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Sample records for pollen promoter severely

  1. Arabidopsis ACTIN-DEPOLYMERIZING FACTOR7 Severs Actin Filaments and Regulates Actin Cable Turnover to Promote Normal Pollen Tube Growth[W

    PubMed Central

    Zheng, Yiyan; Xie, Yurong; Jiang, Yuxiang; Qu, Xiaolu; Huang, Shanjin

    2013-01-01

    Actin filaments are often arranged into higher-order structures, such as the longitudinal actin cables that generate the reverse fountain cytoplasmic streaming pattern present in pollen tubes. While several actin binding proteins have been implicated in the generation of these cables, the mechanisms that regulate their dynamic turnover remain largely unknown. Here, we show that Arabidopsis thaliana ACTIN-DEPOLYMERIZING FACTOR7 (ADF7) is required for turnover of longitudinal actin cables. In vitro biochemical analyses revealed that ADF7 is a typical ADF that prefers ADP-G-actin over ATP-G-actin. ADF7 inhibits nucleotide exchange on actin and severs filaments, but its filament severing and depolymerizing activities are less potent than those of the vegetative ADF1. ADF7 primarily decorates longitudinal actin cables in the shanks of pollen tubes. Consistent with this localization pattern, the severing frequency and depolymerization rate of filaments significantly decreased, while their maximum lifetime significantly increased, in adf7 pollen tube shanks. Furthermore, an ADF7–enhanced green fluorescent protein fusion with defective severing activity but normal G-actin binding activity could not complement adf7, providing compelling evidence that the severing activity of ADF7 is vital for its in vivo functions. These observations suggest that ADF7 evolved to promote turnover of longitudinal actin cables by severing actin filaments in pollen tubes. PMID:24058157

  2. Identification of two highly specific pollen promoters using transcriptomic data.

    PubMed

    Muñoz-Strale, Daniela; León, Gabriel

    2014-10-01

    The mature pollen grain displays a highly specialized function in angiosperms. Accordingly, the male gametophyte development involves many specific biological activities, making it a complex and unique process in plants. In order to accomplish this, during pollen development, a massive transcriptomic remodeling takes place, indicating the switch from a sporophytic to a gametophytic program and involving the expression of many pollen specific genes. Using microarray databases we selected genes showing pollen-specific accumulation of their mRNAs and confirmed this through RT-PCR. We selected five genes (POLLEN SPECIFIC GENE1-5) to investigate the pollen specificity of their expression. Transcriptional fusions between the putative promoters of these genes and the uidA reporter gene in Arabidopsis confirmed the pollen specific expression for at least two of these genes. The expression of the cytotoxin Barnase controlled by these promoters generated pollen specific ablation and male sterility. Through the selection of pollen specific genes from public datasets, we were able to identify promoter regions that confer pollen expression. The use of the cytotoxin Barnase allowed us to demonstrate its expression is exclusively limited to the pollen. These new promoters provide a powerful tool for the expression of genes exclusively in pollen.

  3. Characterization of a pollen-preferential gene OSIAGP from rice (Oryza sativa L. subspecies indica) coding for an arabinogalactan protein homologue, and analysis of its promoter activity during pollen development and pollen tube growth.

    PubMed

    Anand, Saurabh; Tyagi, Akhilesh K

    2010-06-01

    During differential screening of inflorescence-specific cDNA libraries from Oryza sativa indica, an arabinogalactan protein (OSIAGP) cDNA (586 bp) expressing preferentially in the inflorescence has been isolated. It encodes an arabinogalactan protein of 59 amino acids (6.4 kDa) with a transmembrane domain and a secretory domain at the N terminus. The protein shows homology with AGP23 from Arabidopsis, and its homologue in japonica rice is located on chromosome 6. OSIAGP transcripts also accumulate in shoots and roots of rice seedling grown in the dark, but light represses expression of the gene. Analysis of a genomic clone of OSIAGP revealed that its promoter contains several pollen-specificity and light-regulatory elements. The promoter confers pollen-preferential activity on gus, starting from the release of microspores to anther dehiscence in transgenic tobacco, and is also active during pollen tube growth. Analysis of pollen preferential activity of the promoter in the transgenic rice system revealed that even the approximately 300 bp fragment has activity in pollen and the anther wall and further deletion down to approximately 100 bp completely abolishes this activity, which is consistent with in-silico analysis of the promoter. Arabinogalactan proteins have been shown to be involved in the cell elongation process. The homology of OSIAGP with AGP23 and the fact that seedling growth in the dark and pollen tube growth are events based on cell elongation strengthen the possibility of OSIAGP performing a similar function.

  4. Arabidopsis Villins Promote Actin Turnover at Pollen Tube Tips and Facilitate the Construction of Actin Collars[W

    PubMed Central

    Qu, Xiaolu; Zhang, Hua; Xie, Yurong; Wang, Juan; Chen, Naizhi; Huang, Shanjin

    2013-01-01

    Apical actin filaments are crucial for pollen tube tip growth. However, the specific dynamic changes and regulatory mechanisms associated with actin filaments in the apical region remain largely unknown. Here, we have investigated the quantitative dynamic parameters that underlie actin filament growth and disappearance in the apical regions of pollen tubes and identified villin as the major player that drives rapid turnover of actin filaments in this region. Downregulation of Arabidopsis thaliana VILLIN2 (VLN2) and VLN5 led to accumulation of actin filaments at the pollen tube apex. Careful analysis of single filament dynamics showed that the severing frequency significantly decreased, and the lifetime significantly increased in vln2 vln5 pollen tubes. These results indicate that villin-mediated severing is critical for turnover and departure of actin filaments originating in the apical region. Consequently, the construction of actin collars was affected in vln2 vln5 pollen tubes. In addition to the decrease in severing frequency, actin filaments also became wavy and buckled in the apical cytoplasm of vln2 vln5 pollen tubes. These results suggest that villin confers rigidity upon actin filaments. Furthermore, an observed decrease in skewness of actin filaments in the subapical region of vln2 vln5 pollen tubes suggests that villin-mediated bundling activity may also play a role in the construction of actin collars. Thus, our data suggest that villins promote actin turnover at pollen tube tips and facilitate the construction of actin collars. PMID:23715472

  5. Arabidopsis RIC1 Severs Actin Filaments at the Apex to Regulate Pollen Tube Growth

    PubMed Central

    Zhou, Zhenzhen; Shi, Haifan; Chen, Binqing; Zhang, Ruihui; Huang, Shanjin; Fu, Ying

    2015-01-01

    Pollen tubes deliver sperms to the ovule for fertilization via tip growth. The rapid turnover of F-actin in pollen tube tips plays an important role in this process. In this study, we demonstrate that Arabidopsis thaliana RIC1, a member of the ROP-interactive CRIB motif-containing protein family, regulates pollen tube growth via its F-actin severing activity. Knockout of RIC1 enhanced pollen tube elongation, while overexpression of RIC1 dramatically reduced tube growth. Pharmacological analysis indicated that RIC1 affected F-actin dynamics in pollen tubes. In vitro biochemical assays revealed that RIC1 directly bound and severed F-actin in the presence of Ca2+ in addition to interfering with F-actin turnover by capping F-actin at the barbed ends. In vivo, RIC1 localized primarily to the apical plasma membrane (PM) of pollen tubes. The level of RIC1 at the apical PM oscillated during pollen tube growth. The frequency of F-actin severing at the apex was notably decreased in ric1-1 pollen tubes but was increased in pollen tubes overexpressing RIC1. We propose that RIC1 regulates F-actin dynamics at the apical PM as well as the cytosol by severing F-actin and capping the barbed ends in the cytoplasm, establishing a novel mechanism that underlies the regulation of pollen tube growth. PMID:25804540

  6. Arabidopsis microtubule-destabilizing protein 25 functions in pollen tube growth by severing actin filaments.

    PubMed

    Qin, Tao; Liu, Xiaomin; Li, Jiejie; Sun, Jingbo; Song, Leina; Mao, Tonglin

    2014-01-01

    The formation of distinct actin filament arrays in the subapical region of pollen tubes is crucial for pollen tube growth. However, the molecular mechanisms underlying the organization and dynamics of the actin filaments in this region remain to be determined. This study shows that Arabidopsis thaliana MICROTUBULE-DESTABILIZING PROTEIN25 (MDP25) has the actin filament-severing activity of an actin binding protein. This protein negatively regulated pollen tube growth by modulating the organization and dynamics of actin filaments in the subapical region of pollen tubes. MDP25 loss of function resulted in enhanced pollen tube elongation and inefficient fertilization. MDP25 bound directly to actin filaments and severed individual actin filaments, in a manner that was dramatically enhanced by Ca(2+), in vitro. Analysis of a mutant that bears a point mutation at the Ca(2+) binding sites demonstrated that the subcellular localization of MDP25 was determined by cytosolic Ca(2+) level in the subapical region of pollen tubes, where MDP25 was disassociated from the plasma membrane and moved into the cytosol. Time-lapse analysis showed that the F-actin-severing frequency significantly decreased and a high density of actin filaments was observed in the subapical region of mdp25-1 pollen tubes. This study reveals a mechanism whereby calcium enhances the actin filament-severing activity of MDP25 in the subapical region of pollen tubes to modulate pollen tube growth.

  7. Pollen- and anther-specific chi promoters from petunia: tandem promoter regulation of the chiA gene.

    PubMed Central

    van Tunen, A J; Mur, L A; Brouns, G S; Rienstra, J D; Koes, R E; Mol, J N

    1990-01-01

    We have analyzed the spatial and temporal activities of chalcone flavanone isomerase (chi) A and B gene promoters from petunia. To study the tandem promoter regulation of chiA, various chiA promoter fragments were fused with the beta-glucuronidase (GUS) reporter gene. Analysis of transgenic plants containing these chimeric genes provided definitive proof that the chiA coding region is regulated by two distinct promoters (designated PA1 and PA2). We also showed that both promoters can function independently and that the chiA PA1 promoter is expressed in limb (epidermal and parenchyma cells), tube (inner epidermal and parenchyma cells), seed (seed coat, endosperm, and embryo), sepal, leaf, and stem. The use of chiA and chiB promoters in the regulation of anther- and pollen-specific gene expression has been studied. By analyzing transgenic plants containing chimeric genes consisting of chiA and B promoter fragments and the GUS reporter gene, we were able to identify a 0.44-kilobase chiA PA2 promoter fragment that drives pollen-specific gene expression and a 1.75-kilobase chiB PB promoter fragment that confers anther-specific (pollen and tapetum cells) expression to the GUS gene. PMID:2152165

  8. Arabidopsis Microtubule-Destabilizing Protein 25 Functions in Pollen Tube Growth by Severing Actin Filaments[W

    PubMed Central

    Qin, Tao; Liu, Xiaomin; Li, Jiejie; Sun, Jingbo; Song, Leina; Mao, Tonglin

    2014-01-01

    The formation of distinct actin filament arrays in the subapical region of pollen tubes is crucial for pollen tube growth. However, the molecular mechanisms underlying the organization and dynamics of the actin filaments in this region remain to be determined. This study shows that Arabidopsis thaliana MICROTUBULE-DESTABILIZING PROTEIN25 (MDP25) has the actin filament–severing activity of an actin binding protein. This protein negatively regulated pollen tube growth by modulating the organization and dynamics of actin filaments in the subapical region of pollen tubes. MDP25 loss of function resulted in enhanced pollen tube elongation and inefficient fertilization. MDP25 bound directly to actin filaments and severed individual actin filaments, in a manner that was dramatically enhanced by Ca2+, in vitro. Analysis of a mutant that bears a point mutation at the Ca2+ binding sites demonstrated that the subcellular localization of MDP25 was determined by cytosolic Ca2+ level in the subapical region of pollen tubes, where MDP25 was disassociated from the plasma membrane and moved into the cytosol. Time-lapse analysis showed that the F-actin-severing frequency significantly decreased and a high density of actin filaments was observed in the subapical region of mdp25-1 pollen tubes. This study reveals a mechanism whereby calcium enhances the actin filament–severing activity of MDP25 in the subapical region of pollen tubes to modulate pollen tube growth. PMID:24424096

  9. Birch pollen influence the severity of atopic eczema - prospective clinical cohort pilot study and ex vivo penetration study.

    PubMed

    Fölster-Holst, Regina; Galecka, Jagoda; Weißmantel, Sigo; Dickschat, Ute; Rippke, Frank; Bohnsack, Kerstin; Werfel, Thomas; Wichmann, Katja; Buchner, Matthias; Schwarz, Thomas; Vogt, Annika; Lademann, Jürgen; Meinke, Martina C

    2015-01-01

    There is little clinical evidence for a correlation between the severity of atopic eczema (AE) and pollen exposition. To obtain more data, we performed a clinical cohort pilot study about the influence of pollen on AE between sensitized and nonsensitized subjects and an experimental study addressing the cutaneous penetration of pollen into the skin. Fifty-five patients were monitored during birch pollen season. To study the cutaneous penetration, grass pollen allergens were applied on excised skin and the uptake in CD1c-expressing dendritic cells was investigated. The correlation between environmental pollen load and severity of the Scoring Atopic Dermatitis (SCORAD) score and pruritus was observed, regardless of the status of sensitization. The sensitized group recovered significantly worse after the birch pollen season. Remarkably higher amounts of pollen allergens taken up by CD1c cells were detected in epidermal cells derived from skin explants with a disturbed epidermal barrier. These findings suggest an exacerbating role of pollen in AE utilizing the epidermal route.

  10. Birch pollen influence the severity of atopic eczema – prospective clinical cohort pilot study and ex vivo penetration study

    PubMed Central

    Fölster-Holst, Regina; Galecka, Jagoda; Weißmantel, Sigo; Dickschat, Ute; Rippke, Frank; Bohnsack, Kerstin; Werfel, Thomas; Wichmann, Katja; Buchner, Matthias; Schwarz, Thomas; Vogt, Annika; Lademann, Jürgen; Meinke, Martina C

    2015-01-01

    There is little clinical evidence for a correlation between the severity of atopic eczema (AE) and pollen exposition. To obtain more data, we performed a clinical cohort pilot study about the influence of pollen on AE between sensitized and nonsensitized subjects and an experimental study addressing the cutaneous penetration of pollen into the skin. Fifty-five patients were monitored during birch pollen season. To study the cutaneous penetration, grass pollen allergens were applied on excised skin and the uptake in CD1c-expressing dendritic cells was investigated. The correlation between environmental pollen load and severity of the Scoring Atopic Dermatitis (SCORAD) score and pruritus was observed, regardless of the status of sensitization. The sensitized group recovered significantly worse after the birch pollen season. Remarkably higher amounts of pollen allergens taken up by CD1c cells were detected in epidermal cells derived from skin explants with a disturbed epidermal barrier. These findings suggest an exacerbating role of pollen in AE utilizing the epidermal route. PMID:26604810

  11. How does timing, duration and severity of heat stress influence pollen-pistil interactions in angiosperms?

    PubMed Central

    Oosterhuis, Derrick M

    2011-01-01

    Reproductive development in sexual plants is substantially more sensitive to high temperature stress than vegetative development, resulting in negative implications for food and fiber production under the moderate temperature increases projected to result from global climate change. High temperature exposure either during early pollen development or during the progamic phase of pollen development will negatively impact pollen performance and reproductive output; both phases of pollen development are considered exceptionally sensitive to moderate heat stress. However, moderately elevated temperatures either before or during the progamic phase can limit fertilization by negatively impacting important pollen pistil interactions required for successful pollen tube growth toward the ovules. This mini-review identifies the impacts of heat stress on pollen-pistil interactions and sexual reproduction in angiosperms. A special emphasis is placed on the biochemical response of the pistil to moderately high temperature and the resultant influence on in vivo pollen performance and fertilization. PMID:21628998

  12. Functional characterization of the pollen-specific SBgLR promoter from potato (Solanum tuberosum L.).

    PubMed

    Lang, Zhihong; Zhou, Peng; Yu, Jingjuan; Ao, Guangming; Zhao, Qian

    2008-01-01

    SBgLR (Solanum tuberosum genomic lysine-rich) gene was isolated from a potato genomic library using SB401 (S. berthaultii 401) cDNA as probe. RT-PCR analysis of SBgLR gene expression profile and microscopic analysis of green fluorescent protein (GFP) expression in tobacco plants transformed with SBgLR promoter-GFP reporters indicate that SBgLR is a pollen-specific gene. A series of 5'deletions of SBgLR promoter were fused to the beta-glucuronidase (GUS) gene and stably introduced into tobacco plants. Histochemical and quantitative assays of GUS expression in transgenic plants allowed us to localize an enhancer of SBgLR promoter to the region -345 to -269 relative to the translation start site. This 76 bp (-345 to -269) fragment enhanced GUS expression in leaves, stems and roots when fused to -90/+6 CaMV 35S minimal promoter. Deletion analysis showed that a cis-element, which can repress gene expression in root hairs, was located in the region -345 to -311. Further study indicated that the -269 to -9 region was sufficient to confer pollen-specific expression of GFP when fused to CaMV 35S enhancer.

  13. Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growth.

    PubMed

    Chang, Ming; Huang, Shanjin

    2015-08-01

    Actin is an ancient conserved protein that is encoded by multiple isovariants in multicellular organisms. There are eight functional actin genes in the Arabidopsis genome, and the precise function and mechanism of action of each isovariant remain poorly understood. Here, we report the characterization of ACT11, a reproductive actin isovariant. Our studies reveal that loss of function of ACT11 causes a delay in pollen germination, but enhances pollen tube growth. Cytological analysis revealed that the amount of filamentous actin decreased, and the rate of actin turnover increased in act11 pollen. Convergence of actin filaments upon the germination aperture was impaired in act11 pollen, consistent with the observed delay of germination. Reduction of actin dynamics with jasplakinolide suppressed the germination and tube growth phenotypes in act11 pollen, suggesting that the underlying mechanisms involve an increase in actin dynamics. Thus, we demonstrate that ACT11 is required to maintain the rate of actin turnover in order to promote pollen germination and maintain the normal rate of pollen tube growth.

  14. The Pollen Receptor Kinase LePRK2 Mediates Growth-Promoting Signals and Positively Regulates Pollen Germination and Tube Growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In flowering plants, the process of pollen germination and tube growth is required for successful fertilization. A pollen receptor kinase from tomato, LePRK2, has been implicated in signaling during pollen germination and tube growth as well as in mediating pollen (tube)-pistil communication. Here w...

  15. Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther, a MYB domain protein.

    PubMed

    Zhu, Xiaolei; Liang, Wanqi; Cui, Xiao; Chen, Mingjiao; Yin, Changsong; Luo, Zhijing; Zhu, Jiaying; Lucas, William J; Wang, Zhiyong; Zhang, Dabing

    2015-05-01

    Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over-expression of the BR-synthesis gene D11 or a BR-signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non-transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop.

  16. How does pollen chemistry impact development and feeding behaviour of polylectic bees?

    PubMed

    Vanderplanck, Maryse; Moerman, Romain; Rasmont, Pierre; Lognay, Georges; Wathelet, Bernard; Wattiez, Ruddy; Michez, Denis

    2014-01-01

    Larvae and imagos of bees rely exclusively on floral rewards as a food source but host-plant range can vary greatly among bee species. While oligolectic species forage on pollen from a single family of host plants, polylectic bees, such as bumblebees, collect pollen from many families of plants. These polylectic species contend with interspecific variability in essential nutrients of their host-plants but we have only a limited understanding of the way in which chemicals and chemical combinations influence bee development and feeding behaviour. In this paper, we investigated five different pollen diets (Calluna vulgaris, Cistus sp., Cytisus scoparius, Salix caprea and Sorbus aucuparia) to determine how their chemical content affected bumblebee colony development and pollen/syrup collection. Three compounds were used to characterise pollen content: polypeptides, amino acids and sterols. Several parameters were used to determine the impact of diet on micro-colonies: (i) Number and weight of larvae (total and mean weight of larvae), (ii) weight of pollen collected, (iii) pollen efficacy (total weight of larvae divided by weight of the pollen collected) and (iv) syrup collection. Our results show that pollen collection is similar regardless of chemical variation in pollen diet while syrup collection is variable. Micro-colonies fed on S. aucuparia and C. scoparius pollen produced larger larvae (i.e. better mates and winter survivors) and fed less on nectar compared to the other diets. Pollen from both of these species contains 24-methylenecholesterol and high concentrations of polypeptides/total amino acids. This pollen nutritional "theme" seems therefore to promote worker reproduction in B. terrestris micro-colonies and could be linked to high fitness for queenright colonies. As workers are able to selectively forage on pollen of high chemical quality, plants may be evolutionarily selected for their pollen content, which might attract and increase the degree of

  17. How Does Pollen Chemistry Impact Development and Feeding Behaviour of Polylectic Bees?

    PubMed Central

    Rasmont, Pierre; Lognay, Georges; Wathelet, Bernard; Wattiez, Ruddy; Michez, Denis

    2014-01-01

    Larvae and imagos of bees rely exclusively on floral rewards as a food source but host-plant range can vary greatly among bee species. While oligolectic species forage on pollen from a single family of host plants, polylectic bees, such as bumblebees, collect pollen from many families of plants. These polylectic species contend with interspecific variability in essential nutrients of their host-plants but we have only a limited understanding of the way in which chemicals and chemical combinations influence bee development and feeding behaviour. In this paper, we investigated five different pollen diets (Calluna vulgaris, Cistus sp., Cytisus scoparius, Salix caprea and Sorbus aucuparia) to determine how their chemical content affected bumblebee colony development and pollen/syrup collection. Three compounds were used to characterise pollen content: polypeptides, amino acids and sterols. Several parameters were used to determine the impact of diet on micro-colonies: (i) Number and weight of larvae (total and mean weight of larvae), (ii) weight of pollen collected, (iii) pollen efficacy (total weight of larvae divided by weight of the pollen collected) and (iv) syrup collection. Our results show that pollen collection is similar regardless of chemical variation in pollen diet while syrup collection is variable. Micro-colonies fed on S. aucuparia and C. scoparius pollen produced larger larvae (i.e. better mates and winter survivors) and fed less on nectar compared to the other diets. Pollen from both of these species contains 24-methylenecholesterol and high concentrations of polypeptides/total amino acids. This pollen nutritional “theme” seems therefore to promote worker reproduction in B. terrestris micro-colonies and could be linked to high fitness for queenright colonies. As workers are able to selectively forage on pollen of high chemical quality, plants may be evolutionarily selected for their pollen content, which might attract and increase the degree of

  18. A Pollen Primer | NIH MedlinePlus the Magazine

    MedlinePlus

    ... Several types of pollen cause mild to severe seasonal respiratory allergy, including allergic rhinitis and asthma. But helpful defenses ... Pollen Grass pollens are regional as well as seasonal. Their levels also are ... Bermuda grass Johnson grass Kentucky bluegrass Sweet ...

  19. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1992-07-27

    Low severity coal liquefaction allows for solubilization of coal with reduced gas make. These lower severity conditions may result in some selective bond rupture. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin, which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9,10-hexahydroanthracene. These compounds are hydroaromatics without aromatic rings and have been shown to be highly effective donors. The objective of the work performed in this study during this quarter was to evaluate reaction parameters for low severity liquefaction reactions using the cyclic olefin, hexahydroanthracene, and the aromatic, anthracene. These model compounds were reacted under a variety of conditions to evaluate their reactivity without coal. The reactions were performed under both thermal and catalytic conditions. Finely divided catalysts from different molybdenum precursors were used to determine their activity in promoting hydrogenation and hydrogen transfer at low severity conditions. The catalysts used were Molyvan L, sulfurized oxymolybdenum dithiocarbamate, molybdenum naphthenate, and Molyvan 822, organo molybdenum dithiocarbamate.

  20. Enterobacter cloacae, an obligatory endophyte of pollen grains of Mediterranean pines.

    PubMed

    Madmony, A; Chernin, L; Pleban, S; Peleg, E; Riov, J

    2005-01-01

    Enterobacter cloacae was found to be associated with the pollen of several Mediterranean pines. The bacterium was detected only in mature pollen of Pinus halepensis, P. brutia, and P. pinea. E. cloacae is considered to be an obligatory endophyte based on its occurrence in disinfected male cones and the successful inoculation of seedlings of the above 3 species with E. cloacae AS1 isolated from pollen of P. halepensis used as a model strain. Strain AS1 was able to produce indolyl-3-acetic acid (IAA) from L-tryptophan in culture, and this was probably the source of the increased IAA content in the germination medium of pollen. In addition, strain AS1 promoted adventitious root formation in mung bean (Vigna radiata) cuttings. However, it was not possible to obtain bacterium-free pollen to elucidate its role in pollen germination.

  1. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1992-01-01

    Low severity coal liquefaction promoted by cyclic olefins offers a means of liquefying coal at low severity conditions. Lower temperature, 350[degrees]C, and lower hydrogen pressure, 500 psi, have been used to perform liquefaction reactions. The presence of the cyclic olefin, hexahydroanthracene, made a substantial difference in the conversion of Illinois No. 6 coal at these low severity conditions. The Researchperformed this quarter was a parametric evaluation of the effect of different parameters on the coal conversion and product distribution from coal. The effect of the parameters on product distribution from hexahydroanthracene was also determined. The work planned for next quarter includes combining the most effective parametric conditions for the low severity reactions and determining their effect. The second part ofthe research performed this quarter involved performing Fourier transform infrared (FTIR) spectroscopy using cyclic olefins. The objective of this study was to determine the feasibility of using FTIR and a heated cell to determine the reaction pathway that occurs in the hydrogen donation reactions from cyclic olefins. The progress made to date includes evaluating the FTIR spectra of cyclic olefins and their expected reaction products. This work is included in this progress report.

  2. Pollen aquaporins: What are they there for?

    PubMed

    Pérez Di Giorgio, Juliana Andrea; Barberini, María Laura; Amodeo, Gabriela; Muschietti, Jorge Prometeo

    2016-09-01

    In order to provide more insight into the function of aquaporins during pollination, we characterized NIP4;1 and NIP4;2, 2 pollen-specific aquaporins of Arabidopsis thaliana. NIP4;1 and NIP4;2 displayed high amino acid identity. RT-PCR and GUS promoter analysis showed that they have different expression patterns. NIP4;1 is expressed at low levels in mature pollen, while NIP4;2 is highly expressed only during pollen tube growth. Single T-DNA nip4;1 and nip4;2 mutants and double amiRNA nip4;1 nip4;2 knockdowns showed reduced male fertility due to deficient pollen germination and pollen tube length. Functional assays in oocytes showed that NIP4;1 and NIP4;2 transport water and nonionic solutes. Here, the participation of the different pollen aquaporins in pollen hydration and pollen tube growth is discussed.

  3. Long-term monitoring of airborne pollen in Alaska and the Yukon: Possible implications for global change

    SciTech Connect

    Anderson, J.H.

    1992-03-01

    Airborne pollen and spores have been sampled since 1978 in Fairbanks and 1982 Anchorage and other Alaska-Yukon locations for medical and ecological purposes. Comparative analyses of pre- and post-1986 data subsets reveal that after 1986 (1) pollen is in the air earlier, (2) the multiyear average of degree-days promoting pollen onset is little changed while (3) annual variation in degree-days at onset is greater, (4) pollen and spore annual productions are considerably higher, and (5) there is more year-to-year variation in pollen production. These changes probably reflect directional changes in certain weather variables, and there is some indication that they are of global change significance, i.e., related to increasing atmospheric greenhouse gases. Correlations with pollen data suggest that weather variables of high influence are temperatures during specific periods following pollen dispersal in the preceding year and the average temperature in April of the current year. Annual variations in pollen dispersal might be roughly linked to the 11 year sunspot cycle through air temperature mediators. Weather in 1990, apparent pollen production cycles under endogenous control, and the impending sunspot maximum portend a very severe pollen season in 199 existing but unfunded sampling projects.

  4. Tomato pistil factor STIG1 promotes in vivo pollen tube growth by binding to phosphatidylinositol 3-phosphate and the extracellular domain of the pollen receptor kinase LePRK2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The speed of pollen tube growth is a major determinant of reproductive success in flowering plants. Tomato (Solanum lycopersicum) STIGMA-SPECIFIC PROTEIN1 (STIG1), a small Cys-rich protein from the pistil, was previously identified as a binding partner of the pollen receptor kinase LePRK2 and shown ...

  5. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1991-01-01

    The objective of this project is to evaluate the efficacy of low severity coal liquefaction in the presence of highly reactive hydrogen donors, cyclic olefins. The work that was performed this quarter involved performing a literature search in which different aspects of low severity coal liquefaction were examined. In addition, two new mater's graduate students learned the fundamental differences between high severity coal liquefaction and low severity coal liquefaction by examining the literature and reading texts on coal liquefaction. The literature review presented for the first quarter's work is a compilation of the material which we have found to data involving low severity coal liquefaction. Additional review of low severity liquefaction literature is being conducted this quarter and will be reported in the next quarterly report. In addition, a summary of the work involving the reactivity of cyclic olefins in the absence and presence of coal will be presented next quarter.

  6. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1991-01-01

    The objective of this project is to evaluate the efficacy of low severity coal liquefaction in the presence of highly reactive hydrogen donors, cyclic olefins. The work that was performed this quarter involved performing a literature search in which different aspects of low severity coal liquefaction were examined. In addition, two new master's graduate students learned the fundamental differences between high severity coal liquefaction and low severity coal liquefaction by examining the literature and reading texts on coal liquefaction. The literature review presented for the first quarter's work is a compilation of the material which we have found to date involving low severity coal liquefaction. Additional review of low severity liquefaction literature is being conducted this quarter and will be reported in the next quarterly report. In addition, a summary of the work involving the reactivity of cyclic olefins in the absence and presence of coal will be presented next quarter.

  7. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1992-01-01

    The naphthalene hydrogenation performed thermally at 350 and 400[degrees]C showed no reactivity of the naphthalene. The Molyvan L catalyst precursor promoted a small amount of hydrogenation of naphthalene at 400[degrees]C as shown in Table 1. Reaction at the higher initial pressure of 1250 psi resulted in slightly more conversion of naplithalene and a higher production of tetralin but no decalin was observed. The naphthalene hydrogenation reactions with Molyvan L without sulfur yielded a slightly higher % HYD of naphthalene than did the reactions with sulfur. Likewise, the reactions with an initial hydrogen pressure of 1250 psi yielded a higher % HYD of naphthalene than did the reaction with 1000 psi, regardless of whether sulfur was present. The Molyvan 822 catalyst precursor was substantially more active at 400[degrees]C than at 350[degrees]C as presented in Table 2. The presence of sulfur also promoted the activity of Molyvan 822 as a catalyst. Tetralin was the product and was produced in substantial quantities at 400[degrees]C. Molyvan 822 was much more active for naphthalene hydrogenation than was Molyvan L under equivalent conditions. For example, at 400[degrees]C with sulfur the reactions with Molyvan 822 produced 33.5% HYD while Molyvan L yielded 1.8% HYD. With Molyvan L, the less active catalyst, the effect tile mode of agitation (vertical or horizontal) was minimal.

  8. Preferential expression of an alpha-tubulin gene of Arabidopsis in pollen.

    PubMed Central

    Carpenter, J L; Ploense, S E; Snustad, D P; Silflow, C D

    1992-01-01

    The pool of tubulin protein in tissues of Arabidopsis is provided by the expression of multiple alpha-tubulin (TUA) and beta-tubulin genes. Whereas most tubulin genes are expressed in many tissues, previous evidence suggested that the TUA1 gene might be expressed primarily in pollen. We now report a detailed analysis of TUA1 expression during Arabidopsis development. In RNA from tissues of dissected flowers, TUA1 transcripts were detected only in stamens and mature pollen. Chimeric genes containing TUA1 5' flanking DNA fused to the beta-glucuronidase (GUS) coding region were used to create transgenic Arabidopsis plants. Plants containing a chimeric gene with 533 bp of 5' flanking sequence were analyzed by histochemical assay to localize GUS expression within the plant. The blue product of GUS enzyme activity accumulated very rapidly in postmitotic pollen grains. Much lower levels of GUS activity were detected in anthers with uninucleate pollen grains, in flower receptacles, and in a few vegetative tissues. Analysis of 5' deletions of the TUA1 promoter suggested that 97 bp of 5' flanking DNA is sufficient to drive GUS expression in pollen and young anthers, whereas at least 380 bp is required to detect GUS expression in the receptacle. Examination of the TUA1 promoter sequence revealed several motifs that are repeated within the TUA1 promoter and are similar to sequences in other pollen-specific promoters. PMID:1498610

  9. Studies on the mechanism of skin tumor promotion: Evidence for several stages in promotion

    PubMed Central

    Slaga, T. J.; Fischer, S. M.; Nelson, K.; Gleason, G. L.

    1980-01-01

    The effects of nonpromoting and weakly promoting diterpenes on skin tumor promotion by 12-O-tetradecanoylphorbol 13-acetate (TPA) were investigated. When phorbol and phorbol 12,13-diacetate (both nonpromoting) were given simultaneously with TPA after 7,12-dimethylbenz[a]-anthracene (DMBA) initiation in female mice, they had no effect on TPA promotion. However, the nonpromoter 4-O-methyl-TPA and the weak promoter mezerein were found to inhibit TPA promotion in a dose-dependent manner when given simultaneously with TPA. Because mezerein was found to be an effective inhibitor of TPA promotion when given simultaneously and because it induces many biological responses similar to those to TPA, the capacity of mezerein to act as an incomplete promoter in a two-stage promotion protocol was also investigated. Twice-weekly applications of 1,2, or 5 μg of TPA for 2 weeks after DMBA initiation produced 0, 0, and 0.5 papilloma per mouse, respectively, at 20 weeks. When the twice-weekly applications of TPA for 2 weeks were followed by twice-weekly treatments with 2 μg of mezerein for 18 weeks, the number of papillomas per mouse was 2.2, 3.5, and 9.0, respectively. Twice-weekly applications of 2 μg of TPA for 2 weeks followed by twice-weekly treatments with 1, 2, or 4 μg of mezerein for 18 weeks produced 2.1, 3.5, and 6.8 papillomas per mouse, respectively, in DMBA-treated mice. Twice-weekly doses as high as 40 μg of 4-O-methyl-TPA were not effective in producing tumors when given after a limited treatment with TPA; however, 4-O-methyl-TPA had weak activity as a first-stage promoter. The results suggest that although mezerein by itself is a weak promoter and mimics TPA in many biochemical and morphological effects it is a potent second-stage promoter in a two-stage promotion regimen. PMID:6774342

  10. Hepatoprotective potential of chestnut bee pollen on carbon tetrachloride-induced hepatic damages in rats.

    PubMed

    Yıldız, Oktay; Can, Zehra; Saral, Ozlem; Yuluğ, Esin; Oztürk, Ferhat; Aliyazıcıoğlu, Rezzan; Canpolat, Sinan; Kolaylı, Sevgi

    2013-01-01

    Bee pollen has been used as an apitherapy agent for several centuries to treat burns, wounds, gastrointestinal disorders, and various other diseases. The aim of our study was to investigate the hepatoprotective effects of chestnut bee pollen against carbon tetrachloride (CCI4)-induced liver damage. Total phenolic content, flavonoid, ferric reducing/antioxidant power, and DPPH radical activity measurements were used as antioxidant capacity determinants of the pollen. The study was conducted in rats as seven groups. Two different concentrations of chestnut bee pollens (200 and 400 mg/kg/day) were given orally and one group was administered with silibinin (50 mg/kg/day, i.p.) for seven days to the rats following the CCI4 treatment. The protective effect of the bee pollen was monitored by aspartate transaminase (AST) and alanine transaminase (AST) activities, histopathological imaging, and antioxidant parameters from the blood and liver samples of the rats. The results were compared with the silibinin-treated and untreated groups. We detected that CCI4 treatment induced liver damage and both the bee pollen and silibinin-treated groups reversed the damage; however, silibinin caused significant weight loss and mortality due, severe diarrhea in the rats. The chestnut pollen had showed 28.87 mg GAE/g DW of total phenolic substance, 8.07 mg QUE/g DW of total flavonoid, 92.71 mg Cyn-3-glu/kg DW of total anthocyanins, and 9 mg β -carotene/100 g DW of total carotenoid and substantial amount of antioxidant power according to FRAP and DPPH activity. The results demonstrated that the chestnut bee pollen protects the hepatocytes from the oxidative stress and promotes the healing of the liver damage induced by CCI4 toxicity. Our findings suggest that chestnut bee pollen can be used as a safe alternative to the silibinin in the treatment of liver injuries.

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

    PubMed

    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.

  12. 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

  13. Optimized method for growing in vitro Arabidopsis thaliana pollen tubes.

    PubMed

    Borassi, Cecilia; Di Giorgio, Juliana Pérez; Scarpin, María R; Muschietti, Jorge; Estevez, José M

    2015-01-01

    Pollen tubes elongate by tip growth toward the ovule to deliver the sperm cells during fertilization. Since pollen tubes from several species can be grown in vitro maintaining their polarity, pollen tube growth is a suitable model system to study cell polarity and tip growth. A. thaliana pollen tubes germinated in vitro for 6 h can reach up to 800 μm. By studying the phenotype of mutants of T-DNA insertion lines, genes involved in pollen tube growth can be identified. Moreover, components involved in the regulation of pollen tube growth such as calcium ions and reactive oxygen species (ROS) can be analyzed.

