with water. These granules were shown to be recognized by pollen-sensitized rats sera and to trigger lymph node cell proliferation in these rats. These data provide new arguments supporting the implication of grass pollen SG in allergic asthma.

  8. Investigation of heterogeneous ice nucleation in pollen suspensions and washing water

    NASA Astrophysics Data System (ADS)

    Dreischmeier, Katharina; Budke, Carsten; Koop, Thomas

    2014-05-01

    Biological particles such as pollen often show ice nucleation activity at temperatures higher than -20 °C. Immersion freezing experiments of pollen washing water demonstrate comparable ice nucleation behaviour as water containing the whole pollen bodies (Pummer et al., 2012). It was suggested that polysaccharide molecules leached from the grains are responsible for the ice nucleation. Here, heterogeneous ice nucleation in birch pollen suspensions and their washing water was investigated by two different experimental methods. The optical freezing array BINARY (Bielefeld Ice Nucleation ARraY) allows the direct observation of freezing of microliter-sized droplets. The IN spectra obtained from such experiments with birch pollen suspensions over a large concentration range indicate several different ice nucleation active species, two of which are present also in the washing water. The latter was probed also in differential scanning calorimeter (DSC) experiments of emulsified sub-picoliter droplets. Due to the small droplet size in the emulsion samples and at small concentration of IN in the washing water, such DSC experiments can exhibit the ice nucleation behaviour of a single nucleus. The two heterogeneous freezing signals observed in the DSC thermograms can be assigned to two different kinds of ice nuclei, confirming the observation from the BINARY measurements, and also previous studies on Swedish birch pollen washing water (Augustin et al., 2012). The authors gratefully acknowledge funding by the German Research Foundation (DFG) through the project BIOCLOUDS (KO 2944/1-1) and through the research unit INUIT (FOR 1525) under KO 2944/2-1. We particularly thank our INUIT partners for fruitful collaboration and sharing of ideas and IN samples. S. Augustin, H. Wex, D. Niedermeier, B. Pummer, H. Grothe, S. Hartmann, L. Tomsche, T. Clauss, J. Voigtländer, K. Ignatius, and F. Stratmann, Immersion freezing of birch pollen washing water, Atmos. Chem. Phys., 13, 10989

  9. OSL and pollen concentrate 14C dating of dammed lake sediments at Maoxian, east Tibet, and implications for two historical earthquakes in AD 638 and 952

    NASA Astrophysics Data System (ADS)

    Xu, H.; Jiang, H.; Yu, S.; Yang, H.; Chen, J.

    2016-12-01

    Formation of dammed lakes provides exceptionally important information of continental geological processes, responding to tectonic and climatic influences. Establishing accurate geochronological frameworks within lake strata is challenging because the stratigraphy is often bereft of biostratigraphy and directly dateable material. Optically Stimulated Luminescence (OSL) and AMS 14C dating of pollen concentrates are well-established tools for dating lake sediments. Whether they are suitable for lake sediments in high-alpine settings remains uncertain. In this study, OSL and AMS 14C dating of pollen concentrate were conducted on the Diaolin section in a high-alpine setting in the eastern Tibetan Plateau. Good match of both dating results suggests that they are fit for dating lake sediments in high alpine settings. More than 300 g of sediment is required for preparation of pollen concentrates. During the pretreatment, 3% NaOH solution should be added to the sample, and then heated until just boiling ( 5 min) because NaOH treatment easily destroys pollen grains. Applying the heavy liquid flotation with specific gravity of 1.74-1.76 is useful to isolate relatively pure pollen grains. Sieving with a 20-μm and 63-μm mesh can concentrate pollen grains substantially. The OSL and AMS 14C dating yielded the basal age of the Diaolin section (650 AD). This indicates that the dammed-lake formed around 650 AD, probably caused by the earthquake occurring in the study area in 638 AD. The seismites characterized by soft-sediment deformation and phyllite layer happened at 780-980 AD, probably corresponding to the earthquake occurring on November 20, 952 AD in the study area.

  10. CARBON-14 FIXATION IN POLLEN OF YELLOW LUPINE (LUPINUS LUTEUS LINN.)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schwien, W.G.; Frazier, J.C.; Moser, H.C.

    1962-10-31

    Carbon-14 fixation studies were made on germinated pollen of yellow lupine to ascertain whether the chlorophyll reported to be in these grains was functional photosynthetically. Light and dark exposures to atmospheres containing 20 and 500 mu c of carbon-14 labeled carbon dioxide were made for 1.5 and 45 minutes, respectively. The exposed pollen was extracted in 80% ethanol, the resulting extract reduced in volume, and chromatographed two dimensionally. When the chromatograms were cut inio numbered small squares and their activity counted in an automatic sample counting system, a marked similarity was observed in the pattern of radioactivity from all exposures.more » Eluting and co- chromatographing this activity from the squares, with known standards, demonstrated labeling to be specific to certain intermediates of the Krebs cycle and their derived amine acids. The labeling in these intermediates and the absence of labeling in photosynthetic metabolites is strong evidence that only respiratory fixation of carbon-14 occurs in the germinated pollen of this variety of yellow lupine under the conditions of the experiment. (auth)« less

  11. Abortion legalized: challenges ahead.

    PubMed

    Singh, M; Jha, R

    2007-01-01

    To see whether advocacy for abortion law and comprehensive abortion care (CAC) sites after legalization of abortion in Nepal is adequate among educated people (above school leaving certificate). 150 participants were assigned randomly who agreed to be in the survey and were given structured questionnaires to find out their perception of abortion and CAC sites. Majority know abortion is legalized and majority have positive attitude about legalization of abortion, however majority are not aware of abortion service in CAC sites and none knew the cost of abortion service. Proper and adequate advocacy of the new abortion law and CAC service is essential.

  12. The politicization of abortion and the evolution of abortion counseling.

    PubMed

    Joffe, Carole

    2013-01-01

    The field of abortion counseling originated in the abortion rights movement of the 1970s. During its evolution to the present day, it has faced significant challenges, primarily arising from the increasing politicization and stigmatization of abortion since legalization. Abortion counseling has been affected not only by the imposition of antiabortion statutes, but also by the changing needs of patients who have come of age in a very different era than when this occupation was first developed. One major innovation--head and heart counseling--departs in significant ways from previous conventions of the field and illustrates the complex and changing political meanings of abortion and therefore the challenges to abortion providers in the years following Roe v Wade.

  13. Anti-legal attitude toward abortion among abortion patients in the United States.

    PubMed

    Thomas, Rachel G; Norris, Alison H; Gallo, Maria F

    2017-11-01

    To measure the prevalence of believing that abortion should be illegal in all or most cases among women obtaining an abortion in the United States and to identify correlates of holding this belief. Study population was drawn from the nationally-representative 2008 Abortion Patient Survey. The primary outcome was having an anti-legal abortion attitude, defined as agreeing that abortion should be illegal in all or most cases. We assessed potential correlates in bivariable and multivariable analyses using weights to account for the complex sampling. A total of 4769 abortion patients completed the survey module containing the question on abortion legality, of which 4492 (94.2%) had non-missing data for the outcome. Overall, 4.1% of patients (N=183) reported an anti-legal abortion attitude. Correlates of having anti-legal attitude included being married, at <200% federal poverty level, fundamentalist, contraception non-use, no abortion history, perceiving the pregnancy with ambivalence or as unintended, and using misoprostol or another product on their own to bring back their period or end the pregnancy. Abortion patients who do not believe abortion should be legal appear to differ substantially from women who are more supportive of legality. Findings raise important questions about this subset of patients, including whether possible discordance between patient beliefs and behavior could influence their use of medical abortion or other products. Some abortion patients do not agree with abortion legality, and this subset could experience a degree of cognitive dissonance, which could influence the method by which they seek to abort. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Morphological and genetic characterization of a new cytoplasmic male sterility system (oxa CMS) in stem mustard (Brassica juncea).

    PubMed

    Heng, Shuangping; Liu, Sansan; Xia, Chunxiu; Tang, HongYu; Xie, Fei; Fu, Tingdong; Wan, Zhengjie

    2018-01-01

    KEY MESSAGE: oxa CMS is a new cytoplasmic male sterility type in Brassica juncea. oxa CMS is a cytoplasmic male sterility (CMS) line that has been widely used in the production and cultivation of stem mustard in the southwestern China. In this study, different CMS-type specific mitochondrial markers were used to confirm that oxa CMS is distinct from the pol CMS, ogu CMS, nap CMS, hau CMS, tour CMS, Moricandia arvensis CMS, orf220-type CMS, etc., that have been previously reported in Brassica crops. Pollen grains of the oxa CMS line are sterile with a self-fertility rate of almost 0% and the sterility strain rate and sterility degree of oxa CMS is 100% due to a specific flower structure and flowering habit. Scanning electron microscopy revealed that most pollen grains in mature anthers of the oxa CMS line are empty, flat and deflated. Semi-thin section further showed that the abortive stage of anther development in oxa CMS is initiated at the late uninucleate stage. Abnormally vacuolated microspores caused male sterility in the oxa CMS line. This cytological study combined with marker-assisted selection showed that oxa CMS is a novel CMS type in stem mustard (Brassica juncea). Interestingly, the abortive stage of oxa CMS is later than those in other CMS types reported in Brassica crops, and there is no negative effect on the oxa CMS line growth period. This study demonstrated that this novel oxa CMS has a unique flower structure with sterile pollen grains at the late uninucleate stage. Our results may help to uncover the mechanism of oxa CMS in Brassica juncea.

  15. Why Abortion is Illegal? Comparison of Legal and Illegal Abortion: A Critical Review.

    PubMed

    Huq, M E; Raihan, M J; Shirin, H; Chowdhury, S; Jahan, Y; Chowdhury, A S; Rahman, M M

    2017-10-01

    Abortion is the termination of pregnancy that occurs spontaneously or purposely. In the most developed world, abortion is legally allowed for women seeking safe termination of pregnancies. Particularly, when access to legal abortion is restricted, abortion is the resort to unsafe methods. The aim of this review is to necessitate safe abortion and to accentuate the consequences of illegal abortion in case of legal prohibition. We used Pubmed, MedLine and Scopus databases to review previous literatures of safe, unsafe, legal and illegal abortions. Research work and reports from organizations such as World Health Organization (WHO), World Bank (WB) and United Nations (UN) were included. Snowball sampling was used to obtain relevant journals. Abortion is conventional whether it is safe, unsafe, legal or illegal. The intention of the antiabortion policy was to reduce the number of abortions globally. However, instead of decreasing rates, evidences show significant increase in abortions. When abortion is legal, the preconditions to be ensured are availability, accessibility, affordability and acceptability for the safe abortion facilities. When abortion is illegal, risk reduction strategies are needed to decrease maternal morbidity and mortality. We can reduce abortion related morbidity and mortality, whether it is legal or illegal if we can ensure the appropriate access to health care, including abortion services, education on sexuality, access to contraceptives, post abortion care, and suitable interventions and liberalization of laws. The paper reviewed the Mexico City Policy and the US foreign aid strategies and highlighted the evidence based analysis for policy reform. The liberalized abortion law can save pregnant women from abortion related complications and death.

  16. Abortion

    MedlinePlus

    An abortion is a procedure to end a pregnancy. It uses medicine or surgery to remove the embryo or ... personal. If you are thinking of having an abortion, most health care providers advise counseling.

  17. High levels of grass pollen inside European dairy farms: a role for the allergy-protective effects of environment?

    PubMed

    Sudre, B; Vacheyrou, M; Braun-Fahrländer, C; Normand, A-C; Waser, M; Reboux, G; Ruffaldi, P; von Mutius, E; Piarroux, R

    2009-07-01

    There is evidence of an allergy protective effect in children raised on farm. It has been assumed that microbial exposure may confer this protection. However in farm, little attention has been given to the pollen level and to concomitant microbiological exposure, and indoor pollen concentrations have never been precisely quantified. The kinetics of pollen in dairy farms have been studied in a pilot study (n = 9), and exposure in a sub-sample of the ongoing European birth cohort PASTURE (n = 106). Measurements of viable microorganisms and pollen were performed in air samples. To identify factors that modulate the pollen concentration multivariate regression analyses were run. Indoor pollen (95% of Poaceae fragments and grains) were significantly higher in winter than in summer (P = 0.001) and ranged between 858 to 11 265 counts/m(3) during feeding in winter, thus exceeding typical outdoor levels during the pollen season. Geometric mean in French farms was significantly higher than in German and Swiss farms (7 534, 992 and 1 079 count/m(3), respectively). The presence of a ventilation system and loose housing systems significantly reduced indoor pollen levels. This pollen concentration rise after feeding was accompanied by an increase in fungal and actinomycetal levels, whereas the concentration of bacteria was not associated with feeding. Farmers and their children who attend cowsheds during the feeding sessions are exposed perennially to high pollen concentrations. It might be speculated that the combined permanent exposure to microbes from livestock and grass pollen may initiate tolerance in children living on a farm.

  18. The cell wall of the Arabidopsis pollen tube--spatial distribution, recycling, and network formation of polysaccharides.

    PubMed

    Chebli, Youssef; Kaneda, Minako; Zerzour, Rabah; Geitmann, Anja

    2012-12-01

    The pollen tube is a cellular protuberance formed by the pollen grain, or male gametophyte, in flowering plants. Its principal metabolic activity is the synthesis and assembly of cell wall material, which must be precisely coordinated to sustain the characteristic rapid growth rate and to ensure geometrically correct and efficient cellular morphogenesis. Unlike other model species, the cell wall of the Arabidopsis (Arabidopsis thaliana) pollen tube has not been described in detail. We used immunohistochemistry and quantitative image analysis to provide a detailed profile of the spatial distribution of the major cell wall polymers composing the Arabidopsis pollen tube cell wall. Comparison with predictions made by a mechanical model for pollen tube growth revealed the importance of pectin deesterification in determining the cell diameter. Scanning electron microscopy demonstrated that cellulose microfibrils are oriented in near longitudinal orientation in the Arabidopsis pollen tube cell wall, consistent with a linear arrangement of cellulose synthase CESA6 in the plasma membrane. The cellulose label was also found inside cytoplasmic vesicles and might originate from an early activation of cellulose synthases prior to their insertion into the plasma membrane or from recycling of short cellulose polymers by endocytosis. A series of strategic enzymatic treatments also suggests that pectins, cellulose, and callose are highly cross linked to each other.

  19. Terrigenous fluxes of pollen, insect scale and land plant palynodebris observed by sediment traps deployed in the subarctic Pacific

    NASA Astrophysics Data System (ADS)

    Tsutsui, H.; Takahashi, K.; Matsuoka, K.; Jordan, R. W.; Yamamoto, S.

    2016-02-01

    From 1990 to 2009, sediment traps were deployed and recovered in the subarctic Pacific (Station SA; 49°N, 174°W) during each summer, allowing the long-term observation of particle fluxes. As the Pacific Decadal Oscillation index changed in 1999 while air temperatures cooled, this study focused on pollen, land plant debris and insect scale fluxes during 1994 to 2009 at Station SA. The maximum pollen and fern spores flux was 644 grains m2 d-1, with a mean of 74 grains m2 d-1and the following details: 65% of the total pollen counts represented by wind-pollinated trees (e.g., alder, birch and pine), 24% by the herbaceous plants, and 11% by fern spores. Spore, herbaceous and wind-pollinated tree pollen fluxes peaked primarily in May (and sporadically also in April and June) and September-October. The annual flux peaks of insect scales (of unknown origin) and land-plant debris were in May and September, but over the entire study period the maximum insect scale flux of 161 scales m2 d-1 was in August 2002, with a mean of 16 scales m2 d-1. Furthermore, the maximum (in August 2004) and mean land-plant debris fluxes were 107 and 10 plant fragments m2 d-1, respectively. The sediment traps were situated at southern side of the Aleutian Islands, where snow and ice occurred for six months from October to May. The ice-snow season accounts for 25% of the total annual particle flux, with 75% throughout the rest of the year. The correlation coefficient among pollen, insect scales and land plant debris are: 1) 0.58 (probability <1%) between wind-pollinated plant pollen and insect scales, and 2) 0.75 (probability <5%) between herbaceous plant pollen and land plant debris. The production locations, residence time, routes and mode of transport of the particles are important factors. The pollen fluxes observed during April to June appeared to have originated from the Western Alaska, but during the rest of years they appeared to have been from the eastern Russia. That pollen and other

  20. Abortion: a history.

    PubMed

    Hovey, G

    1985-01-01

    This review of abortion history considers sacred and secular practice and traces abortion in the US, the legacy of the 19th century, and the change that occurred in the 20th century. Abortion has been practiced since ancient times, but its legality and availability have been threatened continuously by forces that would denigrate women's fundamental rights. Currently, while efforts to decrease the need for abortion through contraception and education continue, access to abortion remains crucial for the well-being of millions of women. That access will never be secure until profound changes occur in the whole society. Laws that prohibit absolutely the practice of abortion are a relatively recent development. In the early Roman Catholic church, abortion was permitted for male fetuses in the first 40 days of pregnancy and for female fetuses in the first 80-90 days. Not until 1588 did Pope Sixtus V declare all abortion murder, with excommunication as the punishment. Only 3 years later a new pope found the absolute sanction unworkable and again allowed early abortions. 300 years would pass before the Catholic church under Pius IX again declared all abortion murder. This standard, declared in 1869, remains the official position of the church, reaffirmed by the current pope. In 1920 the Soviet Union became the 1st modern state formally to legalize abortion. In the early period after the 1917 revolution, abortion was readily available in state operated facilities. These facilities were closed and abortion made illegal when it became clear that the Soviet Union would have to defend itself against Nazi Germany. After World War II women were encouraged to enter the labor force, and abortion once again became legal. The cases of the Catholic church and the Soviet Union illustrate the same point. Abortion legislation has never been in the hands of women. In the 20th century, state policy has been determined by the rhythms of economic and military expansion, the desire for cheap

  1. Religion and attitudes toward abortion and abortion policy in Brazil.

    PubMed

    Ogland, Curtis P; Verona, Ana Paula

    2011-01-01

    This study examines the association between religion and attitudes toward the practice of abortion and abortion policy in Brazil. Drawing upon data from the 2002 Brazilian Social Research Survey (BSRS), we test a number of hypotheses with regard to the role of religion on opposition to the practice of abortion and its legalization. Findings indicate that frequently attending Pentecostals demonstrate the strongest opposition to the practice of abortion and both frequently attending Pentecostals and Catholics demonstrate the strongest opposition to its legalization. Additional religious factors, such as a commitment to biblical literalism, were also found to be significantly associated with opposition to both abortion issues. Ultimately, the findings have implications for the future of public policy on abortion and other contentious social issues in Brazil.

  2. Atmospheric solids analysis probe mass spectrometry for the rapid identification of pollens and semi-quantification of flavonoid fingerprints.