  14. Visualization of plastids in pollen grains: involvement of FtsZ1 in pollen plastid division.

    PubMed

    Tang, Lay Yin; Nagata, Noriko; Matsushima, Ryo; Chen, Yuling; Yoshioka, Yasushi; Sakamoto, Wataru

    2009-04-01

    Visualizing organelles in living cells is a powerful method to analyze their intrinsic mechanisms. Easy observation of chlorophyll facilitates the study of the underlying mechanisms in chloroplasts, but not in other plastid types. Here, we constructed a transgenic plant enabling visualization of plastids in pollen grains. Combination of a plastid-targeted fluorescent protein with a pollen-specific promoter allowed us to observe the precise number, size and morphology of plastids in pollen grains of the wild type and the ftsZ1 mutant, whose responsible gene plays a central role in chloroplast division. The transgenic material presented in this work is useful for studying the division mechanism of pollen plastids.

  15. Promoting the Self-Determination of Students with Severe Disabilities. ERIC Digest.

    ERIC Educational Resources Information Center

    Wehmeyer, Michael

    This brief paper on promoting the self-determination of students with severe disabilities begins by identifying barriers to training in self-determination skills, such as a perceived lack of student benefit and insufficient staff training. The question of whether students with severe disability benefit from instruction to promote…

  16. Staphylokinase promotes the establishment of Staphylococcus aureus skin infections while decreasing disease severity.

    PubMed

    Kwiecinski, Jakub; Jacobsson, Gunnar; Karlsson, Maria; Zhu, Xuefeng; Wang, Wanzhong; Bremell, Tomas; Josefsson, Elisabet; Jin, Tao

    2013-09-01

    Skin infections are frequently caused by Staphylococcus aureus and can lead to a fatal sepsis. The microbial mechanisms controlling the initiation and progression from mild skin infection to a severe disseminated infection remain poorly understood. Using a combination of clinical data and in vitro and ex vivo assays, we show that staphylokinase, secreted by S. aureus, promoted the establishment of skin infections in humans and increased bacterial penetration through skin barriers by activating plasminogen. However, when infection was established, the interaction between staphylokinase and plasminogen did not promote systemic dissemination but induced the opening and draining of abscesses and decreased disease severity in neutropenic mice. Also, increased staphylokinase production was associated with noninvasive S. aureus infections in patients. Our results point out the dual roles of staphylokinase in S. aureus skin infections as promoting the establishment of infections while decreasing disease severity.

  17. Cadmium stress disrupts the endomembrane organelles and endocytosis during Picea wilsonii pollen germination and tube growth.

    PubMed

    Wang, Xiaoxia; Gao, Yuan; Feng, Yu; Li, Xue; Wei, Qian; Sheng, Xianyong

    2014-01-01

    As one of the most severe pollutants, cadmium has been reported to be harmful to plant cells, but the effects of cadmium on gymnosperm pollen germination and tube growth and the mechanism of this involvement are still unclear. Here, we report that cadmium not only strongly inhibited P. wilsonii pollen germination and tube growth, but also significantly altered tube morphology in a dose-dependent manner. Time-lapse images obtained with a laser scanning confocal microscope revealed that endocytosis was dramatically inhibited by cadmium stress. Further investigation with ER-Tracker dye indicated that cadmium stress reduced the number of the Golgi apparatus, and induced dilation of ER. Additionally, Lyso-Tracker staining showed that cadmium distinctly promoted the formation of acidic organelles in pollen tubes, likely derived from the dilated ER. Taken together, our studies indicated that P. wilsonii pollens were highly susceptible to cadmium stress, and that cadmium stress strongly inhibited pollen germination and tube growth by disrupting the endomembrane organelles, inhibiting endo/exocytosis, and forming acidic vacuoles, resulting in swollen tube tips and irregularly broadened tube diameters. These findings provide a new insight into the effects of cadmium toxicity on the tip growth of pollen tubes.

  18. Cadmium Stress Disrupts the Endomembrane Organelles and Endocytosis during Picea wilsonii Pollen Germination and Tube Growth

    PubMed Central

    Feng, Yu; Li, Xue; Wei, Qian; Sheng, Xianyong

    2014-01-01

    As one of the most severe pollutants, cadmium has been reported to be harmful to plant cells, but the effects of cadmium on gymnosperm pollen germination and tube growth and the mechanism of this involvement are still unclear. Here, we report that cadmium not only strongly inhibited P. wilsonii pollen germination and tube growth, but also significantly altered tube morphology in a dose-dependent manner. Time-lapse images obtained with a laser scanning confocal microscope revealed that endocytosis was dramatically inhibited by cadmium stress. Further investigation with ER-Tracker dye indicated that cadmium stress reduced the number of the Golgi apparatus, and induced dilation of ER. Additionally, Lyso-Tracker staining showed that cadmium distinctly promoted the formation of acidic organelles in pollen tubes, likely derived from the dilated ER. Taken together, our studies indicated that P. wilsonii pollens were highly susceptible to cadmium stress, and that cadmium stress strongly inhibited pollen germination and tube growth by disrupting the endomembrane organelles, inhibiting endo/exocytosis, and forming acidic vacuoles, resulting in swollen tube tips and irregularly broadened tube diameters. These findings provide a new insight into the effects of cadmium toxicity on the tip growth of pollen tubes. PMID:24722362

  19. Airborne birch pollen antigens in different particle sizes.

    PubMed

    Rantio-Lehtimäki, A; Viander, M; Koivikko, A

    1994-01-01

    Two particle samplers for ambient air, situated together: a static size-selective bio-aerosol sampler (SSBAS) and a Burkard pollen and spore trap were compared in sampling intact birch pollen grains through one flowering period of Betula (a total of 44 days). The SSBAS trapped pollen grains three times more efficiently than the Burkard trap, but the variations in pollen counts were significantly correlated. In contrast, birch pollen antigenic activity and the pollen count in the Burkard samples were not closely correlated. The antigenic concentration was occasionally high both before and after the pollination period. There was a high birch pollen antigenic activity in particle size classes where intact pollen grains were absent, even on days when the pollen count was very low. Correspondingly, on days with high birch pollen counts in the air, pollen antigenic activity was on several occasions low, indicating that pollen grains were empty of antigenic material. The small particle size classes are especially important to allergic patients because they are able to penetrate immediately into the alveoli and provoke asthmatic reactions. Therefore, aerobiological information systems based on pollen and spore counts should be supplemented with information concerning antigenic activities in the air.

  20. Exocyst subunit SEC3A marks the germination site and is essential for pollen germination in Arabidopsis thaliana

    PubMed Central

    Li, Yan; Tan, Xiaoyun; Wang, Mengru; Li, Bingxuan; Zhao, Yanxue; Wu, Chengyun; Rui, Qingchen; Wang, Junxia; Liu, Zhongyuan; Bao, Yiqun

    2017-01-01

    Arabidopsis exocyst subunit SEC3A has been reported to participate in embryo development. Here we report that SEC3A is involved during pollen germination. A T-DNA insertion in SEC3A leads to an absolute, male-specific transmission defect that can be complemented by the expression of SEC3A coding sequence from the LAT52 promoter or SEC3A genomic DNA. No obvious abnormalities in the microgametogenesis are observed in the sec3a/SEC3A mutant, however, in vitro and in vivo pollen germination are defective. Further studies reveal that the callose, pectin, and cellulose are apparently not deposited at the germination site during pollen germination. SEC3A is expressed ubiquitously, including in pollen grains and pollen tubes. Notably, SEC3A-GFP fusion proteins are specifically recruited to the future pollen germination site. This particular localization pattern is independent of phosphatidylinositol 4,5-bisphosphate (PI-4,5P2), although SEC3-HIS fusion proteins are able to bind to several phosphoinositols in vitro. These results suggest that SEC3A plays an important role in the establishment of the polar site for pollen germination. PMID:28074928

  1. Variability in bumblebee pollination buzzes affects the quantity of pollen released from flowers.

    PubMed

    De Luca, Paul A; Bussière, Luc F; Souto-Vilaros, Daniel; Goulson, Dave; Mason, Andrew C; Vallejo-Marín, Mario

    2013-07-01

    Buzz-pollination is a plant strategy that promotes gamete transfer by requiring a pollinator, typically bees (Hymenoptera: Apoidea), to vibrate a flower's anthers in order to extract pollen. Although buzz-pollination is widespread in angiosperms with over 20,000 species using it, little is known about the functional connection between natural variation in buzzing vibrations and the amount of pollen that can be extracted from anthers. We characterized variability in the vibrations produced by Bombus terrestris bumblebees while collecting pollen from Solanum rostratum (Solanaceae), a buzz-pollinated plant. We found substantial variation in several buzzing properties both within and among workers from a single colony. As expected, some of this variation was predicted by the physical attributes of individual bumblebees: heavier workers produced buzzes of greater amplitude. We then constructed artificial "pollination buzzes" that varied in three parameters (peak frequency, peak amplitude, and duration), and stimulated S. rostratum flowers with these synthetic buzzes to quantify the relationship between buzz properties and pollen removal. We found that greater amplitude and longer duration buzzes ejected substantially more pollen, while frequency had no directional effect and only a weak quadratic effect on the amount of pollen removed. These findings suggest that foraging bumblebees may improve pollen collection by increasing the duration or amplitude of their buzzes. Moreover, given that amplitude is positively correlated with mass, preferential foraging by heavier workers is likely to result in the largest pollen yields per bee, and this could have significant consequences for the success of a colony foraging on buzz-pollinated flowers.

  2. Recovery-Promoting Care as Experienced by Persons with Severe Mental Illness and Substance Misuse

    ERIC Educational Resources Information Center

    Cruce, Gunilla; Ojehagen, Agneta; Nordstrom, Monica

    2012-01-01

    This paper explores recovery-promoting care as experienced by persons with concomitant severe mental illness and substance misuse. Sixteen in-depth interviews, based on an interview guide concerning their experiences of health, life situation and care, were held with eight participants in an outpatient treatment programme. The analysis aimed to…

  3. Raising the Bar: Significant Advances and Future Needs for Promoting Learning for Students with Severe Disabilities

    ERIC Educational Resources Information Center

    Spooner, Fred; Browder, Diane M.

    2015-01-01

    This essay describes major advances in educating students with severe disabilities. The authors propose that applied behavior analysis, the focus on functional life skills, and the promotion of academic content have been the major advances in the "how" and "what" of learning for this population. An increased focus on literacy,…

  4. Parietaria judaica flowering phenology, pollen production, viability and atmospheric circulation, and expansive ability in the urban environment: impacts of environmental factors

    NASA Astrophysics Data System (ADS)

    Fotiou, Christina; Damialis, Athanasios; Krigas, Nikolaos; Halley, John M.; Vokou, Despoina

    2011-01-01

    Parietaria judaica (Urticaceae) grows abundantly in urban areas of the Mediterranean region. Its pollen is a major allergy source. We studied the species' distribution and abundance in and around Thessaloniki (Greece), pollen production and pollen season. We also examined how urban pollution affects pollen viability. Our ultimate goal was to obtain an estimate of the species' performance and ability to expand under different environmental conditions related to climate change. We mapped P. judaica and the other Urticaceae species. In a north- and a south-facing population, we recorded the progress of P. judaica flowering and estimated the pollen content per flower, shoot and surface unit. We concurrently assessed atmospheric circulation of Urticaceae pollen. We estimated P. judaica pollen viability and Cu, Pb and Zn concentrations in plants collected from sites differing in traffic intensity. P. judaica is the most abundant Urticaceae species in the area; its occurrence has increased dramatically over the last 100 years. Production of flowers is intense in spring and autumn. Flowering started 12 days earlier in the south-facing population in spring, and 3 days later in autumn. Pollen production was higher in spring and in the south-facing population. Flower and pollen production were positively correlated with the size of the plant and the flower, respectively. Copper and lead concentrations in plants were positively correlated with pollen viability, which was higher for plants collected from high-traffic sites. P. judaica has a high phenotypic plasticity; this is a feature that promotes success of expansive and invasive species. It is also well adapted to warm and polluted urban environments. The climatic change forecast for the Mediterranean region could provoke earlier, longer, and more pronounced flowering and, consequently, more P. judaica pollen in the air. In return, this would result in increased severity of Parietaria pollinosis.

  5. Heat requirement for the onset of the Olea europaea L. pollen season in several sites in Andalusia and the effect of the expected future climate change.

    PubMed

    Galán, C; García-Mozo, H; Vázquez, L; Ruiz, L; de la Guardia, C Díaz; Trigo, M M

    2005-01-01

    Olives are one of the largest crops in the Mediterranean region, especially in Andalusia, in southern Spain. A thermal model has been developed for forecasting the start of the olive tree pollen season at five localities in Andalusia: Cordoba, Priego, Jaen, Granada and Malaga using airborne pollen and meteorological data from 1982 to 2001. Threshold temperatures varied between 5 degrees C and 12.5 degrees C depending on bio-geographical characteristics. The external validity of the results was tested using the data for the year 2002 as an independent variable and it confirmed the model's accuracy with only a few days difference from predicted values. All the localities had increasingly earlier start dates during the study period. This could confirm that olive flower phenology can be considered as a sensitive indicator of the effects of climate fluctuations in the Mediterranean area. The theoretical impact of the predicted climatic warming on the olive's flowering phenology at the end of the century is also proposed by applying Regional Climate Model data. A general advance, from 1 to 3 weeks could be expected, although this advance will be more pronounced in mid-altitude inland areas.

  6. Heat requirement for the onset of the Olea europaea L. pollen season in several sites in Andalusia and the effect of the expected future climate change

    NASA Astrophysics Data System (ADS)

    Galán, C.; García-Mozo, H.; Vázquez, L.; Ruiz, L.; Guardia, C. Díaz; Trigo, M. M.

    2005-01-01

    Olives are one of the largest crops in the Mediterranean region, especially in Andalusia, in southern Spain. A thermal model has been developed for forecasting the start of the olive tree pollen season at five localities in Andalusia: Cordoba, Priego, Jaen, Granada and Malaga using airborne pollen and meteorological data from 1982 to 2001. Threshold temperatures varied between 5°C and 12.5°C depending on bio-geographical characteristics. The external validity of the results was tested using the data for the year 2002 as an independent variable and it confirmed the model’s accuracy with only a few days difference from predicted values. All the localities had increasingly earlier start dates during the study period. This could confirm that olive flower phenology can be considered as a sensitive indicator of the effects of climate fluctuations in the Mediterranean area. The theoretical impact of the predicted climatic warming on the olive’s flowering phenology at the end of the century is also proposed by applying Regional Climate Model data. A general advance, from 1 to 3 weeks could be expected, although this advance will be more pronounced in mid-altitude inland areas.

  7. New insights into ragweed pollen allergens.

    PubMed

    Bordas-Le Floch, Véronique; Groeme, Rachel; Chabre, Henri; Baron-Bodo, Véronique; Nony, Emmanuel; Mascarell, Laurent; Moingeon, Philippe

    2015-11-01

    Pollen allergens from short ragweed (Ambrosia artemisiifolia) cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies (IUIS) allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies. This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome.

  8. Aerobiology of Juniperus Pollen in Oklahoma, Texas, and New Mexico

    NASA Technical Reports Server (NTRS)

    Levetin, Estelle; Bunderson, Landon; VandeWater, Pete; Luvall, Jeff

    2014-01-01

    Pollen from members of the Cupressaceae are major aeroallergens in many parts of the world. In the south central and southwest United States, Juniperus pollen is the most important member of this family with J. ashei (JA) responsible for severe winter allergy symptoms in Texas and Oklahoma. In New Mexico, pollen from J. monosperma (JM) and other Juniperus species are important contributors to spring allergies, while J. pinchotii (JP) pollinates in the fall affecting sensitive individuals in west Texas, southwest Oklahoma and eastern New Mexico. Throughout this region, JA, JM, and JP occur in dense woodland populations. Generally monitoring for airborne allergens is conducted in urban areas, although the source for tree pollen may be forested areas distant from the sampling sites. Improved pollen forecasts require a better understanding of pollen production at the source. The current study was undertaken to examine the aerobiology of several Juniperus species at their source areas for the development of new pollen forecasting initiatives.

  9. 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.

  10. [Allergic disease--pollen allergy and climate change].

    PubMed

    Sommer, Janne; Plaschke, Peter; Poulsen, Lars K

    2009-10-26

    Pollen allergy currently affects a fifth of the population. A warmer climate will lead to a longer pollen season and more days with high pollen counts. In addition, a warmer climate increases the risk of proliferation of new plants with well-known allergenic pollens like ragweed, plane tree and wall pellitory, which have not previously caused allergy in Denmark. The consequences will be more people with hay fever and pollen asthma, longer allergy seasons and an increase in the severity of symptoms, disease-related costs and demands on health care for diagnosis and treatment of more complex allergies.

  11. Pollen tube development.

    PubMed

    Johnson, Mark A; Kost, Benedikt

    2010-01-01

    Pollen tubes grow rapidly in a strictly polarized manner as they transport male reproductive cells through female flower tissues to bring about fertilization. Vegetative pollen tube cells are an excellent model system to investigate processes underlying directional cell expansion. In this chapter, we describe materials and methods required for (1) the identification of novel factors essential for polarized cell growth through the isolation and analysis of Arabidopsis mutants with defects in pollen tube growth and (2) the detailed functional characterization of pollen tube proteins based on transient transformation and microscopic analysis of cultured tobacco pollen tubes.

  12. 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

  13. Phosphoproteomics Profiling of Tobacco Mature Pollen and Pollen Activated in vitro.

    PubMed

    Fíla, Jan; Radau, Sonja; Matros, Andrea; Hartmann, Anja; Scholz, Uwe; Feciková, Jana; Mock, Hans-Peter; Čapková, Věra; Zahedi, René Peiman; Honys, David

    2016-04-01

    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.

  14. Pollen season and climate: is the timing of birch pollen release in the UK approaching its limit?

    PubMed

    Newnham, R M; Sparks, T H; Skjøth, C A; Head, K; Adams-Groom, B; Smith, M

    2013-05-01

    In light of heightened interest in the response of pollen phenology to temperature, we investigated recent changes to the onset of Betula (birch) pollen seasons in central and southern England, including a test of predicted advancement of the Betula pollen season for London. We calculated onset of birch pollen seasons using daily airborne pollen data obtained at London, Plymouth and Worcester, determined trends in the start of the pollen season and compared timing of the birch pollen season with observed temperature patterns for the period 1995-2010. We found no overall change in the onset of birch pollen in the study period although there was evidence that the response to temperature was nonlinear and that a lower asymptotic start of the pollen season may exist. The start of the birch pollen season was strongly correlated with March mean temperature. These results reinforce previous findings showing that the timing of the birch pollen season in the UK is particularly sensitive to spring temperatures. The climate relationship shown here persists over both longer decadal-scale trends and shorter, seasonal trends as well as during periods of 'sign-switching' when cooler spring temperatures result in later start dates. These attributes, combined with the wide geographical coverage of airborne pollen monitoring sites, some with records extending back several decades, provide a powerful tool for the detection of climate change impacts, although local site factors and the requirement for winter chilling may be confounding factors.

  15. Pollen viability and transgene expression following storage in honey.

    PubMed

    Eady, C; Twell, D; Lindsey, K

    1995-07-01

    Transgenic plants of tobacco and Arabidopsis that produce genetically marked pollen, expressing the reporter gene uidA (gusA), were generated to determine whether pollen proteins can be expressed and stable in honey, a potential route by which foreign proteins might enter the wider environment. Hydrated tobacco pollen was found to lose viability rapidly in honey, while pollen in the natural dehydrated form remained viable for at least several days and in some cases several weeks, as determined by FDA staining activity and germinability. Dehydrated pollen was found to be capable of transient foreign gene expression, following microprojectile bombardment, after incubation in honey for at least 120 h. PCR amplification of transgene sequences in pollen of transgenic plants revealed that pollen DNA can remain relatively intact after 7 weeks in honey. GUS enzyme activity analysis and SDS-PAGE of pollen proteins revealed that foreign and native pollen proteins are stable in pollen incubated in honey for at least 6 weeks. We conclude that pollen may represent an ecologically important vector for transgenic protein products.

  16. Pollen cultivation and preparation for proteomic studies.

    PubMed

    Pertl-Obermeyer, Heidi; Obermeyer, Gerhard

    2014-01-01

    The quality of the collected experimental data very much depends on the quality of the biological starting material. Especially the proteome analysis of a highly dynamic system like the germinating and tube-growing pollen grain needs several precautions which allow an accurate and acceptable interpretation of the obtained results. Optimized protocols for pollen collection, storage, and in vitro culture as well as pollen organelle separations are described which help to obtain well-defined and reproducible experimental conditions for the subsequent proteomic analysis.

  17. Pollen wall development in flowering plants.

    PubMed

    Blackmore, Stephen; Wortley, Alexandra H; Skvarla, John J; Rowley, John R

    2007-01-01

    The outer pollen wall, or exine, is more structurally complex than any other plant cell wall, comprising several distinct layers, each with its own organizational pattern. Since elucidation of the basic events of pollen wall ontogeny using electron microscopy in the 1970s, knowledge of their developmental genetics has increased enormously. However, self-assembly processes that are not under direct genetic control also play an important role in pollen wall patterning. This review integrates ultrastructural and developmental findings with recent models for self-assembly in an attempt to understand the origins of the morphological complexity and diversity that underpin the science of palynology.

  18. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, April--June 1992

    SciTech Connect

    Curtis, C.W.

    1992-07-27

    Low severity coal liquefaction allows for solubilization of coal with reduced gas make. These lower severity conditions may result in some selective bond rupture. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin, which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9,10-hexahydroanthracene. These compounds are hydroaromatics without aromatic rings and have been shown to be highly effective donors. The objective of the work performed in this study during this quarter was to evaluate reaction parameters for low severity liquefaction reactions using the cyclic olefin, hexahydroanthracene, and the aromatic, anthracene. These model compounds were reacted under a variety of conditions to evaluate their reactivity without coal. The reactions were performed under both thermal and catalytic conditions. Finely divided catalysts from different molybdenum precursors were used to determine their activity in promoting hydrogenation and hydrogen transfer at low severity conditions. The catalysts used were Molyvan L, sulfurized oxymolybdenum dithiocarbamate, molybdenum naphthenate, and Molyvan 822, organo molybdenum dithiocarbamate.

  19. Barrier responses of human bronchial epithelial cells to grass pollen exposure.

    PubMed

    Blume, Cornelia; Swindle, Emily J; Dennison, Patrick; Jayasekera, Nivenka P; Dudley, Sarah; Monk, Phillip; Behrendt, Heidrun; Schmidt-Weber, Carsten B; Holgate, Stephen T; Howarth, Peter H; Traidl-Hoffmann, Claudia; Davies, Donna E

    2013-07-01

    The airway epithelium forms a physical, chemical and immunological barrier against inhaled environmental substances. In asthma, these barrier properties are thought to be abnormal. In this study, we analysed the effect of grass pollen on the physical and immunological barrier properties of differentiated human primary bronchial epithelial cells. Following exposure to Timothy grass (Phleum pratense) pollen extract, the integrity of the physical barrier was not impaired as monitored by measuring the transepithelial resistance and immunofluorescence staining of tight junction proteins. In contrast, pollen exposure affected the immunological barrier properties by modulating vectorial mediator release. CXC chemokine ligand (CXCL)8/interleukin (IL)-8 showed the greatest increase in response to pollen exposure with preferential release to the apical compartment. Inhibition of the extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase pathways selectively blocked apical CXCL8/IL-8 release via a post-transcriptional mechanism. Apical release of CC chemokine ligand (CCL)20/macrophage inflammatory protein-3α, CCL22/monocyte-derived chemokine and tumour necrosis factor-α was significantly increased only in severe asthma cultures, while CCL11/eotaxin-1 and CXCL10/interferon-γ-induced protein-10 were reduced in nonasthmatic cultures. The bronchial epithelial barrier modulates polarised release of mediators in response to pollen without direct effects on its physical barrier properties. The differential response of cells from normal and asthmatic donors suggests the potential for the bronchial epithelium to promote immune dysfunction in asthma.

  20. Pistillate flowers experience more pollen limitation and less geitonogamy than perfect flowers in a gynomonoecious herb.

    PubMed

    Mamut, Jannathan; Xiong, Ying-Ze; Tan, Dun-Yan; Huang, Shuang-Quan

    2014-01-01

    Gynomonoecy, a sexual system in which plants have both pistillate (female) flowers and perfect (hermaphroditic) flowers, occurs in at least 15 families, but the differential reproductive strategies of the two flower morphs within one individual remain unclear. Racemes of Eremurus anisopterus (Xanthorrhoeaceae) have basal pistillate and distal perfect flowers. To compare sex allocation and reproductive success between the two flower morphs, we measured floral traits, pollinator preferences, and pollen movement in the field. Pollen limitation was more severe in pistillate flowers; bee pollinators preferred to visit perfect flowers, which were also capable of partial self-fertilization. Pollen-staining experiments indicated that perfect flowers received a higher proportion of intra-plant pollen (geitonogamy) than pistillate flowers. Plants with greater numbers of pistillate flowers received more outcross pollen. The differential reproductive success conformed with differential floral sex allocation, in which pistillate flowers produce fewer but larger ovules, resulting in outcrossed seeds. Our flower manipulations in these nectarless gynomonoecious plants demonstrated that perfect flowers promote seed quantity in that they are more attractive to pollinators, while pistillate flowers compensate for the loss of male function through better seed quality. These results are consistent with the outcrossing-benefit hypothesis for gynomonoecy.

  1. Flavonols Stimulate Development, Germination, and Tube Growth of Tobacco Pollen 1

    PubMed Central

    Ylstra, Bauke; Touraev, Alisher; Moreno, Rosa Maria Benito; Stöger, Eva; van Tunen, Arjen J.; Vicente, Oscar; Mol, Joseph N. M.; Heberle-Bors, Erwin

    1992-01-01

    The effect of anther-derived substances on pollen function was studied using pollen produced by in vitro culture of immature pollen of tobacco (Nicotiana tabacum L.) and petunia (Petunia hybrida). Addition of conditioned medium consisting of diffusates from in situ matured pollen strongly increased pollen germination frequency and pollen tube growth, as well as seed set after in situ pollination. Thin-layer chromatography and depletion of phenolic substances by Dowex treatment indicated that flavonols are present in the diffusate and may be the active compounds. When added to the germination medium, flavonols (quercetin, kaempferol, myricetin) but not other flavonoids strongly promoted pollen germination frequency and pollen tube growth in vitro. The best results were obtained at very low concentrations of the flavonols (0.15-1.5 μm), indicating a signaling function. The same compounds were also effective when added during pollen development in vitro. Images Figure 1 Figure 5 PMID:16653074

  2. Thunderstorm-asthma and pollen allergy.

    PubMed

    D'Amato, G; Liccardi, G; Frenguelli, G

    2007-01-01

    Thunderstorms have been linked to asthma epidemics, especially during the pollen seasons, and there are descriptions of asthma outbreaks associated with thunderstorms, which occurred in several cities, prevalently in Europe (Birmingham and London in the UK and Napoli in Italy) and Australia (Melbourne and Wagga Wagga). Pollen grains can be carried by thunderstorm at ground level, where pollen rupture would be increased with release of allergenic biological aerosols of paucimicronic size, derived from the cytoplasm and which can penetrate deep into lower airways. In other words, there is evidence that under wet conditions or during thunderstorms, pollen grains may, after rupture by osmotic shock, release into the atmosphere part of their content, including respirable, allergen-carrying cytoplasmic starch granules (0.5-2.5 microm) or other paucimicronic components that can reach lower airways inducing asthma reactions in pollinosis patients. The thunderstorm-asthma outbreaks are characterized, at the beginning of thunderstorms by a rapid increase of visits for asthma in general practitioner or hospital emergency departments. Subjects without asthma symptoms, but affected by seasonal rhinitis can experience an asthma attack. No unusual levels of air pollution were noted at the time of the epidemics, but there was a strong association with high atmospheric concentrations of pollen grains such as grasses or other allergenic plant species. However, subjects affected by pollen allergy should be informed about a possible risk of asthma attack at the beginning of a thunderstorm during pollen season.

  3. [Birch pollen allergy].

    PubMed

    Lavaud, F; Fore, M; Fontaine, J-F; Pérotin, J M; de Blay, F

    2014-02-01

    In the North-East of France, birch is the main tree responsible of spring pollen allergy. However, the epidemiology of sensitization to birch pollen remains unclear. Monosensitization to birch pollen seems rare because of the frequency of cross-reactions with other pollens of the same botanical family via the major allergen Bet v 1. Around one third of patients with allergic rhinoconjunctivitis due to birch pollen are also asthmatics and a half suffer from a food allergy, essentially an oral syndrome due to rosaceae fruits eaten raw. The molecular allergens of birch pollen are well-known and have been cloned. They are available for use in in vitro diagnostic tests and also in clinical trials of specific immunotherapy.

  4. Role of macrophage migration inhibitory factor (MIF) in pollen-induced allergic conjunctivitis and pollen dermatitis in mice.

    PubMed

    Nagata, Yuka; Yoshihisa, Yoko; Matsunaga, Kenji; Rehman, Mati Ur; Kitaichi, Nobuyoshi; Kitaichi, Nobuyuki; Shimizu, Tadamichi

    2015-01-01

    Pollen is a clinically important airborne allergen and one of the major causes of allergic conjunctivitis. A subpopulation of patients with atopic dermatitis (AD) are also known to have exacerbated skin eruptions on the face, especially around the eyelids, after contact with pollen. This pollen-induced skin reaction is now known as pollen dermatitis. Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine that plays an essential role in allergic inflammation. Recent findings suggest that MIF is involved in several allergic disorders, including AD. In this study, MIF knockout (KO), MIF transgenic (Tg) and WT littermate mice were immunized with ragweed (RW) pollen or Japanese cedar (JC) pollen and challenged via eye drops. We observed that the numbers of conjunctiva- and eyelid-infiltrating eosinophils were significantly increased in RW and JC pollen-sensitized MIF Tg compared with WT mice or MIF KO mice. The mRNA expression levels of eotaxin, interleukin (IL)-5 and IL-13 were increased in pollen-sensitized eyelid skin sites of MIF Tg mice. An in vitro analysis revealed that high eotaxin expression was induced in dermal fibroblasts by MIF combined with stimulation of IL-4 or IL-13. This eotaxin expression was inhibited by the treatment with CD74 siRNA in fibroblasts. These findings indicate that MIF can induce eosinophil accumulation in the conjunctiva and eyelid dermis exposed to pollen. Therefore, targeted inhibition of MIF might result as a new option to control pollen-induced allergic conjunctivitis and pollen dermatitis.

  5. Role of Macrophage Migration Inhibitory Factor (MIF) in Pollen-Induced Allergic Conjunctivitis and Pollen Dermatitis in Mice

    PubMed Central

    Nagata, Yuka; Yoshihisa, Yoko; Matsunaga, Kenji; Rehman, Mati Ur; Kitaichi, Nobuyuki; Shimizu, Tadamichi

    2015-01-01

    Pollen is a clinically important airborne allergen and one of the major causes of allergic conjunctivitis. A subpopulation of patients with atopic dermatitis (AD) are also known to have exacerbated skin eruptions on the face, especially around the eyelids, after contact with pollen. This pollen-induced skin reaction is now known as pollen dermatitis. Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine that plays an essential role in allergic inflammation. Recent findings suggest that MIF is involved in several allergic disorders, including AD. In this study, MIF knockout (KO), MIF transgenic (Tg) and WT littermate mice were immunized with ragweed (RW) pollen or Japanese cedar (JC) pollen and challenged via eye drops. We observed that the numbers of conjunctiva- and eyelid-infiltrating eosinophils were significantly increased in RW and JC pollen-sensitized MIF Tg compared with WT mice or MIF KO mice. The mRNA expression levels of eotaxin, interleukin (IL)-5 and IL-13 were increased in pollen-sensitized eyelid skin sites of MIF Tg mice. An in vitro analysis revealed that high eotaxin expression was induced in dermal fibroblasts by MIF combined with stimulation of IL-4 or IL-13. This eotaxin expression was inhibited by the treatment with CD74 siRNA in fibroblasts. These findings indicate that MIF can induce eosinophil accumulation in the conjunctiva and eyelid dermis exposed to pollen. Therefore, targeted inhibition of MIF might result as a new option to control pollen-induced allergic conjunctivitis and pollen dermatitis. PMID:25647395

  6. [Regional and extra-local pollen in tundra pollen samples].

    PubMed

    Vasil'chuk, A K

    2005-01-01

    Patterns of pollen spectra formation in the tundra zone of Eurasia were considered. Changes in total pollen concentration were traced in subfossil pollen samples of the tundra zone. The data on subfossil pollen spectra were used to evaluate the proportion between local and regional plus extra-local components of tundra pollen samples as well as the changes in concentration of pollen of Scots and Siberian stone pines as well as of tree and shrub birches. The diameter of dwarf birch pollen was determined in different tundra subzones of Western Siberia. The role of extra-local and regional pollen was considered for all vegetation subzones of tundra.

  7. [Assertive community treatment: promoting engagement with care of people suffering severe addiction].

    PubMed

    Morandi, Stéphane; Silva, Benedetta; Monnat, Martine; Bonsack, Charles

    2016-06-08

    Despite the increasing number of specialized addiction services and the constant deployment of health care resources, a coordinated needs-based treatment is not always available for people with severe drugs and/or alcohol problems. Too often the involved health care professionals feel helpless and overwhelmed by the complexity of the situation. In order to promote the treatment engagement of the hard-to-reach substance users, a multidisciplinary mobile team project for addiction (SIMA) was developed in Lausanne, Switzerland, in 20174. This paper describes the model of intervention, the profile of the population followed during the first year of intervention and illustrates, through two clinical cases, the advantages of this approach.

  8. Dating Fossil Pollen: A Simulation.

    ERIC Educational Resources Information Center

    Sheridan, Philip

    1992-01-01

    Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

  9. Two distinct factors interact with the promoter regions of several liver-specific genes.

    PubMed Central

    Hardon, E M; Frain, M; Paonessa, G; Cortese, R

    1988-01-01

    A segment of the human alpha 1-antitrypsin (alpha 1AT) 5'-flanking region comprising nucleotides -137 to -37 from the start of transcription is sufficient to drive liver-specific transcription from the homologous alpha 1AT promoter and from the heterologous SV40 promoter. In this paper we characterize two proteins, LF-A1 and LF-B1, whose ability to bind wild-type and mutant alpha 1AT promoter segments correlates with the ability of these segments to activate transcription in vivo. DNase I protection and methylation interference analysis reveals that LF-A1 recognizes sequences present in the regulatory region of the human alpha 1-antitrypsin, apolipoprotein A1 and haptoglobin-related genes. These sequences share a common 5' TGG/A A/C CC 3' motif. LF-B1 binds to the palindrome 5' TGGTTAAT/ATTCACCA 3' which is present in the human alpha 1-antitrypsin gene between positions -78 and -62 from the start of transcription. LF-B1 also recognizes a related sequence present in the human albumin gene between -66 and -50. These results suggest that LF-A1 and LF-B1 are common positive trans-acting factors which are required for the expression of several genes in the hepatocyte. Images PMID:2844524

  10. HIV-1 Promoter Single Nucleotide Polymorphisms Are Associated with Clinical Disease Severity

    PubMed Central

    Feng, Rui; Moldover, Brian; Passic, Shendra; Aiamkitsumrit, Benjamas; Dampier, Will; Wojno, Adam; Kilareski, Evelyn; Blakey, Brandon; Ku, Tse-Sheun Jade; Shah, Sonia; Sullivan, Neil T.; Jacobson, Jeffrey M.; Wigdahl, Brian

    2016-01-01

    The large majority of human immunodeficiency virus type 1 (HIV-1) markers of disease progression/severity previously identified have been associated with alterations in host genetic and immune responses, with few studies focused on viral genetic markers correlate with changes in disease severity. This study presents a cross-sectional/longitudinal study of HIV-1 single nucleotide polymorphisms (SNPs) contained within the viral promoter or long terminal repeat (LTR) in patients within the Drexel Medicine CNS AIDS Research and Eradication Study (CARES) Cohort. HIV-1 LTR SNPs were found to associate with the classical clinical disease parameters CD4+ T-cell count and log viral load. They were found in both defined and undefined transcription factor binding sites of the LTR. A novel SNP identified at position 108 in a known COUP (chicken ovalbumin upstream promoter)/AP1 transcription factor binding site was significantly correlated with binding phenotypes that are potentially the underlying cause of the associated clinical outcome (increase in viral load and decrease in CD4+ T-cell count). PMID:27100290

  11. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, October--December 1992

    SciTech Connect

    Curtis, C.W.

    1992-12-31

    Low severity coal liquefaction promoted by cyclic olefins offers a means of liquefying coal at low severity conditions. Lower temperature, 350{degrees}C, and lower hydrogen pressure, 500 psi, have been used to perform liquefaction reactions. The presence of the cyclic olefin, hexahydroanthracene, made a substantial difference in the conversion of Illinois No. 6 coal at these low severity conditions. The Researchperformed this quarter was a parametric evaluation of the effect of different parameters on the coal conversion and product distribution from coal. The effect of the parameters on product distribution from hexahydroanthracene was also determined. The work planned for next quarter includes combining the most effective parametric conditions for the low severity reactions and determining their effect. The second part ofthe research performed this quarter involved performing Fourier transform infrared (FTIR) spectroscopy using cyclic olefins. The objective of this study was to determine the feasibility of using FTIR and a heated cell to determine the reaction pathway that occurs in the hydrogen donation reactions from cyclic olefins. The progress made to date includes evaluating the FTIR spectra of cyclic olefins and their expected reaction products. This work is included in this progress report.

  12. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, July--September, 1994

    SciTech Connect

    Curtis, C.W.

    1994-12-31

    Previous research indicates that the cyclic olefin, 1,4,5,8,9,10-hexahydroanthracene (HHA), is one of the most effective hydrogen donors tested under low severity conditions. A mild acidic pretreatment of the coal prior to liquefaction has proven to be significant in increasing conversion of low rank coals under low severity conditions as well. Coal conversion can also be improved by employing hydrotreating catalysts. In this study, reactions with coal mild acidic pretreatment were performed with cyclic olefins with and without catalysts. These reactions provided the data to prove whether catalysts are effective under low severity conditions. Evaluating the effect of these three factors (mild acidic pretreatment, hydrogen donation by cyclic olefins, and the use of slurry phase catalysts) on the reactivity of low severity coal liquefaction was the basis of this study. By examining the results, it is clear that the combination of all of the most favorable factors produced coal conversions of more than 50%. The effectiveness of HHA was tested by performing reactions without a cyclic olefin which produced substantially lower coal conversion, thus proving how effective hydrogen donation by cyclic olefins is in low severity coal liquefaction. The mild acidic pretreatment demonstrated its effectiveness on increasing the conversion low rank coals. By promoting higher conversion for the lignite than for the subbituminous coal, suggested that the lower the rank is, the better mild acidic pretreatment works. The catalyst MoNaph proved its effectiveness in low severity coal liquefaction, too, although the reactions with the other slurry phase catalysts NiOct was not effective. Also, synergy among the mild acid pretreatment, HHA and MoNaph occurred yielding high coal conversions for both coals.

  13. Allergies, asthma, and pollen

    MedlinePlus

    ... Some trees Some grasses Weeds Ragweed Watch the Weather and the Season The amount of pollen in the air can affect whether you or your child has hay fever and asthma symptoms. On hot, dry, windy days, more pollen is in the air. ...

  14. Evaluation of health promotion programmes in severe mental illness: theory and practice.

    PubMed

    van Hasselt, Fenneke M; Krabbe, Paul F M; Postma, Maarten J; Loonen, Anton J M

    2015-03-01

    Health promotion programmes for patients with severe mental illness (HPP) are not uniformly evaluated. We discuss the evaluation of HPP in theory and practice, as a prerequisite for future uniform evaluation. We explored the expected outcome and mechanism of HPP in the current literature. Based on this theoretical exploration we selected measures assessing the expected outcome and mechanism in current practice. The individual properties of these measures were described. Based on our theoretical exploration the outcome of HPP can be expressed in several aspects of health. Health can be improved through several mechanisms. In the current evaluation of HPP only some of the expected outcomes were evaluated. The measures used for evaluation were not all representative for the constructs they should assess. Important aspects of HPP are currently not evaluated, based on a comparison between our theoretical exploration of expected outcome and mechanism and current practice. Additionally, not all measures in use are suitable for evaluation of HPP. Therefore, development and identification of suitable measures is necessary. Our framework offers valuable directions for the development of such measures and the future evaluation of HPP.

  15. 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.

  16. Quantitative DNA Analyses for Airborne Birch Pollen.

    PubMed

    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.

  17. 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

  18. Expression of green fluorescent protein in pollen of oilseed rape (Brassica napus L.) and its utility for assessing pollen movement in the field.

    PubMed

    Moon, Hong S; Halfhill, Matthew D; Hudson, Laura C; Millwood, Reginald J; Stewart, C Neal

    2006-10-01

    Transgene movement via pollen is an important component of gene flow from transgenic plants. Here, we present proof-of-concept studies that demonstrate the monitoring of short distant movement of pollen expressing a genetically encoded fluorescent tag in oilseed rape (Brassica napus L. cv. Westar). Transgenic oilseed rape plants were produced using Agrobacterium-mediated transformation method with the pBINDC1 construct containing a green fluorescent protein (GFP) variant, mGFP5-ER, under the control of the pollen-specific LAT59 promoter from tomato. Transgenic pollen was differentiated from non-transgenic pollen in vivo by a unique spectral signature, and was shown to be an effective tool to monitor pollen movement in the greenhouse and field. GFP-tagged pollen also served as a practical marker to determine the zygosity of plants. In a greenhouse pollen flow study, more pollen was captured at closer distances from the source plant plot with consistent wind generated by a fan. Under field conditions, GFP transgenic pollen grains were detected up to a distance of 15 m, the farthest distance from source plants assayed. GFP-tagged pollen was easily distinguishable from non-transgenic pollen using an epifluorescence microscope.

  19. Investigating atmospheric transport of Ambrosia pollen from the Pannonian Plain towards the Balkan region with DEHM-Pollen

    NASA Astrophysics Data System (ADS)

    Ambelas Skjoth, C.

    2009-04-01

    The pollen grains of Ambrosia spp. are considered to be important aeroallergens. The threshold value for clinical symptoms for ragweed pollen grains for the majority of sensitised patients is below 20 grains/m3. Ambrosia pollen appears to induce asthma about twice as often as other pollen. Each ragweed plant produces millions of pollen grains that are small (18-22 μm) and suitable for long-range transport when conditions are favourable. In this study we use DEHM-Pollen to investigate if the Pannonian Plain could be the source area for observed episodes of Ambrosia pollen in the Balkans. A possible Ambrosia pollen inventory for various regions in the Pannonian Plain was constructed using detailed land cover data from Serbia, Hungary, Austria, Croatia, Bosnia-Herzegovina, Slovakia, Romania and Czech Republic in combination with measurements of the annual load of Ambrosia pollen in the source areas. A simple unified pollen release model (SUPREME) was calibrated against daily measurements from Novi Sad in Serbia and implemented in DEHM-Pollen with the Ambrosia pollen inventory. Model simulations was then performed with DEHM-Pollen for the months August and September 2007 and compared with measurements from stations outside the Pannonian Plain. The simulations several times indicate regional scale transport from the Pannonian Plain towards the Balkan region including the 26th - 27th of August and the 1st and 2nd September. During these episode air masses passed over parts of Bosnia and Herzegovina, Southern Serbia, Albania and Macedonia. The verifying measurements at Skopje (Macedonia) show episodes of elevated Ambrosia pollen concentration the 26th -27th of August and for the 1st and 2nd of September. The model experiments with DEHM-Pollen strongly indicate that the Pannonian Plain alone can be a source to significant Ambrosia pollen concentrations in the Balkans. The methods and the model results look promising with respect to future numerical forecasting of Ambrosia

  20. 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.

  1. Serotonin transporter (5-HTTLPR) and monoamine oxidase (MAOA) promoter polymorphisms in women with severe alcoholism.

    PubMed

    Gokturk, Camilla; Schultze, Stefan; Nilsson, Kent W; von Knorring, Lars; Oreland, Lars; Hallman, Jarmila

    2008-12-01

    The serotonin system is known to play a pivotal role for mood, behaviour and psychic illness as e.g. alcoholism. Alcoholism in both males and females has been associated with polymorphisms in genes encoding for proteins of importance for central serotonergic function. Genotyping of two functional polymorphisms in the promoter region of the serotonin transporter and monoamine oxidase-A, respectively, (5-HTT-LPR and MAOA-VNTR), was performed in a group of women with severe alcohol addiction. A large sample of adolescent females from a normal population was used as controls. A significantly higher frequency of the LL 5-HTT genotype (high activity) was found in female addicts without a known co-morbid psychiatric disorder than in the controls. Genotype of the MAOA-VNTR polymorphism did not differ significantly between addicts and controls. However, within the group of alcoholics, when the patients with known co-morbid psychiatric disorders were excluded, aggressive anti-social behaviour was significantly linked to the presence of the high activity MAOA allele. The pattern of associations between genotypes of 5-HTT-LPR and MAOA-VNTR in women with severe alcoholism differs from most corresponding studies on males.

  2. Influence of pollen quality on ovarian development in honeybee workers (Apis mellifera scutellata).

    PubMed

    Human, H; Nicolson, S W; Strauss, K; Pirk, C W W; Dietemann, V

    2007-07-01

    Protein-rich diets are known to promote ovarian and egg development in workers of the honeybee, Apis mellifera, even in the presence of a queen. Since the main source of protein for honeybees is pollen, its quality and digestibility might be important dietary factors determining reproductive capacity. We have compared the effect of two types of pollen-sunflower, Helianthus annuus, and aloe, Aloe greatheadii var davyana-on ovarian development in A. mellifera scutellata workers. Under queenright conditions in the field, worker bees exhibited greater ovarian development when feeding on aloe pollen than on sunflower pollen. In their midgut, we observed higher extraction efficiency for aloe (80%) than for sunflower (69%) pollen. This may be attributed to the morphology and size of the two kinds of pollen grains and explains, together with the high protein content of aloe pollen (32% dry mass in bee-collected pollen) compared to sunflower pollen (15%), why aloe pollen promoted higher ovarian development. However, in the laboratory workers sustained on aloe pollen had significantly less-developed ovaries and higher mortality than those fed sunflower pollen. These detrimental effects may be due to an unbalanced protein:carbohydrate ratio. We discuss the effects of unbalanced diets on the physiology and ecology of honeybee reproduction.

  3. Sunny-side up: flower heliotropism as a source of parental environmental effects on pollen quality and performance in the snow buttercup, Ranunculus adoneus (Ranunculaceae).

    PubMed

    Galen, Candace; Stanton, Maureen L

    2003-05-01

    Floral traits affect mating success via their influence on the microenvironment in which sexual reproduction occurs as well as their impact on pollinator attraction. Here we investigate the importance of flower heliotropism as a source of parental environmental effects on pollen quality and performance. Flowers of the snow buttercup, Ranunculus adoneus, closely track the sun's rays. We experimentally restrained flowers to test for effects of heliotropism on pollen quality and performance after pollination. When equivalent amounts of pollen were transferred to recipient pistils, pollen from solar-tracking donor flowers exhibited a 32% advantage in germination compared to pollen from stationary (tethered) donor flowers. By the end of anthesis, pistils of tracking flowers contained 40% more germinating pollen grains and 44% more pollen tubes midway down the style than pistils of stationary ones. Solar tracking had no direct effect on pollen tube growth. The greater amount of germinating pollen in tracking flowers accounted for the treatment effect on pollen tube density. A survey of pollen receipt and pollen germination in naturally tracking flowers indicated that solar tracking primarily affects pollen tube density by promoting pollen germination rather than pollen deposition. We conclude that flower heliotropism, by enhancing the paternal environment for pollen development and the maternal environment for pollen germination, represents a source of positive parental environmental effects on pollen performance in snow buttercups.

  4. A high-throughput procedure for single pollen grain collection and PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen grains are haploid male gametophytes that share identical genetic contents of the female gametophytes; therefore, one can predict the potential genetic makeup of progeny by genotyping single pollen DNA. Amplification of DNA from single pollen grain using PCR has been accomplished in several ...

  5. Functional promoter haplotypes of interleukin-18 condition susceptibility to severe malarial anemia and childhood mortality.

    PubMed

    Anyona, Samuel B; Kempaiah, Prakasha; Raballah, Evans; Ouma, Collins; Were, Tom; Davenport, Gregory C; Konah, Stephen N; Vulule, John M; Hittner, James B; Gichuki, Charity W; Ong'echa, John M; Perkins, Douglas J

    2011-12-01

    Severe malarial anemia (SMA) is a leading cause of morbidity and mortality in children residing in regions where Plasmodium falciparum transmission is holoendemic. Although largely unexplored in children with SMA, interleukin-18 (IL-18) is important for regulating innate and acquired immunity in inflammatory and infectious diseases. As such, we selected two functional single-nucleotide polymorphisms (SNPs) in the IL-18 promoter (-137G→C [rs187238] and -607C→A [rs1946518]) whose haplotypes encompass significant genetic variation due to the presence of strong linkage disequilibrium among these variants. The relationship between the genotypes/haplotypes, SMA (hemoglobin [Hb], <5.0 g/dl], and longitudinal clinical outcomes were then investigated in Kenyan children (n = 719). Multivariate logistic regression analyses controlling for age, gender, sickle cell trait, glucose-6-phosphate dehydrogenase (G6PD) deficiency, HIV-1, and bacteremia revealed that carriage of the -607AA genotype was associated with protection against SMA (odds ratio [OR] = 0.440 [95% confidence interval {CI} = 0.21 to 0.90], P = 0.031) in children with acute infection. In contrast, carriers of the -137G/-607C (GC) haplotype had increased susceptibility to SMA (OR = 2.050 [95% CI = 1.04 to 4.05], P = 0.039). Measurement of IL-18 gene expression in peripheral blood leukocytes demonstrated that elevated IL-18 transcripts were associated with reduced hemoglobin concentrations (ρ = -0.293, P = 0.010) and that carriers of the "susceptible" GC haplotype had elevated IL-18 transcripts (P = 0.026). Longitudinal investigation of clinical outcomes over a 3-year follow-up period revealed that carriers of the rare CC haplotype (∼1% frequency) had 5.76 times higher mortality than noncarriers (P = 0.001). Results presented here demonstrate that IL-18 promoter haplotypes that condition elevated IL-18 gene products during acute infection are associated with increased risk of SMA. Furthermore, carriage of the

  6. Several different upstream promoter elements can potentiate transactivation by the BPV-1 E2 protein.

    PubMed Central

    Ham, J; Dostatni, N; Arnos, F; Yaniv, M

    1991-01-01

    The enhancer and upstream promoter regions of RNA polymerase II transcribed genes modulate the rate of transcription initiation and establish specific patterns of gene expression. Both types of region consist of clusters of DNA binding sites for nuclear proteins. To determine how efficiently the same factor can activate transcription when acting as an enhancer or promoter factor, we have studied transactivation by the BPV-1 E2 protein, a papillomavirus transcriptional regulator. By cotransfecting a BPV-1 E2 expression vector and a series of reporter plasmids containing well-defined chimeric promoters we have found that whilst E2 can strongly stimulate complex promoters such as that of the HSV tk gene, it does not efficiently activate constructions containing only a TATA box and initiation site. We show that insertion of upstream promoter elements, but not of spacer DNA, between E2 binding sites and the TATA box greatly increases E2 activation. This effect was observed with more than one type of upstream promoter element, is not related to the strength of the promoter and is unlikely to result from co-operative DNA binding by E2 and the transcription factors tested. These results would suggest that E2 has the properties of an enhancer rather than promoter factor and that in certain cases promoter and enhancer factors may affect different steps in the process of transcriptional activation. Images PMID:1655407

  7. Boreal pollen contain ice-nucleating as well as ice-binding ‘antifreeze’ polysaccharides

    NASA Astrophysics Data System (ADS)

    Dreischmeier, Katharina; Budke, Carsten; Wiehemeier, Lars; Kottke, Tilman; Koop, Thomas

    2017-02-01

    Ice nucleation and growth is an important and widespread environmental process. Accordingly, nature has developed means to either promote or inhibit ice crystal formation, for example ice-nucleating proteins in bacteria or ice-binding antifreeze proteins in polar fish. Recently, it was found that birch pollen release ice-nucleating macromolecules when suspended in water. Here we show that birch pollen washing water exhibits also ice-binding properties such as ice shaping and ice recrystallization inhibition, similar to antifreeze proteins. We present spectroscopic evidence that both the ice-nucleating as well as the ice-binding molecules are polysaccharides bearing carboxylate groups. The spectra suggest that both polysaccharides consist of very similar chemical moieties, but centrifugal filtration indicates differences in molecular size: ice nucleation occurs only in the supernatant of a 100 kDa filter, while ice shaping is strongly enhanced in the filtrate. This finding may suggest that the larger ice-nucleating polysaccharides consist of clusters of the smaller ice-binding polysaccharides, or that the latter are fragments of the ice-nucleating polysaccharides. Finally, similar polysaccharides released from pine and alder pollen also display both ice-nucleating as well as ice-binding ability, suggesting a common mechanism of interaction with ice among several boreal pollen with implications for atmospheric processes and antifreeze protection.

  8. Boreal pollen contain ice-nucleating as well as ice-binding ‘antifreeze’ polysaccharides

    PubMed Central

    Dreischmeier, Katharina; Budke, Carsten; Wiehemeier, Lars; Kottke, Tilman; Koop, Thomas

    2017-01-01

    Ice nucleation and growth is an important and widespread environmental process. Accordingly, nature has developed means to either promote or inhibit ice crystal formation, for example ice-nucleating proteins in bacteria or ice-binding antifreeze proteins in polar fish. Recently, it was found that birch pollen release ice-nucleating macromolecules when suspended in water. Here we show that birch pollen washing water exhibits also ice-binding properties such as ice shaping and ice recrystallization inhibition, similar to antifreeze proteins. We present spectroscopic evidence that both the ice-nucleating as well as the ice-binding molecules are polysaccharides bearing carboxylate groups. The spectra suggest that both polysaccharides consist of very similar chemical moieties, but centrifugal filtration indicates differences in molecular size: ice nucleation occurs only in the supernatant of a 100 kDa filter, while ice shaping is strongly enhanced in the filtrate. This finding may suggest that the larger ice-nucleating polysaccharides consist of clusters of the smaller ice-binding polysaccharides, or that the latter are fragments of the ice-nucleating polysaccharides. Finally, similar polysaccharides released from pine and alder pollen also display both ice-nucleating as well as ice-binding ability, suggesting a common mechanism of interaction with ice among several boreal pollen with implications for atmospheric processes and antifreeze protection. PMID:28157236

  9. Immunochemical Characterization of Acacia Pollen Allergens and Evaluation of Cross-Reactivity Pattern with the Common Allergenic Pollens

    PubMed Central

    Shamsbiranvand, Mohammad-Hosein; Khodadadi, Ali; Assarehzadegan, Mohammad-Ali; Borsi, Seyed Hamid; Amini, Akram

    2014-01-01

    Pollen from the Acacia has been reported as an important source of pollinosis in tropical and subtropical regions of the world. The aim of this study was to characterize the IgE binding protein of Acacia farnesiana pollen extract and evaluate cross-reactivity with the most allergenic pollens. In this study, pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting and specific ELISA using forty-two Acacia allergic patients. Potential cross-reactivity among Acacia and selected allergenic plants was evaluated with ELISA and immunoblotting inhibition experiments. There were several resolved protein fractions on SDS-PAGE which ranged from 12 to 85 kDa. Several allergenic protein bands with molecular weights approximately between 12 and 85 kDa were recognized by IgE-specific antibodies from Acacia allergic patients in the immunoblot assay. The inhibition by the Prosopis juliflora pollen extract was more than those by other pollen extracts. Moreover, the wheal diameters generated by the Acacia pollen extract were highly correlated with those of P. juliflora pollen extracts. The findings suggest that several proteins such as 15, 23, 45, and 50 kDa proteins could be used as diagnostic and therapeutic reagents for patients allergic to A. farnesiana and P. juliflora. PMID:24949020

  10. Antisense-mediated silencing of a gene encoding a major ryegrass pollen allergen.

    PubMed

    Bhalla, P L; Swoboda, I; Singh, M B

    1999-09-28

    Type 1 allergic reactions, such as hay fever and allergic asthma, triggered by grass pollen allergens are a global health problem that affects approximately 20% of the population in cool, temperate climates. Ryegrass is the dominant source of allergens because of its prodigious production of airborne pollen. Lol p 5 is the major allergenic protein of ryegrass pollen, judging from the fact that almost all of the individuals allergic to grass pollen show presence of serum IgE antibodies against this protein. Moreover, nearly two-thirds of the IgE reactivity of ryegrass pollen has been attributed to this protein. Therefore, it can be expected that down-regulation of Lol p 5 production can significantly reduce the allergic potential of ryegrass pollen. Here, we report down-regulation of Lol p 5 with an antisense construct targeted to the Lol p 5 gene in ryegrass. The expression of antisense RNA was regulated by a pollen-specific promoter. Immunoblot analysis of proteins with allergen-specific antibodies did not detect Lol p 5 in the transgenic pollen. The transgenic pollen showed remarkably reduced allergenicity as reflected by low IgE-binding capacity of pollen extract as compared with that of control pollen. The transgenic ryegrass plants in which Lol p 5 gene expression is perturbed showed normal fertile pollen development, indicating that genetic engineering of hypoallergenic grass plants is possible.

  11. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, July--September 1993

    SciTech Connect

    Curtis, C.W.

    1993-12-31

    Low-severity coal liquefaction allows for the solubilization of coal with reduced gas make. The idea being tested in this research is whether selective bond rupture occurs during liquefaction at low temperatures that can be satisfied by hydrogen donation from highly active hydrogen donor compounds. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective hydrogen donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin (ISO), which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9, 10hexahydroanthracene (HHA). These compounds have been shown to highly effective donors (Bedell and Curtis, 1991) which release their hydrogen at fairly low temperatures, in the 200 to 300{degrees}C range. ISO has been shown to be much more effective than its hydroaromatic analogue tetralin (TET) in releasing hydrogen at low temperatures and transferring that hydrogen to an acceptor molecule or to coal (Bedell and Curtis, 1991). Likewise, at 380{degrees}C, the ability of HHA to release hydrogen in both N{sub 2} and H{sub 2} atmospheres was greater than a comparative hydroaromatic compound, dihydroanthracene (DHA). However, when an acceptor molecule or coal was present, DHA was as or more active than HHA in transferring hydrogen (Bedell et al., 1993). In another study, at equivalent reaction conditions and in the presence of anthracene (ANT) as a hydrogen acceptor, ISO released more than 200 times as much hydrogen as TET and HHA released 18 to 25 times as much hydrogen as DHA (Wang, 1992).

  12. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, April--June 1993

    SciTech Connect

    Curtis, C.W.

    1993-11-01

    Low-severity coal liquefaction allows for the solubilization of coal with reduced gas make. The idea being tested in this research is whether selective bond rupture occurs during liquefaction at low temperatures that can be satisfied by hydrogen donation from highly active hydrogen donor compounds. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective hydrogen donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin (ISO), which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9,10-hexahydroanthracene (HHA). These compounds have been shown to highly effective donors (Bedell and Curtis, 1991) which release their hydrogen at fairly low temperatures, in the 200 to 300{degree}C range. ISO has been shown to be much more effective than its hydroaromatic analogue tetralin (TET) in releasing hydrogen at low temperatures and transferring that hydrogen to an acceptor molecule or to coal (Bedell and Curtis, 1991). Likewise, at 380{degree}C, the ability of HHA to release hydrogen in both N{sub 2} and H{sub 2} atmospheres was greater than a comparative hydroaromatic compound, dihydroanthracene (DHA). However, when an acceptor molecule or coal was present, DHA was as or more active than HHA in transferring hydrogen (Bedell et al., 1993). In another study, at equivalent reaction conditions and in the presence of anthracene (ANT) as a hydrogen acceptor, ISO released more than 200 times as much hydrogen as TET and HHM released 18 to 25 times as much hydrogen as DHA (Wang, 1992).

  13. Pollen Season Trends (1973-2013) in Stockholm Area, Sweden

    PubMed Central

    Lind, Tomas; Ekebom, Agneta; Alm Kübler, Kerstin; Östensson, Pia; Bellander, Tom

    2016-01-01

    In the present study, the phenological and quantitative changes in the pollen seasons between 1973 and 2013 in the Stockholm region of Sweden were studied for nine types of pollen (hazel, alder, elm, birch, oak, grass, mugwort, willow and pine). Linear regression models were used to estimate the long term trends in duration, start- and end-dates, peak-values and the yearly accumulated pollen sums of the pollen seasons. The pollen seasons of several arboreal plant species (e.g. birch, oak and pine) were found to start significantly earlier today compared to 41 years earlier, and have an earlier peak-date, while the season of other species seemed largely unaffected. However, the long term trends in the end-dates of pollen seasons differed between arboreal and herbaceous species. For herbaceous species (grass and mugwort), a significant change towards later end-dates was observed and the duration of season was found to have increased. A significant trend towards an earlier end-date was found in the majority of the arboreal plant species (i.e. elm, oak, pine and birch), but the length of the season seemed unaffected. A trend towards an increase in yearly concentrations of pollen was observed for several species; however the reasons for this phenomenon cannot be explained unambiguously by the present study design. The trend of increasing yearly mean air temperatures in the Stockholm area may be the reason to changed phenological patterns of pollen seasons. PMID:27898718

  14. Pollen Viability and Pollen Tube Attrition in Cranberry (Vaccinium macrocarpon)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The content of mature seed in a cranberry fruit increases with stigmatic pollen load. On average, however, only two seeds result for every tetrad of pollen deposited. What then is the fate of the two remaining pollen grains fused in each tetrad? Germination in vitro revealed that most of the grains ...

  15. [Allergenic pollens in Spain].

    PubMed

    Subiza Garrido-Lestache, J

    2004-01-01

    Allergenic pollens that cause rhinoconjuctivitis and/or asthma are those from trees or plants that pollinate through the air (anemophilic pollination) and not through insects (entomophilic pollination). Although pollen grains would seem to be too large to easily reach the intrapulmonary airways, the relationship between pollen counts and the presence of asthmatic symptoms is only too evident. This is probably because the allergens inducing seasonal asthma are not only found within pollen grains but also outside the grains in particles of less than 10 mm that are freely found in the atmosphere. The most important pollens producing pollinosis in Spain are those from cypress trees from January-March, birch trees in April (macizo galaico), Platanus hispanica (March-April), grasses and olive trees from April-June, Parietaria from April-July and Chenopodium and/or Salsola from July-September. By geographical areas, the main cause of pollinosis are grasses in the center and north of the peninsula, olive trees in the south (Jaén, Sevilla, Granada, Córdoba) and Parietaria in the Mediterranean coast (Barcelona, Murcia, Valencia).

  16. Pectic arabinan side chains are essential for pollen cell wall integrity during pollen development.

    PubMed

    Cankar, Katarina; Kortstee, Anne; Toonen, Marcel A J; Wolters-Arts, Mieke; Houbein, Rudolf; Mariani, Celestina; Ulvskov, Peter; Jorgensen, Bodil; Schols, Henk A; Visser, Richard G F; Trindade, Luisa M

    2014-05-01

    Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure-function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pectin composition was analysed. The expression of genes encoding enzymes involved in pectin acetylation, degradation of the rhamnogalacturonan backbone and type and length of neutral side chains, arabinan and galactan in particular, has been altered. Upon crossing of different transgenic lines, some transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different developmental stages were microscopically examined to study the phenotype in more detail. Scanning electron microscopy of flowers showed collapsed pollen grains in mature anthers and in earlier stages cytoplasmic protrusions at the site of the of kin pore, eventually leading to bursting of the pollen grain and leaking of the cytoplasm. This phenomenon is only observed after the microspores are released and the tapetum starts to degenerate. Timing of the phenotype indicates a role for pectic arabinan side chains during remodelling of the cell wall when the pollen grain is maturing and dehydrating.

  17. Studies of genetic transformation of higher plants using irradiated pollen

    SciTech Connect

    Chyi, Y.S.

    1984-01-01

    Pandey has reported extensively on an unusual genetic phenomenon he called egg transformation. When compatible pollen was treated wth genetically lethal dosage of ..gamma..-radiation (100,000 rad), and used as mentor pollen to overcome selfincompatibility of several Nicotiana species, some genetic characters were found to be transferred from the radiation killed pollen to nonhybrid progeny. Observed transformants were fertile, cytogenetically normal, and had maternal phenotypes except for those specific traits transferred from the donors. Heavily irradiated pollen was believed to discharge its radiation-fragmented DNA (chromatin) into the embryo sac and bring about the transformation of the egg. The frequency of gene transfer was reported to be over 50%, and happened for all three characters Pandey studied - self incompatible specificities, flower color, and pollen color. Plant species studied were tomato, pea, apple, rapeseed, and Nicotiana species, including various stocks from Dr. Pandey. Treatments included pollinations with soley irradiated donor pollen, with a mixture of irradiated donor and normal self pollen, with a mixture of normal donor and self pollen, and double pollinations with irradiated donor pollen and normal self pollen, using different time intervals to separate the two pollinations. A total of 6210 pollinations were made, and 17,522 seedlings representing 87,750 potential transformational events were screened. In no case was an unambiguous transformant recovered. This research was unable to confirm or expand upon the findings of Dr. Pandey, or elucidate the mechanisms underlying such phenomena. Alternative explanations for Pandey's data were postulated. This approach to gene transfer by using irradiated pollen appears to be of little practical use to plant breeders.

  18. High levels of protein expression using different mammalian CMV promoters in several cell lines.

    PubMed

    Xia, Wei; Bringmann, Peter; McClary, John; Jones, Patrick P; Manzana, Warren; Zhu, Ying; Wang, Soujuan; Liu, Yi; Harvey, Susan; Madlansacay, Mary Rose; McLean, Kirk; Rosser, Mary P; MacRobbie, Jean; Olsen, Catherine L; Cobb, Ronald R

    2006-01-01

    With the recent completion of the human genome sequencing project, scientists are faced with the daunting challenge of deciphering the function of these newly found genes quickly and efficiently. Equally as important is to produce milligram quantities of the therapeutically relevant gene products as quickly as possible. Mammalian expression systems provide many advantages to aid in this task. Mammalian cell lines have the capacity for proper post-translational modifications including proper protein folding and glycosylation. In response to the needs described above, we investigated the protein expression levels driven by the human CMV in the presence or absence of intron A, the mouse and rat CMV promoters with intron A, and the MPSV promoter in plasmid expression vectors. We evaluated the different promoters using an in-house plasmid vector backbone. The protein expression levels of four genes of interest driven by these promoters were evaluated in HEK293EBNA and CHO-K1 cells. Stable and transient transfected cells were utilized. In general, the full-length human CMV, in the presence of intron A, gave the highest levels of protein expression in transient transfections in both cell lines. However, the MPSV promoter resulted in the highest levels of stable protein expression in CHO-K1 cells. Using the CMV driven constitutive promoters in the presence of intron A, we have been able to generate >10 microg/ml of recombinant protein using transient transfections.

  19. 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

    Gao, Xin-Qi; Liu, Chang Zhen; Li, Dan Dan; Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-07-01

    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.

  20. Bet Anywhere, Anytime: An Analysis of Internet Sports Bettors' Responses to Gambling Promotions During Sports Broadcasts by Problem Gambling Severity.

    PubMed

    Hing, Nerilee; Russell, Alex Myles Thomas; Lamont, Matthew; Vitartas, Peter

    2017-02-01

    Promotions for online sports betting during televised sports broadcasts are regularly viewed by millions of Australians, raising concerns about their impacts on vulnerable groups including at-risk and problem gamblers. This study examined whether responses to these promotions varied with problem gambling severity amongst 455 Australian Internet sports bettors participating in an online survey. Results indicated that young male Internet sports bettors are especially vulnerable to gambling problems, particularly if they hold positive attitudes to gambling sponsors who embed promotions into sports broadcasts and to the promotional techniques they use and this heightens the risk that alluring messages contribute to excessive gambling. As problem gambling severity increased, so too did recognition that these promotions have impacted negatively on their sports betting behaviour. Because a plethora of sports betting brands and promotions are now heavily integrated into sports coverage, social marketing efforts are needed to offset their persuasive appeal and counter the positive attitudes towards them that appear linked to excessive gambling amongst Internet sports bettors.

  1. Impact of the IL-10 Promoter Gene Polymorphisms in the Severity of Chronic Hepatitis B Infection

    PubMed Central

    Ghaleh Baghi, Sahand; Alavian, Seyed Moayed; Mehrnoush, Leila; Salimi, Shima

    2015-01-01

    Background: Interleukin-10 (IL-10) is an important anti-inflammatory cytokine. The polymorphisms of its promoter gene have been considered to be related with the chronicity of hepatitis B infection. Objectives: The aim of this study was to evaluate the polymorphisms at different positions in the IL-10 promoter gene in patients with chronic hepatitis B. Patients and Methods: Totally, 166 patients with chronic hepatitis B infection were enrolled. Genotypes at different positions (i.e. -819, - 592, and - 1082) in the IL-10 gene promoter were determined. Results: The C/A genotype at position -592, C/T genotype at position -819, and GCC/ATA haplotype of the IL-10 gene promoter were significantly more common in the patients with cirrhosis. The genotypes were significantly different between the hepatitis B e antigen (HBeAg)-negative and HBeAg-positive patients at position -592 (C/A and C/C), position -819 (C/C and C/T), and position -1082 (A/A and G/A). Conclusions: Some IL-10 promoter gene polymorphisms predisposed the infected hepatitis B virus cases to cirrhosis in our study population. PMID:26300930

  2. 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.

  3. Relationship between Pollen Counts and Weather Variables in East-Mediterranean Coast of Turkey

    PubMed Central

    Karakoç, Gülbin Bingöl; Yilmaz, Mustafa; Pinar, Münevver; Kendirli, Seval Güneçer; Çakan, Halil

    2004-01-01

    Background: Aeroallergen sampling provides information regarding the onset, duration and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. Objectives: This atmospheric survey reports (1) airborne pollen contributions in Adana in one-year period (2) pollen onset, duration and peak level (3) the relationship between airborne pollen and selected meteorological variables and; (4) effects on symptoms in pollen allergic children. Methods: Pollen sampling was performed with a volumetric Burkard Spore Trap. Meteorological data were measured daily from April 2001 to April 2002. Asthma symptom scores were investigated in 186 pollen allergic children that were on follow up in pediatric allergy outpatient clinics during same period. Results: Average measurements included 82.5% tree pollen, 7.7% grass pollen and 9.8% herb pollen 54 taxa were identified during one year. The most prominent tree pollens were Cupressaceae, Eucalyptus and Pinus. The most common herb was Chenopodiaceae pollen family. When airborne pollen levels were examined in relation to single meteorological conditions; daily variations in total pollen counts were not significantly correlated with any variable studied (humidity, rainfall, temperature and wind) (p>0.05). On the other hand, statistically significant relationship between pollen concentration and symptom scores were found (p>0.05). Positive correlations were seen between both Gramineae and Herb pollen, and humidity and rainfall from March to July. However, positive correlations were detected between tree pollen counts and temperature and humidity in May and June. Conclusion: This survey is the first volumetric airborne pollen analysis conducted in the survey area in Adana. This study suggested that the effects of weather on pollen count and symptom scores in this population could not be clearly identified with the evaluation of one-year data. However, pollen counts had effect on allergic

  4. Carbohydrate metabolism before and after dehiscence in the recalcitrant pollen of pumpkin (Cucurbita pepo L.).

    PubMed

    Carrizo García, C; Guarnieri, M; Pacini, E

    2015-05-01

    Pumpkin (Cucurbita pepo L.) pollen is starchy, sucrose-poor and recalcitrant, features opposite to those of several model species; therefore, some differences in carbohydrate metabolism could be expected in this species. By studying pumpkin recalcitrant pollen, the objective was to provide new biochemical evidence to improve understanding of how carbohydrate metabolism might be involved in pollen functioning in advanced stages. Four stages were analysed: immature pollen from 1 day before anthesis, mature pollen, mature pollen exposed to the environment for 7 h, and pollen rehydrated in a culture medium. Pollen viability, water and carbohydrate content and activity of enzymes involved in carbohydrate metabolism were quantified in each stage. Pollen viability and water content dropped quickly after dehiscence, as expected. The slight changes in carbohydrate concentration and enzyme activity during pollen maturation contrast with major changes recorded with ageing and rehydration. Pumpkin pollen seems highly active and closely related to its surrounding environment in all the stages analysed; the latter is particularly evident among insoluble sucrolytic enzymes, mainly wall-bound acid invertase, which would be the most relevant for sucrose cleavage. Each stage was characterised by a particular metabolic/enzymatic profile; some particular features, such as the minor changes during maturation, fast sucrolysis upon rehydration or sharp decrease in insoluble sucrolytic activity with ageing seem to be related to the lack of dormancy and recalcitrant nature of pumpkin pollen.

  5. Variability within the 10-Year Pollen Rain of a Seasonal Neotropical Forest and Its Implications for Paleoenvironmental and Phenological Research

    PubMed Central

    Haselhorst, Derek S.; Moreno, J. Enrique; Punyasena, Surangi W.