    PubMed

    Xiao, Xiaoyin; Miller, Lance L; Parchert, Kylea J; Hayes, Dulce; Hochrein, James M

    2016-07-15

    From allergies to plant reproduction, pollens have important impacts on the health of human and plant populations, yet identification of pollen grains remains difficult and time-consuming. Low-volatility flavonoids generated from pollens cannot be easily characterized and quantified with current analytical techniques. Here we present the novel use of atmospheric solids analysis probe mass spectrometry (ASAP-MS) for the characterization of flavonoids in pollens. Flavonoid patterns were generated for pollens collected from different plant types (trees and bushes) in addition to bee pollens from distinct geographic regions. Standard flavonoids (kaempferol and rhamnazin) and those produced from pollens were compared and assessed with ASAP-MS using low-energy collision MS/MS. Results for a semi-quantitative method for assessing the amount of a flavonoid in pollens are also presented. Flavonoid patterns for pollen samples were distinct with variability in the number and relative abundance of flavonoids in each sample. Pollens contained 2-5 flavonoids, and all but Kochia scoparia contained kaempferol or kaempferol isomers. We establish this method as a reliable and applicable technique for analyzing low-volatility compounds with minimal sample preparation. Standard curves were generated using 0.2-5 μg of kaempferol; from these experiments, it was estimated that there is approximately 2 mg of kaempferol present in 1 g of P. nigra italica pollen. Pollens can be characterized with a simple flavonoid pattern rather than analyzing the whole product pattern or the products-temperature profiles. ASAP-MS is a rapid analytical technique that can be used to distinguish between plant pollens and between bee pollens originating from different regions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Behaviour of Quercus pollen in the air, determination of its sources and transport through the atmosphere of Mexico City and conurbated areas.

    PubMed

    Calderón-Ezquerro, M C; Martinez-Lopez, B; Guerrero-Guerra, C; López-Espinosa, E D; Cabos-Narvaez, W D

    2018-06-15

    Pollen allergies have a remarkable clinical impact all over world. Quercus pollen is the main allergen in many parts of world. Due to the health impacts caused by exposure to oak pollen, the objectives of this study are to characterise the aerobiological behaviour of Quercus pollen and to determine its potential sources as well as their transport through the atmosphere of Mexico City and surrounding areas between January 2012 and June 2015. Airborne Quercus pollen monitoring was carried out simultaneously in five zones of Mexico City. The percentage of Quercus pollen of the total pollen collected from the air showed that the highest concentration was recorded in 2014, followed by 2012. The annual seasonal variation indicated that flowering and pollen emission into the atmosphere began between February and March. The maximum concentration of Quercus pollen was reached at Cuajimalpa. In 2012, the amount of pollen grains was distributed in March and April uniformly, whilst in 2014, the largest amount of pollen was concentrated in March. In 2012 and 2014 (years with the highest pollen concentrations), corresponding intraday variations were quite similar, with a low relative maximum in the morning and the highest concentrations in the evening. The largest values were recorded in 2014, and two processes can explain these. In the afternoon, pollen from secondary forest is carried by southwesterly converging winds, increasing the pollen concentration in Cuajimalpa. In the evening, there is an additional pollen contribution from primary forest via transport by NW winds.

  4. Abortion trends from 1996 to 2011 in Estonia: special emphasis on repeat abortion

    PubMed Central

    2014-01-01

    Background The study aimed to describe the overall and age-specific trends of induced abortions from 1996 to 2011 with an emphasis on socio-demographic characteristics and contraceptive use of women having had repeat abortions in Estonia. Methods Data were retrieved from the Estonian Medical Birth and Abortion Registry and Statistics Estonia. Total induced abortion numbers, rates, ratios and age-specific rates are presented for 1996–2011. The percentage change in the number of repeat abortions within selected socio-demographic subgroups, contraception use and distribution of induced abortions among Estonians and non-Estonians for the first, second, third, fourth and subsequent abortions were calculated for the periods 1996–2003 and 2004–2011. Results Observed trends over the 16-year study period indicated a considerable decline in induced abortions with a reduction in abortion rate of 57.1%, which was mainly attributed to younger cohorts. The percentage of women undergoing repeat abortions fell steadily from 63.8% during 1996–2003 to 58.0% during 2004–2011. The percentage of women undergoing repeat abortions significantly decreased over the 16 years within all selected socio-demographic subgroups except among women with low educational attainment and students. Within each time period, a greater percentage of non-Estonians than Estonians underwent repeat abortions and obtained third and subsequent abortions. Most women did not use any contraceptive method prior to their first or subsequent abortion. Conclusion A high percentage of women obtaining repeat abortions reflects a high historical abortion rate. If current trends continue, a rapid decline in repeat abortions may be predicted. To decrease the burden of sexual ill health, routine contraceptive counselling, as standard care in the abortion process, should be seriously addressed with an emphasis on those groups - non-Estonians, women with lower educational attainment, students and women with children

  5. Effect of abortion protesters on women's emotional response to abortion.

    PubMed

    Foster, Diana Greene; Kimport, Katrina; Gould, Heather; Roberts, Sarah C M; Weitz, Tracy A

    2013-01-01

    Little is known about women's experiences with and reactions to protesters and how protesters affect women's emotional responses to abortion. We interviewed 956 women seeking abortion between 2008 and 2010 at 30 U.S. abortion care facilities and informants from 27 of these facilities. Most facilities reported a regular protester presence; one third identified protesters as aggressive towards patients. Nearly half (46%) of women interviewed saw protesters; of those, 25% reported being "a little" upset, and 16% reported being "quite a lot" or "extremely" upset. Women who had difficulty deciding to abort had higher odds of reporting being upset by protesters. In multivariable models, exposure to protesters was not associated with differences in emotions 1 week after the abortion. Protesters do upset some women seeking abortion services. However, exposure to protesters does not seem to have an effect on women's emotions about the abortion 1 week later. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Misinformation on abortion.

    PubMed

    Rowlands, Sam

    2011-08-01

    To find the latest and most accurate information on aspects of induced abortion. A literature survey was carried out in which five aspects of abortion were scrutinised: risk to life, risk of breast cancer, risk to mental health, risk to future fertility, and fetal pain. Abortion is clearly safer than childbirth. There is no evidence of an association between abortion and breast cancer. Women who have abortions are not at increased risk of mental health problems over and above women who deliver an unwanted pregnancy. There is no negative effect of abortion on a woman's subsequent fertility. It is not possible for a fetus to perceive pain before 24 weeks' gestation. Misinformation on abortion is widespread. Literature and websites are cited to demonstrate how data have been manipulated and misquoted or just ignored. Citation of non-peer reviewed articles is also common. Mandates insisting on provision of inaccurate information in some US State laws are presented. Attention is drawn to how women can be misled by Crisis Pregnancy Centres. There is extensive promulgation of misinformation on abortion by those who oppose abortion. Much of this misinformation is based on distorted interpretation of the scientific literature.

  7. Modelling of pollen dispersion in the atmosphere: evaluation with a continuous 1β+1δ lidar

    NASA Astrophysics Data System (ADS)

    Sicard, Michaël; Izquierdo, Rebeca; Jorba, Oriol; Alarcón, Marta; Belmonte, Jordina; Comerón, Adolfo; De Linares, Concepción; Baldasano, José Maria

    2018-04-01

    Pollen allergenicity plays an important role on human health and wellness. It is thus of large public interest to increase our knowledge of pollen grain behavior in the atmosphere (source, emission, processes involved during their transport, etc.) at fine temporal and spatial scales. First simulations with the Barcelona Supercomputing Center NMMB/BSC-CTM model of Platanus and Pinus dispersion in the atmosphere were performed during a 5-day pollination event observed in Barcelona, Spain, between 27 - 31 March, 2015. The simulations are compared to vertical profiles measured with the continuous Barcelona Micro Pulse Lidar system. First results show that the vertical distribution is well reproduced by the model in shape, but not in intensity, the model largely underestimating in the afternoon. Guidelines are proposed to improve the dispersion of airborne pollen by numerical prediction models.

  8. Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. 'Bluecrop' (VACCINIUM CORYMBOSUM; Ericaceae).

    PubMed

    Dogterom, M H; Winston, M L; Mukai, A

    2000-11-01

    Reproductive fitness of a plant is ultimately determined by both number and quality of seed offspring. This is determined by sexual selection of pollen microspores and ovules during pollination and fertilization. These processes may include pollen competition and seed abortion, which reduce the number of microspores and ovules available for final seed production. Thus, even an excess of pollen microspores to ovules does not result in fertile seeds equal to ovule number. We investigated pollen requirements of highbush blueberry (Vaccinium corymbosum cultivar 'Bluecrop') for maximal seed production and how fertile seed number translates into fruit quality, since fruit quality would ultimately determine the dispersal of its offspring. We demonstrate that individual blueberry flowers with a mean of 106 ovules reach their maximum fruit set and mass and minimum time to ripen when 125 outcross pollen tetrads pollinate a flower, compared to 10 or 25. Three hundred tetrads resulted in the increase of fertile seeds, but did not result in a further increase of fruit mass or fruit set, or decrease in time to ripen. We also examined the effect of pure and mixed loads of self and outcross pollen (25 and 125 tetrads), and found no differences in fertile seed number, fruit mass, or percentage fruit set when pollen loads were either 25 self or outcross pollen tetrads, although number of days to ripen was significantly shorter by 8 d with 25 outcross tetrads. When the pollen load of 125 tetrads consisted of self or a 50:50 mixture of self and outcross pollen, fruit mass, days to ripen, and percentage fruit set were not different from loads of 125 outcross pollen. In addition, a pollen load of 25 outcross tetrads resulted in fertile seed number and fruit quality in between that of 25 self, and 125 self, 125 mixed, or 125 outcross tetrads. Large, small, and flat seed types were identified, and only large seeds (length = 1.7 mm) were fertile. These results improve our understanding of

  9. Abortion.

    PubMed

    Cattanach, J F

    1979-03-10

    As abortion is the destruction of individual human life, if an abortion is to be performed at all there must be grave reasons for it which should necessitate complete documentation. Surely human life should be given that respect at least. Legislation should oblige any doctor intending to perform an induced abortion to list the indications which in his or her opinion make that abortion lawful. A signed copy of that opinion should be sent to an official authority of notification. This authority could be developed along the lines of the Neonatal Deaths Committees with authority to check any such notification through consultant tribunals, similar to those existing in New Zealand, which would have access to the patient. The simplest way to ensure that an induced abortion of a viable pregnancy has not occurred at any curettage is to pass legislation which would make it mandatory that all tissue obtained at all uterine curettages or evacuations be sent for histopathological examination. Should the pathologist find evidence of an induced abortion or hysterotomy a copy of the pathology report would then be sent to the official committee. The usual copies would be sent to the doctor and hospital concerned. All such procedures would have to be carried out at registered hospitals. All medical staff members and nurses would have access to such reports. It would be a grave offence for the doctor, pathologist or hospital not to comply with the above procedure. The official committee would have the power to demand samples of tissue for examination by its own consultant pathologist, and to investigate irregularities in the above procedure. Pathologists concur that induced abortion can be accurately differentiated from other types of abortion, as there is an infiltration of polymorphs into the decidua within about three hours of fetal death in incomplete abortion, and there are other features such as hyalinization of placental villi. Apparently, these differences are so basic that a

  10. Chromosome number, microsporogenesis, microgametogenesis, and pollen viability in the Brazilian native grass Mesosetum chaseae (Poaceae).

    PubMed

    Silva, L A C; Pagliarini, M S; Santos, S A; Silva, N; Souza, V F

    2012-11-28

    The genus Mesosetum is a primarily South American genus with 42 species. Mesosetum chaseae, regionally known as 'grama-do-cerrado', is abundant in the Pantanal Matogrossense (Brazil); it is a valuable resource for livestock and for environmental conservation. We collected specimens from the Nhecolandia sub-region of the Brazilian Pantanal, located in Corumbá, Mato Grosso do Sul, Brazil. We examined chromosome number, ploidy level, meiotic behavior, microgametogenesis, and pollen viability of 10 accessions. All the accessions were diploid, derived from x = 8, presenting 2n = 2x = 16 chromosomes. Chromosomes paired as bivalents showing, predominantly, two terminal chiasmata. Interstitial chiasmata were rare. Meiosis was quite normal producing only a few abnormal tetrads in some accessions. Microgametogenesis, after two mitotic divisions, produced three-celled pollen grains. Pollen viability was variable among plant and accessions and was not correlated with meiotic abnormalities.

  11. Cypress surrogate mother produces haploid progeny from alien pollen.

    PubMed

    Pichot, Christian; Liens, Benjamin; Nava, Juana L Rivera; Bachelier, Julien B; El Maâtaoui, Mohamed

    2008-01-01

    Although most living organisms reproduce sexually, some have developed a uniparental reproduction where the embryo usually derives from the female parent. A unique case of paternal apomixis in plants has been recently reported in Cupressus dupreziana, an endangered Mediterranean conifer. This species produces unreduced pollen that develop into all-paternal embryos within the seed tissues. We analyzed seedlings produced by open-pollinated C. dupreziana seed trees using morphological descriptors, ploidy levels assessed through flow cytometry, and AFLP genetic diversity. In situ C. dupreziana seed trees (from Algeria) produced only diploid C. dupreziana progeny. In contrast, only one-third of the progeny produced by ex situ C. dupreziana seed trees planted in French collections were similar to C. dupreziana seedlings; the other progeny were haploid or diploid C. sempervirens seedlings. These results demonstrate that C. dupreziana ovules allow for the development of all-paternal embryos from pollen produced by another species, C. sempervirens. Thus, the in planta androgenesis is achieved through the combination of the embryogenic behavior of pollen grains and the ability of seed tree ovules to act as a surrogate mother. This phenomenon offers a unique opportunity to produce, by natural means, highly valuable material for genetic studies and selection of sterile cultivars.

  12. Functional architecture of two exclusively late stage pollen-specific promoters in rice (Oryza sativa L.).

    PubMed

    Yan, Shuo; Wang, Zhongni; Liu, Yuan; Li, Wei; Wu, Feng; Lin, Xuelei; Meng, Zheng

    2015-07-01

    Late stage pollen-specific promoters are important tools in crop molecular breeding. Several such promoters, and their functional motifs, have been well characterized in dicotyledonous plants such as tomato and tobacco. However, knowledge about the functional architecture of such promoters is limited in the monocotyledonous plant rice. Here, pollen-late-stage-promoter 1 (PLP1) and pollen-late-stage-promoter 2 (PLP2) were characterized using a stable transformation system in rice. Histochemical staining showed that the two promoters exclusively drive GUS expression in late-stage pollen grains in rice. 5' deletion analysis revealed that four regions, including the -1159 to -720 and the -352 to -156 regions of PLP1 and the -740 to -557 and the -557 to -339 regions of PLP2, are important in maintaining the activity and specificity of these promoters. Motif mutation analysis indicated that 'AGAAA' and 'CAAT' motifs in the -740 to -557 region of PLP2 act as enhancers in the promoter. Gain of function experiments indicated that the novel TA-rich motif 'TACATAA' and 'TATTCAT' in the core region of the PLP1 and PLP2 promoters is necessary, but not sufficient, for pollen-specific expression in rice. Our results provide evidence that the enhancer motif 'AGAAA' is conserved in the pollen-specific promoters of both monocots and eudicots, but that some functional architecture characteristics are different.

  13. Population Group Abortion Rates and Lifetime Incidence of Abortion: United States, 2008-2014.

    PubMed

    Jones, Rachel K; Jerman, Jenna

    2017-12-01

    To assess the prevalence of abortion among population groups and changes in rates between 2008 and 2014. We used secondary data from the Abortion Patient Survey, the American Community Survey, and the National Survey of Family Growth to estimate abortion rates. We used information from the Abortion Patient Survey to estimate the lifetime incidence of abortion. Between 2008 and 2014, the abortion rate declined 25%, from 19.4 to 14.6 per 1000 women aged 15 to 44 years. The abortion rate for adolescents aged 15 to 19 years declined 46%, the largest of any group. Abortion rates declined for all racial and ethnic groups but were larger for non-White women than for non-Hispanic White women. Although the abortion rate decreased 26% for women with incomes less than 100% of the federal poverty level, this population had the highest abortion rate of all the groups examined: 36.6. If the 2014 age-specific abortion rates prevail, 24% of women aged 15 to 44 years in that year will have an abortion by age 45 years. The decline in abortion was not uniform across all population groups.

  14. [Demand for abortion. Pre-abortion discussion].

    PubMed

    Guiol, L

    1994-03-01

    The preabortion interview required by French law takes place between the medical consultation and the aspiration or administration of RU-486. The three marriage counselors at the Center for Social Gynecology in Marseilles have each undertaken a course of personal therapy to enable them to understand their own reactions and motivations as a way of improving their effectiveness with clients. The preabortion interview is an opportunity to listen to and support women who may be experiencing anguish, sadness, ambivalence, or aggressivity. Each client determines the content of the interview. Often the reason for the abortion is given, frequently in terms of economic problems, unemployment, or other justification. The women almost always state that they "cannot", not that they "do not want", to continue the pregnancy, as if external circumstances had made their decision. The decision is usually made with little discussion. Young adolescents are often astounded to find themselves pregnant. Among young girls, the pregnancy may represent an appeal to the parents for attention or understanding. Sometimes the abortion represents a repetition or a reminder of some difficult event in the past, such as a previous abortion or the death of a child. Often the abortion exacerbates problems in the couple's relationship. The mother often experiences rejection of the pregnancy by the father as rejection of herself. Repeat abortions raise questions about whether some aspect of counseling was neglected. The abortion request always occasions a great feeling of guilt, both for being pregnant and for refusing the pregnancy. The interview permits the client to express her feelings and may help her make sense of the experience.

  15. Two callose synthases, GSL1 and GSL5, play an essential and redundant role in plant and pollen development and in fertility.

    PubMed

    Enns, Linda C; Kanaoka, Masahiro M; Torii, Keiko U; Comai, Luca; Okada, Kiyotaka; Cleland, Robert E

    2005-06-01

    Callose, a beta-1,3-glucan that is widespread in plants, is synthesized by callose synthase. Arabidopsis thaliana contains a family of 12 putative callose synthase genes (GSL1-12). The role of callose and of the individual genes in plant development is still largely uncertain. We have now used TILLING and T-DNA insertion mutants (gsl1-1, gsl5-2 and gsl5-3) to study the role of two closely related and linked genes, GSL1 and GSL5, in sporophytic development and in reproduction. Both genes are expressed in all parts of the plant. Sporophytic development was nearly normal in gsl1-1 homozygotes and only moderately defective in homozygotes for either of the two gsl5 alleles. On the other hand, plants that were gsl1-1/+ gsl5/gsl5 were severely defective, with smaller leaves, shorter roots and bolts and smaller flowers. Plants were fertile when the sporophytes had either two wild-type GSL1 alleles, or one GSL5 allele in a gsl1-1 background, but gsl1-1/+ gsl5/gsl5 plants produced an extremely reduced number of viable seeds. A chromosome with mutations in both GSL1 and GSL5 rendered pollen infertile, although such a chromosome could be transmitted via the egg. As a result, it was not possible to obtain plants that were homozygous for mutations in both the GSL genes. Pollen grain development was severely affected in double mutant plants. Many pollen grains were collapsed and inviable in the gsl1-1/gsl1-1 gsl5/+ and gsl1-1/+ gsl5/gsl5 plants. In addition, gsl1-1/+ gsl5/gsl5 plants produced abnormally large pollen with unusual pore structures, and had problems with tetrad dissociation. In this particular genotype, while the callose wall formed around the pollen mother cells, no callose wall separated the resulting tetrads. We conclude that GSL1 and GSL5 play important, but at least partially redundant roles in both sporophytic development and in the development of pollen. They are responsible for the formation of the callose wall that separates the microspores of the tetrad

  16. Vegetative and sperm cell-specific aquaporins of Arabidopsis highlight the vacuolar equipment of pollen and contribute to plant reproduction.

    PubMed

    Wudick, Michael M; Luu, Doan-Trung; Tournaire-Roux, Colette; Sakamoto, Wataru; Maurel, Christophe

    2014-04-01

    The water and nutrient status of pollen is crucial to plant reproduction. Pollen grains of Arabidopsis (Arabidopsis thaliana) contain a large vegetative cell and two smaller sperm cells. Pollen grains express AtTIP1;3 and AtTIP5;1, two members of the Tonoplast Intrinsic Protein subfamily of aquaporins. To address the spatial and temporal expression pattern of the two homologs, C-terminal fusions of AtTIP1;3 and AtTIP5;1 with green fluorescent protein and mCherry, respectively, were expressed in transgenic Arabidopsis under the control of their native promoter. Confocal laser scanning microscopy revealed that AtTIP1;3 and AtTIP5;1 are specific for the vacuoles of the vegetative and sperm cells, respectively. The tonoplast localization of AtTIP5;1 was established by reference to fluorescent protein markers for the mitochondria and vacuoles of sperm and vegetative cells and is at variance with the claim that AtTIP5;1 is localized in vegetative cell mitochondria. AtTIP1;3-green fluorescent protein and AtTIP5;1-mCherry showed concomitant expression, from first pollen mitosis up to pollen tube penetration in the ovule, thereby revealing the dynamics of vacuole morphology in maturating and germinating pollen. Transfer DNA insertion mutants for either AtTIP1;3 or AtTIP5;1 showed no apparent growth phenotype and had no significant defect in male transmission of the mutated alleles. By contrast, a double knockout displayed an abnormal rate of barren siliques, this phenotype being more pronounced under limited water or nutrient supply. The overall data indicate that vacuoles of vegetative and sperm cells functionally interact and contribute to male fertility in adverse environmental conditions.

  17. Update on abortion policy.

    PubMed

    Conti, Jennifer A; Brant, Ashley R; Shumaker, Heather D; Reeves, Matthew F

    2016-12-01

    To review the status of antiabortion restrictions enacted over the last 5 years in the United States and their impact on abortion services. In recent years, there has been an alarming rise in the number of antiabortion laws enacted across the United States. In total, various states in the union enacted 334 abortion restrictions from 2011 to July 2016, accounting for 30% of all abortion restrictions since the legalization of abortion in 1973. Data confirm, however, that more liberal abortion laws do not increase the number of abortions, but instead greatly decrease the number of abortion-related deaths. Several countries including Romania, South Africa and Nepal have seen dramatic decreases in maternal mortality after liberalization of abortion laws, without an increase in the total number of abortions. In the United States, abortions are incredibly safe with very low rates of complications and a mortality rate of 0.7 per 100 000 women. With increasing abortion restrictions, maternal mortality in the United States can be expected to rise over the coming years, as has been observed in Texas recently. Liberalization of abortion laws saves women's lives. The rising number of antiabortion restrictions will ultimately harm women and their families.

  18. BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris

    PubMed Central

    Lyu, Meiling; Yu, Youjian; Jiang, Jingjing; Song, Limin; Liang, Ying; Ma, Zhiming; Xiong, Xingpeng; Cao, Jiashu

    2015-01-01

    Polygalacturonase (PG) is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a) and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants. PMID:26153985

  19. Native bee diversity and pollen foraging specificity in cultivated highbush blueberry (Ericaceae: Vaccinium corymbosum) in Rhode Island

    USGS Publications Warehouse

    Scott, Zachary; Ginsberg, Howard; Alm, Steven R.

    2016-01-01

    We identified 41 species of native bees from a total of 1,083 specimens collected at cultivated highbush blueberry plantings throughout Rhode Island in 2014 and 2015. Andrena spp., Bombus spp., and Xylocopa virginica (L.) were collected most often. Bombus griseocollis (DeGeer), B. impatiens Cresson, B. bimaculatus Cresson, B. perplexus Cresson, and Andrena vicina Smith collected the largest mean numbers of blueberry pollen tetrads. The largest mean percent blueberry pollen loads were carried by the miner bees Andrena bradleyi Viereck (91%), A. carolina Viereck (90%), and Colletes validus Cresson (87%). The largest mean total pollen grain loads were carried by B. griseocollis (549,844), B. impatiens (389,558), X. virginica (233,500), and B. bimaculatus (193,132). Xylocopa virginica was the fourth and fifth most commonly collected bee species in 2014 and 2015, respectively. They exhibit nectar robbing and females carried relatively low blueberry pollen loads (mean 33%). Overall, we found 10 species of bees to be the primary pollinators of blueberries in Rhode Island.

  20. Public funding of abortions and abortion counseling for poor women.

    PubMed

    Edwards, R B

    1997-01-01

    This essay seeks to reveal the weakness in arguments against public funding of abortions and abortion counseling in the US based on economic, ethico-religious, anti-racist, and logical-consistency objections and to show that public funding of abortion is strongly supported by appeals to basic human rights, to freedom of speech, to informed consent, to protection from great harm, to justice, and to equal protection under the law. The first part of the article presents the case against public funding with detailed considerations of the economic argument, the ethico/religious argument, the argument that such funding supports racist genocide or eugenic quality control, and arguments that a logical inconsistency exists between the principles used to justify the legalization of abortions and arguments for public funding. The second part of the article presents the case for public funding by discussing the spending of public funds on morally offensive programs, arguments for public funding of abortion counseling for the poor, and arguments for public funding of abortions for the poor. It is concluded that it is morally unacceptable and rationally unjustifiable to refuse to expend public funds for abortions for low income women, because after all most money for legal abortions for the poor comes from welfare payments made to women. If conservative forces want to insure that no public funds pay for abortions, they must stop all welfare payments to pregnant women.

  1. Visual Recognition Software for Binary Classification and Its Application to Spruce Pollen Identification

    PubMed Central

    Tcheng, David K.; Nayak, Ashwin K.; Fowlkes, Charless C.; Punyasena, Surangi W.

    2016-01-01

    Discriminating between black and white spruce (Picea mariana and Picea glauca) is a difficult palynological classification problem that, if solved, would provide valuable data for paleoclimate reconstructions. We developed an open-source visual recognition software (ARLO, Automated Recognition with Layered Optimization) capable of differentiating between these two species at an accuracy on par with human experts. The system applies pattern recognition and machine learning to the analysis of pollen images and discovers general-purpose image features, defined by simple features of lines and grids of pixels taken at different dimensions, size, spacing, and resolution. It adapts to a given problem by searching for the most effective combination of both feature representation and learning strategy. This results in a powerful and flexible framework for image classification. We worked with images acquired using an automated slide scanner. We first applied a hash-based “pollen spotting” model to segment pollen grains from the slide background. We next tested ARLO’s ability to reconstruct black to white spruce pollen ratios using artificially constructed slides of known ratios. We then developed a more scalable hash-based method of image analysis that was able to distinguish between the pollen of black and white spruce with an estimated accuracy of 83.61%, comparable to human expert performance. Our results demonstrate the capability of machine learning systems to automate challenging taxonomic classifications in pollen analysis, and our success with simple image representations suggests that our approach is generalizable to many other object recognition problems. PMID:26867017

  2. Accounting for abortion: Accomplishing transnational reproductive governance through post-abortion care in Senegal.

    PubMed

    Suh, Siri

    2018-06-01

    Reproductive governance operates through calculating demographic statistics that offer selective truths about reproductive practices, bodies, and subjectivities. Post-abortion care, a global reproductive health intervention, represents a transnational reproductive regime that establishes motherhood as women's primary legitimate reproductive status. Drawing on ethnographic fieldwork conducted in Senegal between 2010 and 2011, I illustrate how post-abortion care accomplishes reproductive governance in a context where abortion is prohibited altogether and the US is the primary bilateral donor of population aid. Reproductive governance unfolds in hospital gynecological wards and the national health information system through the mobilization and interpretation of post-abortion care data. Although health workers search women's bodies and behavior for signs of illegal abortion, they minimize police intervention in the hospital by classifying most post-abortion care cases as miscarriage. Health authorities deploy this account of post-abortion care to align the intervention with national and global maternal health policies that valorize motherhood. Although post-abortion care offers life-saving care to women with complications of illegal abortion, it institutionalizes abortion stigma by scrutinizing women's bodies and masking induced abortion within and beyond the hospital. Post-abortion care reinforces reproductive inequities by withholding safe, affordable obstetric care from women until after they have resorted to unsafe abortion.

  3. The use of soil pollen to determine the sex of overhead individuals of a temperate dioecious shrub.

    PubMed

    Sugiyama, Anna; Shichi, Koji; Masaki, Takashi; Hubbell, Stephen P

    2017-04-01

    In dioecious species, determining the sex of individual plants from one-time phenological observations is rarely feasible when some individuals capable of reproducing are not flowering or fruiting at the time of observation. Currently, sexing those individuals requires long-term phenological data on individuals and populations, but such data are rarely available or feasible to collect. We tested the hypothesis that differences in soil pollen concentrations beneath the crowns of female and male plants would exist and be sufficient to reliably determine the sex of the individual plant overhead in a dioecious species. We predicted that soil pollen concentrations beneath male plants would be significantly higher than beneath female plants because only males produce pollen and pollen should accumulate in the soil underneath the male plants over repeated flowering events. We collected samples from surface soil under both sexes of the insect-pollinated dioecious shrub, Aucuba japonica (Garryaceae). Pollen grains were present in surface soil in both Oe and A horizons, and mean pollen concentration under males was significantly higher than under females. Pollen concentrations beneath males were positively correlated with male plant height, potentially reflecting greater pollen production by larger individuals. Considering the small plant size and relatively low pollen production of A. japonica , this method may hold promise for sexing other dioecious species in the absence of direct phenological data. Our phenology-free and relatively low-cost method for sexing dioecious plants may be especially useful in tropical forests where many species are dioecious. © 2017 Botanical Society of America.

  4. Pollen (quick guide)

    USDA-ARS?s Scientific Manuscript database

    What is pollen, and is it haploid or diploid? Pollen is a crucial stage of the plant life cycle — without pollen there will be no seed. When someone says “Think of a plant,” the plant you think of (whether it’s a tree, a tomato plant, or a geranium) is a sporophyte. Most land plants are sporophytes...

  5. The determination of the botanical origin in honeys with over-represented pollen: combination of melissopalynological, sensory and physicochemical analysis.

    PubMed

    Rodopoulou, Maria-Anna; Tananaki, Chrysoula; Dimou, Maria; Liolios, Vasilios; Kanelis, Dimitrios; Goras, Georgios; Thrasyvoulou, Andreas

    2018-05-01

    Pollen analysis of honey is the basic method for the determination of its botanical origin. However, the presence of over-represented pollen in honeys may lead the analysis to false results. This can be more severe if this pollen is present in unifloral under-represented honeys of commercial importance (e.g. thyme honey). In the present study, we investigated the abundance of over-represented pollen grains on several quality characteristics in honey samples. In particular, we mixed honeys characterised as over-represented, specifically chestnut and eucalyptus, with thyme honeys in different analogies, and we also analysed the melissopalynological, organoleptic, physicochemical (water content, electrical conductivity, colour) and volatile characteristics of the blends. The most sensitive parameters were the microscopic characteristics, followed by the organoleptic ones. Blends of thyme honey with an originally low percentage of thyme pollen were the most influenced and could not be characterised as unifloral regarding their melissopalynological characteristics, even when they were mixed with small quantities of honeys with over-represented pollen (i.e. 5%). The present study confirms that, in the case of presence of over-represented pollen in honeys, pollen analysis alone cannot give trustworthy results for the determination of the botanical origin, even though their exclusion during pollen analysis, when they are present in percentages of up to 30%, could provide more accurate results. Consequently, pollen analysis should also be combined with the other analyses, especially in honeys with under-represented and over-represented pollens, to give safer results for the botanical characterisation of honeys. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Pollen-mediated gene flow from transgenic to non-transgenic switchgrass (Panicum virgatum L.) in the field.

    PubMed

    Millwood, Reginald; Nageswara-Rao, Madhugiri; Ye, Rongjian; Terry-Emert, Ellie; Johnson, Chelsea R; Hanson, Micaha; Burris, Jason N; Kwit, Charles; Stewart, C Neal

    2017-05-02

    Switchgrass is C 4 perennial grass species that is being developed as a cellulosic bioenergy feedstock. It is wind-pollinated and considered to be an obligate outcrosser. Genetic engineering has been used to alter cell walls for more facile bioprocessing and biofuel yield. Gene flow from transgenic cultivars would likely be of regulatory concern. In this study we investigated pollen-mediated gene flow from transgenic to nontransgenic switchgrass in a 3-year field experiment performed in Oliver Springs, Tennessee, U.S.A. using a modified Nelder wheel design. The planted area (0.6 ha) contained sexually compatible pollen source and pollen receptor switchgrass plants. One hundred clonal switchgrass 'Alamo' plants transgenic for an orange-fluorescent protein (OFP) and hygromycin resistance were used as the pollen source; whole plants, including pollen, were orange-fluorescent. To assess pollen movement, pollen traps were placed at 10 m intervals from the pollen-source plot in the four cardinal directions extending to 20 m, 30 m, 30 m, and 100 m to the north, south, west, and east, respectively. To assess pollination rates, nontransgenic 'Alamo 2' switchgrass clones were planted in pairs adjacent to pollen traps. In the eastward direction there was a 98% decrease in OFP pollen grains from 10 to 100 m from the pollen-source plot (Poisson regression, F1,8 = 288.38, P < 0.0001). At the end of the second and third year, 1,820 F 1 seeds were collected from pollen recipient-plots of which 962 (52.9%) germinated and analyzed for their transgenic status. Transgenic progeny production detected in each pollen-recipient plot decreased with increased distance from the edge of the transgenic plot (Poisson regression, F1,15 = 12.98, P < 0.003). The frequency of transgenic progeny detected in the eastward plots (the direction of the prevailing wind) ranged from 79.2% at 10 m to 9.3% at 100 m. In these experiments we found transgenic pollen movement and hybridization rates to be

  7. A Six-Year Study on the Changes in Airborne Pollen Counts and Skin Positivity Rates in Korea: 2008–2013

    PubMed Central

    Park, Hye Jung; Lee, Jae-Hyun; Park, Kyung Hee; Kim, Kyu Rang; Han, Mae Ja; Choe, Hosoeng

    2016-01-01

    Purpose The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. Materials and Methods We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of 4442 skin-prick tests conducted at the Severance Hospital Allergy-Asthma Clinic from January 1, 2008 to December 31, 2013. Results For 6 years, the mean monthly total pollen count showed two peaks, one in May and the other in September. Pollen count for grasses also showed the same trend. The pollen counts for trees, grasses, and weeds changed annually, but the changes were not significant. The annual skin positivity rates in response to pollen from grasses and weeds increased significantly over the 6 years. Among trees, the skin positivity rates in response to pollen from walnut, popular, elm, and alder significantly increased over the 6 years. Further, there was a significant correlation between the annual rate of change in pollen count and the rate of change in skin positivity rate for oak and hop Japanese. Conclusion The pollen counts and skin positivity rates should be monitored, as they have changed annually. Oak and hop Japanese, which showed a significant correlation with the annual rate of change in pollen count and the rate of change in skin positivity rate over the 6 years may be considered the major allergens in Korea. PMID:26996572

  8. A Conserved, Mg2+-Dependent Exonuclease Degrades Organelle DNA during Arabidopsis Pollen Development[C][W

    PubMed Central

    Matsushima, Ryo; Tang, Lay Yin; Zhang, Lingang; Yamada, Hiroshi; Twell, David; Sakamoto, Wataru

    2011-01-01

    In plant cells, mitochondria and plastids contain their own genomes derived from the ancestral bacteria endosymbiont. Despite their limited genetic capacity, these multicopy organelle genomes account for a substantial fraction of total cellular DNA, raising the question of whether organelle DNA quantity is controlled spatially or temporally. In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. By staining mature pollen grains with fluorescent DNA dye, we screened Arabidopsis thaliana for mutants in which extrachromosomal DNAs had accumulated. Such a recessive mutant, termed defective in pollen organelle DNA degradation1 (dpd1), showing elevated levels of DNAs in both plastids and mitochondria, was isolated and characterized. DPD1 encodes a protein belonging to the exonuclease family, whose homologs appear to be found in angiosperms. Indeed, DPD1 has Mg2+-dependent exonuclease activity when expressed as a fusion protein and when assayed in vitro and is highly active in developing pollen. Consistent with the dpd phenotype, DPD1 is dual-targeted to plastids and mitochondria. Therefore, we provide evidence of active organelle DNA degradation in the angiosperm male gametophyte, primarily independent of maternal inheritance; the biological function of organellar DNA degradation in pollen is currently unclear. PMID:21521697

  9. Identifying the pollen of an extinct spruce species in the Late Quaternary sediments of the Tunica Hills region, south-eastern United States

    USGS Publications Warehouse

    Luke Mander,; Jacklyn Rodriguez,; Pietra G. Mueller,; Jackson, Stephen T.; Surangi W. Punyasena,

    2014-01-01

    Late Quaternary fluvial deposits in the Tunica Hills region of Louisiana and Mississippi are rich in spruce macrofossils of the extinct species Picea critchfieldii, the one recognized plant extinction of the Late Quaternary. However, the morphology of P. critchfieldii pollen is unknown, presenting a barrier to the interpretation of pollen spectra from the last glacial of North America. To address this issue, we undertook a morphometric study of Picea pollen from Tunica Hills. Morphometric data, together with qualitative observations of pollen morphology using Apotome fluorescence microscopy, indicate that Picea pollen from Tunica Hills is morphologically distinct from the pollen of P. glauca, P. mariana and P. rubens. Measurements of grain length, corpus width and corpus height indicate that Picea pollen from Tunica Hills is larger than the pollen of P. mariana and P. rubens, and is slightly larger than P. glauca pollen. We argue that the morphologically distinctive Tunica Hills Picea pollen was probably produced by the extinct spruce species P. critchfieldii. These morphological differences could be used to identify P. critchfieldii in existing and newly collected pollen records, which would refine its paleoecologic and biogeographic history and clarify the nature and timing of its extinction in the Late Quaternary.