    2013-01-01

    Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1–3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen

  6. Variability within the 10-year pollen rain of a seasonal neotropical forest and its implications for paleoenvironmental and phenological research.

    PubMed

    Haselhorst, Derek S; Moreno, J Enrique; Punyasena, Surangi W

    2013-01-01

    Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1-3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen traps

  7. Floral emasculation reveals pollen quality limitation of seed output in Bulbine bulbosa (Asphodelaceae)1.

    PubMed

    Vaughton, Glenda; Ramsey, Mike

    2010-01-01

    Pollen commonly limits seed output in natural plant populations, but the relative contributions of pollen quantity and quality to pollen limitation remain largely unexplored. Estimates of these contributions are needed to promote better understanding of the ecological and evolutionary consequences of pollen limitation. We assessed pollen limitation and distinguished how pollen quantity and quality contributed to seed output in the predominantly outcrossing herb Bulbine bulbosa. We compared seed output of emasculated and cross-pollinated plants that could not self-pollinate with that of intact plants. Seed output was similar in emasculated and cross-pollinated plants, but it was about 50% less in intact plants. These findings indicate that the quantity of cross-pollen deposited by pollinators did not limit seed output. However, pollinators also deposited self-pollen, which reduced seed output because selfing disabled ovules, rendering them unavailable for cross-fertilization. We conclude that pollen quality rather than quantity can limit seed output under natural conditions, which supports recent proposals for greater consideration of pollen quality in the study of pollen limitation.

  8. The effect of meteorological factors on airborne Betula pollen concentrations in Lublin (Poland).

    PubMed

    Piotrowska, Krystyna; Kubik-Komar, Agnieszka

    2012-12-01

    The present study investigated the pattern of the birch atmospheric pollen seasons in Lublin in the period 2001-2010. Pollen monitoring was conducted using a Lanzoni VPPS 2000 sampler. The atmospheric pollen seasons were determined with the 98% method. Regression analysis was used to determine correlations between meteorological conditions and the pattern of the birch pollen season. On average, the birch pollen season started on 12 April, ended on 13 May, and lasted 32 days. The peak value and the Seasonal Pollen Index showed the greatest variation in particular years. All the seasons were right-skewed. During the study years, a trend was found towards earlier occurrence of the seasonal peak. Regression equations were developed for the following parameters of the atmospheric pollen season: start, duration, peak value and average pollen concentration during the season. The obtained model fit was at a level of 64-81%. Statistical analysis shows that minimum temperature of February and March and total rainfall in June in the year preceding pollen release have the greatest effect on the birch atmospheric pollen season in Lublin. Low temperatures in February promote the occurrence of high pollen concentrations.

  9. Native pollen thieves reduce the reproductive success of a hermaphroditic plant, Aloe maculata.

    PubMed

    Hargreaves, Anna L; Harder, Lawrence D; Johnson, Steven D

    2010-06-01

    Pollen is unique among floral rewards in functioning as both a carrier of gametes and an attractant and nutritious resource for floral visitors. Animals that collect pollen without pollinating (pollen thieves) could reduce siring success of thieved plants and cause pollen limitation of seed set at the population level; however, such impacts on plant reproduction have not been demonstrated experimentally. To test these effects we added hives of native honey bees (Apis mellifera scutellata) to populations of a primarily bird-pollinated plant, Aloe maculata, in eastern South Africa. In field and aviary trials, bee addition increased pollen removal from anthers but decreased pollen deposition on stigmas, and so reduced both male and female pollination components. Further, total seed production decreased with hive addition in the aviary experiment and in three of four field populations, indicating that population-level pollen theft can also compromise reproductive success. In the field, naturally occurring allodapine bees also seemed to act as pollen thieves, outweighing the effect of honey bee hive addition at one of the four aloe populations. Our results highlight the importance of social bees as pollen thieves, even of plants that have evolved in their presence, and the role of dichogamy in promoting pollen theft. Given the commonness of both social bees and dichogamy, pollen theft is likely a much more common influence on floral ecology and evolution than suggested by the sparse literature.

  10. [Formation of reactive oxygen species during pollen grain germination].

    PubMed

    Smirnova, A V; Matveeva, N P; Polesskaia, O G; Ermakov, I P

    2009-01-01

    The formation of reactive oxygen species in pollen at the early germination stage, which precedes the formation of the pollen tube, was studied. During this period, pollen grain is being hydrated, abruptly increasing its volume, and it passes from the resting state to active metabolism. Fluorescent methods have made it possible to reveal reactive oxygen species in the cytoplasm and inner layer of the pollen wall, intine. The cytoplasmic reactive oxygen species were mostly found in mitochondria, while extracellular ones were localized in aperture zones of intine, as well as in the solution surrounding pollen grains in vitro. The content of extracellular reactive oxygen species decreased after superoxide dismutase (100 units per ml) and diphenylene iodonium (100 microM), which indicates NADPH oxidase as one of possible producent of them. In conditions of suppression of extracellular reactive oxygen species production (100 microM diphenilene iodonium) or their promoted removal (after addition of 10 to 100 microM ascorbic acid), the number of germinating pollen grains increased. This effect disappeared after further increase in the concentration of the listed reagents. The result is evidence of the significance of processes of generation/removal of extracellular reactive oxygen species for pollen germination.

  11. A novel method for efficient in vitro germination and tube growth of Arabidopsis thaliana pollen.

    PubMed

    Rodriguez-Enriquez, M J; Mehdi, S; Dickinson, H G; Grant-Downton, R T

    2013-01-01

    In addition to its importance in studies of plant reproduction and fertility, pollen is as widely employed as a model system of cell growth and development. This work demands robust, reproducible methods to induce pollen germination and morphologically normal growth of pollen tubes in vitro. Despite numerous advantages of Arabidopsis thaliana as a model plant, such experiments on pollen germination and pollen tube growth have often proved challenging. Our new method employs a physical cellulosic membrane, overlying an agarose substrate. By modulating the substrate composition, we provide important insights into the mechanisms promoting pollen growth both in vitro and in vivo. This effective new technical approach to A. thaliana pollen germination and tube growth results in swift, consistent and unprecedented levels of germination to over 90%. It can also promote rapid growth of long, morphologically normal pollen tubes. This technical development demonstrates that exogenous spermidine and a cellulosic substrate are key factors in stimulating germination. It has potential to greatly assist the study of reproduction in A. thaliana and its closest relatives, not only for the study of germination levels and pollen tube growth dynamics by microscopy, but also for biochemical and molecular analysis of germinating pollen.

  12. Emerging pollen allergens.

    PubMed

    Rodríguez, Rosalía; Villalba, Mayte; Batanero, Eva; Palomares, Oscar; Salamanca, Guillermo

    2007-01-01

    Numerous pollen allergens have been reported over the last few years. Most of them belong to well-known families of proteins but some others constitute the first member of new allergenic families. Some of the factors that can contribute to the detection and identification of new pollen allergens are: a) advances in the technology tools for molecular analysis; and b) the deep knowledge of many allergenic sources. The combination of these factors has provided vast information on the olive pollen allergogram and the identification of minor allergens that become major ones for a significant population. The close taxonomical relationship between olive tree and ash -both Oleaceae- has permitted to identify Fra e 1 (the Ole e 1-like allergen) in ash pollen and to detect the presence of protein homologues of Ole e 3 and Ole e 6. In the other hand, extensive areas of south Europe are suffering an increasing desertification. As a consequence of this, new botanical species are spontaneously growing in these areas or being used in greening ground programs: Chenopodium album and Salsola kali are some examples recently recognized as allergenic woods. The identification of the complete panel of allergens from the hypersensitizing sources might help to develop more accurate diagnosis, and efficient and safer therapy tools for Type-I allergic diseases.

  13. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, October 1991--December 1991

    SciTech Connect

    Curtis, C.W.

    1991-12-31

    The objective of this project is to evaluate the efficacy of low severity coal liquefaction in the presence of highly reactive hydrogen donors, cyclic olefins. The work that was performed this quarter involved performing a literature search in which different aspects of low severity coal liquefaction were examined. In addition, two new mater`s graduate students learned the fundamental differences between high severity coal liquefaction and low severity coal liquefaction by examining the literature and reading texts on coal liquefaction. The literature review presented for the first quarter`s work is a compilation of the material which we have found to data involving low severity coal liquefaction. Additional review of low severity liquefaction literature is being conducted this quarter and will be reported in the next quarterly report. In addition, a summary of the work involving the reactivity of cyclic olefins in the absence and presence of coal will be presented next quarter.

  14. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, October 1991--December 1991

    SciTech Connect

    Curtis, C.W.

    1991-12-31

    The objective of this project is to evaluate the efficacy of low severity coal liquefaction in the presence of highly reactive hydrogen donors, cyclic olefins. The work that was performed this quarter involved performing a literature search in which different aspects of low severity coal liquefaction were examined. In addition, two new master`s graduate students learned the fundamental differences between high severity coal liquefaction and low severity coal liquefaction by examining the literature and reading texts on coal liquefaction. The literature review presented for the first quarter`s work is a compilation of the material which we have found to date involving low severity coal liquefaction. Additional review of low severity liquefaction literature is being conducted this quarter and will be reported in the next quarterly report. In addition, a summary of the work involving the reactivity of cyclic olefins in the absence and presence of coal will be presented next quarter.

  15. Characteristics of modern pollen rain and the relationship to vegetation in sagebrush-steppe environments of Montana, USA

    NASA Astrophysics Data System (ADS)

    Briles, C.; Bryant, V.

    2010-12-01

    Variations in pollen production and dispersal characteristics among plant species complicate our ability to determine direct relationships between deposited pollen and actual vegetation. In order to better understand modern pollen-vegetation relationships, we analyzed pollen from 61 samples taken from sagebrush-steppe environments across Montana and compared them with the actual vegetation composition at each site. We also determined to what degree sagebrush-steppe communities can be geographically distinguished from one another based on their pollen signature. Pollen preservation was good, especially in wetter environments, with pollen degradataion ranging from 4-15%. Diploxylon Pinus was the primary contributor to the pollen rain, even in plots where pine trees did not occur or were several kilometers from the plot. Artemisia and grass pollen are underrepresented in the soils samples, while Chenopodiaceae and Juniperus pollen are overrepresented when compared to actual vegetation composition. Insect-pollinated species are present only in very minor amounts in the soil samples, even though some (e.g., Brassica) are abundant in the plots. In general, pollen spectra show significant differences between regions, however, within each region the individual spectra are not statistically significant from one another. An understanding of modern pollen-vegetation relationships and the palynological “fingerprint” of sagebrush-steppe communities aid in climatic and ecological interpretations of fossil pollen assemblages. The data also provide important control samples for forensics studies that use pollen to geolocate an object or person to a crime scene.

  16. Elevation of Pollen Mitochondrial DNA Copy Number by WHIRLY2: Altered Respiration and Pollen Tube Growth in Arabidopsis1

    PubMed Central

    Cai, Qiang; Guo, Liang; Shen, Zhao-Rui; Wang, Dan-Yang; Zhang, Quan; Sodmergen

    2015-01-01

    In plants, the copy number of the mitochondrial DNA (mtDNA) can be much lower than the number of mitochondria. The biological significance and regulatory mechanisms of this phenomenon remain poorly understood. Here, using the pollen vegetative cell, we examined the role of the Arabidopsis (Arabidopsis thaliana) mtDNA-binding protein WHIRLY2 (AtWHY2). AtWHY2 decreases during pollen development, in parallel with the rapid degradation of mtDNA; to examine the importance of this decrease, we used the pollen vegetative cell-specific promoter Lat52 to express AtWHY2. The transgenic plants (LWHY2) had very high mtDNA levels in pollen, more than 10 times more than in the wild type (ecotype Columbia-0). LWHY2 plants were fertile, morphologically normal, and set seeds; however, reciprocal crosses with heterozygous plants showed reduced transmission of LWHY2-1 through the male and slower growth of LWHY2-1 pollen tubes. We found that LWHY2-1 pollen had significantly more reactive oxygen species and less ATP compared with the wild type, indicating an effect on mitochondrial respiration. These findings reveal that AtWHY2 affects mtDNA copy number in pollen and suggest that low mtDNA copy numbers might be the normal means by which plant cells maintain mitochondrial genetic information. PMID:26195569

  17. Studies of modern pollen assemblages for pollen dispersal- deposition- preservation process understanding and for pollen-based reconstructions of past vegetation, climate, and human impact: A review based on case studies in China

    NASA Astrophysics Data System (ADS)

    Xu, Qinghai; Zhang, Shengrui; Gaillard, Marie-jose; Li, Manyue; Cao, Xianyong; Tian, Fang; Li, Furong

    2016-10-01

    Fossil pollen, as a direct proxy record of past vegetation, and indirect proxy record of past climate, plays an essential role in revealing and reconstructing past vegetation and climate. However, relationships between pollen, vegetation and climate are not linear, hence quantitative reconstructions of past vegetation and climate based on pollen records are not straightforward, and results may be highly contradictory and difficult to interpret. One of the main causes of discrepancies between results has been the lack of comprehensive and systematical studies on modern pollen dispersal and deposition processes, particularly on the quantification of these processes. Based on empirical studies performed in China over the last 30 years, this paper provides the state-of-the-art of the understanding of pollen dispersal and deposition processes in China and the remaining questions to be investigated. We show that major progress has been achieved in the study of modern pollen dispersal and deposition processes, and in the application of models of the pollen-vegetation-climate relationships for quantitative reconstruction of past vegetation and climate. However, several issues are not entirely solved or understood yet, such as how to quantify the reworking and re-deposition of pollen grains in quaternary alluvial sediments, the influence of pollen preservation on pollen assemblages, and human impact on vegetation. Even so, the progress made during the last decades makes it possible to achieve significantly more precise and informative reconstructions of past vegetation, land-use and climate in China than was possible earlier.

  18. Taxonomic description of in situ bee pollen from the middle Eocene of Germany

    PubMed Central

    Grímsson, FriĐgeir; Zetter, Reinhard; Labandeira, Conrad C.; Engel, Michael S.; Wappler, Torsten

    2017-01-01

    Abstract The middle Eocene Messel and Eckfeld localities are renowned for their excellently preserved faunas and diverse floras. Here we describe for the first time pollen from insect-pollinated plants found in situ on well-preserved ancient bees using light and scanning electron microscopy. There have been 140 pollen types reported from Messel and 162 pollen types from Eckfeld. Here we document 23 pollen types, six from Messel and 18 from Eckfeld (one is shared). The taxa reported here are all pollinated by insects and mostly not recovered in the previously studied dispersed fossil pollen records. Typically, a single or two pollen types are found on each fossil bee specimen, the maximum number of distinct pollen types on a single individual is five. Only five of the 23 pollen types obtained are angiosperms of unknown affinity, the remainder cover a broad taxonomic range of angiosperm trees and include members of several major clades: monocots (1 pollen type), fabids (7), malvids (4), asterids (5) and other core eudicots (1). Seven types each can be assigned to individual genera or infrafamilial clades. Since bees visit only flowers in the relative vicinity of their habitat, the recovered pollen provides a unique insight into the autochthonous palaeo-flora. The coexistence of taxa such as Decodon, Elaeocarpus, Mortoniodendron and other Tilioideae, Mastixoideae, Olax, Pouteria and Nyssa confirms current views that diverse, thermophilic forests thrived at the Messel and Eckfeld localities, probably under a warm subtropical, fully humid climate. Our study calls for increased attention to pollen found in situ on pollen-harvesting insects such as bees, which can provide new insights on insect-pollinated plants and complement even detailed palaeo-palynological knowledge obtained mostly from pollen of wind-pollinated plants in the dispersed pollen record of sediments. In the case of Elaeocarpus, Mortoniodendron, Olax and Pouteria the pollen collected by the middle Eocene

  19. Pollen genetic markers for detection of mutagens in the environment

    SciTech Connect

    Nilan, R.A.; Rosichan, J.L.; Arenaz, P.; Hodgdon, A.L.; Kleinhofs, A.

    1981-01-01

    To utilize pollen for in situ monitoring of the genetic hazards of environmental pollutants, the range of genetic traits in pollen must be identified and analyzed. These include ornamentation, shape and form, male sterility viability, intraspecific incompatibility, proteins, and starch deposition. Several proteins that meet the necessary criteria for mutagen detection systems are discussed. At Washington State Univ., a waxy pollen system is being developed in barley for in situ mutagen monitoring. Studies are being conducted to develop data concerning the nature of the mutations induced by various environmental mutagens.

  20. Comparative studies of pollen and fluorescent dye transport by bumble bees visiting Erythronium grandiflorum.

    PubMed

    Thomson, James D; Price, Mary V; Waser, Nickolas M; Stratton, Donald A

    1986-07-01

    In the Colorado Rocky Mountains the glacier lily Erythronium grandiflorum exhibits a striking dimorphism in pollen color and is commonly pollinated by the bumble bee Bombus occidentalis. We induced bees to visit sequences of flowers in a flight cage, and compared dispersal of distinctively-colored pollen and fluorescent pigment ("dye") that the bee had picked up at a single donor flower. Nonparametric and parametric analyses showed that dispersal properties of pollen and dye differed; consistently less pollen was deposited and it was carried consistently shorter distances than dye. Dye thus does not provide an accurate means of assessing exacty where or how far pollen travels in this plant-pollinator system. On the other hand, both pollen and dye responded similarly to several experimental manipulations of donor and recipient flowers. Hence dye may well be of value for a qualitative investigation of how floral traits influence pollen dispersal.

  1. A biochar application protects rice pollen from high-temperature stress.

    PubMed

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Tanveer, Mohsin; Bajwa, Ali Ahsan; Hassan, Shah; Shah, Adnan Noor; Ullah, Abid; Wu, Chao; Khan, Faheem Ahmed; Shah, Farooq; Ullah, Sami; Chen, Yajun; Huang, Jianliang

    2015-11-01

    The influences of high temperature and fertilization with biochar and phosphorus (P) on the pollen characteristics of two rice cultivars (IR-64 and Huanghuazhan) were examined in controlled growth chambers. Temperature treatments included high daytime temperature (HDT), high nighttime temperature (HNT) and ambient temperature (AT). The fertilization treatments were control, biochar alone, P alone and biochar + P. High temperature severely reduced pollen fertility, anther dehiscence, pollen retention and pollen germination of both rice cultivars, with HNT more destructive than HDT. The Huanghuazhan cultivar performed better than IR-64 under high temperature, with higher pollen fertility, better anther dehiscence and greater pollen retention and germination rates. In both cultivars, the pollen of plants treated with biochar + P were more resistant to heat induced stress. Further studies are needed to test the ability of biochar to ameliorate the effects of different abiotic stresses in rice and other crops.

  2. [The effect of climate change on pollen allergy in the Netherlands].

    PubMed

    de Weger, Letty A; Hiemstra, Pieter S

    2009-01-01

    Climate change can exert a range of effects on pollen, which might have consequences for pollen-allergic patients. New allergenic pollen types might appear in the Netherlands, like common ragweed and olive, which result in allergy patients developing allergies that scarcely occur in the Netherlands at present. Trees, such as birches and planes, might produce larger quantities of pollen, which could result in more severe symptoms. The pollen season might become longer thereby extending the period in which patients suffer from allergy symptoms. This extension of the pollen season could be due to a prolonged flowering period of certain species, e.g. grasses, or the appearance of new species that flower in late summer, e.g. common ragweed. Climate change could cause an increase in heavy thunderstorms on summer days in the grass pollen season, which are known to increase the chance of asthma exacerbations.

  3. Functional polymorphism of the promoter region of the prostacyclin synthase gene and severity of RSV infection in hospitalized children.

    PubMed

    Hashimoto, Koichi; Ishibashi, Kei; Gebretsadik, Tebeb; Hartert, Tina V; Yamamoto, Akihiro; Nakayama, Tomohiro; Ohashi, Kazutaka; Sakata, Hiroshi; Kawasaki, Yukihiko; Katayose, Masahiko; Sakuma, Hiroko; Suzuki, Hitoshi; Hosoya, Mitsuaki; Peebles, Ray Stokes; Suzutani, Tatsuo

    2008-11-01

    Prostaglandin I(2) (PGI(2)) protects against RSV-induced illness in mice. A variable-number tandem repeat (VNTR) polymorphism has been detected in the promoter region of the PGI(2) synthase (PGIS) gene. We sought to determine if PGI(2) concentrations or polymorphisms of the PGIS gene correlate with severity of RSV lower respiratory tract infections (LRTI) in human infants. VNTR polymorphisms were studied in 81 previously healthy children between birth and 12 months of age who were hospitalized for LRTI due to RSV and 98 healthy adult control subjects. The severity of RSV infection was quantified using a clinical scoring system, and infant urine samples were collected during the acute illness for measurement of the urinary metabolite of PGI(2). There were no significant differences in the overall distribution of alleles and genotypes between infants with RSV LRTI and the control subjects. The severity of RSV infection significantly inversely correlated with urinary PGI(2) metabolite concentrations. The urinary PGI(2) metabolite concentration correlated with the number of VNTR. The presence of a genotype with a low number VNTR repeats significantly correlated with the most severe RSV LRTI, and genotypes with the highest number of VNTR correlated with the least severe RSV LRTI. A functional polymorphism in the promoter region of the PGIS gene is associated with both significant differences in urinary PGI(2) concentrations during RSV LRTI, and severity of RSV infection in previously healthy infants.

  4. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1992

    SciTech Connect

    Curtis, C.W.

    1992-10-01

    The naphthalene hydrogenation performed thermally at 350 and 400{degrees}C showed no reactivity of the naphthalene. The Molyvan L catalyst precursor promoted a small amount of hydrogenation of naphthalene at 400{degrees}C as shown in Table 1. Reaction at the higher initial pressure of 1250 psi resulted in slightly more conversion of naplithalene and a higher production of tetralin but no decalin was observed. The naphthalene hydrogenation reactions with Molyvan L without sulfur yielded a slightly higher % HYD of naphthalene than did the reactions with sulfur. Likewise, the reactions with an initial hydrogen pressure of 1250 psi yielded a higher % HYD of naphthalene than did the reaction with 1000 psi, regardless of whether sulfur was present. The Molyvan 822 catalyst precursor was substantially more active at 400{degrees}C than at 350{degrees}C as presented in Table 2. The presence of sulfur also promoted the activity of Molyvan 822 as a catalyst. Tetralin was the product and was produced in substantial quantities at 400{degrees}C. Molyvan 822 was much more active for naphthalene hydrogenation than was Molyvan L under equivalent conditions. For example, at 400{degrees}C with sulfur the reactions with Molyvan 822 produced 33.5% HYD while Molyvan L yielded 1.8% HYD. With Molyvan L, the less active catalyst, the effect tile mode of agitation (vertical or horizontal) was minimal.

  5. Control of pollen-mediated gene flow in transgenic trees.

    PubMed

    Zhang, Chunsheng; Norris-Caneda, Kim H; Rottmann, William H; Gulledge, Jon E; Chang, Shujun; Kwan, Brian Yow-Hui; Thomas, Anita M; Mandel, Lydia C; Kothera, Ronald T; Victor, Aditi D; Pearson, Leslie; Hinchee, Maud A W

    2012-08-01

    Pollen elimination provides an effective containment method to reduce direct gene flow from transgenic trees to their wild relatives. Until now, only limited success has been achieved in controlling pollen production in trees. A pine (Pinus radiata) male cone-specific promoter, PrMC2, was used to drive modified barnase coding sequences (barnaseH102E, barnaseK27A, and barnaseE73G) in order to determine their effectiveness in pollen ablation. The expression cassette PrMC2-barnaseH102E was found to efficiently ablate pollen in tobacco (Nicotiana tabacum), pine, and Eucalyptus (spp.). Large-scale and multiple-year field tests demonstrated that complete prevention of pollen production was achieved in greater than 95% of independently transformed lines of pine and Eucalyptus (spp.) that contained the PrMC2-barnaseH102E expression cassette. A complete pollen control phenotype was achieved in transgenic lines and expressed stably over multiple years, multiple test locations, and when the PrMC2-barnaseH102E cassette was flanked by different genes. The PrMC2-barnaseH102E transgenic pine and Eucalyptus (spp.) trees grew similarly to control trees in all observed attributes except the pollenless phenotype. The ability to achieve the complete control of pollen production in field-grown trees is likely the result of a unique combination of three factors: the male cone/anther specificity of the PrMC2 promoter, the reduced RNase activity of barnaseH102E, and unique features associated with a polyploid tapetum. The field performance of the PrMC2-barnaseH102E in representative angiosperm and gymnosperm trees indicates that this gene can be used to mitigate pollen-mediated gene flow associated with large-scale deployment of transgenic trees.

  6. Promotion

    PubMed Central

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed. PMID:24436683

  7. Isolation and characterization of the plant glsA promoter from Alstroemeria.

    PubMed

    Igawa, T; Hoshino, Y; Yanagawa, Y

    2009-11-01

    The differentiation of a vegetative cell and a generative cell is a critical event during pollen development. The Lilium GlsA is known to localize in pollen and is considered to be involved in development of the generative cell. Here, we cloned a glsA ortholog from Alstroemeria, a commercially important cut flower. The expression of AaglsA (Alstroemeria aurea glsA) transcripts increased gradually after pollen mitosis I (PMI) and reached a significant level when the generative cell started to elongate. Analysis of the promoter of AaglsA suggests that AaglsA expression is controlled by several cis-regulatory elements during pollen development. This is the first investigation of reproductive factors regulating male gametogenesis in Alstroemeria.

  8. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, April 1994--June 1994

    SciTech Connect

    Curtis, C.W.

    1994-10-01

    New ways to improve the coal liquefaction process continue to be sought with the goal being to find the least expensive method to achieve the greatest coal conversion and the best product slate. Low severity is at logical route taken with this goal in mind. Low severity reduces the need for expensive high-pressure valves, pumps and fittings and reduces the problems of construction and handling of severe slurries. However, because of the often diminished conversion of liquefaction reactions at lower temperatures and pressures, methods must be found to increase reactivity of the coal. The basis for this study is the increase of coal liquefaction reactivity through the combination of the use of cyclic olefins with pretreatment to remove cations.

  9. The Plastidial Glyceraldehyde-3-Phosphate Dehydrogenase Is Critical for Viable Pollen Development in Arabidopsis1[W

    PubMed Central

    Muñoz-Bertomeu, Jesús; Cascales-Miñana, Borja; Irles-Segura, Asunción; Mateu, Isabel; Nunes-Nesi, Adriano; Fernie, Alisdair R.; Segura, Juan; Ros, Roc

    2010-01-01

    Plant metabolism is highly coordinated with development. However, an understanding of the whole picture of metabolism and its interactions with plant development is scarce. In this work, we show that the deficiency in the plastidial glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPCp) leads to male sterility in Arabidopsis (Arabidopsis thaliana). Pollen from homozygous gapcp double mutant plants (gapcp1gapcp2) displayed shrunken and collapsed forms and were unable to germinate when cultured in vitro. The pollen alterations observed in gapcp1gapcp2 were attributed to a disorganized tapetum layer. Accordingly, the expression of several of the genes involved in tapetum development was down-regulated in gapcp1gapcp2. The fertility of gapcp1gapcp2 was rescued by transforming this mutant with a construct carrying the GAPCp1 cDNA under the control of its native promoter (pGAPCp1::GAPCp1c). However, the GAPCp1 or GAPCp2 cDNA under the control of the 35S promoter (p35S::GAPCp), which is poorly expressed in the tapetum, did not complement the mutant fertility. Mutant GAPCp isoforms deficient in the catalytic activity of the enzyme were unable to complement the sterile phenotype of gapcp1gapcp2, thus confirming that both the expression and catalytic activity of GAPCp in anthers are necessary for mature pollen development. A metabolomic study in flower buds indicated that the most important difference between the sterile (gapcp1gapcp2, gapcp1gapcp2-p35S::GAPCp) and the fertile (wild-type plants, gapcp1gapcp2-pGAPCp1::GAPCp1c) lines was the increase in the signaling molecule trehalose. This work corroborates the importance of plastidial glycolysis in plant metabolism and provides evidence for the crucial role of GAPCps in pollen development. It additionally brings new insights into the complex interactions between metabolism and development. PMID:20107025

  10. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, April--June, 1995

    SciTech Connect

    Curtis, C.W.

    1996-01-01

    The goal of this research is to develop a methodology for analyzing the reactivity of cyclic alkenes in situ in a high temperature and high pressure infrared cell. Cyclic alkenes are highly reactive donors of hydrogen to coal in low severity coal liquefaction.

  11. Aspects Concerning "Play" for the Promotion of Preschool Children with Severe Speech- and Language Impairment

    ERIC Educational Resources Information Center

    Ullrich, Dieter; Marten, Magret

    2016-01-01

    Speech and language abilities are of great importance for later participation in economical and social life. In Lower Saxony/Germany, severely speech-/language (SL) impaired children may obtain special treatment during preschool in a so-called "Sprachheilkindergarten" (STK), a kindergarten focusing on early SL therapy. Purpose: This work…

  12. Does extreme environmental severity promote plant facilitation? An experimental field test in a subtropical coastal dune.

    PubMed

    Castanho, Camila T; Oliveira, Alexandre A; Prado, Paulo Inácio K L

    2015-07-01

    The stress gradient hypothesis (SGH) postulates how the balance between plant competition and facilitation shifts along environmental gradients. Early formulations of the SGH predicted that facilitation should increase monotonically with stress. However, a recent theoretical refinement of the SGH postulates stronger facilitation under moderate stress, followed by a decreasing role of facilitation in the most severe environments. We conducted field experiments along the most severe part of a coastal dune gradient in southeast Brazil to test the effect of stress on the intensity and importance of the net interactions between two tree species. First, we compared the performance of distinct life stages of Ternstroemia brasiliensis in the presence and absence of Guapira opposita adults along a beach-to-inland gradient, a gradient of environmental severity. To test the effect of one stress factor in particular, we also manipulated water availability, a limiting resource due to the sandy soils. At the most severe part of the coastal gradient (i.e. closest to the seashore), both intensity and importance of the interaction between G. opposita and T. brasiliensis were negatively related to stress, with a pattern consistent across distinct life stages of the target species. However, the sign of the net interaction depended on the life stage of the target species. Our results provide empirical evidence that the role of facilitation tends to wane, leading to neutral or even negative net interactions between species as stress reaches its maximum, as predicted by the recent refinements of the SGH.

  13. Promoting Listening Reading Comprehension for Nonverbal English Language Learners Who Have a Severe Intellectual Delay

    ERIC Educational Resources Information Center

    Kemper, Talya

    2012-01-01

    This study used an alternating treatment design to examine the use of a listening reading comprehension intervention package. This package was implemented in English as well as bilingually (on alternating days). This package was applied to four participants who were English Language Learners, were diagnosed with a severe intellectual delay, and…

  14. Pollen tube growth and guidance: roles of small, secreted proteins

    PubMed Central

    Chae, Keun; Lord, Elizabeth M.

    2011-01-01

    Background Pollination is a crucial step in angiosperm (flowering plant) reproduction. Highly orchestrated pollen–pistil interactions and signalling events enable plant species to avoid inbreeding and outcrossing as a species-specific barrier. In compatible pollination, pollen tubes carrying two sperm cells grow through the pistil transmitting tract and are precisely guided to the ovules, discharging the sperm cells to the embryo sac for fertilization. Scope In Lilium longiflorum pollination, growing pollen tubes utilize two critical mechanisms, adhesion and chemotropism, for directional growth to the ovules. Among several molecular factors discovered in the past decade, two small, secreted cysteine-rich proteins have been shown to play major roles in pollen tube adhesion and reorientation bioassays: stigma/style cysteine-rich adhesin (SCA, approx. 9·3 kDa) and chemocyanin (approx. 9·8 kDa). SCA, a lipid transfer protein (LTP) secreted from the stylar transmitting tract epidermis, functions in lily pollen tube tip growth as well as in forming the adhesive pectin matrix at the growing pollen tube wall back from the tip. Lily chemocyanin is a plantacyanin family member and acts as a directional cue for reorienting pollen tubes. Recent consecutive studies revealed that Arabidopsis thaliana homologues for SCA and chemocyanin play pivotal roles in tip polarity and directionality of pollen tube growth, respectively. This review outlines the biological roles of various secreted proteins in angiosperm pollination, focusing on plant LTPs and chemocyanin. PMID:21307038

  15. 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.

  16. Grass Pollen Allergens

    PubMed Central

    Augustin, Rosa

    1959-01-01

    Heat and pH stability studies and experiments with organic solvents show that the A-antigens discussed in the preceding paper (Augustin, 1959c) are much more labile than the I- (`inner ring') antigens. Breakdown products and/or aggregates are produced which no longer precipitate with antisera to the original extracts, but act as inhibitors. Solutions of pollen allergens, on the other hand, are found to withstand even autoclaving for 15 min. at 20 atm. and vigorous boiling over the naked flame of a bunsen burner. None of the carbohydrates tested has a demonstrable effect on skin reactivity which is, however, destroyed by crystalline pepsin, crystalline trypsin, a crystalline mould protease and a tissue protease (a partially purified extract from rabbit spleen). It follows that the bulk of the allergens—if not all—are proteins. The relation of skin reactivity, immuno-electrophoretic patterns, carbohydrate and protein reactions to the selective destruction of the pollen antigens is investigated. Pollen components prove to have a somewhat wider range of electrophoretic mobilities than serum proteins and are probably as complicated a mixture. The most and least highly negatively charged components are without skin reactivity in allergic subjects. The skin reactive allergens appear to have the mobilities of α- and β-globulins. Not all the hay fever subjects react equally to all the components, and Cocksfoot and Timothy activity patterns vary in different subjects. ImagesFIG. 5 PMID:13795119

  17. Interleukin-17 Could Promote Breast Cancer Progression at Several Stages of the Disease

    PubMed Central

    Welte, Thomas; Zhang, Xiang H.-F.

    2015-01-01

    Metastatic disease accounts for more than 90% of deaths from breast cancer. Yet the factors that trigger metastasis, often years after primary tumor removal, are not understood well. Recently the proinflammatory cytokine interleukin- (IL-) 17 family has been associated with poor prognosis in breast cancer. Here we review current literature on the pathogenic mechanisms driven by IL-17 during breast cancer progression and connect these findings to metastasis. These include (1) direct effects of IL-17 on tumor cells promoting tumor cell survival and invasiveness, (2) regulation of tumor angiogenesis, and (3) interaction with myeloid derived suppressor cells (MDSCs) to inhibit antitumor immune response and collaborate at the distant metastatic site. Furthermore, IL-17 might also be a culprit in bone destruction caused by late stage bone metastasis. Interestingly, in addition to these potential prometastasis functions, there is also evidence for an opposite, antitumor role of IL-17 during cancer therapies. We hypothesize that these contradictory roles may be due to chronic, imbalanced versus acute transient nature of the immune reactions, as well as differences in the cells that interact with IL-17+ cells under different circumstances. PMID:26783383

  18. Assistive technology for promoting choice behaviors in three children with cerebral palsy and severe communication impairments.

    PubMed

    Stasolla, Fabrizio; Caffò, Alessandro O; Picucci, Luciana; Bosco, Andrea

    2013-09-01

    A technology-based program to promote independent choice behaviors by three children with cerebral palsy and multiple disabilities was assessed. The program was based on learning principles and assistive technology (i.e., customized input devices/sensors, personal computers, screening of preferred stimuli according to a binomial criterion). The first purpose of the present study was to provide the participants with a new set-up of assistive technology and to allow them to choose among three categories (i.e., food, beverage and leisure), and to request a specific item out of four in each category, adopting a procedure that minimized (according to a conditional probability criterion) unintentional choices. The second aim of the study was to carry out the effects of the program on detectable mood signs (i.e., happiness index). The study was conducted according to an ABAB sequence with a subsequent post intervention check for each participant. The results showed an increase of engagement and of the happiness index during intervention phases. Psychological as well as educational implications were discussed.

  19. Combined promoter haplotypes of the IL10R genes are associated with protection against severe malaria in Gabonese children.

    PubMed

    Velavan, T P; Büyükyazici, Birgül; Kremsner, Peter G; Kun, Jürgen F J

    2012-02-01

    The critical barrier in control of infections remains the failure of the immune system to clear parasites despite antigen recognition. We examined and validated possible association of regulatory immune gene polymorphisms in a cohort of children with mild and severe malaria. We focussed on two precursors of the Interleukin 10 Receptor (IL10R) gene namely the IL10R alpha and IL10R beta that play a fundamental role in initiation of signal transduction. Initial screening across 40 Gabonese adult individuals revealed two promoter variants for the IL10R alpha and three for the IL10R beta precursor, respectively. Validation of these variants for their allelic gene expression by transient transfection assays exhibited an altered expression in rs56356146 and rs7925112 of the IL10R alpha (P < 0.5); rs8178435 and rs999788 in the IL10R beta constructs (P < 0.0001), respectively. We further investigated the functional role of those SNP variants exhibiting altered expression in a cohort of children with mild and severe malaria. We genotyped 145 children with mild and 185 children with severe malaria for IL10R alpha; for IL10R beta, 102 children with mild and 101 children with severe malaria. We found that none of the SNP variants had any significant association neither in children with mild or severe malaria. The haplotype -185/-116 of IL10R alpha (TT) in combination with the haplotype -754/-750 of IL10R beta (AC) contributed towards mild malaria in comparison to severe malaria [TT + AC odds ratio of 0.73 (95% CI 0.56-0.94) P = 0.01]. This study may provide a better understanding on the role of IL10R promoter allelic variants contribution to a protective effect on the development of severe malaria.