  10. Penetration of the Stigma and Style Elicits a Novel Transcriptome in Pollen Tubes, Pointing to Genes Critical for Growth in a Pistil

    PubMed Central

    Qin, Yuan; Leydon, Alexander R.; Manziello, Ann; Pandey, Ritu; Mount, David; Denic, Stojan; Vasic, Bane; Johnson, Mark A.; Palanivelu, Ravishankar

    2009-01-01

    Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. Using microarray analysis in Arabidopsis, we show that pollen tubes that have grown through stigma and style tissues of a pistil have a distinct gene expression profile and express a substantially larger fraction of the Arabidopsis genome than pollen grains or pollen tubes grown in vitro. Genes involved in signal transduction, transcription, and pollen tube growth are overrepresented in the subset of the Arabidopsis genome that is enriched in pistil-interacted pollen tubes, suggesting the possibility of a regulatory network that orchestrates gene expression as pollen tubes migrate through the pistil. Reverse genetic analysis of genes induced during pollen tube growth identified seven that had not previously been implicated in pollen tube growth. Two genes are required for pollen tube navigation through the pistil, and five genes are required for optimal pollen tube elongation in vitro. Our studies form the foundation for functional genomic analysis of the interactions between the pollen tube and the pistil, which is an excellent system for elucidation of novel modes of cell–cell interaction. PMID:19714218

  11. Trying to prevent abortion.

    PubMed

    Bromham, D R; Oloto, E J

    1997-06-01

    It is known that, since antiquity, women confronted with an unwanted pregnancy have used abortion as a means of resolving their dilemma. Although undoubtedly widely used in all historical ages, abortion has come to be regarded as an event preferably avoided because of the impact on the women concerned as well as considerations for fetal life. Policies to reduce numbers and rates of abortion must acknowledge certain observations. Criminalization does not prevent abortion but increases maternal risks. A society's 'openness' in discussing sexual matters inversely correlates with abortion rates. Correlation between contraceptive use and abortion is also inverse but relates most closely to the efficacy of contraceptive methods used. 'Revolution' in the range of contraceptive methods used will have an equivalent impact on abortion rates. Secondary or emergency contraceptive methods have a considerable role to play in the reduction of abortion numbers. Good sex (and 'relationships') education programs may delay sexual debut, increase contraceptive usage and be associated with reduced abortion. Finally, interaction between socioeconomic factors and the choice between abortion and ongoing pregnancy are complex. Abortion is not necessarily chosen by those least able to support a child financially.

  12. [Abortion in Japan].

    PubMed

    Yamamoto, K; Yamamoto, Y; Hayase, T

    1993-01-01

    In Japan, the artificial abortion is a penal offence; only in the presence of certain conditions it is authorized under the provision of the Eugenic Protection Law which was promulgated in 1948. According to the law, the artificial abortion is restricted to the period, in which the fetus is not viable outside of the uterus. This period is prescribed by notification from the Ministry of Public Welfare; up to now it has been shortened twice (1976, 1991). Due to the introduction of economic reasons in the list of conditions and the simplification of the procedure the artificial abortion in Japan was virtually liberalized. Prosecution for illegal abortion is very rare in recent years. The number of reported artificial abortions decreases; in the about last 30 years it reduced by half. However, the increase in the number of abortions in women younger than 20 years of age is a problem. The abortion in teenagers is late compared with that in other age groups. Although the number of neonaticides does not seem to increase, the increase in the number of abortions in teenagers remains a serious problem in Japan.

  13. Pollen mitosis and pollen tube growth inhibition by SO/sub 2/ in cultured pollen tubes of Tradescantia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, T.H.; Khan, S.H.

    Mature pollen of Tradescantia paludosa Anders, Sax clone-3 was collected from greenhouse grown plants and desiccated in the dark for 4--5 hours. The pollen was sown on microslides coated with lactose agar medium (supplemented with 0.02 percent colchicine). Five minutes after sowing, pollen cultures were treated with various concentrations (0.075--2000 ppM) of SO/sub 2/ obtained from the chemical reaction between K/sub 2/S/sub 2/O/sub 5/ and HCl. Treatments were carried out in an airtight Plexiglas chamber throughout the full incubation period of 19 hours. Treated and control pollen cultures were fixed and stained in aceto-carmine or Feulgen reaction to determine themore » tube lengths and mitotic indices. Results of repeated experiments indicated that the values of mitotic indices dropped from the normal 38.7 percent in the control to the range of 24.3--3.8 percent when treated with 0.075--50.00 ppM of SO/sub 2/. Pollen tube growth was inhibited from the normal length of 1.5 mm in the control to the range of 800--100 ..mu..m when treated with 10--2000 ppM of SO/sub 2/. The inhibitory effect of SO/sub 2/ presumably resulted from physiological disturbance of the cell and severe damage to chromosomes of both generative and tube nuclei of the pollen tubes.« less

  14. Abortion surveillance - United States, 2007.

    PubMed

    Pazol, Karen; Zane, Suzanne; Parker, Wilda Y; Hall, Laura R; Gamble, Sonya B; Hamdan, Saeed; Berg, Cynthia; Cook, Douglas A

    2011-02-25

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2007. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). This information is provided voluntarily. For 2007, data were received from 49 reporting areas. For the purpose of trend analysis, data were evaluated from the 45 areas that reported data every year during the preceding decade (1998-2007). Abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births) were calculated using census and natality data, respectively. A total of 827,609 abortions were reported to CDC for 2007. Among the 45 reporting areas that provided data every year during 1998-2007, a total of 810,582 abortions (97.9% of the total) were reported for 2007; the abortion rate was 16.0 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 231 abortions per 1,000 live births. Compared with 2006, the total number and rate of reported abortions decreased 2%, and the abortion ratio decreased 3%. Reported abortion numbers, rates, and ratios were 6%, 7%, and 14% lower, respectively, in 2007 than in 1998. Women aged 20-29 years accounted for 56.9% of all abortions in 2007 and for the majority of abortions during the entire period of analysis (1998-2007). In 2007, women aged 20-29 years also had the highest abortion rates (29.4 abortions per 1,000 women aged 20-24 years and 21.4 abortions per 1,000 women aged 25-29 years). Adolescents aged 15-19 years accounted for 16.5% of all abortions in 2007 and had an abortion rate of 14.5 abortions per 1,000 adolescents aged 15-19 years; women aged ≥35 years accounted for a smaller percentage (12.0%) of abortions and had lower abortion rates (7.7 abortions per 1,000 women aged 35-39 years and 2.6 abortions per 1,000 women aged ≥40 years

  15. Lignin biomarkers and pollen in the postglacial sediment of an Alaskan Lake

    NASA Astrophysics Data System (ADS)

    Hu, Feng Sheng; Hedges, John I.; Gordon, Elizabeth S.; Brubaker, Linda B.

    1999-05-01

    We analyzed a 12,000-yr sediment core from Wien Lake, central Alaska, for a suite of phenolic products from CuO oxidation of lignin polymers and compared their composition with pollen data from the same core to assess lignin phenols as sedimentary biomarkers. Inferences of the gross taxonomic origin of sediment organic matter from lignin-phenol composition agree with vegetational reconstructions based on pollen assemblages. In particular, the ratios of syringyl to vanillyl phenols are consistently higher before 6500 yr BP, when angiosperms dominated or codominated the regional vegetation, than after 6500 yr BP, when gymnosperms dominated. However, the ratios of cinnamyl ( p-coumaric and ferulic acids) to total vanillyl phenols (C/V) do not show patterns expected from the abundance of woody plants. C/V ratios are particularly high (0.7-0.85) after 6500 yr BP when pollen spectra suggest closed boreal forests dominated by Picea, and the stratigraphic patterns are strikingly similar between C/V and Picea pollen concentrations. CuO oxidation of modern pollen of P. glauca and P. mariana yields exceptionally high amounts of cinnamyl phenols (8.90 and 6.41 mg/100 mg OC for P. glauca and P. mariana, respectively). In particular, p-coumaric acid is obtained in large amounts (8.87 and 6.41 mg/100 mg OC for P. glauca and P. mariana, respectively) versus vanillyl phenols (0.25 and 0.49 mg/100 mg OC for P. glauca and P. mariana, respectively) and ferulic acid (0.03 and 0.00 mg/100 mg OC for P. glauca and P. mariana, respectively). Thus lignin phenols derived from fossil Picea pollen preserved in sediments likely drive the C/V profile of the Wien Lake core. These data imply that if Picea pollen concentrations are sufficiently high, the amount of nonwoody tissue in sediments may be grossly overestimated when the lignin composition of gymnosperm needles is used as the end member of nonwoody tissues. Given that pollen grains are among the most resistant components of sedimentary

  16. Programmed cell death progressively models the development of anther sporophytic tissues from the tapetum and is triggered in pollen grains during maturation.

    PubMed

    Varnier, Anne-Lise; Mazeyrat-Gourbeyre, Florence; Sangwan, Rajbir S; Clément, Christophe

    2005-11-01

    To characterize the spatial and temporal occurrence of programmed cell death (PCD) in Lilium anther tissues, we used both microscopical and molecular markers of apoptosis for developmental stages from meiosis to pollen release. The first hallmarks of PCD include cell condensation and shrinkage of the cytoplasm, separation of chromatin into delineated masses, and DNA fragmentation in the tapetum as early as the premeiosis stage. PCD then extended to other anther sporophytic tissues, leading to anther dehiscence. Although the PCD clearly affected the endothecium and the epidermis, these two cell layers remained alive until anther dehiscence. In pollen, no sign of PCD was found until pollen mitosis I, after what apoptotic features developed progressively in the vegetative cell. In addition, DNA ladders were detected in all sporophytic tissues and cell types throughout pollen development, whereas in the male gametophyte DNA ladders were only detected during pollen maturation. Our data suggest that PCD is a progressive and active process affecting all the anther tissues, first being triggered in the tapetum.

  17. Abortion clinic patients' opinions about obtaining abortions from general women's health care providers.

    PubMed

    Weitz, Tracy Ann; Cockrill, Kate

    2010-12-01

    Most U.S. women obtain abortions at specialty clinics. This qualitative study explores abortion clinic patients' opinions about receiving abortions from general women's health care providers. We conducted 20 h-long, semi-structured interviews with diverse women who had abortions in the U.S. Heartland. Each described her usual health care provider and how she accessed abortion care. We used qualitative analytic methods to organize and interpret the data. Despite having a general provider, most women sought clinic abortions. Some women offered reasons for preferring specialty care and others for preferring abortion from their general provider. Most women assumed their general provider did not "do abortion" and many believed those providers were opposed to abortion. Women who had delivered a baby were concerned with their image in their general provider's eyes. Two women were denied care by their general providers. Women's preferences for abortion care centered on privacy, cost, empathy, ability to control their image, and desire for safe quality care. Two women who sought abortions through their general providers experienced negative repercussions. General providers should proactively make patients aware of their positions on abortion and if supportive indicate that they can provide that care and/or a referral. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Impact of traffic-related air pollution on the expression of Platanus orientalis pollen allergens.

    PubMed

    Sedghy, Farnaz; Sankian, Mojtaba; Moghadam, Maliheh; Ghasemi, Ziba; Mahmoudi, Mahmoud; Varasteh, Abdol-Reza

    2017-01-01

    Air pollutants and their interaction with environmental allergens have been considered as an important reason for the recent increase in the prevalence of allergic diseases. The aim of this study was to investigate the traffic pollution effect, as a stressor, on Platanus orientalis pollen allergens messenger RNA (mRNA) and protein expression. P. orientalis pollen grains were collected along main streets of heavy traffic and from unpolluted sites in Mashhad city, in northeast Iran. The pollen samples were examined by scanning electron microscopy. To assess the abundance of pollen allergens (Pla or 1, Pla or 2, and Pla or 3) from polluted and unpolluted sites, immunoblotting was performed. Moreover, the sequences encoding P. orientalis allergens were amplified using real-time PCR. Scanning electron microscopy showed a number of particles of 150-550 nm on the surface of pollen from polluted sites. Also, protein and gene expression levels of Pla or 1 and Pla or 3 were considerably greater in pollen samples from highly polluted areas than in pollen from unpolluted areas (p < 0.05). In contrast, no statically significant difference in Pla or 2 protein and mRNA expression level was found between samples from the two areas. We found greater expression of allergens involved in plant defense mechanisms (Pla or 1 and Pla or 3) in polluted sites than in unpolluted ones. The high expression of these proteins can lead to an increase in the prevalence of allergic diseases. These findings suggest the necessity of supporting public policies aimed at controlling traffic pollution to improve air quality and prevent the subsequent clinical outcomes and new cases of asthma.

  19. [Abortion].

    PubMed

    Nunes, J P

    1998-01-01

    Abortion is the interruption of a dynamic process in a final and irreversible form. The legalization of abortion is applied to human ontogenesis, that is, the development of the human being. However, the embryo that is growing in the uterus is not a human being because a human being is a complex organism with differentiated systems, its own identity and intrinsic autonomy in its process of development. There are basically four levels of the analysis of the problem of abortion: 1) fundamental emotional arguments; 2) profound ignorance of technical and scientific facts; 3) rational positions obfuscated by the dramatic intensity of everyday situations; and 4) the conjunction of deliberated position where culpability is avoided with solidarity for all subjects of the process with a socially oriented view. The phenomenon of abortion from an epidemiological point of view summons the facts with which it is associated: poverty, illiteracy, shortage or lack of community health resources, absence of centers for adolescents, degradation of the environment, and precariousness of employment.

  20. [Use of contraception and reasons for choosing abortion among abortion applicants].

    PubMed

    Hansen, S K; Birkebaek, J S; Husfeldt, C; Munck, C B; Nøddebo, S M; Petersson, B H

    1996-10-07

    The object of this study was to describe a group of women applying for legal abortion in relation to their use of contraception and reasons for choosing an abortion. During a period of 13 months (1991-92) a questionnaire was distributed to women applying for legal abortion at Hillerød Hospital in Denmark. Three hundred and thirty-nine women participated. Fifty-nine percent of the women had become pregnant although they had used contraception. As seen in other studies, women still state demographic factors as their most important reasons for choosing an abortion. Women with two or more children do not want to have more children. Single women do not want children without being in a stable relationship. Furthermore occupation and education were frequently stated as important reasons for having an abortion. Economy and housing were not main reasons but contributory factors. Thirty percent of the women expressed ambivalence about the choice of abortion at the time when the abort was due.

  1. Post-abortion and induced abortion services in two public hospitals in Colombia.

    PubMed

    Darney, Blair G; Simancas-Mendoza, Willis; Edelman, Alison B; Guerra-Palacio, Camilo; Tolosa, Jorge E; Rodriguez, Maria I

    2014-07-01

    Until 2006, legal induced abortion was completely banned in Colombia. Few facilities are equipped or willing to offer abortion services; often adolescents experience even greater barriers of access in this context. We examined post abortion care (PAC) and legal induced abortion in two large public hospitals. We tested the association of hospital site, procedure type (manual vacuum aspiration vs. sharp curettage), and age (adolescents vs. women 20 years and over) with service type (PAC or legal induced abortion). Retrospective cohort study using 2010 billing data routinely collected for reimbursement (N=1353 procedures). We utilized descriptive statistics, multivariable logistic regression and predicted probabilities. Adolescents made up 22% of the overall sample (300/1353). Manual vacuum aspiration was used in one-third of cases (vs. sharp curettage). Adolescents had lower odds of documented PAC (vs. induced abortion) compared with women over age 20 (OR=0.42; 95% CI=0.21-0.86). The absolute difference of service type by age, however, is very small, controlling for hospital site and procedure type (.97 probability of PAC for adolescents compared with .99 for women 20 and over). Regardless of age, PAC via sharp curettage is the current standard in these two public hospitals. Both adolescents and women over 20 are in need of access to legal abortion services utilizing modern technologies in the public sector in Colombia. Documentation of abortion care is an essential first step to determining barriers to access and opportunities for quality improvement and better health outcomes for women. Following partial decriminalization of abortion in Colombia, in public hospitals nearly all abortion services are post-abortion care, not induced abortion. Sharp curettage is the dominant treatment for both adolescents and women over 20. Women seek care in the public sector for abortion, and must have access to safe, quality services. Copyright © 2014. Published by Elsevier Inc.

  2. [Bioethics and abortion. Debate].

    PubMed

    Diniz, D; Gonzalez Velez, A C

    1998-06-01

    Although abortion has been the most debated of all issues analyzed in bioethics, no moral consensus has been achieved. The problem of abortion exemplifies the difficulty of establishing social dialogue in the face of distinct moral positions, and of creating an independent academic discussion based on writings that are passionately argumentative. The greatest difficulty posed by the abortion literature is to identify consistent philosophical and scientific arguments amid the rhetorical manipulation. A few illustrative texts were selected to characterize the contemporary debate. The terms used to describe abortion are full of moral meaning and must be analyzed for their underlying assumptions. Of the four main types of abortion, only 'eugenic abortion', as exemplified by the Nazis, does not consider the wishes of the woman or couple--a fundamental difference for most bioethicists. The terms 'selective abortion' and 'therapeutic abortion' are often confused, and selective abortion is often called eugenic abortion by opponents. The terms used to describe abortion practitioners, abortion opponents, and the 'product' are also of interest in determining the style of the article. The video entitled "The Silent Scream" was a classic example of violent and seductive rhetoric. Its type of discourse, freely mixing scientific arguments and moral beliefs, hinders analysis. Within writings about abortion three extreme positions may be identified: heteronomy (the belief that life is a gift that does not belong to one) versus reproductive autonomy; sanctity of life versus tangibility of life; and abortion as a crime versus abortion as morally neutral. Most individuals show an inconsistent array of beliefs, and few groups or individuals identify with the extreme positions. The principal argument of proponents of legalization is respect for the reproductive autonomy of the woman or couple based on the principle of individual liberty, while heteronomy is the main principle of

  3. Abortion Surveillance - United States, 2014.

    PubMed

    Jatlaoui, Tara C; Shah, Jill; Mandel, Michele G; Krashin, Jamie W; Suchdev, Danielle B; Jamieson, Denise J; Pazol, Karen

    2017-11-24

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2014. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2014, data were received from 49 reporting areas. For trend analysis, abortion data were evaluated from 48 areas that reported data every year during 2005-2014. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women aged 15-44 years) and ratios (number of abortions per 1,000 live births). A total of 652,639 abortions were reported to CDC for 2014. Of these abortions, 98.4% were from the 48 reporting areas that provided data every year during 2005-2014. Among these 48 reporting areas, the abortion rate for 2014 was 12.1 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 186 abortions per 1,000 live births. From 2013 to 2014, the total number and rate of reported abortions decreased 2%, and the ratio decreased 7%. From 2005 to 2014, the total number, rate, and ratio of reported abortions decreased 21%, 22%, and 21%, respectively. In 2014, all three measures reached their lowest level for the entire period of analysis (2005-2014). In 2014 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates; women in their 30s and older accounted for a much smaller percentage of abortions and had lower abortion rates. In 2014, women aged 20-24 and 25-29 years accounted for 32.2% and 26.7% of all reported abortions, respectively, and had abortion rates of 21.3 and 18.4 abortions per 1,000 women aged 20-24 and 25-29 years, respectively. In contrast, women aged 30-34, 35-39, and ≥40 years accounted for 17.1%, 9.7%, and 3.6% of all reported abortions

  4. Influence of meteorological parameters and air pollution on hourly fluctuation of birch (Betula L.) and ash (Fraxinus L.) airborne pollen.