  20. 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

  1. [Allergy, pollen and the environment].

    PubMed

    Terán, Luis Manuel; Haselbarth-López, Michelle Marie Margarete; Quiroz-García, David Leonor

    2009-01-01

    Allergic respiratory diseases such asthma and allergic rhinitis are a health problem throughout the world. In Mexico City, pollens are an important cause of allergic respiratory disease. Both, the geographic location- and the vegetation surrounding this City favor the distribution of pollens leading to respiratory disease in susceptible patients. Aerobiological studies have shown that during the mild dry winter there is a large amount of pollens in the environment with tree pollens being the most abundant of all. The most frequent tree pollens found in Mexico City include Fraxinus, Cupressaseae, Alnus, Liquidambar, Callistemon, Pinus, and Casuarina. In contrast, grass- and weed pollens predominate during the summer (rainy season) including Compositae, Cheno-Am, Ambrosia and Gramineae. An additional health problem in Mexico City is the air pollution that exerts a direct effect on individuals. This in turn increases pollen allergenicity by disrupting them leading to the release of their particles which then penetrate the human airways causing disease. Thus, the polluted environment along with global warming which is also known to increase pollen quantities by inducing longer pollen seasons may represent a health risk to Mexico City inhabitants.

  2. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, October--December 1993

    SciTech Connect

    Curtis, C.W.

    1993-12-31

    Acid pretreatment removes those alkaline metal and alkaline earth cations which inhibit coal reactivity and hydrogen transfer. Shams et al. (1992) found that through this pretreatment a large portion of the calcium present in coal was removed. Hydrochloric acid was used in that study, but sulfurous acid, if similar results are achieved, would be a much more suitable acid for processing. Another pretreatment method to remove these cations is one using ammonium acetate (Hengel and Walker, 1984). This study will evaluate the effect of combining these two principles, acid pretreatment of coal and rapid hydrogen transfer, for improving hydrogen transfer under low severity conditions. The acid pretreatment methods showed more success with low rank, subbituminous coals and lignite. Therefore, Wyodak subbituminous coal (WY) from the Argonne Premium Sample Bank and Black Thunder subbituminous coal (BT) from Amoco are being used and compared in this study. The cyclic olefin, 1,4,5,8-tetrahydronaphthalene (isotetralin, ISO) and its analogue, 1,2,3,4-tetrahydronaphthalene (tetralin, TET), will also be used and compared in this study. The efficacy of the two-ringed ISO can then be compared with the previously studied three-ringed HHA. Dr. James Hool, Professor of Industrial Engineering and an expert in statistics and experimental design, assisted in formulating the four-dimensional experimental matrix found in Figure 1. It is through this parametric analysis that the effect of each factor in this pretreatment and low severity liquefaction system will be determined.

  3. Association between Interleukin-6 Promoter Polymorphism (-174 G/C), Serum Interleukin-6 Levels and Mortality in Severe Septic Patients

    PubMed Central

    Lorente, Leonardo; Martín, María M.; Pérez-Cejas, Antonia; Barrios, Ysamar; Solé-Violán, Jordi; Ferreres, José; Labarta, Lorenzo; Díaz, César; Jiménez, Alejandro

    2016-01-01

    The association between interleukin (IL)-6 promoter polymorphism (-174 G/C), circulating IL-6 levels and mortality in septic patients has scarcely been addressed, and then only in studies of small sample size, and a direct association among them has not been previously reported. Therefore, the purpose of our study was to determine whether this association exists. An observational, prospective and multicenter study including severe septic patients was undertaken and serum IL-6 levels at severe sepsis diagnosis and IL-6 promoter polymorphism (-174 G/C) were determined. The end-point of the study was 30-day mortality. The study included 263 patients with the following genotypes of IL-6 promoter polymorphism (-174 G/C): 123 (46.8%) GG, 110 (41.8%) GC and 30 (11.4%) CC. CC homozygous patients showed lower sepsis-related organ failure assessment (SOFA) score, serum IL-6 levels and mortality at 30 days compared to those with other genotypes (GC or GG). On regression analysis, CC homozygous patients showed lower 30-day mortality than those with genotype GG (odds ratio = 0.21; 95% CI = 0.053−0.838; p = 0.03) or GC (hazard ratio = 0.28; 95% CI = 0.074−1.037; p = 0.06). The most important results of our study were that CC might be a favorable genotype in septic patients showing lower serum IL-6 levels and lower risk of death within 30 days. PMID:27834822

  4. Molecular Ice Nucleation Activity of Birch Pollen

    NASA Astrophysics Data System (ADS)

    Felgitsch, Laura; Bichler, Magdalena; Häusler, Thomas; Weiss, Victor U.; Marchetti-Deschmann, Martina; Allmaier, Günter; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation plays a major part in ecosystem and climate. Due to the triggering of ice cloud formation it influences the radiation balance of the earth, but also on the ground it can be found to be important in many processes of nature. So far the process of heterogeneous ice nucleation is not fully understood and many questions remain to be answered. Biological ice nucleation is hereby from great interest, because it shows the highest freezing temperatures. Several bacteria and fungi act as ice nuclei. A famous example is Pseudomonas syringae, a bacterium in commercial use (Snomax®), which increases the freezing from homogeneous freezing temperatures of approx. -40° C (for small volumes as in cloud droplets) to temperatures up to -2° C. In 2001 it was found that birch pollen can trigger ice nucleation (Diehl et al. 2001; Diehl et al. 2002). For a long time it was believed that this is due to macroscopic features of the pollen surface. Recent findings of Bernhard Pummer (2012) show a different picture. The ice nuclei are not attached on the pollen surface directly, but on surface material which can be easily washed off. This shows that not only the surface morphology, but also specific molecules or molecular structures are responsible for the ice nucleation activity of birch pollen. With various analytic methods we work on elucidating the structure of these molecules as well as the mechanism with which they trigger ice nucleation. To solve this we use various instrumental analytic techniques like Nuclear Magnetic Resonance spectroscopy (NMR), Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS), and Gas-phase Electrophoretic Mobility Molecular Analysis (GEMMA). Also standard techniques like various chromatographic separation techniques and solvent extraction are in use. We state here that this feature might be due to the aggregation of small molecules, with agglomerates showing a specific surface structure. Our results

  5. 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

  6. Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands).

    PubMed

    Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia

    2011-01-01

    The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees (Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs (Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea

  7. Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands)

    NASA Astrophysics Data System (ADS)

    Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia

    2011-01-01

    The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees ( Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs ( Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea

  8. Low severity coal liquefaction promoted by cyclic olefins. Quarterly technical progress report, April--June 1996

    SciTech Connect

    Curtis, C.W.

    1997-12-31

    The goal of this research is to develop a methodology for analyzing the reactivity of cyclic olefins in situ in a high temperature and high pressure infrared cell. Cyclic olefins, such as 1,4,5,8-tetrahydronaphthalene (isotetralin) and 1,4,5,8,9,10-hexahydroanthracene (HHA), are highly reactive donor compounds that readily donate their hydrogen to coal and model acceptors when heated to temperatures of 200{degrees}C and above. These donors are active donors in the low severity liquefaction of coal at 350{degrees}C as shown in the research performed in this project. The infrared studies are being performed in a high temperature infrared cell that was obtained from AABSPEC. Modifications to that cell have been made and have been reported in previous progress reports.

  9. Elaborate spatial patterning of cell-wall PME and PMEI at the pollen tube tip involves PMEI endocytosis, and reflects the distribution of esterified and de-esterified pectins.

    PubMed

    Röckel, Nina; Wolf, Sebastian; Kost, Benedikt; Rausch, Thomas; Greiner, Steffen

    2008-01-01

    In dicots, pectins are the major structural determinant of the cell wall at the pollen tube tip. Recently, immunological studies revealed that esterified pectins are prevalent at the apex of growing pollen tubes, where the cell wall needs to be expandable. In contrast, lateral regions of the cell wall contain mostly de-esterified pectins, which can be cross-linked to rigid gels by Ca(2+) ions. In pollen tubes, several pectin methylesterases (PMEs), enzymes that de-esterify pectins, are co-expressed with different PME inhibitors (PMEIs). This raises the possibility that interactions between PMEs and PMEIs play a key role in the regulation of cell-wall stability at the pollen tube tip. Our data establish that the PME isoform AtPPME1 (At1g69940) and the PMEI isoform AtPMEI2 (At3g17220), which are both specifically expressed in Arabidopsis pollen, physically interact, and that AtPMEI2 inactivates AtPPME1 in vitro. Furthermore, transient expression in tobacco pollen tubes revealed a growth-promoting activity of AtPMEI2, and a growth-inhibiting effect of AtPPME1. Interestingly, AtPPME1:YFP accumulated to similar levels throughout the cell wall of tobacco pollen tubes, including the tip region, whereas AtPMEI2:YFP was exclusively detected at the apex. In contrast to AtPPME1, AtPMEI2 localized to Brefeldin A-induced compartments, and was found in FYVE-induced endosomal aggregates. Our data strongly suggest that the polarized accumulation of PMEI isoforms at the pollen tube apex, which depends at least in part on local PMEI endocytosis at the flanks of the tip, regulates cell-wall stability by locally inhibiting PME activity.

  10. Connective Tissue Growth Factor Promotes Pulmonary Epithelial Cell Senescence and Is Associated with COPD Severity.

    PubMed

    Jang, Jun-Ho; Chand, Hitendra S; Bruse, Shannon; Doyle-Eisele, Melanie; Royer, Christopher; McDonald, Jacob; Qualls, Clifford; Klingelhutz, Aloysius J; Lin, Yong; Mallampalli, Rama; Tesfaigzi, Yohannes; Nyunoya, Toru

    2017-04-01

    The purpose of this study was to determine whether expression of connective tissue growth factor (CTGF) protein in chronic obstructive pulmonary disease (COPD) is consistent in humans and animal models of COPD and to investigate the role of this protein in lung epithelial cells. CTGF in lung epithelial cells of ex-smokers with COPD was compared with ex-smokers without COPD by immunofluorescence. A total of twenty C57Bl/6 mice and sixteen non-human primates (NHPs) were exposed to cigarette smoke (CS) for 4 weeks. Ten mice of these CS-exposed mice and eight of the CS-exposed NHPs were infected with H3N2 influenza A virus (IAV), while the remaining ten mice and eight NHPs were mock-infected with vehicle as control. Both mRNA and protein expression of CTGF in lung epithelial cells of mice and NHPs were determined. The effects of CTGF overexpression on cell proliferation, p16 protein, and senescence-associated β-galactosidase (SA-β-gal) activity were examined in cultured human bronchial epithelial cells (HBECs). In humans, CTGF expression increased with increasing COPD severity. We found that protein expression of CTGF was upregulated in lung epithelial cells in both mice and NHPs exposed to CS and infected with IAV compared to those exposed to CS only. When overexpressed in HBECs, CTGF accelerated cellular senescence accompanied by p16 accumulation. Both CTGF and p16 protein expression in lung epithelia are positively associated with the severity of COPD in ex-smokers. These findings show that CTGF is consistently expressed in epithelial cells of COPD lungs. By accelerating lung epithelial senescence, CTGF may block regeneration relative to epithelial cell loss and lead to emphysema.

  11. LIM kinase/cofilin dysregulation promotes macrothrombocytopenia in severe von Willebrand disease-type 2B

    PubMed Central

    Poirault-Chassac, Sonia; Adam, Frédéric; Muczynski, Vincent; Aymé, Gabriel; Casari, Caterina; Bordet, Jean-Claude; Soukaseum, Christelle; Rothschild, Chantal; Proulle, Valérie; Pietrzyk-Nivau, Audrey; Berrou, Eliane; Christophe, Olivier D.; Rosa, Jean-Philippe; Lenting, Peter J.; Bryckaert, Marijke; Baruch, Dominique

    2016-01-01

    von Willebrand disease type 2B (VWD-type 2B) is characterized by gain-of-function mutations of von Willebrand factor (vWF) that enhance its binding to platelet glycoprotein Ibα and alter the protein’s multimeric structure. Patients with VWD-type 2B display variable extents of bleeding associated with macrothrombocytopenia and sometimes with thrombopathy. Here, we addressed the molecular mechanism underlying the severe macrothrombocytopenia both in a knockin murine model for VWD-type 2B by introducing the p.V1316M mutation in the murine Vwf gene and in a patient bearing this mutation. We provide evidence of a profound defect in megakaryocyte (MK) function since: (a) the extent of proplatelet formation was drastically decreased in 2B MKs, with thick proplatelet extensions and large swellings; and (b) 2B MKs presented actin disorganization that was controlled by upregulation of the RhoA/LIM kinase (LIMK)/cofilin pathway. In vitro and in vivo inhibition of the LIMK/cofilin signaling pathway rescued actin turnover and restored normal proplatelet formation, platelet count, and platelet size. These data indicate, to our knowledge for the first time, that the severe macrothrombocytopenia in VWD-type 2B p.V1316M is due to an MK dysfunction that originates from a constitutive activation of the RhoA/LIMK/cofilin pathway and actin disorganization. This suggests a potentially new function of vWF during platelet formation that involves regulation of actin dynamics. PMID:27734030

  12. Bacterial Respiratory Tract Infections are Promoted by Systemic Hyperglycemia after Severe Burn Injury in Pediatric Patients

    PubMed Central

    Kraft, Robert; Herndon, David N; Mlcak, Ronald P; Finnerty, Celeste C; Cox, Robert A; Williams, Felicia N; Jeschke, Marc G

    2014-01-01

    Background Burn injuries are associated with hyperglycemia leading to increased incidence of infections with pneumonia being one of the most prominent and adverse complication. Recently, various studies in critically ill patients indicated that increased pulmonary glucose levels with airway/blood glucose threshold over 150 mg/dl lead to an overwhelming growth of bacteria in the broncho-pulmonary system, subsequently resulting in an increased risk of pulmonary infections. The aim of the present study was to determine whether a similar cutoff value exists for severely burned pediatric patients. Methods One-hundred six severely burned pediatric patients were enrolled in the study. Patients were divided in two groups: high (H) defined as daily average glucose levels >75% of LOS >150 mg/dl), and low (L) with daily average glucose levels >75% of the LOS <150 mg/dl). Incidences of pneumonia, atelectasis, and acute respiratory distress syndrome (ARDS) were assessed. Incidence of infections, sepsis, and respiratory parameters were recorded. Blood was analyzed for glucose and insulin levels. Statistical analysis was performed using Student’s t-test and chi-square test. Significance was set at p<0.05. Results Patient groups were similar in demographics and injury characteristics. Pneumonia in patients on the mechanical ventilation (L: 21% H: 32%) and off mechanical ventilation (L: 5% H: 15%), as well as ARDS were significantly higher in the high group (L: 3% H: 19%), p<0.05, while atelectasis was not different. Patients in the high group required significantly longer ventilation compared to low patients (p<0.05). Furthermore, incidence of infection and sepsis were significantly higher in the high group, p<0.05. Conclusion Our results indicate that systemic glucose levels over 150 mg/dl are associated with a higher incidence of pneumonia confirming the previous studies in critically ill patients. PMID:24074819

  13. Asteraceae Pollen Provisions Protect Osmia Mason Bees (Hymenoptera: Megachilidae) from Brood Parasitism.

    PubMed

    Spear, Dakota M; Silverman, Sarah; Forrest, Jessica R K

    2016-06-01

    Many specialist herbivores eat foods that are apparently low quality. The compensatory benefits of a poor diet may include protection from natural enemies. Several bee lineages specialize on pollen of the plant family Asteraceae, which is known to be a poor-quality food. Here we tested the hypothesis that specialization on Asteraceae pollen protects bees from parasitism. We compared rates of brood parasitism by Sapyga wasps on Asteraceae-specialist, Fabeae-specialist, and other species of Osmia bees in the field over several years and sites and found that Asteraceae-specialist species were parasitized significantly less frequently than other species. We then tested the effect of Asteraceae pollen on parasites by raising Sapyga larvae on three pollen mixtures: Asteraceae, Fabeae, and generalist (a mix of primarily non-Asteraceae pollens). Survival of parasite larvae was significantly reduced on Asteraceae provisions. Our results suggest that specialization on low-quality pollen may evolve because it helps protect bees from natural enemies.

  14. Functional conservation of MIKC*-Type MADS box genes in Arabidopsis and rice pollen maturation.

    PubMed

    Liu, Yuan; Cui, Shaojie; Wu, Feng; Yan, Shuo; Lin, Xuelei; Du, Xiaoqiu; Chong, Kang; Schilling, Susanne; Theißen, Günter; Meng, Zheng

    2013-04-01

    There are two groups of MADS intervening keratin-like and C-terminal (MIKC)-type MADS box genes, MIKC(C) type and MIKC* type. In seed plants, the MIKC(C) type shows considerable diversity, but the MIKC* type has only two subgroups, P- and S-clade, which show conserved expression in the gametophyte. To examine the functional conservation of MIKC*-type genes, we characterized all three rice (Oryza sativa) MIKC*-type genes. All three genes are specifically expressed late in pollen development. The single knockdown or knockout lines, respectively, of the S-clade MADS62 and MADS63 did not show a mutant phenotype, but lines in which both S-clade genes were affected showed severe defects in pollen maturation and germination, as did knockdown lines of MADS68, the only P-clade gene in rice. The rice MIKC*-type proteins form strong heterodimeric complexes solely with partners from the other subclade; these complexes specifically bind to N10-type C-A-rich-G-boxes in vitro and regulate downstream gene expression by binding to N10-type promoter motifs. The rice MIKC* genes have a much lower degree of functional redundancy than the Arabidopsis thaliana MIKC* genes. Nevertheless, our data indicate that the function of heterodimeric MIKC*-type protein complexes in pollen development has been conserved since the divergence of monocots and eudicots, roughly 150 million years ago.

  15. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1996

    SciTech Connect

    Curtis, C.W.

    1996-05-01

    The goal of this research is to develop a methodology for analyzing the reactivity of cyclic olefins in situ in a high temperature and high pressure infrared cell. Cyclic olefins, such as 1,4,5,8-tetrahydronaphthalene (isotetralin) and 1,4,5,8,9, 10-hexahydroanthracene (HHA), are highly reactive donor compounds that readily donate their hydrogen to coal and model acceptors when heated to temperatures of 200 C and above. These donors are active donors in the low severity liquefaction of coal at 350 C as shown in the research performed in this project. The infrared studies are being performed in a high temperature infrared cell that was obtained from AABSPEC. Modifications to that cell have been made and have been reported in previous progress reports. Previous studies had shown that naphthalene was quite stable at temperatures up to 230 C, but a more definitive stability study was conducted to confirm this observation. Stability studies also confirmed the non-reactivity of decaline and tetralin at elevated temperatures up to 230 C. High temperature FTIR analysis of isotetralin showed that isotetralin reacted at temperatures of 100 C and higher to 230 C. This quarter, the reaction product spectrum was analyzed to determine the primary product.

  16. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, July--September 1996

    SciTech Connect

    Curtis, C.W.

    1997-05-01

    The goal of this research is to develop a methodology for analyzing the reactivity of cyclic olefins in situ in a high temperature and high pressure infrared cell. Cyclic olefins, such as 1,4,5,8-tetrahydronaphthalene (isotetralin) and 1,4,5,8,9,10-hexahydroanthracene (HHA), are highly reactive donor compounds that readily donate their hydrogen to coal and model acceptors when heated to temperatures of 200 C and above. These donors are active donors in the low severity liquefaction of coal at 350 C as shown in the research performed in this project. The infrared studies are being performed in a high temperature infrared cell that was obtained from AABSPEC. Modifications to that cell have been made and have been reported in previous progress reports. The useful temperature range of the high temperature infrared cell has been extended to 230 C through the use of a high-boiling perfluorocarbon solvent. High temperature infrared analyses have been performed using isotetralin, tetralin, naphthalene, 1,4-dihydronaphthalene and 1,2-dihydronaphthalene. Stability studies have shown that naphthalene was quite stable at temperatures up to 230 C, as were tetralin, decalin and 1,4-dihydronaphthalene. High temperature FTIR analysis of isotetralin and 1,2-dihydronaphthalene reacted at elevated temperatures forming tetralin and 1,4-dihydronaphthalene, respectively. The results of stability studies are reported.

  17. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1995

    SciTech Connect

    Curtis, C.W.

    1995-09-01

    The research performed during the quarter, January to March 1995, focused on two areas. The first area involved completing the writing of a manuscript based on research performed on this project concerning the mild acidic pretreatment of low rank coals and their liquefaction behavior in the presence of hydrogen donors with different reactivities. The manuscript was submitted for review to Energy and Fuels. A second manuscript was begun which discussed the research involving the hydrogen donation at low severity condition by hexahydroanthracene. The catalytic enhancement of hydrogen transfer by cyclic olefins was also examined. The data from this research was reexamined; it was decided that before writing the paper than the data should be reanalyzed. Therefore, this quarter was spent taking the raw data and reanalyzing the data, putting the solvent fractionation data on a solvent-free basis. The recalculated data and the calculational method is given as Part 1 in this report. The second area that was worked on this quarter was the high temperature infrared analysis of cyclic olefins. The work is ongoing and is currently involving a considerable amount of equipment and technique development. Part 2 is the discussion on the high temperature infrared analysis of cyclic olefins.

  18. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1994

    SciTech Connect

    Curtis, C.W.

    1994-06-01

    Previous research has suggested that using a more effective hydrogen donor solvent in the low severity coal liquefaction reaction improves coal conversion. In order to understand the results of these methods, both independently and combined, a factorial experiment was designed. Pretreating coal with hydrochloric and sulfurous acid solutions in both water and methanol is compared with pretreating coal using only methanol and with no pretreatment. The effects of these pretreatments on coal liquefaction behavior are contrasted with the ammonium acetate pretreatment. Within each of these, individual reactions are performed with the hydroaromatic 1,2,3,4-tetrahydronaphthalene (tetralin, TET) and the cyclic olefin 1,4,5,8-tetrahydronaphthalene (isotetralin, ISO). The final aspect of the factorial experiment is the comparison of Wyodak subbituminous coal (WY) from the Argonne Premium Sample Bank and Black Thunder subbituminous coal (BT) provided by Amoco. Half of the reactions in the matrix have now been completed. In all but one case, Black Thunder-HCl/H{sub 2}O, the ISO proved to be more reactive than TET. After the other four reactions using this combination are complete, the average conversion may be greater with the cyclic olefin. The second part of this paper describes the current and future work with Fourier transform infrared spectroscopy. The objective of this work is to determine the kinetics of reaction of isotetralin at high temperatures and pressures. This quarter combinations of three products typically produced from isotetralin were used in spectral subtraction.

  19. Pollen genetic markers for detection of mutagens in the environment

    SciTech Connect

    Nilan, R.A.; Rosichan, J.L.; Arenaz, P.; Hodgdon, A.L.; Kleinhofs, A.

    1980-01-01

    To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. To be useful for the development of mutagen detection systems proteins should be: (1) activity stainable or immunologically identifiable in the pollen, (2) the products of one to three loci; and (3) gametophytic and nuclear in origin. Several proteins, including alcohol dehydrogenase in maize, which meet these criteria are discussed. The waxy locus in barley and maize which controls starch deposition for pollen screening and mutant detection. Thirty waxy mutant lines, induced by sodium azide and gamma-rays are characterized for spontaneous and induced reversion frequencies, allelism, karyotype, amylose content, and UDPglucose glucosyltransferase (waxy gene product) activity. Twelve mutant alleles are being mapped by recombinant frequencies.

  20. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1993

    SciTech Connect

    Curtis, C.W.

    1993-07-01

    The combination of some of these methods could further improve low severity conversion. It seems logical that a combination of a proven pretreatment technique with a good dissolution catalyst or a good hydrogen donor would increase reactivity. The importance of surface chemistry with yield and nature of reactions shown in early research indicates the physical importance of pretreatment. Swelling of the coal with an organic solvent improves the contact. This good contact is also important to slowing retrogressive reactions. The best conversions come when the initial products of liquefaction are preserved. In addition to the physical importance of pretreatment, there is a chemical advantage. Shams saw not only the effect of minimization of organic oxygen coupling reactions, but with his process there also seemed to be a demineralization. The minerals removed the catalysts for retrogressive reactions. The chemistry of liquefaction is still not well understood. Stansberry`s attempt to determine whether catalysts liberate species or just further decomposition was largely inconclusive. There was improvement in conversion so the catalysts seemingly assisted in bond breakage. These good catalytic effects were also seen in the work involving coprocessing. The most compelling factor in each of these procedures, is the ability of the coal to receive the hydrogen that it needs to be liquefied. Bedell and Curtis (1991) found that cyclic olefins gave their hydrogen up much more readily than did hydroaromatics. The coal conversion was a significantly improved. The combination of retrogressive reaction suppression and good hydrogen donability should provide for good coal conversion. It was this reasoning that influenced the decision to investigate a combination of the HCl/methanol pretreatment and the usage of cyclic olefins as hydrogen donors. The increased reactivity of the pretreated coal should enhance the effect of the hydrogen donability of the cyclic olefins.

  1. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, October 1995--December 1995

    SciTech Connect

    Curtis, C.W.

    1995-12-31

    The goal of this research is to develop a methodology for analyzing the reactivity of cyclic olefins in situ in a high temperature and high pressure infrared cell. Cyclic olefins, such as 1,4,5,8-tetrahydronaphthalene (isotetralin) and 1,4,5,8,9,10-hexahydroanthracene (HHA), are highly reactive donor compounds that readily donate their hydrogen to coal and model acceptors when heated to temperatures of 200{degrees}C and above. These donors are active donors in the low severity liquefaction of coal at 350{degrees}C as shown in the research performed in this project. The infrared studies are being performed in a high temperature infrared cell that was obtained from AABSPEC. Modifications to that cell have been made and have been reported in previous progress reports. During this last quarter the useful temperature range of the high temperature infrared cell was extended to 230{degrees}C through the use of a high-boiling perfluorocarbon solvent. The solvent used was an Air Products and Chemicals Company proprietary product trade named Multifluor APF-240. Solubilities of aromatics and cyclic olefins were quite low in APF-240, usually less than 0.1 wt% at room temperature, but were found to be a strong function of temperature, increasing markedly when the mixtures were heated to 65{degrees}C. Spectra have been obtained of n-hexadecane and naphthalene at temperatures of 65, 100, 125, 150, 175, 200 and 230{degrees}C. This demonstration of the safe operation of the high temperature IR cell and the acquisition of spectra at elevated temperatures paves the way for kinetic studies of the hydrogen donor capability of isotetralin. A perfluoroether has been obtained from Dupont which should extend the useful temperature range of the high temperature IR cell to 350{degrees}C.

  2. SEC8, a subunit of the putative Arabidopsis exocyst complex, facilitates pollen germination and competitive pollen tube growth.

    PubMed

    Cole, Rex A; Synek, Lukás; Zarsky, Viktor; Fowler, John E

    2005-08-01

    The exocyst, a complex of eight proteins, contributes to the morphogenesis of polarized cells in a broad range of eukaryotes. In these organisms, the exocyst appears to facilitate vesicle docking at the plasma membrane during exocytosis. Although we had identified orthologs for each of the eight exocyst components in Arabidopsis (Arabidopsis thaliana), no function has been demonstrated for any of them in plants. The gene encoding one exocyst component ortholog, AtSEC8, is expressed in pollen and vegetative tissues of Arabidopsis. Genetic studies utilizing an allelic series of six independent T-DNA mutations reveal a role for SEC8 in male gametophyte function. Three T-DNA insertions in SEC8 cause an absolute, male-specific transmission defect that can be complemented by expression of SEC8 from the LAT52 pollen promoter. Microscopic analysis shows no obvious abnormalities in the microgametogenesis of the SEC8 mutants, and the mutant pollen grains appear to respond to the signals that initiate germination. However, in vivo assays indicate that these mutant pollen grains are unable to germinate a pollen tube. The other three T-DNA insertions are associated with a partial transmission defect, such that the mutant allele is transmitted through the pollen at a reduced frequency. The partial transmission defect is only evident when mutant gametophytes must compete with wild-type gametophytes, and arises in part from a reduced pollen tube growth rate. These data support the hypothesis that one function of the putative plant exocyst is to facilitate the initiation and maintenance of the polarized growth of pollen tubes.

  3. SEC8, a Subunit of the Putative Arabidopsis Exocyst Complex, Facilitates Pollen Germination and Competitive Pollen Tube Growth1[w

    PubMed Central

    Cole, Rex A.; Synek, Lukás; Zarsky, Viktor; Fowler, John E.

    2005-01-01

    The exocyst, a complex of eight proteins, contributes to the morphogenesis of polarized cells in a broad range of eukaryotes. In these organisms, the exocyst appears to facilitate vesicle docking at the plasma membrane during exocytosis. Although we had identified orthologs for each of the eight exocyst components in Arabidopsis (Arabidopsis thaliana), no function has been demonstrated for any of them in plants. The gene encoding one exocyst component ortholog, AtSEC8, is expressed in pollen and vegetative tissues of Arabidopsis. Genetic studies utilizing an allelic series of six independent T-DNA mutations reveal a role for SEC8 in male gametophyte function. Three T-DNA insertions in SEC8 cause an absolute, male-specific transmission defect that can be complemented by expression of SEC8 from the LAT52 pollen promoter. Microscopic analysis shows no obvious abnormalities in the microgametogenesis of the SEC8 mutants, and the mutant pollen grains appear to respond to the signals that initiate germination. However, in vivo assays indicate that these mutant pollen grains are unable to germinate a pollen tube. The other three T-DNA insertions are associated with a partial transmission defect, such that the mutant allele is transmitted through the pollen at a reduced frequency. The partial transmission defect is only evident when mutant gametophytes must compete with wild-type gametophytes, and arises in part from a reduced pollen tube growth rate. These data support the hypothesis that one function of the putative plant exocyst is to facilitate the initiation and maintenance of the polarized growth of pollen tubes. PMID:16040664

  4. [Cypress pollen allergy].

    PubMed

    Charpin, D; Calleja, M; Pichot, C; Penel, V; Hugues, B; Poncet, P

    2013-12-01

    Cypress belongs to the Cupressaceae family, which includes 140 species with non-deciduous foliage. The most important genera in allergic diseases are Cupressus sempervirens or Green cypress, Cupressus arizonica or Blue cypress, Juniperus oxycedrus, Juniperus communis and Thuya. Because J. oxycedrus pollinates in October, C. sempervirens in January and February, C. arizonica in February and March, J. communis in April, the symptomatic period is long-lasting. Because of global warming, the pollination period is tending to last longer and Cupressaceae species are becoming established further the north. In Mediterranean countries, cypress is by far the most important pollinating species, accounting for half of the total pollination. The major allergens belong to group 1. The other allergens from cypress and Juniper share 75 to 97 % structural homology with group 1 major allergens. The prevalence of cypress allergy in the general population ranges from 5 % to 13 %, according to exposure to the pollen. Among outpatients consulting an allergist, between 9 and 35 %, according to different studies, are sensitized to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy. Risk factors include a genetic predisposition and/or a strong exposure to pollen, but air pollutants could play a synergistic role. The study of the natural history of cypress allergy allows the identification of a subgroup of patients who have no personal or family history of atopy, whose disease began later in life, with low total IgE and often monosensitization to cypress pollen. In these patients, the disease is allergic than rather atopic. In the clinical picture, rhinitis is the most prevalent symptom but conjunctivitis the most disabling. A cross-reactivity between cypress and peach allergy has been demonstrated. The pharmacological treatment of cypress allergy is not different from

  5. 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

  6. A Single Nucleotide Polymorphism in the Il17ra Promoter Is Associated with Functional Severity of Ankylosing Spondylitis

    PubMed Central

    Vidal-Castiñeira, Jose Ramón; López-Vázquez, Antonio; Diaz-Peña, Roberto; Diaz-Bulnes, Paula; Martinez-Camblor, Pablo; Coto, Eliecer; Coto-Segura, Pablo; Bruges-Armas, Jacome; Pinto, Jose Antonio; Blanco, Francisco Jose; Sánchez, Alejandra; Mulero, Juan; Queiro, Ruben; Lopez-Larrea, Carlos

    2016-01-01

    The aim of this study was to identify new genetic variants associated with the severity of ankylosing spondylitis (AS). We sequenced the exome of eight patients diagnosed with AS, selected on the basis of the severity of their clinical parameters. We identified 27 variants in exons and regulatory regions. The contribution of candidate variants found to AS severity was validated by genotyping two Spanish cohorts consisting of 180 cases/300 controls and 419 cases/656 controls. Relationships of SNPs and clinical variables with the Bath Ankylosing Spondylitis Disease Activity and Functional Indices BASDAI and BASFI were analyzed. BASFI was standardized by adjusting for the duration of the disease since the appearance of the first symptoms. Refining the analysis of SNPs in the two cohorts, we found that the rs4819554 minor allele G in the promoter of the IL17RA gene was associated with AS (p<0.005). This variant was also associated with the BASFI score. Classifying AS patients by the severity of their functional status with respect to BASFI/disease duration of the 60th, 65th, 70th and 75th percentiles, we found the association increased from p60 to p75 (cohort 1: p<0.05 to p<0.01; cohort 2: p<0.01 to p<0.005). Our findings indicate a genetic role for the IL17/ILRA axis in the development of severe forms of AS. PMID:27415816

  7. [Investigations on variability of pollen tube growth in diploid and tetraploid plants of sugar beet : I. Conditions for germination of Beta pollen in vitro].

    PubMed

    Glenk, H O; Blaschke, G; Barocka, K H

    1969-01-01

    a) Attempts to germinate freshly harvested pollen of Beta vulgaris L. on semisolid media were carried out in 1966/67. The basic nutrient medium consisted of 5% gelatin, 30% sucrose and 0.03% boric acid (pH 6.4). Very poor germination occurred in aqueous solutions. During the flowering time from August to October the pollen was taken from field grown plants and during the rest of the year from greenhouse plants. b) One of the requirements for satisfactory in vitro germination rates is the optimal degree of ripeness of the pollen grains which is attained immediately after the dehiscence of the anthers. c) From January to March in vitro germination was very poor. Highest germination rates occurred during August and September. d) The germination of Beta pollen is strictly dependent upon the presence of boron in the medium. Optimal concentration of boric acid for pollen germination is 10(-1)% and for pollen tube growth 10(-2)% ; pollen tubes in this case reached a maximum length of 750 μm, in rare cases even of up to 1200 μm. Borax and butyl boric acid are less active in promoting germination. Phenyl boric acid has a very slight promoting effect and becomes toxic with concentrations higher than 10(-3)%. e) Highest germination rates (85%) were obtained on the basic medium at pH 5.4 to 5.7 after addition of n/10 HCl. Ca(++)-ions had no positive effect on germination. f) Germination of Beta pollen as compared to other pollen is relatively slow. g) A coating of callose was always observed on the inside of the walls of in vitro grown pollen tubes, less frequently callose plugs were found. Occasionally branching of the tubes occurred.

  8. Transgenic rice seeds accumulating recombinant hypoallergenic birch pollen allergen Bet v 1 generate giant protein bodies.

    PubMed

    Wang, Shuyi; Takahashi, Hideyuki; Kajiura, Hiroyuki; Kawakatsu, Taiji; Fujiyama, Kazuhito; Takaiwa, Fumio

    2013-06-01

    A versatile hypoallergenic allergen derivative against multiple allergens is an ideal tolerogen for allergen-specific immunotherapy. Such a tolerogen should exhibit high efficacy, without side effects, when administered at high doses and should be applicable to several allergens. Tree pollen chimera 7 (TPC7), a hypoallergenic Bet v 1 tolerogen against birch pollen allergy, was previously selected by DNA shuffling of 14 types of Fagales tree pollen allergens. In this study, transgenic rice seed accumulating TPC7 was generated as an oral vaccine against birch pollen allergy by expressing this protein as a secretory protein using the N-terminal signal peptide and the C-terminal KDEL tag under the control of an endosperm-specific glutelin promoter. The highest level of TPC7 accumulation was approximately 207 µg grain(-1). Recombinant TPC7 is a glycoprotein with high mannose-type N-glycan, but without β1,2-xylose or α1,3-fucose, suggesting that TPC7 is retained in the endoplasmic reticulum (ER). TPC7 is deposited as a novel, giant spherical ER-derived protein body, >20 µm in diameter, which is referred to as the TPC7 body. Removal of the KDEL retention signal or mutation of a cysteine residue resulted in an alteration of TPC7 body morphology, and deletion of the signal peptide prevented the accumulation of TPC7 in rice seeds. Therefore, the novel TPC7 bodies may have formed aggregates within the ER lumen, primarily due to the intrinsic physicochemical properties of the protein.

  9. Grass Pollen Allergens

    PubMed Central

    Augustin, Rosa

    1959-01-01

    Grass pollen allergens are shown to remain associated with protein material and a yellow pigment during paper chromatography and during dialyses and ultrafiltrations of various types. Dialysable* allergens comprise only a fraction of 1 per cent of the total activity and the amount of activity extractable by diethylene glycol (DEG) and similar solvents is of the same order. Besides the allergens, the DEG and aqueous extracts contain large amounts of inositol, glucose and fructose, also some yellow pigments and phosphates. Larger amounts of free and combined amino acids are found in the aqueous than in the DEG extracts, but the reverse is true for sucrose. In addition the DEG extracts contain a yellow glucoside different from the dactylen of the aqueous extracts, a glucosan and an arabinose-galactose-pigment complex, only the latter being associated with any activity. The spontaneous release of the crystalline dactylen from originally clear aqueous pollen extracts is found not to be caused by enzymes. The washed crystals are found to be chromatographically and electrophoretically homogeneous and devoid of allergenic activity. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7 PMID:13640676

  10. High Invasive Pollen Transfer, Yet Low Deposition on Native Stigmas in a Carpobrotus-invaded Community

    PubMed Central

    Bartomeus, Ignasi; Bosch, Jordi; Vilà, Montserrat

    2008-01-01

    Background and Aims Invasive plants are potential agents of disruption in plant–pollinator interactions. They may affect pollinator visitation rates to native plants and modify the plant–pollinator interaction network. However, there is little information about the extent to which invasive pollen is incorporated into the pollination network and about the rates of invasive pollen deposition on the stigmas of native plants. Methods The degree of pollinator sharing between the invasive plant Carpobrotus affine acinaciformis and the main co-flowering native plants was tested in a Mediterranean coastal shrubland. Pollen loads were identified from the bodies of the ten most common pollinator species and stigmatic pollen deposition in the five most common native plant species. Key Results It was found that pollinators visited Carpobrotus extensively. Seventy-three per cent of pollinator specimens collected on native plants carried Carpobrotus pollen. On average 23 % of the pollen on the bodies of pollinators visiting native plants was Carpobrotus. However, most of the pollen found on the body of pollinators belonged to the species on which they were collected. Similarly, most pollen on native plant stigmas was conspecific. Invasive pollen was present on native plant stigmas, but in low quantity. Conclusions Carpobrotus is highly integrated in the pollen transport network. However, the plant-pollination network in the invaded community seems to be sufficiently robust to withstand the impacts of the presence of alien pollen on native plant pollination, as shown by the low levels of heterospecific pollen deposition on native stigmas. Several mechanisms are discussed for the low invasive pollen deposition on native stigmas. PMID:18593688

  11. Pollen Performance in Clarkia Taxa with Contrasting Mating Systems: Implications for Male Gametophytic Evolution in Selfers and Outcrossers

    PubMed Central

    Hove, Alisa A.; Mazer, Susan J.

    2013-01-01

    We tested three predictions regarding the joint evolution of pollen performance and mating system. First, due to the potential for intense intrasexual competition in outcrossing populations, we predicted that outcrossers would produce faster-growing pollen than their selfing relatives. Second, if elevated competition promotes stronger selection on traits that improve pollen performance, then, among-plant variation in pollen performance would be lower in outcrossers than in selfers. Third, given successive generations of adaptation to the same maternal genotype in selfers, we predicted that, in selfing populations (but not in outcrossing ones), pollen would perform better following self- than cross-pollinations. We tested these predictions in field populations of two pairs of Clarkia (Onagraceae) sister taxa. Consistent with our predictions, one outcrosser (C. unguiculata) exhibited faster pollen germination and less variation in pollen tube growth rate (PTGR) among pollen donors than its selfing sister species, C. exilis. Contrary to our predictions, the selfing C. xantiana ssp. parviflora exhibited faster PTGR than the outcrossing ssp. xantiana, and these taxa showed similar levels of variation in this trait. Pollen performance following self- vs. cross-pollinations did not differ within either selfing or outcrossing taxa. While these findings suggest that mating system and pollen performance may jointly evolve in Clarkia, other factors clearly contribute to pollen performance in natural populations. PMID:27137375

  12. S-Adenosylmethionine Synthetase 3 Is Important for Pollen Tube Growth1[OPEN

    PubMed Central

    Zou, Ting

    2016-01-01

    S-Adenosylmethionine is widely used in a variety of biological reactions and participates in the methionine (Met) metabolic pathway. In Arabidopsis (Arabidopsis thaliana), one of the four S-adenosylmethionine synthetase genes, METHIONINE ADENOSYLTRANSFERASE3 (MAT3), is highly expressed in pollen. Here, we show that mat3 mutants have impaired pollen tube growth and reduced seed set. Metabolomics analyses confirmed that mat3 pollen and pollen tubes overaccumulate Met and that mat3 pollen has several metabolite profiles, such as those of polyamine biosynthesis, which are different from those of the wild type. Additionally, we show that disruption of Met metabolism in mat3 pollen affected transfer RNA and histone methylation levels. Thus, our results suggest a connection between metabolism and epigenetics. PMID:27482079

  13. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  14. 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 ...

  15. 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.

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

    SciTech Connect

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

    1985-01-01

    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 pollen 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.

  17. City scale pollen concentration variability

    NASA Astrophysics Data System (ADS)

    van der Molen, Michiel; van Vliet, Arnold; Krol, Maarten

    2016-04-01

    Pollen are emitted in the atmosphere both in the country-side and in cities. Yet the majority of the population is exposed to pollen in cities. Allergic reactions may be induced by short-term exposure to pollen. This raises the question how variable pollen concentration in cities are in temporally and spatially, and how much of the pollen in cities are actually produced in the urban region itself. We built a high resolution (1 × 1 km) pollen dispersion model based on WRF-Chem to study a city's pollen budget and the spatial and temporal variability in concentration. It shows that the concentrations are highly variable, as a result of source distribution, wind direction and boundary layer mixing, as well as the release rate as a function of temperature, turbulence intensity and humidity. Hay Fever Forecasts based on such high resolution emission and physical dispersion modelling surpass traditional hay fever warning methods based on temperature sum methods. The model gives new insights in concentration variability, personal and community level exposure and prevention. The model will be developped into a new forecast tool to serve allergic people to minimize their exposure and reduce nuisance, coast of medication and sick leave. This is an innovative approach in hay fever warning systems.

  18. 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.

  19. 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

  20. Proteomic analyses of Oryza sativa mature pollen reveal novel proteins associated with pollen germination and tube growth.

    PubMed

    Dai, Shaojun; Li, Lei; Chen, Taotao; Chong, Kang; Xue, Yongbiao; Wang, Tai

    2006-04-01

    As a highly reduced organism, pollen performs specialized functions to generate and carry sperm into the ovule by its polarily growing pollen tube. Yet the molecular genetic basis of these functions is poorly understood. Here, we identified 322 unique proteins, most of which were not reported previously to be in pollen, from mature pollen of Oryza sativa L. ssp japonica using a proteomic approach, 23% of them having more than one isoform. Functional classification reveals that an overrepresentation of the proteins was related to signal transduction (10%), wall remodeling and metabolism (11%), and protein synthesis, assembly and degradation (14%), as well as carbohydrate and energy metabolism (25%). Further, 11% of the identified proteins are functionally unknown and do not contain any conserved domain associated with known activities. These analyses also identified 5 novel proteins by de novo sequencing and revealed several important proteins, mainly involved in signal transduction (such as protein kinases, receptor kinase-interacting proteins, guanosine 5'-diphosphate dissociation inhibitors, C2 domain-containing proteins, cyclophilins), protein synthesis, assembly and degradation (such as prohibitin, mitochondrial processing peptidase, putative UFD1, AAA+ ATPase), and wall remodeling and metabolism (such as reversibly glycosylated polypeptides, cellulose synthase-like OsCsLF7). The study is the first close investigation, to our knowledge, of protein complement in mature pollen, and presents useful molecular information at the protein level to further understand the mechanisms underlying pollen germination and tube growth.

  1. IRREGULAR POLLEN EXINE1 Is a Novel Factor in Anther Cuticle and Pollen Exine Formation1[OPEN

    PubMed Central

    Chen, Xiaoyang; Zhang, Hua; Luo, Hongbing; Zhao, Li; Dong, Zhaobin; Yan, Shuangshuang; Liu, Renyi; Xu, Chunyan; Li, Song; Chen, Huabang

    2017-01-01

    Anther cuticle and pollen exine are protective barriers for pollen development and fertilization. Despite that several regulators have been identified for anther cuticle and pollen exine development in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), few genes have been characterized in maize (Zea mays) and the underlying regulatory mechanism remains elusive. Here, we report a novel male-sterile mutant in maize, irregular pollen exine1 (ipe1), which exhibited a glossy outer anther surface, abnormal Ubisch bodies, and defective pollen exine. Using map-based cloning, the IPE1 gene was isolated as a putative glucose-methanol-choline oxidoreductase targeted to the endoplasmic reticulum. Transcripts of IPE1 were preferentially accumulated in the tapetum during the tetrad and early uninucleate microspore stage. A biochemical assay indicated that ipe1 anthers had altered constituents of wax and a significant reduction of cutin monomers and fatty acids. RNA sequencing data revealed that genes implicated in wax and flavonoid metabolism, fatty acid synthesis, and elongation were differentially expressed in ipe1 mutant anthers. In addition, the analysis of transfer DNA insertional lines of the orthologous gene in Arabidopsis suggested that IPE1 and their orthologs have a partially conserved function in male organ development. Our results showed that IPE1 participates in the putative oxidative pathway of C16/C18 ω-hydroxy fatty acids and controls anther cuticle and pollen exine development together with MALE STERILITY26 and MALE STERILITY45 in maize. PMID:28049856

  2. Christmas tree allergy: mould and pollen studies.

    PubMed

    Wyse, D M; Malloch, D

    1970-12-05

    A history of respiratory or other allergic symptoms during the Christmas season is occasionally obtained from allergic patients and can be related to exposure to conifers at home or in school. Incidence and mechanism of production of these symptoms were studied. Of 1657 allergic patients, respiratory and skin allergies to conifers occurred in 7%. This seasonal syndrome includes sneezing, wheezing and transitory skin rashes. The majority of patients develop their disease within 24 hours, but 15% experience symptoms after several days' delay. Mould and pollen studies were carried out in 10 test sites before, during and after tree placement in the home. Scrapings from pine and spruce bark yielded large numbers of Penicillium, Epicoccum and Alternaria, but these failed to become airborne. No significant alteration was discovered in the airborne fungi in houses when trees were present. Pollen studies showed release into air of weed, grass and tree pollens while Christmas trees were in the house. Oleoresins of the tree balsam are thought to be the most likely cause of the symptoms designated as Christmas tree allergy.

  3. Current understanding of cross-reactivity of food allergens and pollen.

    PubMed

    Vieths, Stefan; Scheurer, Stephan; Ballmer-Weber, Barbara

    2002-05-01

    Pollen-allergic patients frequently present allergic symptoms after ingestion of several kinds of plant-derived foods. The majority of these reactions is caused by four distinct cross-reactive structures that are present in birch pollen. Proteins that share common epitopes with Bet v 1, the major birch pollen allergen, occur in pollens of several tree species: apples, stone fruits, celery, carrot, nuts, and soybeans. Approximately 70% of our patients who are allergic to birch pollen may experience symptoms after consumption of foods from these groups. In contrast, two minor allergenic structures-profilins and cross-reactive carbohydrate determinants (CCD)-that sensitize approximately 10-20% of all pollen-allergic patients are also present in grass pollen and weed pollen. Moreover, IgE-binding proteins related to the birch pollen minor allergen Bet v 6 have been found in many vegetable foods such as apple, peach, orange, lychee fruit, strawberry, persimmon, zucchini, and carrot. Frequently, the occurrence of cross-reactive IgE antibodies is not correlated with the development of clinical food allergy. In particular, the clinical relevance of sensitization to CCD is doubtful. Generally, pollen-related allergens tend to be more labile during heating procedures and in the digestive tract compared to allergens from classical allergenic foods such as peanut. However, recent DBPCFC studies have shown that both cooked celery and roasted hazelnuts still pose an allergenic risk for pollen-sensitized subjects. Since pathogenesis-related proteins share several common features with allergens and both the Bet v 1 and the Bet v 6-related food allergens are defense-related proteins, approaches to introduce such proteins as a measure to protect plants against diseases should be performed with caution as they may increase the allergenicity of these crops.

  4. Long-term trends in atmospheric pollen levels in the city of Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Damialis, Athanasios; Halley, John M.; Gioulekas, Dimitrios; Vokou, Despina

    We examined the long-term trends in pollen atmospheric levels in Thessaloniki, the second largest city of Greece. On the basis of data collected during the period 1987-2005, we estimated trends in the atmospheric pollen levels for the 16 different taxa, each of whose contribution to the total atmospheric pollen concentration was at least 0.5%. We also tested for trends towards earlier, longer or more highly peaked pollen seasons. The salient feature of these data is that the levels of pollen have been increasing; this is true for the majority of the individual taxa examined (12 out of 16) and for their aggregate. On average, the atmospheric pollen concentration is doubling every decade, but for some species the rate is much higher, with doubling times less than 5 years. Among the taxa with the highest rate of long-term trend in atmospheric pollen concentration, four belong to the group of woody plants (Cupressaceae, Quercus, Platanus, Pinaceae) and only one to that of herbs (Urticaceae). For the pollen-season-related attributes (onset, peak, end and duration), there was no systematic tendency and the changes were more nuanced. The observed increase in pollen abundance coincides with a rise in air temperature, which is the only meteorological factor to have experienced a sustained and significant change over the same period in Thessaloniki. Our results suggest that changes in pollen distributions are dominated by increases in pollen production rather than changes in flowering phenology and that several species showing strong trends might serve as bio-indicators of expected climate change. Given that the pollen-producing reservoir around the city has not increased, these results provide further evidence of the impact of climate change on plant biota.

  5. Impact of pollen resources drift on common bumblebees in NW Europe.

    PubMed

    Roger, Nathalie; Moerman, Romain; Carvalheiro, Luísa Gigante; Aguirre-Guitiérrez, Jesús; Jacquemart, Anne-Laure; Kleijn, David; Lognay, Georges; Moquet, Laura; Quinet, Muriel; Rasmont, Pierre; Richel, Aurore; Vanderplanck, Maryse; Michez, Denis

    2017-01-01

    Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant abundance and quality. Here, we investigate whether generalist bumblebee species, with stable population trends over the past years, adapted their diets in response to changes in the distribution and chemical quality of their pollen resources. We selected five common species of bumblebee in NW Europe for which we had a precise description of their pollen diet through two time periods ('prior to 1950' and '2004-2005'). For each species, we assessed whether the shift in their pollen diet was related with the changes in the suitable area of their pollen resources. Concurrently, we evaluated whether the chemical composition of pollen resources changed over time and experimentally tested the impact of new major pollen species on the development of B. terrestris microcolonies. Only one species (i.e. B. lapidarius) significantly included more pollen from resources whose suitable area expanded. This opportunist pattern could partly explain the expansion of B. lapidarius in Europe. Regarding the temporal variation in the chemical composition of the pollen diet, total and essential amino acid contents did not differ significantly between the two time periods while we found significant differences among plant species. This result is driven by the great diversity of resources used by bumblebee species in both periods. Our bioassay revealed that the shift to new major pollen resources allowed microcolonies to develop, bringing new evidence on the opportunist feature of bumblebee in their diets. Overall, this study shows that the response to pollen resource drift varies among closely related pollinators, and a species-rich plant community ensures generalist species to select a nutrient-rich pollen diet.

  6. Organization and regulation of the actin cytoskeleton in the pollen tube

    PubMed Central

    Qu, Xiaolu; Jiang, Yuxiang; Chang, Ming; Liu, Xiaonan; Zhang, Ruihui; Huang, Shanjin

    2015-01-01

    Proper organization of the actin cytoskeleton is crucial for pollen tube growth. However, the precise mechanisms by which the actin cytoskeleton regulates pollen tube growth remain to be further elucidated. The functions of the actin cytoskeleton are dictated by its spatial organization and dynamics. However, early observations of the distribution of actin filaments at the pollen tube apex were quite perplexing, resulting in decades of controversial debate. Fortunately, due to improvements in fixation regimens for staining actin filaments in fixed pollen tubes, as well as the adoption of appropriate markers for visualizing actin filaments in living pollen tubes, this issue has been resolved and has given rise to the consensus view of the spatial distribution of actin filaments throughout the entire pollen tube. Importantly, recent descriptions of the dynamics of individual actin filaments in the apical region have expanded our understanding of the function of actin in regulation of pollen tube growth. Furthermore, careful documentation of the function and mode of action of several actin-binding proteins expressed in pollen have provided novel insights into the regulation of actin spatial distribution and dynamics. In the current review, we summarize our understanding of the organization, dynamics, and regulation of the actin cytoskeleton in the pollen tube. PMID:25620974

  7. Modern pollen data from North America and Greenland for multi-scale paleoenvironmental applications

    USGS Publications Warehouse

    Whitmore, J.; Gajewski, K.; Sawada, M.; Williams, J.W.; Shuman, B.; Bartlein, P.J.; Minckley, T.; Viau, A.E.; Webb, T.; Shafer, S.; Anderson, P.; Brubaker, L.

    2005-01-01

    The modern pollen network in North America and Greenland is presented as a database for use in quantitative calibration studies and paleoenvironmental reconstructions. The georeferenced database includes 4634 samples from all regions of the continent and 134 pollen taxa that range from ubiquitous to regionally diagnostic taxa. Climate data and vegetation characteristics were assigned to every site. Automated and manual procedures were used to verify the accuracy of geographic coordinates and identify duplicate records among datasets, incomplete pollen sums, and other potential errors. Data are currently available for almost all of North America, with variable density. Pollen taxonomic diversity, as measured by the Shannon-Weiner coefficient, varies as a function of location, as some vegetation regions are dominated by one or two major pollen producers, while other regions have a more even composition of pollen taxa. Squared-chord distances computed between samples show that most modern pollen samples find analogues within their own vegetation zone. Both temperature and precipitation inferred from best analogues are highly correlated with observed values but temperature exhibits the strongest relation. Maps of the contemporary distribution of several pollen types in relation to the range of the plant taxon illustrate the correspondence between plant and pollen ranges. ?? 2005 Elsevier Ltd. All rights reserved.

  8. The Metabolic Basis of Pollen Thermo-Tolerance: Perspectives for Breeding

    PubMed Central

    Paupière, Marine J.; van Heusden, Adriaan W.; Bovy, Arnaud G.

    2014-01-01

    Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1–3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of) metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed. PMID:25271355

  9. The metabolic basis of pollen thermo-tolerance: perspectives for breeding.

    PubMed

    Paupière, Marine J; van Heusden, Adriaan W; Bovy, Arnaud G

    2014-09-30

    Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1-3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of) metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed.

  10. Novelties of the flowering plant pollen tube underlie diversification of a key life history stage

    PubMed Central

    Williams, Joseph H.

    2008-01-01

    The origin and rapid diversification of flowering plants has puzzled evolutionary biologists, dating back to Charles Darwin. Since that time a number of key life history and morphological traits have been proposed as developmental correlates of the extraordinary diversity and ecological success of angiosperms. Here, I identify several innovations that were fundamental to the evolutionary lability of angiosperm reproduction, and hence to their diversification. In gymnosperms pollen reception must be near the egg largely because sperm swim or are transported by pollen tubes that grow at very slow rates (< ≈20 μm/h). In contrast, pollen tube growth rates of taxa in ancient angiosperm lineages (Amborella, Nuphar, and Austrobaileya) range from ≈80 to 600 μm/h. Comparative analyses point to accelerated pollen tube growth rate as a critical innovation that preceded the origin of the true closed carpel, long styles, multiseeded ovaries, and, in monocots and eudicots, much faster pollen tube growth rates. Ancient angiosperm pollen tubes all have callosic walls and callose plugs (in contrast, no gymnosperms have these features). The early association of the callose-walled growth pattern with accelerated pollen tube growth rate underlies a striking repeated pattern of faster and longer-distance pollen tube growth often within solid pathways in phylogenetically derived angiosperms. Pollen tube innovations are a key component of the spectacular diversification of carpel (flower and fruit) form and reproductive cycles in flowering plants. PMID:18678915

  11. Pollen Aquaporins: The Solute Factor.

    PubMed

    Pérez Di Giorgio, Juliana A; Soto, Gabriela C; Muschietti, Jorge P; Amodeo, Gabriela

    2016-01-01

    In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen's success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange.

  12. The Arabidopsis FLAKY POLLEN1 gene encodes a 3-hydroxy-3-methylglutaryl-coenzyme A synthase required for development of tapetum-specific organelles and fertility of pollen grains.

    PubMed

    Ishiguro, Sumie; Nishimori, Yuka; Yamada, Miho; Saito, Hiroko; Suzuki, Toshiya; Nakagawa, Tsuyoshi; Miyake, Hiroshi; Okada, Kiyotaka; Nakamura, Kenzo

    2010-06-01

    The pollen coat is a surface component of pollen grains required for fertilization. To study how the pollen coat is produced, we identified and characterized a recessive and conditional male-sterile Arabidopsis mutant, flaky pollen1-1 (fkp1-1), whose pollen grains lack functional pollen coats. FKP1 is a single-copy gene in the Arabidopsis genome and encodes 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMG-CoA synthase), an enzyme of the mevalonate (MVA) pathway involved in biosynthesis of isoprenoids such as sterols. We found that fkp1-1 possesses a T-DNA insertion 550 bp upstream of the initiation codon. RT-PCR and promoter analyses revealed that fkp1-1 results in knockdown of FKP1 predominantly in tapetum. Electron microscopy showed that the mutation affected the development of tapetum-specific lipid-containing organelles (elaioplast and tapetosome), causing the deficient formation of fkp1-1 pollen coats. These results suggest that both elaioplasts, which accumulate vast amount of sterol esters, and tapetosomes, which are unique oil-accumulating structures, require the MVA pathway for development. Null alleles of fkp1 were male-gametophyte lethal upon pollen tube elongation, whereas female gametophytes were normal. These results show that the MVA pathway is essential, at least in tapetal cells and pollen grains, for the development of tapetum-specific organelles and the fertility of pollen grains.

  13. 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.

  14. Personalized symptoms forecasting for pollen-induced allergic rhinitis sufferers

    NASA Astrophysics Data System (ADS)

    Voukantsis, D.; Berger, U.; Tzima, F.; Karatzas, K.; Jaeger, S.; Bergmann, K. C.

    2015-07-01

    Hay fever is a pollen-induced allergic reaction that strongly affects the overall quality of life of many individuals. The disorder may vary in severity and symptoms depending on patient-specific factors such as genetic disposition, individual threshold of pollen concentration levels, medication, former immunotherapy, and others. Thus, information services that improve the quality of life of hay fever sufferers must address the needs of each individual separately. In this paper, we demonstrate the development of information services that offer personalized pollen-induced symptoms forecasts. The backbone of these services consists of data of allergic symptoms reported by the users of the Personal Hay Fever Diary system and pollen concentration levels (European Aeroallergen Network) in several sampling sites. Data were analyzed using computational intelligence methods, resulting in highly customizable forecasting models that offer personalized warnings to users of the Patient Hay Fever Diary system. The overall system performance for the pilot area (Vienna and Lower Austria) reached a correlation coefficient of r = 0.71 ± 0.17 (average ± standard deviation) in a sample of 219 users with major contribution to the Pollen Hay Fever Diary system and an overall performance of r = 0.66 ± 0.18 in a second sample of 393 users, with minor contribution to the system. These findings provide an example of combining data from different sources using advanced data engineering in order to develop innovative e-health services with the capacity to provide more direct and personalized information to allergic rhinitis sufferers.

  15. 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.

  16. 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

  17. A CXCL2 tandem repeat promoter polymorphism is associated with susceptibility to severe sepsis in the Spanish population.

    PubMed

    Flores, C; Maca-Meyer, N; Pérez-Méndez, L; Sangüesa, R; Espinosa, E; Muriel, A; Blanco, J; Villar, J

    2006-03-01

    Sepsis describes a complex clinical syndrome resulting from a systemic inflammatory response to bacteria. Functional studies in animal models of sepsis have catalogued CXCL2 as a candidate gene for the development of the disease. We hypothesized that CXCL2 polymorphisms may confer susceptibility to sepsis and performed an association study using 178 severe sepsis patients and 357 population-based controls. We selected two polymorphisms from the promoter of the gene (-437A/G and -665(AC)n), and analyzed whether haplotypes or single loci were associated with disease susceptibility. An overall test of differentiation showed that haplotype distribution was not different between cases and controls (P=0.407). Likewise, -437A/G was not associated with disease susceptibility (heterozygote odds ratio (OR) 0.68 (0.47-1.03), and homozygote OR 0.86 (0.56-1.32); P=0.706). However, for the -665(AC)n, we found that the 24+/-1 repeat alleles were associated with susceptibility (heterozygote OR 2.82 (1.10-7.24), and homozygote OR 3.65 (1.41-9.43); P=0.0006). This association remained significant when using a multiple logistic regression analysis (OR 2.23; 95% confidence intervals (95% CI) 1.22-4.03; P=0.008) and after a genomic control adjustment (P=0.017). Although replicate studies and functional assays are needed, these results suggest that CXCL2 gene variants may contribute to the development of severe sepsis.

  18. MAP18 regulates the direction of pollen tube growth in Arabidopsis by modulating F-actin organization.

    PubMed

    Zhu, Lei; Zhang, Yan; Kang, Erfang; Xu, Qiangyi; Wang, Miaoying; Rui, Yue; Liu, Baoquan; Yuan, Ming; Fu, Ying

    2013-03-01

    For fertilization to occur in plants, the pollen tube must be guided to enter the ovule via the micropyle. Previous reports have implicated actin filaments, actin binding proteins, and the tip-focused calcium gradient as key contributors to polar growth of pollen tubes; however, the regulation of directional pollen tube growth is largely unknown. We reported previously that Arabidopsis thaliana MICROTUBULE-ASSOCIATED PROTEIN18 (MAP18) contributes to directional cell growth and cortical microtubule organization. The preferential expression of MAP18 in pollen and in pollen tubes suggests that MAP18 also may function in pollen tube growth. In this study, we demonstrate that MAP18 functions in pollen tubes by influencing actin organization, rather than microtubule assembly. In vitro biochemical results indicate that MAP18 exhibits Ca(2+)-dependent filamentous (F)-actin-severing activity. Abnormal expression of MAP18 in map18 and MAP18 OX plants was associated with disorganization of the actin cytoskeleton in the tube apex, resulting in aberrant pollen tube growth patterns and morphologies, inaccurate micropyle targeting, and fewer fertilization events. Experiments with MAP18 mutants created by site-directed mutagenesis suggest that F-actin-severing activity is essential to the effects of MAP18 on pollen tube growth direction. Our study demonstrates that in Arabidopsis, MAP18 guides the direction of pollen tube growth by modulating actin filaments.

  19. 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

  20. Pollen Killer Gene S35 Function Requires Interaction with an Activator That Maps Close to S24, Another Pollen Killer Gene in Rice

    PubMed Central

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2016-01-01

    Pollen killer genes disable noncarrier pollens, and are responsible for male sterility and segregation distortion in hybrid populations of distantly related plant species. The genetic networks and the molecular mechanisms underlying the pollen killer system remain largely unknown. Two pollen killer genes, S24 and S35, have been found in an intersubspecific cross of Oryza sativa ssp. indica and japonica. The effect of S24 is counteracted by an unlinked locus EFS. Additionally, S35 has been proposed to interact with S24 to induce pollen sterility. These genetic interactions are suggestive of a single S24-centric genetic pathway (EFS–S24–S35) for the pollen killer system. To examine this hypothetical genetic pathway, the S35 and the S24 regions were further characterized and genetically dissected in this study. Our results indicated that S35 causes pollen sterility independently of both the EFS and S24 genes, but is dependent on a novel gene close to the S24 locus, named incentive for killing pollen (INK). We confirmed the phenotypic effect of the INK gene separately from the S24 gene, and identified the INK locus within an interval of less than 0.6 Mb on rice chromosome 5. This study characterized the genetic effect of the two independent genetic pathways of INK–S35 and EFS–S24 in indica–japonica hybrid progeny. Our results provide clear evidence that hybrid male sterility in rice is caused by several pollen killer networks with multiple factors positively and negatively regulating pollen killer genes. PMID:27172610

  1. Pollen Killer Gene S35 Function Requires Interaction with an Activator That Maps Close to S24, Another Pollen Killer Gene in Rice.

    PubMed

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2016-05-03

    Pollen killer genes disable noncarrier pollens, and are responsible for male sterility and segregation distortion in hybrid populations of distantly related plant species. The genetic networks and the molecular mechanisms underlying the pollen killer system remain largely unknown. Two pollen killer genes, S24 and S35, have been found in an intersubspecific cross of Oryza sativa ssp. indica and japonica The effect of S24 is counteracted by an unlinked locus EFS Additionally, S35 has been proposed to interact with S24 to induce pollen sterility. These genetic interactions are suggestive of a single S24-centric genetic pathway (EFS-S24-S35) for the pollen killer system. To examine this hypothetical genetic pathway, the S35 and the S24 regions were further characterized and genetically dissected in this study. Our results indicated that S35 causes pollen sterility independently of both the EFS and S24 genes, but is dependent on a novel gene close to the S24 locus, named incentive for killing pollen (INK). We confirmed the phenotypic effect of the INK gene separately from the S24 gene, and identified the INK locus within an interval of less than 0.6 Mb on rice chromosome 5. This study characterized the genetic effect of the two independent genetic pathways of INK-S35 and EFS-S24 in indica-japonica hybrid progeny. Our results provide clear evidence that hybrid male sterility in rice is caused by several pollen killer networks with multiple factors positively and negatively regulating pollen killer genes.

  2. Immunochemical characterization of prosopis juliflora pollen allergens and evaluation of cross-reactivity pattern with the most allergenic pollens in tropical areas.

    PubMed

    Assarehzadegan, Mohammad-Ali; Khodadadi, Ali; Amini, Akram; Shakurnia, Abdol-Hosein; Marashi, Seyed Saeid; Ali-Sadeghi, Hosein; Zarinhadideh, Farnoosh; Sepahi, Najmeh

    2015-02-01

    Allergy to Prosopis juliflora (mesquite) pollen is one of the common causes of respiratory allergy in tropical countries. Mesquite is widely used as street trees in towns and ornamental shade trees in parks and gardens throughout arid and semiarid regions of Iran. The inhalation of mesquite pollen and several species of Amaranthus/Chenopodiaceae family is the most important cause of allergic respiratory symptoms in Khuzestan province. This study was designed to evaluate IgE banding proteins of mesquite pollen extract and its IgE cross-reactivity with other allergenic plants. Twenty patients with allergic symptoms and positive skin prick tests (SPT) for mesquite pollen extract participated in the study. Crude pollen extract was prepared from local mesquite trees and used for the evaluation of allergenic profiles of P. juliflora pollen extract by Sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblotting. There were several protein bands in mesquite pollen extract using SDS-PAGE with the approximate range of molecular weight of 10-85 kDa. The most frequent IgE reactive bands among the patients' sera were approximately 20 and 66 kDa. However, there were other IgE reactive protein bands among the patients' sera with molecular weights of 10, 15, 35, 45, 55 and 85 kDa. Inhibition experiments revealed high IgE cross-reactivity between mesquite and acacia. There are several IgE-binding proteins in P. juliflora pollen extract. Results of this study indicate that proteins with a molecular weight of 10 to 85 kDa are the major allergens in P. juliflora pollen extract.

  3. Endurance exercise promotes cardiorespiratory rehabilitation without neurorestoration in the chronic mouse model of parkinsonism with severe neurodegeneration.

    PubMed

    Al-Jarrah, M; Pothakos, K; Novikova, L; Smirnova, I V; Kurz, M J; Stehno-Bittel, L; Lau, Y-S

    2007-10-12

    release-dependent locomotor activity was markedly inhibited in the sedentary parkinsonian mice and was also inhibited in the exercised parkinsonian mice. Finally, neuronal recovery from the loss of nigrostriatal tyrosine hydroxylase expression and dopamine levels in the severe parkinsonian mice after exercise was not evident. Taken all together, these data suggest that 4 weeks of treadmill exercise promoted physical endurance, resulting in cardiorespiratory and metabolic adaptations in the chronic parkinsonian mice with severe neurodegeneration without demonstrating a restorative potential for the nigrostriatal dopaminergic function.

  4. Pollen Aquaporins: The Solute Factor

    PubMed Central

    Pérez Di Giorgio, Juliana A.; Soto, Gabriela C.; Muschietti, Jorge P.; Amodeo, Gabriela

    2016-01-01

    In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen’s success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange. PMID:27881985

  5. Bioassaying for ozone with pollen systems

    SciTech Connect

    Feder, W.A.

    1981-01-01

    Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Year-round pollen producion can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.

  6. National Allergy Bureau Pollen and Mold Report

    MedlinePlus

    ... Search Search AAAAI National Allergy Bureau Pollen and Mold Report Date: April 12, 2017 Location: San Antonio ( ... Service can automatically email you daily pollen and mold reports. Click here sign up! Return to Map ...

  7. Floral Diversity and Pollen Transfer Mechanisms in Bird-pollinated Salvia Species

    PubMed Central

    Wester, Petra; Claßen-Bockhoff, Regine

    2007-01-01

    Background and Aims Bird-pollinated (ornithophilous) Salvia species (sages) transfer pollen either by means of a staminal lever mechanism or by immovable stamens. As the distribution of the two modes within the genus is not known, we present a survey of all ornithophilous sages. The main focus is given to floral diversity especially with respect to functional lever morphology. Thereby the hypothesis is tested that, due to a pollinator shift from bees to birds, the lever mechanism became unnecessary. Methods To get a general idea about the diversity of pollen transfer mechanisms, 186 ornithophilous Salvia species were classified according to the functional morphology of the stamen and the need for a lever movement. To test the functionality of the staminal levers and the fitting between flowers and birds the process of pollen transfer was examined by pollinator observations and tested by inserting museum skins and metal rods into fresh flowers. Key Results The diversity of pollen transfer mechanisms is represented by eight case studies illustrating three main groups. In group I (approx. 50 %) the staminal lever mechanism is necessary to open access to nectar and to enable the transfer of pollen that is hidden in the upper lip. In group II (approx. 34 %) pollen is freely accessible and the lever mechanism is reduced in different ways and to different degrees. In group III (approx. 4 %) the lever works as in group I, but pollen is freely accessible as in II. The remaining approx. 13 % are not clearly classified. Conclusions It is considered that the driving force behind the diverse modes of reduction is the necessity to increase the distance between nectar and pollen, thereby ensuring pollen deposition on the bird's feathered head. This is achieved several times in parallel by corolla elongation and/or exposure of the pollen-sacs. As soon as pollen is freely accessible, the lever movement loses its significance for pollination. PMID:17522077

  8. High IgE sensitization to maize and rice pollen in the highlands of Madagascar

    PubMed Central

    Ramavovololona; Sénéchal, Hélène; Andrianarisoa, Ange; Rakotoarimanana, Vololona; Godfrin, Dominique; Peltre, Gabriel; Poncet, Pascal; Sutra, Jean-Pierre

    2014-01-01

    Introduction Maize and rice are two crops constituting the main food supply in many under-developed and developing countries. Despite the large area devoted to the culture, the sensitization to the pollen from these plants is reported to be low and often considered as an occupational allergy. Methods Sixty five Malagasy pollen allergic patients were clinically and immunochemically investigated with regard to maize and rice pollen allergens. Pollen extracts were electrophoretically separated in 1 and 2 dimensions and IgE and IgG reactivities detected upon immunoblotting. Results When exploring the sensitization profile of Malagasy allergic patients to maize and rice pollen, it appears that a high proportion of these patients consulting during grass pollinating season were sensitized to both pollen as revealed by skin prick testing (62 vs. 59%) and IgE immunoblotting (85 vs. 40%). Several clinically relevant allergens were recognized by patients’ serum IgE in maize and rice pollen extracts. Conclusion The high levels of maize and rice pollen sensitization should be related, in this tropical region, to a specific environmental exposure including i) a proximity of the population to the allergenic sources and ii) a putative exacerbating effect of a highly polluted urban atmosphere on pollen allergenicity. Cross-reactivities between wild and cultivated grasses and also between rice and maize pollen are involved as well as some specific maize sensitizations. The presence of dense urban and peri-urban agriculture, in various African regions and worldwide, could be a high environmental risk factor for people sensitive to maize pollen. PMID:25870739

  9. Hypersensitivity to pollen of Olea europaea in Israel.

    PubMed

    Geller-Bernstein, C; Arad, G; Keynan, N; Lahoz, C; Cardaba, B; Waisel, Y

    1996-05-01

    The incidence of skin-tested sensitivity to olive pollen allergens among subjects with suspected atopic respiratory allergy was investigated in various populations of Israelis. This incidence was correlated with the olive cultivars, with the abundance of trees in the patient's neighborhoods, and with the history of exposure of the studied populations to olive pollen. Positive skin reactions to olive pollen, among atopic patients of the Jewish population, is rather high where olive trees are abundant (66%), and lower (29%) where trees are scarce (P < 0.003). Sensitization was significantly lower (P < 0.003) among a population of Israeli atopic Arabs (16%), though these Arabs have lived in an olive-rich area for several generations.