    PubMed

    Puc, Małgorzata

    2012-01-01

    Pollen grains are one of the most important groups of atmospheric biological particles that originate allergic processes. Knowledge of intradiurnal variation of the atmospheric pollen may be useful for the treatment and prevention of pollen allergies. Intradiurnal fluctuation of hourly pollen counts in 24 h are related to the daily rhythm of anther opening, and modified by various interacting factors. Flowering and pollen production of individual species are influenced by genetic, phenological, ecological, meteorological and climatic factors. Estimation of the intradiurnal variability in the pollen count permits evaluation of the threat posed by allergens over a given area. Measurements performed in Szczecin over a period of 7 years (2006-2012) permitted analysis of hourly variation of the pollen count of birch (Betula) and ash (Fraxinus) in 24 h, and evaluation of the impact of weather conditions and the concentration of gas air pollutants on the intradiurnal patterns of both taxa. Aerobiological monitoring was conducted using a Hirst volumetric trap (Lanzoni VPPS 2000). Consecutive phases during the day were defined as 1, 5, 25, 50, 75, 95, 99% of annual total pollen. The analysis revealed that 50% of total daily pollen was noted at 14:00 for Betula and Fraxinus. The hourly distribution of birch pollen count skewed to the left and the majority of pollen of this taxon appears in the air in the first 12 hours of the day. However, for ash, the hourly distribution of pollen count skewed to the right. Statistically significant correlation was noted between the Betula and Fraxinus pollen concentration and the mean air temperature, relative humidity, wind speed, air pressure, total radiation and nitrogen oxides (NO(x)).

  5. Abortion Before & After Roe

    PubMed Central

    Joyce, Ted; Tan, Ruoding; Zhang, Yuxiu

    2013-01-01

    We use unique data on abortions performed in New York State from 1971–1975 to demonstrate that women travelled hundreds of miles for a legal abortion before Roe. A100- mile increase in distance for women who live approximately 183 miles from New York was associated with a decline in abortion rates of 12.2 percent whereas the same change for women who lived 830 miles from New York lowered abortion rates by 3.3 percent. The abortion rates of nonwhites were more sensitive to distance than those of whites. We found a positive and robust association between distance to the nearest abortion provider and teen birth rates but less consistent estimates for other ages. Our results suggest that even if some states lost all abortion providers due to legislative policies, the impact on population measures of birth and abortion rates would be small as most women would travel to states with abortion services. PMID:23811233

  6. [Repeat induced abortion: A multicenter study on medical abortions in France in 2014].

    PubMed

    Opatowski, M; Bardy, F; David, P; Dunbavand, A; Saurel-Cubizolles, M-J

    2017-01-01

    To describe the social characteristics of women seeking a medical abortion, and the conditions of that abortion, according to whether they had one or more previous induced abortions. An observational study was carried out in 11 French units in 2013-2014, among women 18 years or older. A self-administered questionnaire on the abortion context and social situation was given to them, as well as a diary to record the pain level for each of five days following the mifepristone intake. The sample included 453 women. Among the respondents, 22% had had one previous abortion and 8% had had two or more. Women having had a previous voluntary abortion were more often isolated and in a poorer social situation than women having their first abortion. Better support for contraception after abortion could reduce the number of repeated abortions. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Post-abortion care: a women's health initiative to combat unsafe abortion.

    PubMed

    Greenslade, F C; Mckay, H; Wolf, M; Mclaurin, K

    1994-01-01

    Improving postabortion care can reduce the negative impact of unsafe abortion. Of the 53 million estimated induced abortions occurring annually about two out of five involve unsafe procedures. About one abortion occurs for every three births annually. 96% of abortions in Africa and 85% of abortions in Latin America are unsafe. About 100,000 to 200,000 women die every year from unsafe abortion, or 1 out of 400 women. Family planning is unavailable to over 120 million women in developing countries who desire contraception. Past moral and political controversies divert attention away from death and injury. The international community can take the opportunity to change affairs by adopting a women's health initiative globally. Improvements are needed in quality of care and accessibility of emergency treatment services. Emergency treatment services are usually only available at the tertiary level of care in urban areas. Poor transportation systems limit access. Access is also impaired by women's attitudes toward treatment centers. Availability of services needs to increased through decentralized centers. Clear protocols and comprehensive, systematic training must be accomplished in tandem with improvements in quality. Provision of technology such as manual vacuum aspiration is cost effective and an easy way to improve quality in primary care or outpatient settings. Unsafe abortion is a byproduct of the failure to provide adequate family planning for prevention of unwanted pregnancy. The obstacles, that interfere with provision of family planning to abortion users, should be removed. These obstacles include providers' lack of understanding of women's needs and motivations, separation between abortion and family planning services, misinformation about contraception following abortion, lack of acknowledgement about unsafe abortion, and women's low status. National and international policies also interfere with provision of contraception. Complete reproductive health care is

  8. Abortion surveillance - United States, 2006.

    PubMed

    Pazol, Karen; Gamble, Sonya B; Parker, Wilda Y; Cook, Douglas A; Zane, Suzanne B; Hamdan, Saeed

    2009-11-27

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2006. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, New York City, and the District of Columbia); these data are provided to CDC voluntarily. In 2006, data were received from 49 reporting areas. For the purpose of trend analysis, data were evaluated from the 46 areas that reported data every year during 1996-2006. For 2006, a total of 846,181 abortions were reported to CDC. Among the 46 areas that provided data consistently during 1996-2006, a total of 835,134 abortions (98.7% of the total) were reported; the abortion rate was 16.1 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 236 abortions per 1,000 live births. During the previous decade (1997-2006), reported abortion numbers, rates, and ratios decreased 5.7%, 8.8%, and 14.8%, respectively; most of these declines occurred before 2001. During the previous year (2005-2006), the total number of abortions increased 3.1%, and the abortion rate increased 3.2%; the abortion ratio was stable. In 2006, as during the previous decade (1997-2006), women aged 20-29 years accounted for the majority (56.8%) of abortions and had the highest abortion rates (29.9 abortions per 1,000 women aged 20-24 years and 22.2 abortions per 1,000 women aged 25-29 years); by contrast, abortion ratios were highest at the extremes of reproductive age. Adolescents aged 15-19 years accounted for 16.5% of all abortions in 2006 and had an abortion rate of 14.8 abortions per 1,000 adolescents aged 15-19 years; women aged >or=35 years accounted for a smaller percentage (12.1%) of abortions and had lower abortion rates (7.8 abortions per 1,000 women aged 35-39 years and 2.6 abortions per 1,000 women aged >or=40 years). During 1997-2006, the percentage of abortions and the abortion rate increased among women

  9. Trends of abortion complications in a transition of abortion law revisions in Ethiopia.

    PubMed

    Gebrehiwot, Yirgu; Liabsuetrakul, Tippawan

    2009-03-01

    Evidence from developed countries has shown that abortion-related mortality and morbidity has decreased with the liberalization of the abortion law. This study aimed to assess the trend of hospital-based abortion complications during the transition of legalization in Ethiopia in May 2005. Medical records of women with abortion complications from 2003 to 2007 were reviewed (n = 773). Abortion and its complications with regard to legalization were described by rates and ratios, and predictors of fatal outcomes were analyzed by logistic regression. The overall and abortion-related maternal mortality ratios (AMMRs) showed a non-statistically significant downward trend over the 5-year period. However, the case fatality rate of abortion increased from 1.1% in 2003 to 3.6% in 2007. Late gestational age, history of interference and presenting after new abortion legislation passed have been found to be significant predictors of mortality. Decreased trends of abortion ratio and the AMMR were identified, but the severity of abortion complications and the case fatality rate increased during the transition of legal revision.

  10. Cytoplasmic connection of sperm cells to the pollen vegetative cell nucleus: potential roles of the male germ unit revisited.

    PubMed

    McCue, Andrea D; Cresti, Mauro; Feijó, José A; Slotkin, R Keith

    2011-03-01

    The male germ cells of angiosperm plants are neither free-living nor flagellated and therefore are dependent on the unique structure of the pollen grain for fertilization. During angiosperm male gametogenesis, an asymmetric mitotic division produces the generative cell, which is completely enclosed within the cytoplasm of the larger pollen grain vegetative cell. Mitotic division of the generative cell generates two sperm cells that remain connected by a common extracellular matrix with potential intercellular connections. In addition, one sperm cell has a cytoplasmic projection in contact with the vegetative cell nucleus. The shared extracellular matrix of the two sperm cells and the physical association of one sperm cell to the vegetative cell nucleus forms a linkage of all the genetic material in the pollen grain, termed the male germ unit. Found in species representing both the monocot and eudicot lineages, the cytoplasmic projection is formed by vesicle formation and microtubule elongation shortly after the formation of the generative cell and tethers the male germ unit until just prior to fertilization. The cytoplasmic projection plays a structural role in linking the male germ unit, but potentially plays other important roles. Recently, it has been speculated that the cytoplasmic projection and the male germ unit may facilitate communication between the somatic vegetative cell nucleus and the germinal sperm cells, via RNA and/or protein transport. This review focuses on the nature of the sperm cell cytoplasmic projection and the potential communicative function of the male germ unit.

  11. Abortion surveillance--United States, 2009.

    PubMed

    Pazol, Karen; Creanga, Andreea A; Zane, Suzanne B; Burley, Kim D; Jamieson, Denise J

    2012-11-23

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2009. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2009, data were received from 48 reporting areas. For the purpose of trend analysis, abortion data were evaluated from the 45 areas that reported data every year during 2000-2009. Census and natality data, respectively, were used to calculated abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births). A total of 784,507 abortions were reported to CDC for 2009. Of these abortions, 772,630 (98.5%) were from the 45 reporting areas that provided data every year during 2000-2009. Among these same 45 reporting areas, the abortion rate for 2009 was 15.1 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 227 abortions per 1,000 live births. Compared with 2008, the total number and rate of reported abortions for 2009 decreased 5%, representing the largest single year decrease for the entire period of analysis. The abortion ratio decreased 2%. From 2000 to 2009, the total number, rate, and ratio of reported abortions decreased 6%, 7%, and 8%, respectively, to the lowest levels for 2000-2009. In 2009 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates, whereas women aged ≥30 years accounted for a much smaller percentage of abortions and had lower abortion rates. In 2009, women aged 20-24 and 25-29 years accounted for 32.7% and 24.4% of all abortions, respectively, and had an abortion rate of 27.4 abortions per 1,000 women aged 20-24 years and 20.4 abortions per 1,000 women aged 25-29 years. In contrast, women aged 30-34, 35-39, and ≥40 years

  12. Abortion Surveillance - United States, 2013.

    PubMed

    Jatlaoui, Tara C; Ewing, Alexander; Mandel, Michele G; Simmons, Katharine B; Suchdev, Danielle B; Jamieson, Denise J; Pazol, Karen

    2016-11-25

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2013. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2013, data were received from 49 reporting areas. For trend analysis, abortion data were evaluated from 47 areas that reported data every year during 2004-2013. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births). A total of 664,435 abortions were reported to CDC for 2013. Of these abortions, 98.2% were from the 47 reporting areas that provided data every year during 2004-2013. Among these 47 reporting areas, the abortion rate for 2013 was 12.5 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 200 abortions per 1,000 live births. From 2012 to 2013, the total number, rate, and ratio of reported abortions decreased 5%. From 2004 to 2013, the total number, rate, and ratio of reported abortions decreased 20%, 21%, and 17%, respectively. In 2013, all three measures reached their lowest level for the entire period of analysis (2004-2013). In 2013 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates; women in their 30s and older accounted for a much smaller percentage of abortions and had lower abortion rates. In 2013, women aged 20-24 and 25-29 years accounted for 32.7% and 25.9% of all abortions, respectively, and had abortion rates of 21.8 and 18.2 abortions per 1,000 women aged 20-24 and 25-29 years, respectively. In contrast, women aged 30-34, 35-39, and ≥40 years accounted for 16.8%, 9.2%, and 3.6% of all abortions, respectively, and had abortion rates of 11.8, 7.0, and 2

  13. Abortion Surveillance - United States, 2012.

    PubMed

    Pazol, Karen; Creanga, Andreea A; Jamieson, Denise J

    2015-11-27

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2012. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2012, data were received from 49 reporting areas. For trend analysis, abortion data were evaluated from 47 areas that reported data every year during 2003-2012. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births). A total of 699,202 abortions were reported to CDC for 2012. Of these abortions, 98.4% were from the 47 reporting areas that provided data every year during 2003-2012. Among these same 47 reporting areas, the abortion rate for 2012 was 13.2 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 210 abortions per 1,000 live births. From 2011 to 2012, the total number and ratio of reported abortions decreased 4% and the abortion rate decreased 5%. From 2003 to 2012, the total number, rate, and ratio of reported abortions decreased 17%, 18%, and 14%, respectively, and reached their lowest level in 2012 for the entire period of analysis (2003-2012). In 2012 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates; women in their 30s and older accounted for a much smaller percentage of abortions and had lower abortion rates. In 2012, women aged 20-24 and 25-29 years accounted for 32.8% and 25.4% of all abortions, respectively, and had abortion rates of 23.3 and 18.9 abortions per 1,000 women aged 20-24 and 25-29 years, respectively. In contrast, women aged 30-34, 35-39, and ≥40 years accounted for 16.4%, 9.1%, and 3.7% of all abortions, respectively, and had abortion rates of

  14. Destigmatising abortion: expanding community awareness of abortion as a reproductive health issue in Ghana.

    PubMed

    Lithur, Nana Oye

    2004-04-01

    Traditional and cultural values, social perceptions, religious teachings and criminalisation have facilitated stigmatisation of abortion in Ghana. Abortion is illegal in Ghana except in three instances. Though the law allows for performance of abortion in three circumstances, the Ghana reproductive health service policy did not have any induced legal abortion services component to cover the three exceptions until it was revised in 2003. The policy only had 'unsafe and post-abortion' care components, and abortions performed in health facilities operated by the Ghana Health Service were performed under this component. Though the policy has been revised, women and girls who need abortion services in Ghana more often resort to the backstreet dangerous methods and procedures. Criminalisation of abortion and those who perform abortions has contributed to unsafe abortion, the second leading cause of maternal deaths in Ghana. Most of these are performed outside the formal health service structures. Traditionally, abortion is perceived as a shameful act and the community may shun and give a woman who has caused anabortion derogatory names. Would provision of legal abortion services be culturally acceptable within a Ghanaian community? Yes, if they are made aware of the reproductive health benefits of providing safe abortion services. Three major strategies that would help to destigmatise abortion in the community are (1) the liberal interpretation of the three exceptions to the law on abortion; (2) expanding community awareness of its reproductive health benefits; and (3) improving and increasing access to legal abortion services within the formal health facilities.

  15. Pollen-mediated gene flow from transgenic cotton is constrained by physical isolation measures.

    PubMed

    Yan, Shuo; Zhu, Weilong; Zhang, Boyu; Zhang, Xinmi; Zhu, Jialin; Shi, Jizhe; Wu, Pengxiang; Wu, Fengming; Li, Xiangrui; Zhang, Qingwen; Liu, Xiaoxia

    2018-02-12

    The public concern about pollen-mediated gene flow (PGF) from genetically modified (GM) crops to non-GM crops heats up in recent years over China. In the current study, we conducted greenhouse and field experiments to measure PGF with various physical isolation measures, including 90, 80, 60 and 40 holes/cm 2 separation nets and Sorghum bicolor, Zea mays and Lycopersicon esculentum separation crops between GM cotton and non-GM line (Shiyuan321) by seed DNA test during 2013 to 2015, and pollen grain dyeing was also conducted to assess the pollen flow in greenhouse during 2013. Our results revealed that (1) PGF varied depending on the physical isolation measures. PGF was the lowest with 90 holes/cm 2 separation net and S. bicolor separation crop, and the highest with 40 holes/cm 2 separation net and no isolation measure. (2) Similar to PGF results, 90 holes/cm 2 separation net and S. bicolor separation crop could minimize the pollen dispersal. (3) PGF declined exponentially with increasing distance between GM cotton and Shiyuan321. Because of the production mode of farm household (limited cultivated area) in China, our study is particularly important, which is not only benefit for constraining PGF, but also has potential application value in practical production and the scientific researches.

  16. Abortion providers' experiences with Medicaid abortion coverage policies: a qualitative multistate study.

    PubMed

    Dennis, Amanda; Blanchard, Kelly

    2013-02-01

    To evaluate the implementation of state Medicaid abortion policies and the impact of these policies on abortion clients and abortion providers. From 2007 to 2010, in-depth interviews were conducted with representatives of 70 abortion-providing facilities in 15 states. In-depth interviews focused on abortion providers' perceptions regarding Medicaid and their experiences working with Medicaid and securing reimbursement in cases that should receive federal funding: rape, incest, and life endangerment. Data were transcribed verbatim before being coded. In two study states, abortion providers reported that 97 percent of submitted claims for qualifying cases were funded. Success receiving reimbursement was attributed to streamlined electronic billing procedures, timely claims processing, and responsive Medicaid staff. Abortion providers in the other 13 states reported reimbursement for 36 percent of qualifying cases. Providers reported difficulties obtaining reimbursement due to unclear rejections of qualifying claims, complex billing procedures, lack of knowledgeable Medicaid staff with whom billing problems could be discussed, and low and slow reimbursement rates. Poor state-level implementation of Medicaid coverage of abortion policies creates barriers for women seeking abortion. Efforts to ensure policies are implemented appropriately would improve women's health. © Health Research and Educational Trust.

  17. Double-blind, placebo-controlled immunotherapy with mixed grass-pollen allergoids. II. Comparison between parameters assessing the efficacy of immunotherapy.

    PubMed

    Bousquet, J; Maasch, H; Martinot, B; Hejjaoui, A; Wahl, R; Michel, F B

    1988-09-01

    Specific immunotherapy is effective in alleviating symptoms in grass pollen-induced rhinitis, but there are no clear data demonstrating a correlation between symptom-medication scores and objective parameters. Twenty-five patients taking part in a double-blind, placebo-controlled immunotherapy with mixed grass pollen-formalinized allergoids were studied. All patients had the same investigations. Symptom-medication scores were significantly (p less than 0.005, Mann-Whitney U test) reduced in the treated group by comparison to the placebo-treated patients. Nasal challenges performed with threefold increasing numbers of orchard grass-pollen grains demonstrated that patients treated with allergoid tolerated a significantly (p less than 0.005, Wilcoxon W test) greater number of grains after treatment, whereas there was no mean difference in the placebo-treated patients. There was a significant (p less than 0.005, Spearman rank-correlation) correlation between nasal challenges and symptom scores during the season. The skin prick test end point was significantly (p less than 0.001, Wilcoxon W test) reduced after treatment in the allergoid-treated group and remained unchanged in the placebo-treated group. There was a significant (p less than 0.001) correlation between the skin prick test end point and symptom scores during the season. Serum grass-pollen IgG titrated by a solid-phase radioimmunoassay with Staphylococcus A protein was significantly (p less than 0.01, Wilcoxon W test) increased after treatment with allergoid, but there was no significant correlation between IgG titer and symptom scores during the season. Serum grass-pollen IgE increased (p less than 0.04, Wilcoxon W test) in the treated group but there was no correlation with symptom scores.

  18. Abortion surveillance--United States, 2008.

    PubMed

    Pazol, Karen; Zane, Suzanne B; Parker, Wilda Y; Hall, Laura R; Berg, Cynthia; Cook, Douglas A

    2011-11-25

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 1999-2008. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). This information is provided voluntarily. For 2008, data were received from 49 reporting areas. For the purpose of trend analysis, data were evaluated from the 45 areas that reported data every year during 1999-2008. Abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births) were calculated using census and natality data, respectively. A total of 825,564 abortions were reported to CDC for 2008. Of these, 808,528 abortions (97.9% of the total) were from the 45 reporting areas that provided data every year during 1999-2008. Among these same 45 reporting areas, the abortion rate for 2008 was 16.0 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 234 abortions per 1,000 live births. Compared with 2007, the total number and rate of reported abortions for these 45 reporting areas essentially were unchanged, although the abortion ratio was 1% higher. Reported abortion numbers, rates, and ratios remained 3%, 4%, and 10% lower, respectively, in 2008 than they had been in 1999. Women aged 20-29 years accounted for 57.1% of all abortions reported in 2008 and for the majority of abortions during the entire period of analysis (1999-2008). In 2008, women aged 20-29 years also had the highest abortion rates (29.6 abortions per 1,000 women aged 20-24 years and 21.6 abortions per 1,000 women aged 25-29 years). Adolescents aged 15-19 years accounted for 16.2% of all abortions in 2008 and had an abortion rate of 14.3 abortions per 1,000 adolescents aged 15-19 years; women aged ≥35 years accounted for a smaller percentage (11.9%) of abortions and had lower abortion rates (7.8 abortions per 1

  19. Abortion surveillance - United States, 2011.

    PubMed

    Pazol, Karen; Creanga, Andreea A; Burley, Kim D; Jamieson, Denise J

    2014-11-28

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2011. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2011, data were received from 49 reporting areas. For trend analysis, abortion data were evaluated from 46 areas that reported data every year during 2002-2011. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births). A total of 730,322 abortions were reported to CDC for 2011. Of these abortions, 98.3% were from the 46 reporting areas that provided data every year during 2002-2011. Among these same 46 reporting areas, the abortion rate for 2011 was 13.9 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 219 abortions per 1,000 live births. From 2010 to 2011, the total number and rate of reported abortions decreased 5% and the abortion ratio decreased 4%, and from 2002 to 2011, the total number, rate, and ratio of reported abortions decreased 13%, 14%, and 12%, respectively. In 2011, all three measures reached their lowest level for the entire period of analysis (2002-2011). In 2011 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates, and women in their 30s and older accounted for a much smaller percentage of abortions and had lower abortion rates. In 2011, women aged 20-24 and 25-29 years accounted for 32.9% and 24.9% of all abortions, respectively, and had abortion rates of 24.9 and 19.4 abortions per 1,000 women aged 20-24 and 25-29 years, respectively. In contrast, women aged 30-34, 35-39, and ≥40 years accounted for 15.8%, 8.9%, and 3.6% of all abortions, respectively

  20. Abortion: a reader's guide.

    PubMed

    Hisel, L M

    1996-01-01

    This review traces the discussion of abortion in the US through 10 of the best books published on the subject in the past 25 years. The first book considered is Daniel Callahan's "Abortion: Law, Choice and Morality," which was published in 1970. Next is book of essays also published in 1970: "The Morality of Abortion: Legal and Historical Perspectives," which was edited by John T. Noonan, Jr., who became a prominent opponent to the Roe decision. It is noted that Roman Catholics would find the essay by Bernard Haring especially interesting since Haring supported the Church's position on abortion but called for acceptance of contraception. Third on the list is historian James C. Mohr's review of "Abortion in America: The Origins and Evolution of National Policy," which was printed five years after the Roe decision. Selection four is "Enemies of Choice: The Right-to-Life Movement and Its Threat to Abortion" by Andrew Merton. This 1981 publication singled out a concern about sexuality as the overriding motivator for anti-abortion groups. Two years later, Beverly Wildung Harrison published a ground-breaking, feminist, moral analysis of abortion entitled "Our Right to Choose: Toward a New Ethic of Abortion. This was followed by a more empirical and sociopolitical feminist analysis in Kristin Luker's 1984 "Abortion and the Politics of Motherhood." The seventh book is by another feminist, Rosalind Pollack Petchesky, whose work "Abortion and Women's Choice: The State, Sexuality, and Reproductive Freedom" was first published in 1984 and reprinted in 1990. The eighth important book was "Abortion and Catholicism: The American Debate," edited by Thomas A. Shannon and Patricia Beattie Jung. Rounding out the list are the 1992 work "Life Itself: Abortion in the American Mind" by Roger Rosenblatt and Ronald Dworkin's 1993 "Life's Dominion: An Argument About Abortion, Euthanasia, and Individual Freedom."

  1. The incidence of abortion worldwide.

    PubMed

    Henshaw, S K; Singh, S; Haas, T

    1999-01-01

    Accurate measurement of induced abortion levels has proven difficult in many parts of the world. Health care workers and policymakers need information on the incidence of both legal and illegal induced abortion to provide the needed services and to reduce the negative impact of unsafe abortion on women's health. Numbers and rates of induced abortions were estimated from four sources: official statistics or other national data on legal abortions in 57 countries; estimates based on population surveys for two countries without official statistics; special studies for 10 countries where abortion is highly restricted; and worldwide and regional estimates of unsafe abortion from the World Health Organization. Approximately 26 million legal and 20 million illegal abortions were performed worldwide in 1995, resulting in a worldwide abortion rate of 35 per 1,000 women aged 15-44. Among the subregions of the world, Eastern Europe had the highest abortion rate (90 per 1,000) and Western Europe to the lowest rate (11 per 1,000). Among countries where abortion is legal without restriction as to reason, the highest abortion rate, 83 per 1,000, was reported for Vietnam and the lowest, seven per 1,000, for Belgium and the Netherlands. Abortion rates are no lower overall in areas where abortion is generally restricted by law (and where many abortions are performed under unsafe conditions) than in areas where abortion is legally permitted. Both developed and developing countries can have low abortion rates. Most countries, however, have moderate to high abortion rates, reflecting lower prevalence and effectiveness of contraceptive use. Stringent legal restrictions do not guarantee a low abortion rate.

  2. [Complications of induced abortion].

    PubMed

    Kretowicz, J

    1984-03-26

    The abortion problem has been a major topic of debate for many years. Polish legislation permitting abortion has both supporters and opponents. It appears that both groups fail to fully recognize the risks of the various medical complications of induced abortion. A literature review of the complications of abortion shows that these complications are often underestimated by the public and the medical community. The review clearly demonstrates that abortion adversely affects women's health. Inflammation of the genital system is the most frequent complication. The ocurrence of complications increases as the term of the pregnancy advances. It is concluded that the public is not fully aware of the immediate danger and aftereffects of induced abortion. Wider popularization of the extensive body of scientific information regarding the risks of induced abortion might change current perceptions about the "safety" of abortion.

  3. [[Abortion: An Unforgivable Sin?].

    PubMed

    Lalli, Chiara

    Abortion has become something to hide, something you can't tell other people, something you have to expiate forever. Besides, abortion is more and more difficult to achieve because of the raising average of consciencious objection (from 70 to 90% of health care providers are conscientious objectors, 2014 data, Ministero della Salute) and illegal abortion is "coming back"from the 70s, when abortion was a crime (Italian law n. 194/1978). Abortion is often blamed as a murder, an unforgivenable sin, even as genocide. Silence against shouting "killers!" to women who are going to have an abortion: this is a common actual scenario. Why is it so difficult to discuss and even to mention abortion?

  4. Leptokurtic pollen-flow, non-leptokurtic gene-flow in a wind-pollinated herb, Plantago lanceolata L.

    PubMed

    Tonsor, Stephen J

    1985-10-01

    The purpose of this study was to simultaneously measure pollen dispersal distance and actual pollen-mediated gene-flow distance in a wind-pollinated herb, Plantago lanceolata. The pollen dispersal distribution, measured as pollen deposition in a wind tunnel, is leptokurtic, as expected from previous studies of wind-pollinated plants. Gene-flow, measured as seeds produced on rows of male-sterile inflorescences in the wind tunnel, is non-leptokurtic, peaking at an intermediate distance. The difference between the two distributions results from the tendency of the pollen grains to cluster. These pollen clusters are the units of gene dispersal, with clusters of intermediate and large size contributing disproportionately to gene-flow. Since many wind-pollinated species show pollen clustering (see text), the common assumption for wind-pollinated plants that gene-flow is leptokurtic requires re-examination. Gene-flow was also measured in an artifical outdoor population of male-steriles, containing a single pollen source plant in the center of the array. The gene flow distribution is significantly platykurtic, and has the same general properties outdoors, where wind speed and turbulence are uncontrolled, as it does in the wind tunnel. I estimated genetic neighborhood size based on my measure of gene-flow in the outdoor population. The estimate shows that populations of Plantago lanceolata will vary in effective number from a few tens of plants to more than five hundred plants, depending on the density of the population in question. Thus, the measured pollen-mediated gene-flow distribution and population density will interact to produce effective population sizes ranging from those in which there is no random genetic drift to those in which random genetic drift plays an important role in determining gene frequencies within and among populations. Despite the platykurtosis in the distribution, pollen-mediated gene dispersal distances are still quite limited, and considerable

  5. Resilience of rice (Oryza spp.) pollen germination and tube growth to temperature stress.

    PubMed

    Coast, Onoriode; Murdoch, Alistair J; Ellis, Richard H; Hay, Fiona R; Jagadish, Krishna S V

    2016-01-01

    Resilience of rice cropping systems to potential global climate change will partly depend on the temperature tolerance of pollen germination (PG) and tube growth (PTG). Pollen germination of high temperature-susceptible Oryza glaberrima Steud. (cv. CG14) and Oryza sativa L. ssp. indica (cv. IR64) and high temperature-tolerant O. sativa ssp. aus (cv. N22), was assessed on a 5.6-45.4 °C temperature gradient system. Mean maximum PG was 85% at 27 °C with 1488 μm PTG at 25 °C. The hypothesis that in each pollen grain, the minimum temperature requirements (Tn ) and maximum temperature limits (Tx ) for germination operate independently was accepted by comparing multiplicative and subtractive probability models. The maximum temperature limit for PG in 50% of grains (Tx(50) ) was the lowest (29.8 °C) in IR64 compared with CG14 (34.3 °C) and N22 (35.6 °C). Standard deviation (sx ) of Tx was also low in IR64 (2.3 °C) suggesting that the mechanism of IR64's susceptibility to high temperatures may relate to PG. Optimum germination temperatures and thermal times for 1 mm PTG were not linked to tolerating high temperatures at anthesis. However, the parameters Tx(50) and sx in the germination model define new pragmatic criteria for successful and resilient PG, preferable to the more traditional cardinal (maximum and minimum) temperatures. © 2014 John Wiley & Sons Ltd.

  6. Exogenous γ-aminobutyric acid (GABA) affects pollen tube growth via modulating putative Ca2+-permeable membrane channels and is coupled to negative regulation on glutamate decarboxylase

    PubMed Central

    Yu, Guang-Hui; Zou, Jie; Feng, Jing; Peng, Xiong-Bo; Wu, Ju-You; Wu, Ying-Liang; Palanivelu, Ravishankar; Sun, Meng-Xiang

    2014-01-01

    γ-Aminobutyric acid (GABA) is implicated in pollen tube growth, but the molecular and cellular mechanisms that it mediates are largely unknown. Here, it is shown that exogenous GABA modulates putative Ca2+-permeable channels on the plasma membranes of tobacco pollen grains and pollen tubes. Whole-cell voltage-clamp experiments and non-invasive micromeasurement technology (NMT) revealed that the influx of Ca2+ increases in pollen tubes in response to exogenous GABA. It is also demonstrated that glutamate decarboxylase (GAD), the rate-limiting enzyme of GABA biosynthesis, is involved in feedback controls of Ca2+-permeable channels to fluctuate intracellular GABA levels and thus modulate pollen tube growth. The findings suggest that GAD activity linked with Ca2+-permeable channels relays an extracellular GABA signal and integrates multiple signal pathways to modulate tobacco pollen tube growth. Thus, the data explain how GABA mediates the communication between the style and the growing pollen tubes. PMID:24799560

  7. Social sources of women's emotional difficulty after abortion: lessons from women's abortion narratives.

    PubMed

    Kimport, Katrina; Foster, Kira; Weitz, Tracy A

    2011-06-01

    The experiences of women who have negative emotional outcomes, including regret, following an abortion have received little research attention. Qualitative research can elucidate these women's experiences and ways their needs can be met and emotional distress reduced. Twenty-one women who had emotional difficulties related to an abortion participated in semi-structured, in-depth telephone interviews in 2009. Of these, 14 women were recruited from abortion support talklines; seven were recruited from a separate research project on women's experience of abortion. Transcripts were analyzed using the principles of grounded theory to identify key themes. Two social aspects of the abortion experience produced, exacerbated or mitigated respondents' negative emotional experience. Negative outcomes were experienced when the woman did not feel that the abortion was primarily her decision (e.g., because her partner abdicated responsibility for the pregnancy, leaving her feeling as though she had no other choice) or did not feel that she had clear emotional support after the abortion. Evidence also points to a division of labor between women and men regarding pregnancy prevention, abortion and childrearing; as a result, the majority of abortion-related emotional burdens fall on women. Experiencing decisional autonomy or social support reduced respondents' emotional distress. Supporting a woman's abortion decision-making process, addressing the division of labor between women and men regarding pregnancy prevention, abortion and childrearing, and offering nonjudgmental support may guide interventions designed to reduce emotional distress after abortion. Copyright © 2011 by the Guttmacher Institute.

  8. Telling stories about abortion: abortion-related plots in American film and television, 1916-2013.

    PubMed

    Sisson, Gretchen; Kimport, Katrina

    2014-05-01

    Popular discourse on abortion in film and television assumes that abortions are under- and misrepresented. Research indicates that such representations influence public perception of abortion care and may play a role in the production of social myths around abortion, with consequences for women's experience of abortion. To date, abortion plotlines in American film and television have not been systematically tracked and analyzed. A comprehensive online search was conducted to identify all representations of pregnancy decision making and abortion in American film and television through January 2013. Search results were coded for year, pregnancy decision and mortality outcome. A total of 310 plotlines were identified, with an overall upward trend over time in the number of representations of abortion decision making. Of these plotlines, 173 (55.8%) resulted in abortion, 80 (25.8%) in parenting, 13 (4.2%) in adoption and 21 (6.7%) in pregnancy loss, and 16 (5.1%) were unresolved. A total of 13.5% (n=42) of stories ended with the death of the woman who considered an abortion, whether or not she obtained one. Abortion-related plotlines occur more frequently than popular discourse assumes. Year-to-year variation in frequency suggests an interactive relationship between media representations, cultural attitudes and policies around abortion regulation, consistent with cultural theory of the relationship between media products and social beliefs. Patterns of outcomes and rates of mortality are not representative of real experience and may contribute to social myths around abortion. The narrative linking of pregnancy termination with mortality is of particular note, supporting the social myth associating abortion with death. This analysis empirically describes the number of abortion-related plotlines in American film and television. It contributes to the systematic evaluation of the portrayal of abortion in popular culture and provides abortion care professionals and

  9. Gibberellin regulates pollen viability and pollen tube growth in rice.

    PubMed

    Chhun, Tory; Aya, Koichiro; Asano, Kenji; Yamamoto, Eiji; Morinaka, Yoichi; Watanabe, Masao; Kitano, Hidemi; Ashikari, Motoyuki; Matsuoka, Makoto; Ueguchi-Tanaka, Miyako

    2007-12-01

    Gibberellins (GAs) play many biological roles in higher plants. We collected and performed genetic analysis on rice (Oryza sativa) GA-related mutants, including GA-deficient and GA-insensitive mutants. Genetic analysis of the mutants revealed that rice GA-deficient mutations are not transmitted as Mendelian traits to the next generation following self-pollination of F1 heterozygous plants, although GA-insensitive mutations are transmitted normally. To understand these differences in transmission, we examined the effect of GA on microsporogenesis and pollen tube elongation in rice using new GA-deficient and GA-insensitive mutants that produce semifertile flowers. Phenotypic analysis revealed that the GA-deficient mutant reduced pollen elongation1 is defective in pollen tube elongation, resulting in a low fertilization frequency, whereas the GA-insensitive semidominant mutant Slr1-d3 is mainly defective in viable pollen production. Quantitative RT-PCR revealed that GA biosynthesis genes tested whose mutations are transmitted to the next generation at a lower frequency are preferentially expressed after meiosis during pollen development, but expression is absent or very low before the meiosis stage, whereas GA signal-related genes are actively expressed before meiosis. Based on these observations, we predict that the transmission of GA-signaling genes occurs in a sporophytic manner, since the protein products and/or mRNA transcripts of these genes may be introduced into pollen-carrying mutant alleles, whereas GA synthesis genes are transmitted in a gametophytic manner, since these genes are preferentially expressed after meiosis.

  10. Abortion Providers' Experiences with Medicaid Abortion Coverage Policies: A Qualitative Multistate Study

    PubMed Central

    Dennis, Amanda; Blanchard, Kelly

    2013-01-01

    Objective To evaluate the implementation of state Medicaid abortion policies and the impact of these policies on abortion clients and abortion providers. Data Source From 2007 to 2010, in-depth interviews were conducted with representatives of 70 abortion-providing facilities in 15 states. Study Design In-depth interviews focused on abortion providers' perceptions regarding Medicaid and their experiences working with Medicaid and securing reimbursement in cases that should receive federal funding: rape, incest, and life endangerment. Data Extraction Data were transcribed verbatim before being coded. Principal Findings In two study states, abortion providers reported that 97 percent of submitted claims for qualifying cases were funded. Success receiving reimbursement was attributed to streamlined electronic billing procedures, timely claims processing, and responsive Medicaid staff. Abortion providers in the other 13 states reported reimbursement for 36 percent of qualifying cases. Providers reported difficulties obtaining reimbursement due to unclear rejections of qualifying claims, complex billing procedures, lack of knowledgeable Medicaid staff with whom billing problems could be discussed, and low and slow reimbursement rates. Conclusions Poor state-level implementation of Medicaid coverage of abortion policies creates barriers for women seeking abortion. Efforts to ensure policies are implemented appropriately would improve women's health. PMID:22742741

  11. Individual pollen exposure measurements: are they feasible?

    PubMed

    Berger, Uwe; Kmenta, Maximilian; Bastl, Katharina

    2014-06-01

    The purpose of the recent review is to give insight into recent attempts to measure individual pollen exposure and to give advice for interpreting such data. It is well recognized that there are various challenges in monitoring the atmospheric content of pollen in the air. Although pollen data gathered by Hirst type spore traps and evaluated by human expertise are of inestimable value because of long-time data series and as the basic foundation for pollen information services as well as for diagnosis and therapy of pollen allergies, there is a need for more precise information for individual pollen allergy sufferers. Different types of individual pollen exposure measurement samplers are presented, and estimates are offered. Further developments, especially standardization of personal pollen samplers, are needed. Improvements should lead to more usability. Because of a variety of factors, a pollen count will always stay a pollen count, and a pollen forecast is not a symptom forecast, something pollen allergy sufferers actually desire. Thus, a different promising path to individualized pollen information was recently chosen: personal pollen information is now possible based on personal symptom data and regional pollen data. In future, personal pollen data could complete this achievement.