  10. Sulfinylated azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils.

    PubMed

    Qin, Yuan; Wysocki, Ronald J; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A; Palanivelu, Ravishankar

    2011-12-01

    Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultra-high resolution electrospray ionization (ESI), Fourier-transform ion cyclotron resonance (FT-ICR) and MS/MS techniques to accurately determine the mass (202.126 Da) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 μm stimulated approximately 50% germination) and elicit accession-specific response. Although N-methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen.

  11. Climate Change and Future Pollen Allergy in Europe

    PubMed Central

    Lake, Iain R.; Jones, Natalia R.; Agnew, Maureen; Goodess, Clare M.; Giorgi, Filippo; Hamaoui-Laguel, Lynda; Semenov, Mikhail A.; Solomon, Fabien; Storkey, Jonathan; Vautard, Robert; Epstein, Michelle M.

    2016-01-01

    Background: Globally, pollen allergy is a major public health problem, but a fundamental unknown is the likely impact of climate change. To our knowledge, this is the first study to quantify the consequences of climate change upon pollen allergy in humans. Objectives: We produced quantitative estimates of the potential impact of climate change upon pollen allergy in humans, focusing upon common ragweed (Ambrosia artemisiifolia) in Europe. Methods: A process-based model estimated the change in ragweed’s range under climate change. A second model simulated current and future ragweed pollen levels. These findings were translated into health burdens using a dose–response curve generated from a systematic review and from current and future population data. Models considered two different suites of regional climate/pollen models, two greenhouse gas emissions scenarios [Representative Concentration Pathways (RCPs) 4.5 and 8.5], and three different plant invasion scenarios. Results: Our primary estimates indicated that sensitization to ragweed will more than double in Europe, from 33 to 77 million people, by 2041–2060. According to our projections, sensitization will increase in countries with an existing ragweed problem (e.g., Hungary, the Balkans), but the greatest proportional increases will occur where sensitization is uncommon (e.g., Germany, Poland, France). Higher pollen concentrations and a longer pollen season may also increase the severity of symptoms. Our model projections were driven predominantly by changes in climate (66%) but were also influenced by current trends in the spread of this invasive plant species. Assumptions about the rate at which ragweed spreads throughout Europe had a large influence upon the results. Conclusions: Our quantitative estimates indicate that ragweed pollen allergy will become a common health problem across Europe, expanding into areas where it is currently uncommon. Control of ragweed spread may be an important adaptation

  12. [The epidemiology of pollen allergy].

    PubMed

    Charpin, D; Caillaud, D

    2014-04-01

    The prevalence of seasonal allergic rhinitis can be established through surveys performed in a sample of the general population. These surveys are based on a questionnaire, which could lead to an overestimate of prevalence rates, and on measurements of specific IgE, which need to be interpreted in the light of the responses to the questionnaire. Such surveys are few in France and need to be updated. Risk factors for seasonal allergic rhinitis are genetic, epigenetic and environmental. Relationships between exposure to pollen and health can be documented through ecological and panel surveys. Panel surveys may give information on threshold levels and dose-response relationships. In addition to pollen exposure, global warming and air pollutants act as cofactors. Monitoring of both pollen exposure and its health effects should be encouraged and strengthened.

  13. Pollen Allergens for Molecular Diagnosis.

    PubMed

    Pablos, Isabel; Wildner, Sabrina; Asam, Claudia; Wallner, Michael; Gadermaier, Gabriele

    2016-04-01

    Pollen allergens are one of the main causes of type I allergies affecting up to 30% of the population in industrialized countries. Climatic changes affect the duration and intensity of pollen seasons and may together with pollution contribute to increased incidences of respiratory allergy and asthma. Allergenic grasses, trees, and weeds often present similar habitats and flowering periods compromising clinical anamnesis. Molecule-based approaches enable distinction between genuine sensitization and clinically mostly irrelevant IgE cross-reactivity due to, e. g., panallergens or carbohydrate determinants. In addition, sensitivity as well as specificity can be improved and lead to identification of the primary sensitizing source which is particularly beneficial regarding polysensitized patients. This review gives an overview on relevant pollen allergens and their usefulness in daily practice. Appropriate allergy diagnosis is directly influencing decisions for therapeutic interventions, and thus, reliable biomarkers are pivotal when considering allergen immunotherapy in the context of precision medicine.

  14. Amplification and analysis of promoter region of insulin receptor gene in a patient with leprechaunism associated with severe insulin resistance.

    PubMed

    Haruta, T; Imamura, T; Iwanishi, M; Egawa, K; Goji, K; Kobayashi, M

    1995-04-01

    A patient with leprechaunism associated with severe insulin resistance was studied to identify the molecular and genetic basis for insulin resistance. Insulin binding and surface labeling of transformed lymphocytes prepared from the patient showed a significantly decreased insulin receptor number on the cell surface. Southern blot analysis of the insulin receptor gene showed no evidence of large insertions or deletions. Furthermore, direct sequencing of all 22 exons and exon-intron junctions of the insulin receptor gene failed to show any missense mutations, nonsense mutations, or mutations at exon-intron junctions. However, Northern blot analysis indicated significantly decreased insulin receptor mRNA expression in the patient's cells. Moreover, restriction endonuclease digestion of the amplified cDNA suggested that the expression levels of one allele were less efficient than the other. These findings suggested that the regulatory region of the insulin receptor gene might have abnormalities. Therefore, we examined the 5' flanking region of the insulin receptor gene. Southern blot analysis showed no major deletions or insertions between positions -1,823 and -2 relative to the translation initiation site. A 5' flanking region of the insulin receptor gene spanning positions -881 approximately +7 was amplified by polymerase chain reaction (PCR) and introduced into a reporter plasmid carrying the human growth hormone (hGH) gene. The nucleotide sequence of the amplified fragment showed two polymorphic sites at positions -603 and -500 in the patient, as well as in normal subjects. No other abnormal sequence was found in the patient. Promoter activity measured by hGH expression in transfected mouse L cells was not influenced by the polymorphism at position -603 located in a cluster of GC boxes.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Application of lime (CaCO3) to promote forest recovery from severe acidification increases potential for earthworm invasion

    USGS Publications Warehouse

    Homan, Caitlin; Beirer, Colin M; McCay, Timothy S; Lawrence, Gregory B.

    2016-01-01

    The application of lime (calcium carbonate) may be a cost-effective strategy to promote forest ecosystem recovery from acid impairment, under contemporary low levels of acidic deposition. However, liming acidified soils may create more suitable habitat for invasive earthworms that cause significant damage to forest floor communities and may disrupt ecosystem processes. We investigated the potential effects of liming in acidified soils where earthworms are rare in conjunction with a whole-ecosystem liming experiment in the chronically acidified forests of the western Adirondacks (USA). Using a microcosm experiment that replicated the whole-ecosystem treatment, we evaluated effects of soil liming on Lumbricus terrestris survivorship and biomass growth. We found that a moderate lime application (raising pH from 3.1 to 3.7) dramatically increased survival and biomass of L. terrestris, likely via increases in soil pH and associated reductions in inorganic aluminum, a known toxin. Very few L. terrestris individuals survived in unlimed soils, whereas earthworms in limed soils survived, grew, and rapidly consumed leaf litter. We supplemented this experiment with field surveys of extant earthworm communities along a gradient of soil pH in Adirondack hardwood forests, ranging from severely acidified (pH < 3) to well-buffered (pH > 5). In the field, no earthworms were observed where soil pH < 3.6. Abundance and species richness of earthworms was greatest in areas where soil pH > 4.4 and human dispersal vectors, including proximity to roads and public fishing access, were most prevalent. Overall our results suggest that moderate lime additions can be sufficient to increase earthworm invasion risk where dispersal vectors are present.

  16. Eccentric Ergometer Training Promotes Locomotor Muscle Strength but Not Mitochondrial Adaptation in Patients with Severe Chronic Obstructive Pulmonary Disease

    PubMed Central

    MacMillan, Norah J.; Kapchinsky, Sophia; Konokhova, Yana; Gouspillou, Gilles; de Sousa Sena, Riany; Jagoe, R Thomas; Baril, Jacinthe; Carver, Tamara E.; Andersen, Ross E.; Richard, Ruddy; Perrault, Hélène; Bourbeau, Jean; Hepple, Russell T.; Taivassalo, Tanja

    2017-01-01

    Eccentric ergometer training (EET) is increasingly being proposed as a therapeutic strategy to improve skeletal muscle strength in various cardiorespiratory diseases, due to the principle that lengthening muscle actions lead to high force-generating capacity at low cardiopulmonary load. One clinical population that may particularly benefit from this strategy is chronic obstructive pulmonary disease (COPD), as ventilatory constraints and locomotor muscle dysfunction often limit efficacy of conventional exercise rehabilitation in patients with severe disease. While the feasibility of EET for COPD has been established, the nature and extent of adaptation within COPD muscle is unknown. The aim of this study was therefore to characterize the locomotor muscle adaptations to EET in patients with severe COPD, and compare them with adaptations gained through conventional concentric ergometer training (CET). Male patients were randomized to either EET (n = 8) or CET (n = 7) for 10 weeks and matched for heart rate intensity. EET patients trained on average at a workload that was three times that of CET, at a lower perception of leg fatigue and dyspnea. EET led to increases in isometric peak strength and relative thigh mass (p < 0.01) whereas CET had no such effect. However, EET did not result in fiber hypertrophy, as morphometric analysis of muscle biopsies showed no increase in mean fiber cross-sectional area (p = 0.82), with variability in the direction and magnitude of fiber-type responses (20% increase in Type 1, p = 0.18; 4% decrease in Type 2a, p = 0.37) compared to CET (26% increase in Type 1, p = 0.04; 15% increase in Type 2a, p = 0.09). EET had no impact on mitochondrial adaptation, as revealed by lack of change in markers of mitochondrial biogenesis, content and respiration, which contrasted to improvements (p < 0.05) within CET muscle. While future study is needed to more definitively determine the effects of EET on fiber hypertrophy and associated underlying

  17. Eccentric Ergometer Training Promotes Locomotor Muscle Strength but Not Mitochondrial Adaptation in Patients with Severe Chronic Obstructive Pulmonary Disease.

    PubMed

    MacMillan, Norah J; Kapchinsky, Sophia; Konokhova, Yana; Gouspillou, Gilles; de Sousa Sena, Riany; Jagoe, R Thomas; Baril, Jacinthe; Carver, Tamara E; Andersen, Ross E; Richard, Ruddy; Perrault, Hélène; Bourbeau, Jean; Hepple, Russell T; Taivassalo, Tanja

    2017-01-01

    Eccentric ergometer training (EET) is increasingly being proposed as a therapeutic strategy to improve skeletal muscle strength in various cardiorespiratory diseases, due to the principle that lengthening muscle actions lead to high force-generating capacity at low cardiopulmonary load. One clinical population that may particularly benefit from this strategy is chronic obstructive pulmonary disease (COPD), as ventilatory constraints and locomotor muscle dysfunction often limit efficacy of conventional exercise rehabilitation in patients with severe disease. While the feasibility of EET for COPD has been established, the nature and extent of adaptation within COPD muscle is unknown. The aim of this study was therefore to characterize the locomotor muscle adaptations to EET in patients with severe COPD, and compare them with adaptations gained through conventional concentric ergometer training (CET). Male patients were randomized to either EET (n = 8) or CET (n = 7) for 10 weeks and matched for heart rate intensity. EET patients trained on average at a workload that was three times that of CET, at a lower perception of leg fatigue and dyspnea. EET led to increases in isometric peak strength and relative thigh mass (p < 0.01) whereas CET had no such effect. However, EET did not result in fiber hypertrophy, as morphometric analysis of muscle biopsies showed no increase in mean fiber cross-sectional area (p = 0.82), with variability in the direction and magnitude of fiber-type responses (20% increase in Type 1, p = 0.18; 4% decrease in Type 2a, p = 0.37) compared to CET (26% increase in Type 1, p = 0.04; 15% increase in Type 2a, p = 0.09). EET had no impact on mitochondrial adaptation, as revealed by lack of change in markers of mitochondrial biogenesis, content and respiration, which contrasted to improvements (p < 0.05) within CET muscle. While future study is needed to more definitively determine the effects of EET on fiber hypertrophy and associated underlying

  18. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Liu, Li; Solmon, Fabien; Viovy, Nicolas; Khvorostyanov, Dmitry; Essl, Franz; Chuine, Isabelle; Colette, Augustin; Semenov, Mikhail A.; Schaffhauser, Alice; Storkey, Jonathan; Thibaudon, Michel; Epstein, Michelle M.

    2015-08-01

    Common ragweed (Ambrosia artemisiifolia) is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals. Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by 2050 airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

  19. Secretory COPII Protein SEC31B Is Required for Pollen Wall Development1[OPEN

    PubMed Central

    Zhao, Bingchun; Shi, Haidan; Wang, Wanlei; Liu, Xiaoyu; Gao, Hui; Wang, Xiaoxiao; Zhang, Yinghui; Yang, Meidi; Li, Rui

    2016-01-01

    The pollen wall protects pollen grains from abiotic and biotic stresses. During pollen wall development, tapetal cells play a vital role by secreting proteins, signals, and pollen wall material to ensure microspore development. But the regulatory mechanism underlying the secretory pathway of the tapetum is largely unknown. Here, we characterize the essential role of the Arabidopsis (Arabidopsis thaliana) COPII protein SECRETORY31B (SEC31B) in pollen wall development and the secretory activity of tapetal cells. The sporophyte-controlled atsec31b mutant exhibits severe pollen and seed abortion. Transmission electron microscopy observation indicates that pollen exine formation in the atsec31b mutant is disrupted significantly. AtSEC31B is a functional COPII protein revealed by endoplasmic reticulum (ER) exit site localization, interaction with AtSEC13A, and retarded ER-Golgi protein trafficking in the atsec31b mutant. A genetic tapetum-specific rescue assay indicates that AtSEC31B functions primarily in the tapetum. Moreover, deletion of AtSEC31B interrupted the formation of the ER-derived tapetosome and altered the location of the ATP-BINDING CASSETTE TRANSPORTER9 protein in the tapetum. Therefore, this work demonstrates that AtSEC31B plays a vital role in pollen wall development by regulating the secretory pathway of the tapetal cells. PMID:27634427

  20. BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana.

    PubMed

    Hoedemaekers, Karin; Derksen, Jan; Hoogstrate, Suzanne W; Wolters-Arts, Mieke; Oh, Sung-Aeong; Twell, David; Mariani, Celestina; Rieu, Ivo

    2015-04-01

    Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery.

  1. 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

  2. An infant with cartilage-hair hypoplasia due to a novel homozygous mutation in the promoter region of the RMRP gene associated with chondrodysplasia and severe immunodeficiency.

    PubMed

    Vatanavicharn, N; Visitsunthorn, N; Pho-iam, T; Jirapongsananuruk, O; Pacharn, P; Chokephaibulkit, K; Limwongse, C; Wasant, P

    2010-01-01

    Cartilage-hair hypoplasia (CHH) is a rare autosomal-recessive disorder characterized by short-limbed dwarfism, sparse hair, and immune deficiency. It is caused by mutations in the RMRP gene, which encodes the RNA component of the mitochondrial RNA-processing ribonuclease (RNase MRP). Several mutations have been identified in its promoter region or transcribed sequence. However, homozygous mutations in the promoter region have been only reported in a patient with primary immunodeficiency without other features of CHH. We report on a Thai girl who first presented with chronic diarrhea, recurrent pneumonia, and severe failure to thrive, without apparently disproportionate dwarfism. The diagnosis of CHH was made after the severe wasting was corrected, and disproportionate growth became noticeable. The patient had the typical features of CHH, including sparse hair and metaphyseal abnormalities. The immunologic profiles were consistent with combined immune deficiency. Mutation analysis identified a novel homozygous mutation, g.-19_-25 dupACTACTC, in the promoter region of the RMRP gene. Identification of the mutation enabled us to provide a prenatal diagnosis in the subsequent pregnancy. This patient is the first CHH case with the characteristic features due to the homozygous mutation in the promoter region of the RMRP gene. The finding of severe immunodeficiency supports that promoter mutations markedly disrupt mRNA cleavage function, which causes cell-cycle impairment.

  3. Proteomics of pollen development and germination.

    PubMed

    Dai, Shaojun; Wang, Tai; Yan, Xiufeng; Chen, Sixue

    2007-12-01

    In higher plants, pollen grains represent the vestiges of a highly reduced male gametophyte generation. After germination, the pollen tube delivers the sperm cells by tip-growing to the embryo sac for fertilization. Besides the intrinsic importance for sexual reproduction, pollen development and germination serve as an attractive system to address important questions related to cell division, cell differentiation, polar growth, cell-cell interaction, and cell fate. Recently, pollen functional specification has been well-studied using multidisciplinary approaches. Here, we review recent advances in proteomics of pollen development and germination.

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

    PubMed

    Zienkiewicz, Agnieszka; Zienkiewicz, Krzysztof; Rejón, Juan David; Rodríguez-García, María Isabel; 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.

  5. Transgene excision in pollen using a codon optimized serine resolvase CinH-RS2 site-specific recombination system.

    PubMed

    Moon, Hong S; Abercrombie, Laura L; Eda, Shigetoshi; Blanvillain, Robert; Thomson, James G; Ow, David W; Stewart, C N

    2011-04-01

    Transgene escape, a major environmental and regulatory concern in transgenic crop cultivation, could be alleviated by removing transgenes from pollen, the most frequent vector for transgene flow. A transgene excision vector containing a codon optimized serine resolvase CinH recombinase (CinH) and its recognition sites RS2 were constructed and transformed into tobacco (Nicotiana tabacum cv. Xanthi). CinH recombinase recognized 119 bp of nucleic acid sequences, RS2, in pollen and excised the transgene flanked by the RS2 sites. In this system, the pollen-specific LAT52 promoter from tomato was employed to control the expression of CinH recombinase. Loss of expression of a green fluorescent protein (GFP) gene under the control of the LAT59 promoter from tomato was used as an indicator of transgene excision. Efficiency of transgene excision from pollen was determined by flow cytometry (FCM)-based pollen screening. While a transgenic event in the absence of CinH recombinase contained about 70% of GFP-synthesizing pollen, three single-copy transgene events contained less than 1% of GFP-synthesizing pollen based on 30,000 pollen grains analyzed per event. This suggests that CinH-RS2 recombination system could be effectively utilized for transgene biocontainment.

  6. Genome-wide identification and analysis of rice genes preferentially expressed in pollen at an early developmental stage.

    PubMed

    Nguyen, Tien Dung; Moon, Sunok; Nguyen, Van Ngoc Tuyet; Gho, Yunsil; Chandran, Anil Kumar Nalini; Soh, Moon-Soo; Song, Jong Tae; An, Gynheung; Oh, Sung Aeong; Park, Soon Ki; Jung, Ki-Hong

    2016-09-01

    Microspore production using endogenous developmental programs has not been well studied. The main limitation is the difficulty in identifying genes preferentially expressed in pollen grains at early stages. To overcome this limitation, we collected transcriptome data from anthers and microspore/pollen and performed meta-expression analysis. Subsequently, we identified 410 genes showing preferential expression patterns in early developing pollen samples of both japonica and indica cultivars. The expression patterns of these genes are distinguishable from genes showing pollen mother cell or tapetum-preferred expression patterns. Gene Ontology enrichment and MapMan analyses indicated that microspores in rice are closely linked with protein degradation, nucleotide metabolism, and DNA biosynthesis and regulation, while the pollen mother cell or tapetum are strongly associated with cell wall metabolism, lipid metabolism, secondary metabolism, and RNA biosynthesis and regulation. We also generated transgenic lines under the control of the promoters of eight microspore-preferred genes and confirmed the preferred expression patterns in plants using the GUS reporting system. Furthermore, cis-regulatory element analysis revealed that pollen specific elements such as POLLEN1LELAT52, and 5659BOXLELAT5659 were commonly identified in the promoter regions of eight rice genes with more frequency than estimation. Our study will provide new sights on early pollen development in rice, a model crop plant.

  7. Bioassaying for ozone with pollen systems.

    PubMed Central

    Feder, W A

    1981-01-01

    Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. Tube growth rates in the presence of a range of ozone dosages, of pollen populations exhibiting differing ozone sensitivity can be measured and different growth rates can be correlated with ozone dosages. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Petunia and tobacco pollen are especially useful because they store well at ordinary freezer temperatures and do not require special preparation prior to storage. Modified Brewbacker's growth medium is suitable for growth of both these pollen types. Four useful cultivars are Bel W-3, ozone-sensitive and Bel B, ozone-tolerant tobacco, and White Bountiful, ozone-sensitive and Blue Lagoon, ozone-tolerant petunia. Observations can be made directly by using a TV scanner, or by time lapse or interval photography. Year-round pollen production can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality. Images FIGURE 2. FIGURE 3. FIGURE 4. PMID:7460876

  8. Cytochemical localization of some hydrolases in the pollen and pollen tubes of Amaryllis vittata Ait.

    PubMed

    Sharma, D

    1982-01-01

    Some hydrolases are localized cytochemically in the pollen and pollen tubes of Amaryllis vittata Ait. The function of different enzymes is discussed in relation to pollen tubes morphogenesis. Activity of most of the enzymes was confined to colpus region, pollen wall and general cytoplasm of pollen and pollen tube. The activity of hydrolytic enzymes like acid monophosphoesterase and lipase and was nil in the exine of both germinated and ungerminated pollen, whereas intense reaction for esterase was observed in exine. Enzyme activity increased after germination which suggest the hydrolysis of stored metabolites and synthesis of proteins and other metabolites for the active growth of pollen tube. Intense reaction for enzymes like alkaline phosphomonoesterase, ATP-ase, 5-nucleotidase etc. at the tip region of pollen tube suggest their role in physiological processes associated with exchange of materials through intercellular transport during tube wall polysaccharide biogenesis.

  9. 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.

  10. Pollen selection under acid rain stress

    SciTech Connect

    Zhang, Y.

    1994-01-01

    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 in 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.

  11. Association between pollen hypersensitivity and edible vegetable allergy: a review.

    PubMed

    Caballero, T; Martín-Esteban, M

    1998-01-01

    Over the last three decades several authors have described the existence of an association between sensitivity to different pollens and sensitivity to diverse edible vegetables. An association between ragweed pollinosis and hypersensitivity to Cucurbitaceae vegetables (e.g., watermelon, melon, cucumber) and banana has been reported. Other authors have found a relationship between birch pollinosis and sensitization to hazelnut, apple, carrot, potato, kiwi and other vegetables. Additionally, several papers have shown the association between mugwort pollinosis and sensitization to celery, carrot, spices, nuts, mustard and Leguminoseae vegetables. Later, some studies showed association between grass pollinosis and sensitization to tomato, potato, green- pea, peanut, watermelon, melon, apple, orange and kiwi. Finally, an association between sensitization to plantain pollen and melon hypersensitivity was also described. The association between pollinosis and edible vegetable sensitization has been explained by the combination of different hypotheses, such as the following: 1) presence of lectins in edible vegetables; 2) existence of IgE to carbohydrates of the glycoproteins (cross-reactive carbohydrate determinants); and, 3) existence of common allergens between pollens and edible vegetables. Up to now three allergens have been identified as responsible for cross-reactivity in these associations: profilin, a 14 kd protein that regulates actin; Bet v 1, the 18 kd birch pollen allergen; and a 60-69 kd allergen. It is important to study in depth these associated sensitizations and the common allergens responsible for them in order to improve diagnostic methods and treatment of these syndromes.

  12. 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.

  13. The biosynthesis, composition and assembly of the outer pollen wall: A tough case to crack.

    PubMed

    Quilichini, Teagen D; Grienenberger, Etienne; Douglas, Carl J

    2015-05-01

    The formation of the durable outer pollen wall, largely composed of sporopollenin, is essential for the protection of the male gametophyte and plant reproduction. Despite its apparent strict conservation amongst land plants, the composition of sporopollenin and the biosynthetic pathway(s) yielding this recalcitrant biopolymer remain elusive. Recent molecular genetic studies in Arabidopsis thaliana (Arabidopsis) and rice have, however, identified key genes involved in sporopollenin formation, allowing a better understanding of the biochemistry and cell biology underlying sporopollenin biosynthesis and pollen wall development. Herein, current knowledge of the biochemical composition of the outer pollen wall is reviewed, with an emphasis on enzymes with characterized biochemical activities in sporopollenin and pollen coat biosynthesis. The tapetum, which forms the innermost sporophytic cell layer of the anther and envelops developing pollen, plays an essential role in sporopollenin and pollen coat formation. Recent studies show that several tapetum-expressed genes encode enzymes that metabolize fatty acid derived compounds to form putative sporopollenin precursors, including tetraketides derived from fatty acyl-CoA starter molecules, but analysis of mutants defective in pollen wall development indicate that other components are also incorporated into sporopollenin. Also highlighted are the many uncertainties remaining in the development of a sporopollenin-fortified pollen wall, particularly in relation to the mechanisms of sporopollenin precursor transport and assembly into the patterned form of the pollen wall. A working model for sporopollenin biosynthesis is proposed based on the data obtained largely from studies of Arabidopsis, and future challenges to complete our understanding of pollen wall biology are outlined.

  14. Mild acidic pretreatment to enhance low severity coal liquefaction promoted by cyclic olefins. Quarterly report, July 1995--September 1995

    SciTech Connect

    Curtis, C.W.

    1996-03-01

    Research continued on low severity coal liquefaction. Research using high temperature infrared of cyclic olefins progressed well during this quarter. Several fluorinated solvents were found that provide a high temperature medium for isotetralin and its aromatic and aliphatic analogues.

  15. Potential of δ13C in Pollen to Serve as Paleotemperature Proxy

    NASA Astrophysics Data System (ADS)

    King, D. P.; Foelber, K.; Schubert, B.; Jahren, A.

    2010-12-01

    Fossil pollen is an invaluable indicator of vegetation composition, is notably resilient against diagenetic alteration, and can be found in large quantities within highly chronologically-resolved substrates such as lake sediments. In addition, several recent isotopic techniques have made possible the analysis of small quantities (approaching <100 pollen grains) while nanomaterials hold promise for efficient shape-sorting of pollen assemblages. Because environmental conditions affect the stable isotope signature of plant tissues, we explored the potential for the δ13C value of pollen produced by plants growing under diverse climate regimes to reflect paleotemperature. We examined the relationship between temperature and δ13C of the pollen produced in several settings including: laboratory growth chambers, single-genus field comparisons, and whole-community comparisons from botanical gardens. In each of these settings the relationship between growing season temperature and the δ13C of pollen produced resulted in a positive correlation with R2 > 0.5; our presentation will discuss the practical implementation of stable isotopes in pollen as a paleotemperature proxy, both in terms of substrate recovery and produced-certainty of temperature estimates.

  16. Does bee pollen cause to eosinophilic gastroenteropathy?

    PubMed Central

    Güç, Belgin Usta; Asilsoy, Suna; Canan, Oğuz; Kayaselçuk, Fazilet

    2015-01-01

    Bee pollen is given to children by mothers in order to strengthen their immune systems. There are no studies related with the side effects of bee polen in the literature. In this article, the literature was reviewed by presenting a case of allergic eosinophilic gastropathy related with bee polen. A 5-year old child was admitted due to abdominal pain. Edema was detected on the eyelids and pretibial region. In laboratory investigations, pathology was not detected in terms of hepatic and renal causes that would explain the protein loss of the patient diagnosed with hypoproteinemia and hypoalbuminemia. Urticaria was detected during the follow-up visit. When the history of the patient was deepened, it was learned that bee pollen was given to the patient every day. The total eosinophil count was found to be 1 800/mm3. Allergic gastroenteropathy was considered because of hypereosinophilia and severe abdominal pain and endoscopy was performed. Biopsy revealed abundant eosinophils in the whole gastric mucosa. A diagnosis of allergic eosinophilic gastropathy was made. Bee polen was discontinued. Abdominal pain and edema disappeared in five days. Four weeks later, the levels of serum albumin and total eosinophil returned to normal. PMID:26568697

  17. Does bee pollen cause to eosinophilic gastroenteropathy?

    PubMed

    Güç, Belgin Usta; Asilsoy, Suna; Canan, Oğuz; Kayaselçuk, Fazilet

    2015-09-01

    Bee pollen is given to children by mothers in order to strengthen their immune systems. There are no studies related with the side effects of bee polen in the literature. In this article, the literature was reviewed by presenting a case of allergic eosinophilic gastropathy related with bee polen. A 5-year old child was admitted due to abdominal pain. Edema was detected on the eyelids and pretibial region. In laboratory investigations, pathology was not detected in terms of hepatic and renal causes that would explain the protein loss of the patient diagnosed with hypoproteinemia and hypoalbuminemia. Urticaria was detected during the follow-up visit. When the history of the patient was deepened, it was learned that bee pollen was given to the patient every day. The total eosinophil count was found to be 1 800/mm(3). Allergic gastroenteropathy was considered because of hypereosinophilia and severe abdominal pain and endoscopy was performed. Biopsy revealed abundant eosinophils in the whole gastric mucosa. A diagnosis of allergic eosinophilic gastropathy was made. Bee polen was discontinued. Abdominal pain and edema disappeared in five days. Four weeks later, the levels of serum albumin and total eosinophil returned to normal.

  18. A tale of two morphs: modeling pollen transfer, magic traits, and reproductive isolation in parapatry.

    PubMed

    Haller, Benjamin C; de Vos, Jurriaan M; Keller, Barbara; Hendry, Andrew P; Conti, Elena

    2014-01-01

    The evolution of the flower is commonly thought to have spurred angiosperm diversification. Similarly, particular floral traits might have promoted diversification within specific angiosperm clades. We hypothesize that traits promoting the precise positional transfer of pollen between flowers might promote diversification. In particular, precise pollen transfer might produce partial reproductive isolation that facilitates adaptive divergence between parapatric populations differing in their reproductive-organ positions. We investigate this hypothesis with an individual-based model of pollen transfer dynamics associated with heterostyly, a floral syndrome that depends on precise pollen transfer. Our model shows that precise pollen transfer can cause sexual selection leading to divergence in reproductive-organ positions between populations served by different pollinators, pleiotropically causing an increase in reproductive isolation through a "magic trait" mechanism. Furthermore, this increased reproductive isolation facilitates adaptive divergence between the populations in an unlinked, ecologically selected trait. In a different pollination scenario, however, precise pollen transfer causes a decrease in adaptive divergence by promoting asymmetric gene flow. Our results highlight the idea that magic traits are not "magic" in isolation; in particular, the effect size of magic traits in speciation depends on the external environment, and also on other traits that modify the strength of the magic trait's influence on non-random mating. Overall, we show that the evolutionary consequences of pollen transfer dynamics can depend strongly on the available pollinator fauna and on the morphological fit between flowers and pollinators. Furthermore, our results illustrate the potential importance of even weak reproductive isolating barriers in facilitating adaptive divergence.

  19. A Tale of Two Morphs: Modeling Pollen Transfer, Magic Traits, and Reproductive Isolation in Parapatry

    PubMed Central

    Haller, Benjamin C.; de Vos, Jurriaan M.; Keller, Barbara; Hendry, Andrew P.; Conti, Elena

    2014-01-01

    The evolution of the flower is commonly thought to have spurred angiosperm diversification. Similarly, particular floral traits might have promoted diversification within specific angiosperm clades. We hypothesize that traits promoting the precise positional transfer of pollen between flowers might promote diversification. In particular, precise pollen transfer might produce partial reproductive isolation that facilitates adaptive divergence between parapatric populations differing in their reproductive-organ positions. We investigate this hypothesis with an individual-based model of pollen transfer dynamics associated with heterostyly, a floral syndrome that depends on precise pollen transfer. Our model shows that precise pollen transfer can cause sexual selection leading to divergence in reproductive-organ positions between populations served by different pollinators, pleiotropically causing an increase in reproductive isolation through a “magic trait” mechanism. Furthermore, this increased reproductive isolation facilitates adaptive divergence between the populations in an unlinked, ecologically selected trait. In a different pollination scenario, however, precise pollen transfer causes a decrease in adaptive divergence by promoting asymmetric gene flow. Our results highlight the idea that magic traits are not “magic” in isolation; in particular, the effect size of magic traits in speciation depends on the external environment, and also on other traits that modify the strength of the magic trait's influence on non-random mating. Overall, we show that the evolutionary consequences of pollen transfer dynamics can depend strongly on the available pollinator fauna and on the morphological fit between flowers and pollinators. Furthermore, our results illustrate the potential importance of even weak reproductive isolating barriers in facilitating adaptive divergence. PMID:25211280

  20. Characterization and functional analysis of a pollen-specific gene st901 in Solanum tuberosum.

    PubMed

    Zhao, Yan; Zhao, Qian; Ao, Guangming; Yu, Jingjuan

    2006-07-01

    A pollen-specific gene, sb401, which was isolated from a cDNA library of in vitro geminated pollen of the diploid potato species Solanum berthaultii, belongs to the class of genes expressed late during pollen development. Using sb401 as a probe, a pollen-specific gene st901 was isolated from the genomic library of a potato species Solanum tuberosum cv. Desiree. Sequencing and RT-PCR analysis showed that the st901 genomic gene is 2,889 bp long, contains three exons and two introns, and encodes a putative polypeptide of 217 residues. The predicted protein sequence contains four imperfect repeated motifs of V-V-E-K-K-N/E-E; the core sequence of the repeats (K-K-N/E-E) resembles a microtubule-binding domain of the microtubule-associated protein MAP1B from mouse. The examination of a promoter-reporter construct in transgenic potato plants revealed that the st901 is expressed exclusively in mature pollen grains, which is consistent with the results of Northern blot and RT-PCR. For analysis of the function of st901, transgenic plants harboring antisense copies of st901 cDNA driven by a native st901 promoter were generated. Suppression of st901 gene in potato resulted in aberrant pollen at maturation and pollen viability of transgenic plants ranged from 4.4 to 14.8%, while that of control plants were more than 90%. These results strongly suggest that st901 has an essential role in pollen development.

  1. Tree pollen spectra and pollen allergy risk in the Osijek-Baranja County.

    PubMed

    Sikora, Magdalena; Valek, Marina; Šušić, Zdenka; Santo, Vera; Brdarić, Dario

    2013-01-01

    The forests of north-eastern Croatia, as well as various plants and trees in the parks and streets of the Osijek-Baranja County, produce large amounts of pollen during the pollen season, which can cause allergy symptoms in pollen sensitive individuals. The aim of this study was to determine the most frequent types of pollen in this area and estimate possible health risks, especially the risk of allergy. In 2009 and 2010, the staff of the Health Ecology Department of the Osijek Public Health Institute monitored tree pollen concentrations in four cities from the Osijek - Baranja County (Osijek, Našice, Đakovo and Beli Manastir) using a Burkard volumetric instrument. The results were affected by weather conditions. Windy and sunny days facilitated the transfer of pollen, whereas during rainy days, the concentration of pollen grains decreased. High pollen concentrations of Cupressaceae/Taxaceae, Betulaceae, Salicaceae and Aceraceae could be the cause for symptoms of pollen allergy. In 2009, conifers, birch and poplar pollen were dominant at all monitoring stations with 5000 pollen grains (PG), 3188 PG and 3113 PG respectively. The highest number of pollen grains was recorded at measuring site Osijek. The variations in airborne pollen concentration between pollen seasons were recorded at all monitoring stations. The most obvious variations were recorded at measuring site Osijek. The usual pollination period lasts two to three months, which means that most pollen grains remain present from February to early June. However, the Cupressaceae / Taxaceae pollination periods last the longest and their pollen grains remain present until the end of summer. The risk of allergy was determined at four monitored measuring stations and the obtained data confirmed that the largest number of days with a high health risk was at the Đakovo measuring station for a species of birch. The research information aims to help allergologists and individuals allergic to plant pollen develop

  2. Towards a "crime pollen calendar" - pollen analysis on corpses throughout one year.

    PubMed

    Montali, Elisa; Mercuri, Anna Maria; Trevisan Grandi, Giuliana; Accorsi, Carla Alberta

    2006-11-22

    A palynological study was carried out on 28 corpses brought in one year (June 2003-May 2004) to the morgue of the Institute of Legal Medicine of Parma (Northern Italy). This preliminary research focuses on the date of death, which was known for all corpses examined. Pollen sampling and analyses were made with the first aim of comparing the pollen grains found on corpses with those diffused in the atmosphere in the region in the same season as the known date of death. Eyebrows, hair-line near the forehead, facial skin and nasal cavities were sampled. Most of the corpses had trapped pollen grains, with the exception of two December corpses. All pollen grains were found with cytoplasm and in a good state of preservation. In this way, a series of reference data was collected for the area where the deaths occurred, and we examined whether pollen grains on corpses could be an index of the season of death. To verify this hypothesis, the pollen analyses were compared with data reported in the airborne pollen calendars of Parma and the region around. Pollen calendars record pollen types and their concentrations in the air, month by month. The quantity of pollen recorded on corpses did not prove to be directly related to the quantity of pollen in the air. But qualitatively, many pollen types which are seasonal markers were found on corpses. Main corpse/air discrepancies were also observed due to the great influence that the local environmental conditions of the death scene have in determining the pollen trapped by a corpse. Qualitative plus quantitative pollen data from corpses appeared helpful in indicating the season of death. A preliminary sketch of a "crime pollen calendar" in a synthetic graphic form was made by grouping the corpse pollen records into three main seasons: A, winter/spring; B, spring/summer; C, summer/autumn. Trends match the general seasonal trend of pollen types in the air.