  12. Allergenic weed pollen forecast under the mathematical modeling method implementation in ukraine.

    PubMed

    Motruk, Irina I; Antomonov, Michael Yu; Rodinkova, Victoria V; Aleksandrova, Olena E; Yermishev, Oleh V

    2018-01-01

    Introduction: Allergies are the most common reason of the chronic diseases in developed countries and represent an important medical, social and economic issue, the relevance of which is growing both in these countries and in Ukraine. The most famous of these allergens group is the pollen of ambrosia and pollen of poaceae, which are ubiquitously distributed in the subtropical and temperate climate. The aim: The objective of our study was to develop the mathematical models, which will be able to indicate the probability of the pollen circulation, and thus these models can simplify the forecast of symptoms risk and improve the prophylaxis of pollinosis. Materials and methods: The research was conducted on the basis of the research center of National Pirogov Memorial Medical University, Vinnytsia in the years 2012-2014. A volumetric sampler of the Hirst type was used for the air sampling. The observation was conducted from the first of April to the thirty-first of October. For the initial preparation of the tables and intermediate calculations, Excel software package was used. The software STATISTICA 10.0 was applied to calculate the average coefficients values and their statistical characteristics (beta-values, errors of the mean values, Student's t-test, veracity and the factors percentage contribution into the function variation). Results: Statistically significant correlation between pollen concentrations of herbaceous plants and individual meteorological factors was found; classificational functions were designed by which it is possible to calculate the probability of presence or absence of Artemisia pollen in the atmosphere; the risks of increasing of the Artemisia pollen concentration are determined under exceeding of the critical temperature of 18°С, relative humidity of 67% and atmospheric pressure of 980 Pa. Conclusions. The results of the research can be used to predict the emission of potentially hazardous concentrations of weed pollen grains in the

  13. Influence of Pollen Nutrition on Honey Bee Health: Do Pollen Quality and Diversity Matter?

    PubMed Central

    Di Pasquale, Garance; Salignon, Marion; Le Conte, Yves; Belzunces, Luc P.; Decourtye, Axel; Kretzschmar, André; Suchail, Séverine; Brunet, Jean-Luc; Alaux, Cédric

    2013-01-01

    Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen) necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens) and diversity (polyfloral pollen diet) on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level), and on the tolerance to the microsporidian parasite Nosema ceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification), phenoloxidase (immunity) and alkaline phosphatase (metabolism)). We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context) of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health. PMID:23940803

  14. Influence of pollen nutrition on honey bee health: do pollen quality and diversity matter?

    PubMed

    Di Pasquale, Garance; Salignon, Marion; Le Conte, Yves; Belzunces, Luc P; Decourtye, Axel; Kretzschmar, André; Suchail, Séverine; Brunet, Jean-Luc; Alaux, Cédric

    2013-01-01

    Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen) necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens) and diversity (polyfloral pollen diet) on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level), and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification), phenoloxidase (immunity) and alkaline phosphatase (metabolism)). We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context) of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health.

  15. Abortion surveillance--United States, 1992.

    PubMed

    Koonin, L M; Smith, J C; Ramick, M; Green, C A

    1996-05-03

    From 1980 through 1992, the number of legal induced abortions reported to the CDC remained stable, varying each year by < or = 5%. This report summarizes and reviews information reported to CDC regarding legal induced abortions obtained in the United States during 1992. This report also includes recently reported abortion-related deaths for 1988-1991 and an update on abortion-related deaths for 1985-1987. For each year since 1969, CDC has compiled abortion data received from 52 reporting areas (i.e., the 50 states, the District of Columbia, and New York City). In 1992, 1,359,145 abortions were reported--a 2.1% decrease from 1991. The abortion ratio was 335 legal induced abortions per 1,000 live births, and the abortion rate was 23 per 1,000 women 15-44 years of age. Women who were undergoing an abortion were more likely to be young, white, and unmarried; most had had no previous live births and were obtaining an abortion for the first time. More than half (51%) of all abortions were performed at or before the 8th week of gestation, and 87% were before the 13th week. Approximately 14% of abortions were performed at < or = 6 weeks of gestation, 15% were performed at 7 weeks of gestation, and 22% at 8 weeks of gestation. Younger women (i.e., women < or = 19 years of age) were more likely to obtain abortions later in pregnancy than were older women. Sixteen deaths in 1988, 12 deaths in 1989, and five deaths in 1990 were associated with legal induced abortion. The case-fatality rates for 1988, 1989, and 1990, respectively, were 1.2, 0.9, and 0.3 abortion-related deaths per 100,000 legal induced abortions. Since 1980, the number and rate of abortions have remained relatively stable, with only small year-to-year fluctuations of < or = 5%. However, since 1987, the abortion-to-live-birth ratio has declined; in 1992, the abortion ratio was the lowest recorded since 1977. More pregnant women have been opting to carry their pregnancies to term rather than choosing to have an

  16. Arabidopsis Formin3 Directs the Formation of Actin Cables and Polarized Growth in Pollen Tubes[W

    PubMed Central

    Ye, Jianrong; Zheng, Yiyan; Yan, An; Chen, Naizhi; Wang, Zhangkui; Huang, Shanjin; Yang, Zhenbiao

    2009-01-01

    Cytoplasmic actin cables are the most prominent actin structures in plant cells, but the molecular mechanism underlying their formation is unknown. The function of these actin cables, which are proposed to modulate cytoplasmic streaming and intracellular movement of many organelles in plants, has not been studied by genetic means. Here, we show that Arabidopsis thaliana formin3 (AFH3) is an actin nucleation factor responsible for the formation of longitudinal actin cables in pollen tubes. The Arabidopsis AFH3 gene encodes a 785–amino acid polypeptide, which contains a formin homology 1 (FH1) and a FH2 domain. In vitro analysis revealed that the AFH3 FH1FH2 domains interact with the barbed end of actin filaments and have actin nucleation activity in the presence of G-actin or G actin-profilin. Overexpression of AFH3 in tobacco (Nicotiana tabacum) pollen tubes induced excessive actin cables, which extended into the tubes' apices. Specific downregulation of AFH3 eliminated actin cables in Arabidopsis pollen tubes and reduced the level of actin polymers in pollen grains. This led to the disruption of the reverse fountain streaming pattern in pollen tubes, confirming a role for actin cables in the regulation of cytoplasmic streaming. Furthermore, these tubes became wide and short and swelled at their tips, suggesting that actin cables may regulate growth polarity in pollen tubes. Thus, AFH3 regulates the formation of actin cables, which are important for cytoplasmic streaming and polarized growth in pollen tubes. PMID:20023198

  17. The effect of geographical and climatic properties on grass pollen and Phl p 5 allergen release

    NASA Astrophysics Data System (ADS)

    Alan, Şenol; Şahin, Aydan Acar; Sarışahin, Tuğba; Şahin, Serap; Kaplan, Ayşe; Pınar, Nur Münevver

    2018-04-01

    The Poaceae family, including grasses, comprises several cosmopolitan and allergenic species. The aim of this study was to determine the correlations between Poaceae pollen and Phl p 5 allergen concentrations in two cities with different geographical and climatic properties in Turkey. Pollen were collected from Burkard traps in Ankara and Zonguldak. Phl p 5 sampling was carried out between March and October in both 2015 and 2016 using a BGI900 Cascade High Volume Air Sampler (900 L/min.). The concentrations of Phl p 5 were measured by the enzyme-linked immunosorbent assay (ELISA) technique. The annual sum of Poaceae pollen (pollen index) during 2015-2016 was 5454 in Ankara and 4142 in Zonguldak. The total Phl p 5 concentration was 1309 pg/m3 in Zonguldak, whereas it was 8181 pg/m3 in Ankara over 2 years. About 90% of the allergen was found in the fraction with particulate matter (PM) > 10 μm in both cities. It was found that the main meteorological parameter which affected pollen and Phl p 5 was temperature in both stations. Rainfall was also found to be important for Zonguldak, due to its climatic and geographic properties. Lastly, we suggest that the primary wind direction, which is from the south of Zonguldak, could have a `drift effect' for allergens because of the airborne pollen concentrations and the dates on which the allergen is released into the atmosphere. The wind direction may be an important factor in the distribution of allergen and pollen grains in stations, especially those with a hilly topography.

  18. The Response of Abortion Demand to Changes in Abortion Costs

    ERIC Educational Resources Information Center

    Medoff, Marshall H.

    2008-01-01

    This study uses pooled cross-section time-series data, over the years 1982, 1992 and 2000, to estimate the impact of various restrictive abortion laws on the demand for abortion. This study complements and extends prior research by explicitly including the price of obtaining an abortion in the estimation. The empirical results show that the real…

  19. Effects of virus infection on pollen production and pollen performance: Implications for the spread of resistance alleles.

    PubMed

    Harth, Jacquelyn E; Winsor, James A; Weakland, Danelle R; Nowak, Kayla J; Ferrari, Matthew J; Stephenson, Andrew G

    2016-03-01

    Studies over the past 25 years have shown that environmental stresses adversely affect male function, including pollen production and pollen performance (germination and pollen tube growth rate). Consequently, genetic variation among plants in resistance to a stress has the potential to impact pollen donation to conspecifics and, if deposited onto a stigma, the ability of the pollen to achieve fertilization. We examined the effects of a nonlethal virus epidemic on pollen production and pollen performance in a population of susceptible and resistant (transgenic) wild squash (Cucurbita pepo subsp. texana). We grew 135 susceptible and 45 virus-resistant wild squash plants in each of two 0.4-ha fields, initiated a zucchini yellow mosaic virus (ZYMV) epidemic, and recorded staminate and pistillate flower production per plant over the field season and the total number of mature fruit. We also assessed pollen production per flower on ZYMV-infected and non-infected plants and the ability of pollen from flowers on infected and non-infected plants to achieve fertilization under competitive conditions. ZYMV infection reduced flower and fruit production per plant and pollen production per flower. Pollen from infected plants was also less likely to sire a seed under competitive conditions. ZYMV infection adversely impacts the amount of pollen that can be donated to conspecifics, and pollen competition within the styles increases the probability that the ovules are fertilized by pollen from plants that are thriving when challenged by a viral disease. © 2016 Botanical Society of America.

  20. Abortion surveillance - United States, 2010.

    PubMed

    Pazol, Karen; Creanga, Andreea A; Burley, Kim D; Hayes, Brenda; Jamieson, Denise J

    2013-11-29

    Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States. 2010. Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2010, data were received from 49 reporting areas. For the purpose of trend analysis, abortion data were evaluated from the 46 areas that reported data every year during 2001-2010. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births). A total of 765,651 abortions were reported to CDC for 2010. Of these abortions, 753,065 (98.4%) were from the 46 reporting areas that provided data every year during 2001-2010. Among these same 46 reporting areas, the abortion rate for 2010 was 14.6 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 228 abortions per 1,000 live births. Compared with 2009, the total number and rate of reported abortions for 2010 decreased 3% and reached the lowest levels for the entire period of analysis (2001-2010); the abortion ratio was stable, changing only 0.4%. From 2001 to 2010, the total number, rate, and ratio of reported abortions decreased 9%, 10%, and 8%, respectively. Given the 3% decrease from 2009 to 2010 in the total number and rate of reported abortions, in combination with the 5% decrease that had occurred in the previous year from 2008 to 2009, the overall decrease for both measures was greater during 2006-2010 than during 2001-2005, despite the annual variations that resulted in no net decrease during 2006-2008. In 2010 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates, whereas women in their 30s and older accounted for a much smaller

  1. The cell wall pectic polymer rhamnogalacturonan-II is required for proper pollen tube elongation: implications of a putative sialyltransferase-like protein.

    PubMed

    Dumont, Marie; Lehner, Arnaud; Bouton, Sophie; Kiefer-Meyer, Marie Christine; Voxeur, Aline; Pelloux, Jérôme; Lerouge, Patrice; Mollet, Jean-Claude

    2014-10-01

    Rhamnogalacturonan-II (RG-II) is one of the pectin motifs found in the cell wall of all land plants. It contains sugars such as 2-keto-3-deoxy-d-lyxo-heptulosaric acid (Dha) and 2-keto-3-deoxy-d-manno-octulosonic acid (Kdo), and within the wall RG-II is mostly found as a dimer via a borate diester cross-link. To date, little is known regarding the biosynthesis of this motif. Here, after a brief review of our current knowledge on RG-II structure, biosynthesis and function in plants, this study explores the implications of the presence of a Golgi-localized sialyltransferase-like 2 (SIA2) protein that is possibly involved in the transfer of Dha or Kdo in the RG-II of Arabidopsis thaliana pollen tubes, a fast-growing cell type used as a model for the study of cell elongation. Two heterozygous mutant lines of arabidopsis (sia2-1+/- and qrt1 × sia2-2+/-) were investigated. sia2-2+/- was in a quartet1 background and the inserted T-DNA contained the reporter gene β-glucuronidase (GUS) under the pollen-specific promoter LAT52. Pollen germination and pollen tube phenotype and growth were analysed both in vitro and in vivo by microscopy. Self-pollination of heterozygous lines produced no homozygous plants in the progeny, which may suggest that the mutation could be lethal. Heterozygous mutants displayed a much lower germination rate overall and exhibited a substantial delay in germination (20 h of delay to reach 30 % of pollen grain germination compared with the wild type). In both lines, mutant pollen grains that were able to produce a tube had tubes that were either bursting, abnormal (swollen or dichotomous branching tip) or much shorter compared with wild-type pollen tubes. In vivo, mutant pollen tubes were restricted to the style, whereas the wild-type pollen tubes were detected at the base of the ovary. This study highlights that the mutation in arabidopsis SIA2 encoding a sialyltransferase-like protein that may transfer Dha or Kdo on the RG-II motif has a dramatic

  2. Estimating the probability of spontaneous abortion in the presence of induced abortion and vice versa.

    PubMed Central

    Hammerslough, C R

    1992-01-01

    An integrated approach to estimate the total number of pregnancies that begin in a population during one calendar year and the probability of spontaneous abortion is described. This includes an indirect estimate of the number of pregnancies that result in spontaneous abortions. The method simultaneously takes into account the proportion of induced abortions that are censored by spontaneous abortions and vice versa in order to estimate the true annual number of spontaneous and induced abortions for a population. It also estimates the proportion of pregnancies that women intended to allow to continue to a live birth. The proposed indirect approach derives adjustment factors to make indirect estimates by combining vital statistics information on gestational age at induced abortion (from the 12 States that report to the National Center for Health Statistics) with a life table of spontaneous abortion probabilities. The adjustment factors are applied to data on induced abortions from the Alan Guttmacher Institute Abortion Provider Survey and data on births from U.S. vital statistics. For the United States in 1980 the probability of a spontaneous abortion is 19 percent, given the presence of induced abortion. Once the effects of spontaneous abortion are discounted, women in 1980 intended to allow 73 percent of their pregnancies to proceed to a live birth. One medical benefit to a population practicing induced abortion is that induced abortions avert some spontaneous abortions, leading to a lower mean gestational duration at the time of spontaneous abortion. PMID:1594736

  3. Coconut (Cocos nucifera l.) pollen cryopreservation.

    PubMed

    Karun, A; Sjini, K K; Niral, V; Amarnth, C H; Remya, P; Rajesh, M K; Samsudeen, K; Jerard, B A; Engelmann, F

    2014-01-01

    Coconut genetic resources are threatened by pests and pathogens, natural hazards and human activities. Cryopreservation is the only method allowing the safe and cost-effective long-term conservation of recalcitrant seed species such as coconut. The objective of this work was to test the effect of cryopreservation and of cryostorage duration on coconut pollen germination and fertility. Pollen of two coconut varieties (West Coast Tall WWCTW and Chowghat Orange Dwarf CODC) was collected in March-May over three successive years, desiccated to 7.5 % moisture content (FW) and cryopreserved by direct immersion in liquid nitrogen. Germination and pollen tube length (PTL) of desiccated and cryopreserved pollen were not significantly different for both WCT and COD over the three harvest months of the three consecutive years of study. Pollen germination ranged from 24 to 32 % in desiccated pollen whereas it was between 26 and 29 % in cryopreserved COD pollen. In the case of WCT, germination ranged from 30 to 31 % in desiccated pollen, while it was between 28 and 32 % in cryopreserved pollen. PTL of cryopreserved pollen ranged between 224-390 nm and 226-396 mm for COD and WCT, respectively. Germination of COD pollen varied between 29.0 and 44.1 % after 4 years and 1.0/1.5 years cryostorage, respectively. Germination of WCT pollen did not change significantly between 0 and 6 years cryostorage, being comprised between 32 (24 h) and 40 % (1.5 years). Germination and vigour of cryopreserved pollen were generally higher compared to that of pollen dried in oven and non-cryopreserved. Normal seed set was observed in COD and WCT palms using pollen cryostored for 6 months and 4 years. Cryopreserved pollen of five Tall and five Dwarf accessions displayed 24-31 % and 25-49 % germination, respectively. These results show that it is now possible to establish pollen cryobanks to contribute to coconut germplasm long-term conservation.

  4. Abortion surveillance--United States, 1997.

    PubMed

    Koonin, L M; Strauss, L T; Chrisman, C E; Parker, W Y

    2000-12-08

    In 1969, CDC began abortion surveillance to document the number and characteristics of women obtaining legal induced abortions, to monitor unintended pregnancy, and to assist efforts to identify and reduce preventable causes of morbidity and mortality associated with abortions. This report summarizes and reviews information reported to CDC regarding legal induced abortions obtained in the United States in 1997. For each year since 1969, CDC has compiled abortion data by state where the abortion occurred. The data are received from 52 reporting areas in the United States: 50 states, the District of Columbia, and New York City. In 1997, a total of 1,186,039 legal abortions were reported to CDC, representing a 3% decrease from the number reported for 1996. The abortion ratio was 306 legal induced abortions per 1,000 live births, and since 1995, the abortion rate has remained at 20 per 1,000 women aged 15-44 years. The availability of information about characteristics of women who obtained an abortion in 1997 varied by state and by the number of states reporting each characteristic. The total number of legal induced abortions by state is reported by state of residence and state of occurrence; characteristics of women obtaining abortions in 1997 are reported by state of occurrence. Women who were undergoing an abortion were more likely to be young (i.e., aged < 25 years), white, and unmarried; approximately one half were obtaining an abortion for the first time. More than one half of all abortions for which gestational age was reported (55%) were performed at < or = 8 weeks of gestation, and 88% were performed before 13 weeks. Overall, 18% of abortions were performed at the earliest weeks of gestation (< or = 6 weeks), 18% at 7 weeks of gestation, and 20% at 8 weeks of gestation. From 1992 through 1997, increases have occurred in the percentage of abortions performed at the very early weeks of gestation. Few abortions were provided after 15 weeks of gestation--4% of

  5. Abortion surveillance--United States, 1998.

    PubMed

    Herndon, Joy; Strauss, Lilo T; Whitehead, Sara; Parker, Wilda Y; Bartlett, Linda; Zane, Suzanne

    2002-06-07

    In 1969, CDC began abortion surveillance to document the number and characteristics of women obtaining legal induced abortions, to monitor unintended pregnancy, and to assist efforts to identify and reduce preventable causes of morbidity and mortality associated with abortions. This report summarizes and reviews information reported to CDC regarding legal induced abortions obtained in the United States in 1998. For each year since 1969, CDC has compiled abortion data by occurrence. From 1973 to 1997, data were received from or estimated for 52 reporting areas in the United States: 50 states, the District of Columbia, and New York City. In 1998, CDC compiled abortion data from only 48 reporting areas; Alaska, California, New Hampshire, and Oklahoma did not report. In 1998, 884,273 legal induced abortions were reported to CDC, representing a 2% decrease from the 900,171 legal induced abortions reported by the same 48 reporting areas for 1997. The abortion ratio, defined as the number of abortions per 1,000 live births, was 264, compared with 274 in 1997 (for the same 48 areas); the abortion rate for these 48 areas was 17 per 1,000 women aged 15-44 years for both 1997 and 1998. The availability of information about characteristics of women who obtained an abortion in 1998 varied by state and by the number of states reporting each characteristic. The total number of legal induced abortions by state is reported by state of residence and state of occurrence; characteristics of women obtaining abortions in 1998 are reported by state of occurrence. Women undergoing an abortion were likely to be young (i.e., age < 25 years), white, and unmarried; slightly more than one half were obtaining an abortion for the first time. Of all abortions for which gestational age was reported, 56% were performed at < or = 8 weeks of gestation, and 88% were performed before 13 weeks. Overall, 19% of abortions were performed at the earliest weeks of gestation (< or = 6 weeks), 18% at 7 weeks

  6. Honey bees preferentially consume freshly-stored pollen

    USDA-ARS?s Scientific Manuscript database

    Honey bees collect and store pollen in cells in a preserved form known as stored pollen, or beebread. To preserve pollen, bees add nectar and honey to collected pollen to form stored pollen. Bees eat stored pollen from a wide selection of pollen cells that have been stored for different lengths of...

  7. Ectopic Expression of BnaC.CP20.1 Results in Premature Tapetal Programmed Cell Death in Arabidopsis.

    PubMed

    Song, Liping; Zhou, Zhengfu; Tang, Shan; Zhang, Zhiqiang; Xia, Shengqian; Qin, Maomao; Li, Bao; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Fu, Tingdong; Tu, Jinxing

    2016-09-01

    Tapetal programmed cell death (PCD) is essential in pollen grain development, and cysteine proteases are ubiquitous enzymes participating in plant PCD. Although the major papain-like cysteine proteases (PLCPs) have been investigated, the exact functions of many PLCPs are still poorly understood in PCD. Here, we identified a PLCP gene, BnaC.CP20.1, which was closely related to XP_013596648.1 from Brassica oleracea. Quantitative real-time PCR analysis revealed that BnaC.CP20.1 expression was down-regulated in male-sterile lines in oilseed rape, suggesting a connection between this gene and male sterility. BnaC.CP20.1 is especially active in the tapetum and microspores in Brassica napus from the uninucleate stage until formation of mature pollen grains during anther development. On expression of BnaC.CP20.1 prior to the tetrad stage, BnA9::BnaC.CP20.1 transgenic lines in Arabidopsis thaliana showed a male-sterile phenotype with shortened siliques containing fewer or no seeds by self-crossing. Scanning electron microscopy indicated that the reticulate exine was defective in aborted microspores. Callose degradation was delayed and microspores were not released from the tetrad in a timely fashion. Additionally, the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay indicated that BnaC.CP20.1 ectopic expression led to premature tapetal PCD. Transmission electron microscopy analyses further demonstrated that the pollen abortion was due to the absence of tectum connections to the bacula in the transgenic anthers. These findings suggest that timely expression of BnaC.CP20.1 is necessary for tapetal degeneration and pollen wall formation. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Estimates of the incidence of induced abortion and consequences of unsafe abortion in Senegal.

    PubMed

    Sedgh, Gilda; Sylla, Amadou Hassane; Philbin, Jesse; Keogh, Sarah; Ndiaye, Salif

    2015-03-01

    Abortion is highly restricted by law in Senegal. Although women seek care for abortion complications, no national estimate of abortion incidence exists. Data on postabortion care and abortion in Senegal were collected in 2013 using surveys of a nationally representative sample of 168 health facilities that provide postabortion care and of 110 professionals knowledgeable about abortion service provision. Indirect estimation techniques were applied to the data to estimate the incidence of induced abortion in the country. Abortion rates and ratios were calculated for the nation and separately for the Dakar region and the rest of the country. The distribution of pregnancies by planning status and by outcome was estimated. In 2012, an estimated 51,500 induced abortions were performed in Senegal, and 16,700 (32%) resulted in complications that were treated at health facilities. The estimated abortion rate was 17 per 1,000 women aged 15-44 and the abortion ratio was 10 per 100 live births. The rate was higher in Dakar (21 per 1,000) than in the rest of the country (16 per 1,000). Poor women were far more likely to experience abortion complications, and less likely to receive treatment for complications, than nonpoor women. About 31% of pregnancies were unintended, and 24% of unintended pregnancies (8% of all pregnancies) ended in abortion. Unsafe abortion exacts a heavy toll on women in Senegal. Reducing the barriers to effective contraceptive use and ensuring access to postabortion care without the risk of legal consequences may reduce the incidence of and complications from unsafe abortion.

  9. Estimates of the Incidence of Induced Abortion And Consequences of Unsafe Abortion in Senegal

    PubMed Central

    Sedgh, Gilda; Sylla, Amadou Hassane; Philbin, Jesse; Keogh, Sarah; Ndiaye, Salif

    2015-01-01

    CONTEXT Abortion is highly restricted by law in Senegal. Although women seek care for abortion complications, no national estimate of abortion incidence exists. METHODS Data on postabortion care and abortion in Senegal were collected in 2013 using surveys of a nationally representative sample of 168 health facilities that provide postabortion care and of 110 professionals knowledgeable about abortion service provision. Indirect estimation techniques were applied to the data to estimate the incidence of induced abortion in the country. Abortion rates and ratios were calculated for the nation and separately for the Dakar region and the rest of the country. The distribution of pregnancies by planning status and by outcome was estimated. RESULTS In 2012, an estimated 51,500 induced abortions were performed in Senegal, and 16,700 (32%) resulted in complications that were treated at health facilities. The estimated abortion rate was 17 per 1,000 women aged 15–44 and the abortion ratio was 10 per 100 live births. The rate was higher in Dakar (21 per 1,000) than in the rest of the country (16 per 1,000). Poor women were far more likely to experience abortion complications, and less likely to receive treatment for complications, than nonpoor women. About 31% of pregnancies were unintended, and 24% of unintended pregnancies (8% of all pregnancies) ended in abortion. CONCLUSIONS Unsafe abortion exacts a heavy toll on women in Senegal. Reducing the barriers to effective contraceptive use and ensuring access to postabortion care without the risk of legal consequences may reduce the incidence of and complications from unsafe abortion. PMID:25856233

  10. Framing a 'social problem': Emotion in anti-abortion activists' depiction of the abortion debate.

    PubMed

    Ntontis, Evangelos; Hopkins, Nick

    2018-02-27

    Social psychological research on activism typically focuses on individuals' social identifications. We complement such research through exploring how activists frame an issue as a social problem. Specifically, we explore anti-abortion activists' representation of abortion and the abortion debate's protagonists so as to recruit support for the anti-abortion cause. Using interview data obtained with UK-based anti-abortion activists (N = 15), we consider how activists characterized women having abortions, pro-abortion campaigners, and anti-abortion campaigners. In particular, we consider the varied ways in which emotion featured in the representation of these social actors. Emotion featured in different ways. Sometimes, it was depicted as constituting embodied testament to the nature of reality. Sometimes, it was depicted as blocking the rational appraisal of reality. Our analysis considers how such varied meanings of emotion shaped the characterization of abortion and the abortion debate's protagonists such that anti-abortion activists were construed as speaking for women and their interests. We discuss how our analysis of the framing of issues as social problems complements and extends social psychological analyses of activism. © 2018 The British Psychological Society.

  11. Proteomes and Phosphoproteomes of Anther and Pollen: Availability and Progress.

    PubMed

    Zhang, Zaibao; Hu, Menghui; Feng, Xiaobing; Gong, Andong; Cheng, Lin; Yuan, Hongyu

    2017-10-01

    In flowering plants, anther development plays crucial role in sexual reproduction. Within the anther, microspore mother cells meiosis produces microspores, which further develop into pollen grains that play decisive role in plant reproduction. Previous studies on anther biology mainly focused on single gene functions relying on genetic and molecular methods. Recently, anther development has been expanded from multiple OMICS approaches like transcriptomics, proteomics/phosphoproteomics, and metabolomics. The development of proteomics techniques allowing increased proteome coverage and quantitative measurements of proteins which can characterize proteomes and their modulation during normal development, biotic and abiotic stresses in anther development. In this review, we summarize the achievements of proteomics and phosphoproteomics with anther and pollen organs from model plant and crop species (i.e. Arabidopsis, rice, tobacco). The increased proteomic information facilitated translation of information from the models to crops and thus aid in agricultural improvement. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Honey bees preferentially consume freshly-stored pollen.

    PubMed

    Carroll, Mark J; Brown, Nicholas; Goodall, Craig; Downs, Alexandra M; Sheenan, Timothy H; Anderson, Kirk E

    2017-01-01

    Honey bees (Apis mellifera) collect and store both honey and pollen in preserved forms. Pollen storage involves the addition of honey or nectar and oral secretions to pollen granules. It is controversial whether the duration of pollen storage alters the palatability or nutritive value of the pollen storage medium. We examined how bees utilize different-aged stored pollen during an extended pollen flow. The deposition of pollen into wax cells and subsequent consumption were monitored daily on 18 brood frames from 6 colonies over an 8d observation period. Despite a greater abundance of older stored pollen cells on brood frames, bees showed a marked preference for the consumption of freshly-stored pollen. Two to four day-old pollen cell contents were significantly more likely to be consumed, while pollen cell contents more than seven days old were eaten at much lower rates. Similar experiments that controlled for cell abundance and spatial effects using cage assays yielded the same result. One day-old stored pollen was consumed approximately three times more often than 10d-old stored pollen, and two times more often than 5d-old stored pollen. These consumption preferences for freshly-stored pollen occurred despite a lack of clear developmental advantages. Young adult workers reared for 7 days on 1d-, 5d-, or 10d-old stored pollen showed no difference in body mass, stored pollen consumption, hindgut fecal material accumulation, or hypopharyngeal gland (HPG) protein titers, suggesting that different-aged pollen stores did not vary in their nutritional value to adult bees. These findings are inconsistent with the hypothesis promoting a period of microbially-mediated, "beebread maturation" that results in greater palatability or nutritive value for aged pollen stores. Rather, stored pollen that is not eaten in the first few days accumulates as excess stores preserved in a less preferred, but nutritionally-similar state.

  13. Abortion among Adolescents.

    ERIC Educational Resources Information Center

    Adler, Nancy E.; Ozer, Emily J.; Tschann, Jeanne

    2003-01-01

    Reviews the current status of abortion laws pertaining to adolescents worldwide, examining questions raised by parental consent laws in the United States and by the relevant psychological research (risk of harm from abortion, informed consent, consequences of parental involvement in the abortion decision, and current debate). Discusses issues…

  14. Identification and expression analysis of BoMF25, a novel polygalacturonase gene involved in pollen development of Brassica oleracea.

    PubMed

    Lyu, Meiling; Liang, Ying; Yu, Youjian; Ma, Zhiming; Song, Limin; Yue, Xiaoyan; Cao, Jiashu

    2015-06-01

    BoMF25 acts on pollen wall. Polygalacturonase (PG) is a pectin-digesting enzyme involved in numerous plant developmental processes and is described to be of critical importance for pollen wall development. In the present study, a PG gene, BoMF25, was isolated from Brassica oleracea. BoMF25 is the homologous gene of At4g35670, a PG gene in Arabidopsis thaliana with a high expression level at the tricellular pollen stage. Collinear analysis revealed that the orthologous gene of BoMF25 in Brassica campestris (syn. B. rapa) genome was probably lost because of genome deletion and reshuffling. Sequence analysis indicated that BoMF25 contained four classical conserved domains (I, II, III, and IV) of PG protein. Homology and phylogenetic analyses showed that BoMF25 was clustered in Clade F. The putative promoter sequence, containing classical cis-acting elements and pollen-specific motifs, could drive green fluorescence protein expression in onion epidermal cells. Quantitative RT-PCR analysis suggested that BoMF25 was mainly expressed in the anther at the late stage of pollen development. In situ hybridization analysis also indicated that the strong and specific expression signal of BoMF25 existed in pollen grains at the mature pollen stage. Subcellular localization showed that the fluorescence signal was observed in the cell wall of onion epidermal cells, which suggested that BoMF25 may be a secreted protein localized in the pollen wall.

  15. No. 360-Induced Abortion: Surgical Abortion and Second Trimester Medical Methods.

    PubMed

    Costescu, Dustin; Guilbert, Édith

    2018-06-01

    This guideline reviews evidence relating to the provision of surgical induced abortion (IA) and second trimester medical abortion, including pre- and post-procedural care. Gynaecologists, family physicians, nurses, midwives, residents, and other health care providers who currently or intend to provide and/or teach IAs. Women with an unintended or abnormal first or second trimester pregnancy. PubMed, Medline, and the Cochrane Database were searched using the key words: first-trimester surgical abortion, second-trimester surgical abortion, second-trimester medical abortion, dilation and evacuation, induction abortion, feticide, cervical preparation, cervical dilation, abortion complications. Results were restricted to English or French systematic reviews, randomized controlled trials, clinical trials, and observational studies published from 1979 to July 2017. National and international clinical practice guidelines were consulted for review. Grey literature was not searched. The quality of evidence in this document was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology framework. The summary of findings is available upon request. IA is safe and effective. The benefits of IA outweigh the potential harms or costs. No new direct harms or costs identified with these guidelines. Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. All rights reserved.

  16. Outdoor pollen is a trigger of child and adolescent asthma emergency department presentations: A systematic review and meta-analysis.

    PubMed

    Erbas, B; Jazayeri, M; Lambert, K A; Katelaris, C H; Prendergast, L A; Tham, R; Parrodi, M J; Davies, J; Newbigin, E; Abramson, M J; Dharmage, S C

    2018-01-13

    In the context of increased asthma exacerbations associated with climatic changes such as thunderstorm asthma, interest in establishing the link between pollen exposure and asthma hospital admissions has intensified. Here, we systematically reviewed and performed a meta-analysis of studies on pollen and emergency department (ED) attendance. A search for studies with appropriate search strategy in MEDLINE, EMBASE, Web of Science and CINAHL was conducted. Each study was assessed for quality and risk of bias. The available evidence was summarized both qualitatively and meta-analysed using random-effects models when moderate heterogeneity was observed. Fourteen studies were included. The pollen taxa investigated differed between studies, allowing meta-analysis only of the effect of grass pollen. A statistically significant increase in the percentage change in the mean number of asthma ED presentations (MPC) (pooled results from 3 studies) was observed for an increase in 10 grass pollen grains per cubic metre of exposure 1.88% (95% CI = 0.94%, 2.82%). Time series studies showed positive correlations between pollen concentrations and ED presentations. Age-stratified studies found strongest associations in children aged 5-17 years old. Exposure to ambient grass pollen is an important trigger for childhood asthma exacerbations requiring ED attendance. As pollen exposure is increasingly a problem especially in relation to thunderstorm asthma, studies with uniform measures of pollen and similar analytical methods are necessary to fully understand its impact on human health. © 2018 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  17. A flash-lamp based device for fluorescence detection and identification of individual pollen grains.

    PubMed

    Kiselev, Denis; Bonacina, Luigi; Wolf, Jean-Pierre

    2013-03-01

    We present a novel optical aerosol particle detector based on Xe flash lamp excitation and spectrally resolved fluorescence acquisition. We demonstrate its performances on three natural pollens acquiring in real-time scattering intensity at two wavelengths, sub-microsecond time-resolved scattering traces of the particles' passage in the focus, and UV-excited fluorescence spectra. We show that the device gives access to a rather specific detection of the bioaerosol particles.

  18. Induced abortion in Taiwan.

    PubMed

    Wang, P D; Lin, R S

    1995-04-01

    Induced abortion is widely practised in Taiwan; however, it had been illegal until 1985. It was of interest to investigate induced abortion practices in Taiwan after its legalization in 1985 in order to calculate the prevalence rate and ratio of induced abortion to live births and to pregnancies in Taiwan. A study using questionnaires through personal interviews was conducted on more than seventeen thousand women who attended a family planning service in Taipei metropolitan areas between 1991 and 1992. The reproductive history and sexual behaviour of the subjects were especially focused on during the interviews. Preliminary findings showed that 46% of the women had a history of having had an induced abortion. Among them, 54.8% had had one abortion, 29.7% had had two, and 15.5% had had three or more. The abortion ratio was 379 induced abortions per 1,000 live births and 255 per 1,000 pregnancies. The abortion ratio was highest for women younger than 20 years of age, for aboriginal women and for nulliparous women. When logistic regression was used to control for confounding variables, we found that the number of previous live births is the strongest predictor relating to women seeking induced abortion. In addition, a significant positive association exists between increasing number of induced abortions and cervical dysplasia.

  19. The evolution of self-fertilization and inbreeding depression under pollen discounting and pollen limitation.

    PubMed

    Porcher, E; Lande, R

    2005-05-01

    We model the evolution of plant mating systems under the joint effects of pollen discounting and pollen limitation, using a dynamic model of inbreeding depression, allowing for partial purging of recessive lethal mutations by selfing. Stable mixed mating systems occur for a wide range of parameter values with pollen discounting alone. However, when typical levels of pollen limitation are combined with pollen discounting, stable selfing rates are always high but less than 1 (0.9pollen discounting becomes very large at high selfing rates, so that the automatic advantage of selfing changes to a disadvantage. These results suggest that mixed mating systems with high selfing rates can be maintained by selection, whereas mixed mating systems with low to moderate selfing rates are more likely attributable to unavoidable geitonogamous selfing.

  20. Abortion Stigma Among Low-Income Women Obtaining Abortions in Western Pennsylvania: A Qualitative Assessment.

    PubMed

    Gelman, Amanda; Rosenfeld, Elian A; Nikolajski, Cara; Freedman, Lori R; Steinberg, Julia R; Borrero, Sonya

    2017-03-01

    Abortion stigma may cause psychological distress in women who are considering having an abortion or have had one. This phenomenon has been relatively underexplored in low-income women, who may already be at an increased risk for poor abortion-related outcomes because of difficulties accessing timely and safe abortion services. A qualitative study conducted between 2010 and 2013 used semistructured interviews to explore pregnancy intentions among low-income women recruited from six reproductive health clinics in Western Pennsylvania. Transcripts from interviews with 19 participants who were planning to terminate a pregnancy or had had an abortion in the last two weeks were examined through content analysis to identify the range of attitudes they encountered that could contribute to or reflect abortion stigma, the sources of these attitudes and women's responses to them. Women commonly reported that partners, family members and they themselves held antiabortion attitudes. Such attitudes communicated that abortion is morally reprehensible, a rejection of motherhood, rare and thus potentially deviant, detrimental to future fertility and an irresponsible choice. Women reacted to external and internal negative attitudes by distinguishing themselves from other women who obtain abortions, experiencing negative emotions, and concealing or delaying their abortions. Women's reactions to antiabortion attitudes may perpetuate abortion stigma. Further research is needed to inform interventions to address abortion stigma and improve women's abortion experiences. Copyright © 2016 by the Guttmacher Institute.