  3. Pollen-Associated Microbiome Correlates with Pollution Parameters and the Allergenicity of Pollen.

    PubMed

    Obersteiner, Andrea; Gilles, Stefanie; Frank, Ulrike; Beck, Isabelle; Häring, Franziska; Ernst, Dietrich; Rothballer, Michael; Hartmann, Anton; Traidl-Hoffmann, Claudia; Schmid, Michael

    2016-01-01

    Pollen allergies have been rapidly increasing over the last decades. Many allergenic proteins and non-allergenic adjuvant compounds of pollen are involved in the plant defense against environmental or microbial stress. The first aim of this study was to analyze and compare the colonizing microbes on allergenic pollen. The second aim was to investigate detectable correlations between pollen microbiota and parameters of air pollution or pollen allergenicity. To reach these aims, bacterial and fungal DNA was isolated from pollen samples of timothy grass (Phleum pratense, n = 20) and birch trees (Betula pendula, n = 55). With this isolated DNA, a terminal restriction fragment length polymorphism analysis was performed. One result was that the microbial diversity on birch tree and timothy grass pollen samples (Shannon/Simpson diversity indices) was partly significantly correlated to allergenicity parameters (Bet v 1/Phl p 5, pollen-associated lipid mediators). Furthermore, the microbial diversity on birch pollen samples was correlated to on-site air pollution (nitrogen dioxide (NO2), ammonia (NH3), and ozone (O3)). What is more, a significant negative correlation was observed between the microbial diversity on birch pollen and the measured NO2 concentrations on the corresponding trees. Our results showed that the microbial composition of pollen was correlated to environmental exposure parameters alongside with a differential expression of allergen and pollen-associated lipid mediators. This might translate into altered allergenicity of pollen due to environmental and microbial stress.

  4. Pollen-Associated Microbiome Correlates with Pollution Parameters and the Allergenicity of Pollen

    PubMed Central

    Obersteiner, Andrea; Gilles, Stefanie; Frank, Ulrike; Beck, Isabelle; Häring, Franziska; Ernst, Dietrich; Rothballer, Michael; Hartmann, Anton; Traidl-Hoffmann, Claudia; Schmid, Michael

    2016-01-01

    Pollen allergies have been rapidly increasing over the last decades. Many allergenic proteins and non-allergenic adjuvant compounds of pollen are involved in the plant defense against environmental or microbial stress. The first aim of this study was to analyze and compare the colonizing microbes on allergenic pollen. The second aim was to investigate detectable correlations between pollen microbiota and parameters of air pollution or pollen allergenicity. To reach these aims, bacterial and fungal DNA was isolated from pollen samples of timothy grass (Phleum pratense, n = 20) and birch trees (Betula pendula, n = 55). With this isolated DNA, a terminal restriction fragment length polymorphism analysis was performed. One result was that the microbial diversity on birch tree and timothy grass pollen samples (Shannon/Simpson diversity indices) was partly significantly correlated to allergenicity parameters (Bet v 1/Phl p 5, pollen-associated lipid mediators). Furthermore, the microbial diversity on birch pollen samples was correlated to on-site air pollution (nitrogen dioxide (NO2), ammonia (NH3), and ozone (O3)). What is more, a significant negative correlation was observed between the microbial diversity on birch pollen and the measured NO2 concentrations on the corresponding trees. Our results showed that the microbial composition of pollen was correlated to environmental exposure parameters alongside with a differential expression of allergen and pollen-associated lipid mediators. This might translate into altered allergenicity of pollen due to environmental and microbial stress. PMID:26910418

  5. Influence of 2-meter temperature bias on birch pollen season and concentrations in the Enviro-HIRLAM

    NASA Astrophysics Data System (ADS)

    Kurganskiy, Alexander; Kaas, Eigil; Baklanov, Alexander; Mahura, Alexander; Nuterman, Roman; Rasmussen, Alix

    2016-04-01

    Forecasting the start of the birch pollen season as well as birch pollen concentrations is a challenging task from a modeling point of view. The start of birch pollen season is commonly determined by so-called Growing-Degree-Days (GDD) parameterization. GDD is based on accumulation of 2-meter daily mean air temperatures above a given threshold and supposes that birch flowering starts as soon as the accumulated temperature reaches a certain value depending on geographical location. Therefore, even a minor bias (for example, 0.5 °C) of 2-meter air temperature forecasted by a numerical weather prediction model can lead to an error of several days for simulated start of the birch pollen season. Moreover, birch pollen emission is strongly dependent on such meteorological parameters as 2-meter temperature and relative humidity, 10-meter wind speed and direction, and accumulated precipitation. So, 2-meter air temperature biases can also influence the modeled birch pollen emissions and, consequently, modeled atmospheric birch pollen concentrations. In our study, the online-coupled meteorology chemistry model Enviro-HIRLAM (Environment - High Resolution Limited Area Model) was employed to simulate birch pollen emissions, atmospheric transport, dispersion and deposition for the European domain with 15-km horizontal resolution. Model runs were performed for a case study of birch pollen season 2006 with and without attempts to correct for 2-meter air temperature biases and related changes in relative humidity. The modeled birch pollen concentrations were compared with aerobiological observations for European measurement sites. The influence of 2-meter air temperature bias correction on the start of birch pollen season and magnitude of birch pollen concentrations turns out to be important and should be included in operational setups.

  6. Too low to kill: concentration of the secondary metabolite ranunculin in buttercup pollen does not affect bee larval survival.

    PubMed

    Sedivy, Claudio; Piskorski, Rafal; Müller, Andreas; Dorn, Silvia

    2012-08-01

    Growing evidence suggests that the freely accessible pollen of some plants is chemically protected against pollen-feeding flower visitors. For example, a diet of pollen from buttercup plants (Ranunculus) recently was shown to have a deleterious effect on developing larvae of several bee species not specialized on Ranunculus. Numerous Ranunculus species contain ranunculin, the glucosyl hydrate form of the highly reactive and toxic lactone protoanemonin, that causes the toxicity of these plants. We tested whether the presence of ranunculin is responsible for the lethal effects of R. acris pollen on the larvae of two bee species that are not Ranunculus specialists. To investigate the effect on bee larval development, we added ranunculin to the pollen provisions of the Campanula specialist bee Chelostoma rapunculi and the Asteraceae specialist bee Heriades truncorum, and allowed the larvae to feed on these provisions. We quantified ranunculin in pollen of R. acris and in brood cell provisions collected by the Ranunculus specialist bee Chelostoma florisomne. We demonstrated that although ranunculin was lethal to both tested bee species in high concentrations, the concentration in the pollen of R. acris was at least fourfold lower than that tolerated by the larvae of C. rapunculi and H. truncorum in the feeding experiments. Ranunculin concentration in the brood cells of C. florisomne was on average even twentyfold lower than that in Ranunculus pollen, suggesting that a mechanism different from ranunculin intoxication accounts for the larval mortality reported for bees not specialized on Ranunculus pollen.

  7. Atmospheric Poaceae pollen frequencies and associations with meteorological parameters in Brisbane, Australia: a 5-year record, 1994-1999

    NASA Astrophysics Data System (ADS)

    Green, Brett James; Dettmann, Mary; Yli-Panula, Eija; Rutherford, Shannon; Simpson, Rod

    Grass pollen is an important risk factor for allergic rhinitis and asthma in Australia and is the most prevalent pollen component of the aerospora of Brisbane, accounting for 71.6% of the annual airborne pollen load. A 5-year (June 1994-May 1999) monitoring program shows the grass pollen season to occur during the summer and autumn months (December-April), however the timing of onset and intensity of the season vary from year to year. During the pollen season, Poaceae counts exceeding 30 grains m-3 were recorded on 244 days and coincided with maximum temperatures of 28.1 +/- 2.0 °C. In this study, statistical associations between atmospheric grass pollen loads and several weather parameters, including maximum temperature, minimum temperature and precipitation, were investigated. Spearman's correlation analysis demonstrated that daily grass pollen counts were positively associated (P < 0.0001) with maximum and minimum temperature during each sampling year. Precipitation, although considered a less important daily factor (P < 0.05), was observed to remove pollen grains from the atmosphere during significant periods of rainfall. This study provides the first insight into the influence of meteorological variables, in particular temperature, on atmospheric Poaceae pollen counts in Brisbane. An awareness of these associations is critical for the prevention and management of allergy and asthma for atopic individuals within this region.

  8. Ankylosing spondylitis susceptibility and severity--contribution of TNF gene promoter polymorphisms at positions -238 and -308.

    PubMed

    Sousa, Elsa; Caetano-Lopes, Joana; Pinto, Patrícia; Pimentel, Fernando; Teles, José; Canhão, Helena; Rodrigues, Ana; Resende, Catarina; Mourão, Ana Filipa; Ribeiro, Célia; Pinto, Teresa Laura; Rosa, Carlos Miranda; da Silva, José Alberto Pereira; Branco, Jaime; Ventura, Francisco; Queiroz, Mário Viana; Fonseca, João Eurico

    2009-09-01

    Ankylosing spondylitis (AS) is a chronic inflammatory disease in which genetic factors play a central role. The efficacy of TNF blockers has reoriented research in this field in order to explain the influence of TNF in AS pathogenesis. The objective of this study was to access the influence of single nucleotide polymorphisms (SNPs) at positions -308 and -238 of the promoter region of TNF gene on AS susceptibility and prognosis. SNPs were determined by restriction fragment length polymorphisms in patients and controls. AS patients exhibited a decreased frequency of the A allele at position -238 (10%) when compared with controls (18%), suggesting that this could be a protective factor for disease susceptibility. In addition, the -308 GA/AA genotypes were associated with later disease onset in AS patients. These results suggest that TNF gene promoter polymorphisms at positions -238 and -308 could have a small influence on AS susceptibility and prognosis.

  9. Pollen dispersal slows geographical range shift and accelerates ecological niche shift under climate change

    PubMed Central

    Aguilée, Robin; Raoul, Gaël; Rousset, François; Ronce, Ophélie

    2016-01-01

    Species may survive climate change by migrating to track favorable climates and/or adapting to different climates. Several quantitative genetics models predict that species escaping extinction will change their geographical distribution while keeping the same ecological niche. We introduce pollen dispersal in these models, which affects gene flow but not directly colonization. We show that plant populations may escape extinction because of both spatial range and ecological niche shifts. Exact analytical formulas predict that increasing pollen dispersal distance slows the expected spatial range shift and accelerates the ecological niche shift. There is an optimal distance of pollen dispersal, which maximizes the sustainable rate of climate change. These conclusions hold in simulations relaxing several strong assumptions of our analytical model. Our results imply that, for plants with long distance of pollen dispersal, models assuming niche conservatism may not accurately predict their future distribution under climate change. PMID:27621443

  10. [Identification of cattail pollen (puhuang), pine pollen (songhuafen) and its adulterants by ITS2 sequence].

    PubMed

    Ma, Xiao-Xi; Sun, Wei; Ren, Wei-Chao; Xiang, Li; Zhao, Bo; Zhang, Ya-Qin; Song, Ming; Mu, Ze-Jing; Chen, Shi-Lin

    2014-06-01

    DNA barcoding method was conducted for the authentication of pollen materials due to difficulty of discriminating pollen materials bearing morphological similarity. In this study, a specific focus was to identify cattail pollen (Puhuang) and pine pollen (Songhuafen) samples from their adulterants which are frequently mixed-together. Regions of the internal transcribed spacer (ITS2) from 60 samples were sequenced, and new primers for cattail pollen were designed according to the sequence information. The results from the NJ trees showed that the species of pine pollen, Puhuang and their adulterants can be classified as obvious monophyly. Therefore, we propose to adapt DNA barcoding methodology to accurately distinguish cattail pollen, pine pollen and their adulterant materials. It is a great help for drug regulatory agency to supervise the quality of medicinal materials.

  11. Pollen Raman spectra database: application to the identification of airborne pollen.

    PubMed

    Guedes, A; Ribeiro, H; Fernández-González, M; Aira, M J; Abreu, I

    2014-02-01

    Raman microspectroscopy allows a non-destructive identification of airborne particles. However, the identification of particles such as pollen is hindered by the absence of a spectral library. Although reference spectra of pollen have been published before, they have always been limited to a certain number of species. In this work, Raman spectra of 34 pollen types are presented and were used to build a pollen spectra primary library. Afterward, the applicability of this database for detecting and identifying pollen in airborne samples was tested. Airborne pollen samples collected during April, May and August were compared with blank pollen spectra by means of Hit Quality Index. Although a much larger library would be required, our results showed that all first hits correspond to the same blank pollen species of the questioned sample from the air. This possibility is an innovative idea and a promising line of investigation for future RAMAN technology development in the area of aerobiology.

  12. Identification of aqueous pollen extracts using surface enhanced Raman scattering (SERS) and pattern recognition methods.

    PubMed

    Seifert, Stephan; Merk, Virginia; Kneipp, Janina

    2016-01-01

    Aqueous pollen extracts of varying taxonomic relations were analyzed with surface enhanced Raman scattering (SERS) by using gold nanoparticles in aqueous suspensions as SERS substrate. This enables a selective vibrational characterization of the pollen water soluble fraction (mostly cellular components) devoid of the spectral contributions from the insoluble sporopollenin outer layer. The spectra of the pollen extracts are species-specific, and the chemical fingerprints can be exploited to achieve a classification that can distinguish between different species of the same genus. In the simple experimental procedure, several thousands of spectra per species are generated. Using an artificial neural network (ANN), it is demonstrated that analysis of the intrinsic biochemical information of the pollen cells in the SERS data enables the identification of pollen from different plant species at high accuracy. The ANN extracts the taxonomically-relevant information from the data in spite of high intra-species spectral variation caused by signal fluctuations and preparation specifics. The results show that SERS can be used for the reliable characterization and identification of pollen samples. They have implications for improved investigation of pollen physiology and for allergy warning.

  13. Gamma, Gaussian and logistic distribution models for airborne pollen grains and fungal spore season dynamics.

    PubMed

    Kasprzyk, I; Walanus, A

    2014-01-01

    The characteristics of a pollen season, such as timing and magnitude, depend on a number of factors such as the biology of the plant and environmental conditions. The main aim of this study was to develop mathematical models that explain dynamics in atmospheric concentrations of pollen and fungal spores recorded in Rzeszów (SE Poland) in 2000-2002. Plant taxa with different characteristics in the timing, duration and curve of their pollen seasons, as well as several fungal taxa were selected for this analysis. Gaussian, gamma and logistic distribution models were examined, and their effectiveness in describing the occurrence of airborne pollen and fungal spores was compared. The Gaussian and differential logistic models were very good at describing pollen seasons with just one peak. These are typically for pollen types with just one dominant species in the flora and when the weather, in particular temperature, is stable during the pollination period. Based on s parameter of the Gaussian function, the dates of the main pollen season can be defined. In spite of the fact that seasonal curves are often characterised by positive skewness, the model based on the gamma distribution proved not to be very effective.

  14. Impact of Bt corn pollen on monarch butterfly populations: a risk assessment.

    PubMed

    Sears, M K; Hellmich, R L; Stanley-Horn, D E; Oberhauser, K S; Pleasants, J M; Mattila, H R; Siegfried, B D; Dively, G P

    2001-10-09

    A collaborative research effort by scientists in several states and in Canada has produced information to develop a formal risk assessment of the impact of Bt corn on monarch butterfly (Danaus plexippus) populations. Information was sought on the acute toxic effects of Bt corn pollen and the degree to which monarch larvae would be exposed to toxic amounts of Bt pollen on its host plant, the common milkweed, Asclepias syriaca, found in and around cornfields. Expression of Cry proteins, the active toxicant found in Bt corn tissues, differed among hybrids, and especially so in the concentrations found in pollen of different events. In most commercial hybrids, Bt expression in pollen is low, and laboratory and field studies show no acute toxic effects at any pollen density that would be encountered in the field. Other factors mitigating exposure of larvae include the variable and limited overlap between pollen shed and larval activity periods, the fact that only a portion of the monarch population utilizes milkweed stands in and near cornfields, and the current adoption rate of Bt corn at 19% of North American corn-growing areas. This 2-year study suggests that the impact of Bt corn pollen from current commercial hybrids on monarch butterfly populations is negligible.

  15. A Pollen Coat–Inducible Autoinhibited Ca2+-ATPase Expressed in Stigmatic Papilla Cells Is Required for Compatible Pollination in the Brassicaceae[W

    PubMed Central

    Iwano, Megumi; Igarashi, Motoko; Tarutani, Yoshiaki; Kaothien-Nakayama, Pulla; Nakayama, Hideki; Moriyama, Hideki; Yakabe, Ryo; Entani, Tetsuyuki; Shimosato-Asano, Hiroko; Ueki, Masao; Tamiya, Gen; Takayama, Seiji

    2014-01-01

    In the Brassicaceae, intraspecific non-self pollen (compatible pollen) can germinate and grow into stigmatic papilla cells, while self-pollen or interspecific pollen is rejected at this stage. However, the mechanisms underlying this selective acceptance of compatible pollen remain unclear. Here, using a cell-impermeant calcium indicator, we showed that the compatible pollen coat contains signaling molecules that stimulate Ca2+ export from the papilla cells. Transcriptome analyses of stigmas suggested that autoinhibited Ca2+-ATPase13 (ACA13) was induced after both compatible pollination and compatible pollen coat treatment. A complementation test using a yeast Saccharomyces cerevisiae strain lacking major Ca2+ transport systems suggested that ACA13 indeed functions as an autoinhibited Ca2+ transporter. ACA13 transcription increased in papilla cells and in transmitting tracts after pollination. ACA13 protein localized to the plasma membrane and to vesicles near the Golgi body and accumulated at the pollen tube penetration site after pollination. The stigma of a T-DNA insertion line of ACA13 exhibited reduced Ca2+ export, as well as defects in compatible pollen germination and seed production. These findings suggest that stigmatic ACA13 functions in the export of Ca2+ to the compatible pollen tube, which promotes successful fertilization. PMID:24569769

  16. Heterospecific pollen deposition in Delphinium barbeyi: linking stigmatic pollen loads to reproductive output in the field

    PubMed Central

    Briggs, Heather M.; Anderson, Lucy M.; Atalla, Laila M.; Delva, André M.; Dobbs, Emily K.; Brosi, Berry J.

    2016-01-01

    Background and Aims Most pollinators are generalists and therefore are likely to transfer heterospecific pollen among co-flowering plants. Most work on the impacts of heterospecific pollen deposition on plant fecundity has utilized hand-pollination experiments in greenhouse settings, and we continue to know very little about the reproductive effects of heterospecific pollen in field settings. Methods We explored how patterns of naturally deposited heterospecific pollen relate to the reproductive output of Delphinium barbeyi, a common subalpine perennial herb in the Rocky Mountains (USA). We assessed a wide range of naturally occurring heterospecific pollen proportions and pollen load sizes, and linked stigmatic pollen deposition directly to seed set in individual carpels in the field. Key Results We found that heterospecific pollen deposition in D. barbeyi is common, but typically found at low levels across stigmas collected in our sites. Neither conspecific nor heterospecific pollen deposition was related to carpel abortion. By contrast, we saw a significant positive relationship between conspecific pollen amount and viable seed production, as well as a significant negative interaction between the effects of conspecific pollen and heterospecific pollen amount, whereby the effect of conspecific pollen on viable seed production became weaker with greater heterospecific deposition on stigmas. Conclusions To our knowledge, this is the first demonstration of a relationship between heterospecific pollen and seed production in a field setting. In addition, it is the first report of an interaction between conspecific and heterospecific pollen quantities on seed production. These findings, taken with the results from other studies, suggest that greenhouse hand-pollination studies and field studies should be more tightly integrated in future work to better understand how heterospecific pollen transfer can be detrimental for plant reproduction. PMID:26658101

  17. 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.

  18. Roles of pollen-specific boron efflux transporter, OsBOR4, in the rice fertilization process.

    PubMed

    Tanaka, Nobuhiro; Uraguchi, Shimpei; Saito, Akihiro; Kajikawa, Masataka; Kasai, Koji; Sato, Yutaka; Nagamura, Yoshiaki; Fujiwara, Toru

    2013-12-01

    Arabidopsis thaliana BOR1 was the first boron (B) transporter identified in living systems. There are four AtBOR1-like genes, OsBOR1, 2, 3 and 4, present in the rice genome. We characterized the activity, expression and physiological function of OsBOR4. OsBOR4 is an active efflux transporter of B. Quantitative PCR analysis and OsBOR4 promoter-green fluorescent protein (GFP) fusion revealed that OsBOR4 was both highly and specifically expressed in pollen. We obtained five Tos17 insertion mutants of osbor4. The pollen grains were viable and development of floral organs was normal in the homozygous osbor4 mutants. We observed that in all Tos17 insertion lines tested, the frequency of osbor4 homozygous plants was lower than expected in the progeny of self-fertilized heterozygous plants. These results establish that OsBOR4 is essential for normal reproductive processes. Pollen from osbor4 homozygous plants elongated fewer tubes on wild-type stigmas, and tube elongation of mutant pollen was less efficient compared with the wild-type pollen, suggesting reduced competence of osbor4 mutant pollen. The reduced competence of mutant pollen was further supported by the crosses of independent Tos17-inserted alleles of OsBOR4. Our results suggest that OsBOR4, a boron efflux transporter, is required for normal pollen germination and/or tube elongation.

  19. Self-incompatibility-induced programmed cell death in field poppy pollen involves dramatic acidification of the incompatible pollen tube cytosol.

    PubMed

    Wilkins, Katie A; Bosch, Maurice; Haque, Tamanna; Teng, Nianjun; Poulter, Natalie S; Franklin-Tong, Vernonica E

    2015-03-01

    Self-incompatibility (SI) is an important genetically controlled mechanism to prevent inbreeding in higher plants. SI involves highly specific interactions during pollination, resulting in the rejection of incompatible (self) pollen. Programmed cell death (PCD) is an important mechanism for destroying cells in a precisely regulated manner. SI in field poppy (Papaver rhoeas) triggers PCD in incompatible pollen. During SI-induced PCD, we previously observed a major acidification of the pollen cytosol. Here, we present measurements of temporal alterations in cytosolic pH ([pH]cyt); they were surprisingly rapid, reaching pH 6.4 within 10 min of SI induction and stabilizing by 60 min at pH 5.5. By manipulating the [pH]cyt of the pollen tubes in vivo, we show that [pH]cyt acidification is an integral and essential event for SI-induced PCD. Here, we provide evidence showing the physiological relevance of the cytosolic acidification and identify key targets of this major physiological alteration. A small drop in [pH]cyt inhibits the activity of a soluble inorganic pyrophosphatase required for pollen tube growth. We also show that [pH]cyt acidification is necessary and sufficient for triggering several key hallmark features of the SI PCD signaling pathway, notably activation of a DEVDase/caspase-3-like activity and formation of SI-induced punctate actin foci. Importantly, the actin binding proteins Cyclase-Associated Protein and Actin-Depolymerizing Factor are identified as key downstream targets. Thus, we have shown the biological relevance of an extreme but physiologically relevant alteration in [pH]cyt and its effect on several components in the context of SI-induced events and PCD.

  20. Automated DNA extraction from pollen in honey.

    PubMed

    Guertler, Patrick; Eicheldinger, Adelina; Muschler, Paul; Goerlich, Ottmar; Busch, Ulrich

    2014-04-15

    In recent years, honey has become subject of DNA analysis due to potential risks evoked by microorganisms, allergens or genetically modified organisms. However, so far, only a few DNA extraction procedures are available, mostly time-consuming and laborious. Therefore, we developed an automated DNA extraction method from pollen in honey based on a CTAB buffer-based DNA extraction using the Maxwell 16 instrument and the Maxwell 16 FFS Nucleic Acid Extraction System, Custom-Kit. We altered several components and extraction parameters and compared the optimised method with a manual CTAB buffer-based DNA isolation method. The automated DNA extraction was faster and resulted in higher DNA yield and sufficient DNA purity. Real-time PCR results obtained after automated DNA extraction are comparable to results after manual DNA extraction. No PCR inhibition was observed. The applicability of this method was further successfully confirmed by analysis of different routine honey samples.

  1. Controlling Hay Fever Symptoms with Accurate Pollen Counts

    MedlinePlus

    ... Library ▸ Hay fever and pollen counts Share | Controlling Hay Fever Symptoms with Accurate Pollen Counts This article has ... Pongdee, MD, FAAAAI Seasonal allergic rhinitis known as hay fever is caused by pollen carried in the air ...

  2. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    PubMed

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  3. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    PubMed

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.

  4. [A monoclonal antibody against ragweed pollen cross-reacting with yellow dock pollen].

    PubMed

    Shen, H D; Chang, L Y; Gong, Y J; Chang, H N; Han, S H

    1985-11-01

    Using monoclonal antibodies with different specificity against the major allergenic components of ragweed pollen, we analyzed their cross-reactivity with two tree pollens, two grass pollens and five other weed pollens which are common in Taiwan by the immunoblot method. It was found that besides reacting with AgE and AgK of the ragweed pollen, the monoclonal antibody 48-5 also reacted with antigens of yellow dock pollen with molecular weights of 40K, 38K, 24K, and 21K. In a preliminary study, sera of two patients containing IgE antibodies to ragweed pollen antigens also reacted to the 40K component of the yellow dock pollen. Furthermore, from the results of allergenic skin testings on 109 patients with bronchial asthma, we found that of 22 patients who had a positive reaction to a crude extract of ragweed pollen, 18(81.8%) also reacted to the crude extract of yellow dock pollen. In conclusion, our results suggest that there exists a common allergenic determinant between pollens of ragweed and yellow dock. It may play an important role in the expression of the sensitivity of patients to these two kinds of pollens.

  5. Some carbohydrates found in pollen and pollen substitutes are toxic to honey bees.

    PubMed

    Barker, R J

    1977-10-01

    Carbohydrates in some pollen substitutes (galactose, lactose, raffinose, stachyose, glucuronic acid, galacturonic acid, polygalacturonic acid, and pectin) were toxic to caged adult Apis mellifera L. These toxins can be diluted to safe levels by sucrose. Collected nectar apparently dilutes the toxic sugars in pollen thus permitting assimilation of essential nutrients from pollen.

  6. Cross-reactivity to olive tree pollen and orchard grass pollen in patients with pollinosis.

    PubMed

    Miyahara, S; Nakada, M; Nishizaki, K; Kawarai, Y; Nishioka, K; Hino, H

    1997-06-01

    We studied 92 patients with allergic rhinitis in Syodoshima, Japan, during the pollen season between April and June to evaluate the cross-reactivity to different antigens, including pollen from the olive tree (Olea europaea) and orchard grass (Dactylis glomerata). Olive tree pollen was present in the atmosphere for 23 days, from May 19 to June 12, 1994. Specific IgE antibodies for olive tree pollen antigen were present in 21 (26.9%) of the 78 patients with allergic rhinitis. Nine (24.3%) of the 37 patients with allergic rhinitis exhibited positive skin reactivity to an extract of olive tree pollen. Fifteen (88.2%) of the 17 patients who had IgE reactivity in their sera to olive tree pollen antigen demonstrated allergic reactions to an extract of olive tree pollen. Specific IgE antibodies for orchard grass pollen antigen were present in 43 (48.3%) of the 89 patients with allergic rhinitis and 20 (95.2%) of the 21 patients who had IgE reactivity in their sera to olive tree pollen antigen. The inhibition test using the CAP System revealed that the reactivity of the IgE antibody specific for olive tree pollen antigen was inhibited dose-dependently by an extract of orchard grass pollen. These findings show that there is a reaction in some patients with grass (Gramineae) pollinosis that might be induced by olive tree pollen.

  7. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.)

    PubMed Central

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media. PMID:25405230

  8. Personal pollen exposure compared to stationary measurements.

    PubMed

    Riediker, M; Keller, S; Wüthrich, B; Koller, T; Monn, C

    2000-01-01

    The aim of this study was to examine to what extent stationary outdoor pollen measurements are representative for estimating personal exposure to pollen. Ten subjects were studied during a total of 36 days in spring and summer Pollen was sampled using personal SKC total dust samplers and stationary Burkard pollen traps. The personal activity pattern was recorded quarter-hourly as well as the time spent outdoors. As a reference, SKC and Burkard samplers were run stationary and in parallel. Stationary comparison of the samplers showed good correlation (r = 0.981, p <0.001). However, the SKC sampler collected systematically about four times less pollen than the Burkard sampler. Taking into account the systematic difference between the sampling devices, the personal exposure data were about 30% of the stationary pollen concentrations with significant correlation (log-transformed data, r = 0.719, p <0.0001). Considering the average time the subjects spent outdoors (14% of sampling time), the indoor-outdoor ratio for pollen was 0.2. In conclusion, pollen reports are reliable for estimating personal exposure over a limited time period although personal pollen exposure is much lower.

  9. Simultaneous allergy to vine pollen and grape.

    PubMed

    Mur, P; Feo Brito, F; Bartolomé, B; Galindo, P A; Gómez, E; Borja, J; Alonso, A

    2006-01-01

    We report the case of an 18-year-old female student suffering from seasonal rhinoconjunctivitis with sensitization to pollens from vine and also from grass, olive, and Chenopodiaceae plants who had recently developed episodes of itching, maculopapular rash, and facial angioedema after eating grapes. Testing revealed positive reactions to vine pollen and grapes, and specific IgE were found for both allergens. Immunoblotting and inhibition assays revealed cross-reactivity between the allergenic structures of vine pollen and grape fruit and also among botanically unrelated pollens.

  10. MAP18 Regulates the Direction of Pollen Tube Growth in Arabidopsis by Modulating F-Actin Organization[C][W][OA

    PubMed Central

    Zhu, Lei; Zhang, Yan; Kang, Erfang; Xu, Qiangyi; Wang, Miaoying; Rui, Yue; Liu, Baoquan; Yuan, Ming; Fu, Ying

    2013-01-01

    For fertilization to occur in plants, the pollen tube must be guided to enter the ovule via the micropyle. Previous reports have implicated actin filaments, actin binding proteins, and the tip-focused calcium gradient as key contributors to polar growth of pollen tubes; however, the regulation of directional pollen tube growth is largely unknown. We reported previously that Arabidopsis thaliana MICROTUBULE-ASSOCIATED PROTEIN18 (MAP18) contributes to directional cell growth and cortical microtubule organization. The preferential expression of MAP18 in pollen and in pollen tubes suggests that MAP18 also may function in pollen tube growth. In this study, we demonstrate that MAP18 functions in pollen tubes by influencing actin organization, rather than microtubule assembly. In vitro biochemical results indicate that MAP18 exhibits Ca2+-dependent filamentous (F)-actin-severing activity. Abnormal expression of MAP18 in map18 and MAP18 OX plants was associated with disorganization of the actin cytoskeleton in the tube apex, resulting in aberrant pollen tube growth patterns and morphologies, inaccurate micropyle targeting, and fewer fertilization events. Experiments with MAP18 mutants created by site-directed mutagenesis suggest that F-actin-severing activity is essential to the effects of MAP18 on pollen tube growth direction. Our study demonstrates that in Arabidopsis, MAP18 guides the direction of pollen tube growth by modulating actin filaments. PMID:23463774

  11. Zm908p11, encoded by a short open reading frame (sORF) gene, functions in pollen tube growth as a profilin ligand in maize

    PubMed Central

    Dong, Xue; Wang, Dongxue; Liu, Peng; Li, Chengxia; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2013-01-01

    Double fertilization of flowering plants depends on the targeted transportation of sperm to the embryo sac by the pollen tube. Currently, little is known about the underlying molecular mechanisms that regulate pollen germination and pollen tube growth in maize (Zea mays). Here, a maize pollen-predominant gene Zm908, with several putative short open reading frames (sORFs), was isolated and characterized. The longest ORF of Zm908 encodes a small protein of 97 amino acids. This was designated as Zm908p11 and is distributed throughout the maize pollen tube. Western blot detected the small peptide in mature pollen. Quantitative reverse transcription–PCR and northern blot analysis revealed that Zm908p11 was expressed predominantly in mature pollen grains. Ectopic overexpression of full-length Zm908 and Zm908p11 in tobacco resulted in defective pollen, while transgenic tobacco plants with a site-specific mutation or a frameshift mutation of Zm908p11 showed normal pollen development. Overexpression of Zm908p11 in maize decreased pollen germination efficiency. Maize pollen cDNA library screening and protein–protein interaction assays demonstrated that Zm908p11 interacts with maize profilin 1 (ZmPRO1). A microarray analysis identified 273 up-regulated and 203 down-regulated genes in the overexpressing transgenic Zm908p11 pollen. Taken together, these results indicate that Zm908 functions as Zm908p11, and binds to profilins as a novel ligand, with a required role during pollen tube growth in maize. Accordingly, a model is proposed for the role of Zm908p11 during pollen tube growth in maize. PMID:23676884

  12. Organismal versus Environmental Control of the Carbon Isotope Composition of Dicot Angiosperm Pollen: Implications for Paleoenvironmental Reconstruction

    NASA Astrophysics Data System (ADS)

    King, D. P.; Schubert, B.; Foelber, K.; Jahren, H.

    2011-12-01

    The prevalence and diagenetic resilience of palynomorphs in Proterozoic and Phanerozoic sediments has led researchers to investigate its potential as an environmental proxy based on its stable isotope composition. Towards this, Loader and Hemming (2001), noted that the carbon isotope composition (δ13C) of modern Pinus sylvestris pollen exine correlates with the developmental period temperature (°C) of the pollen (R2=0.68), implying that the δ13C of gymnosperm pollen could be quantitatively utilized as a paleotemperature proxy. However, the majority of pollen-producing organisms during the last ~120 million years have been angiosperms, which are subject to complex internal signaling for reproduction, in addition to environmental triggers. Because these internal signals control the relative proportion of lipids, long-chain fatty acids, and polysaccharides within pollen grains, we hypothesized that the δ13C variability in pollen (δ13Cpollen) from several plants subject to the same external environmental parameters is of the same magnitude as the amount attributed to the environment for gymnosperms. Within growth chambers, the test organism (Brassica rapa) was cultivated under constant light, water, pCO2, and nutrient supply, but exhibited average δ13Cpollen variability = 4.35% within any chamber (n = 6 to 8 plants per chamber). Field experiments were also conducted in which the pollen from the test organism (Hibiscus spp.) was sampled from several botanical gardens within the state of Hawaii. Pollen collected from any one botanical garden exhibited an average δ13Cpollen variability = 4.5% (up to 5 plants per garden). Upon comparing chambers operating at different temperatures (17°C to 32°C), we discovered no correlation (R2=0.01) between the developmental period temperature (°C) and the δ13C of B. rapa pollen; similarly, no correlation was found between the δ13C of Hibiscus pollen and its developmental period temperature (°C) (R2=0.12). This work

  13. Expression and Protein Interaction Analyses Reveal Combinatorial Interactions of LBD Transcription Factors During Arabidopsis Pollen Development.

    PubMed

    Kim, Mirim; Kim, Min-Jung; Pandey, Shashank; Kim, Jungmook

    2016-11-01

    LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor gene family members play key roles in diverse aspects of plant development. LBD10 and LBD27 have been shown to be essential for pollen development in Arabidopsis thaliana. From the previous RNA sequencing (RNA-Seq) data set of Arabidopsis pollen, we identified the mRNAs of LBD22, LBD25 and LBD36 in addition to LBD10 and LBD27 in Arabidopsis pollen. Here we conducted expression and cellular analysis using GFP:GUS (green fluorescent protein:β-glucuronidase) reporter gene and subcellular localization assays using LBD:GFP fusion proteins expressed under the control of their own promoters in Arabidopsis. We found that these LBD proteins display spatially and temporally distinct and overlapping expression patterns during pollen development. Bimolecular fluorescence complementation and GST (glutathione S-transferase) pull-down assays demonstrated that protein-protein interactions occur among the LBDs exhibiting overlapping expression during pollen development. We further showed that LBD10, LBD22, LBD25, LBD27 and LBD36 interact with each other to form heterodimers, which are localized to the nucleus in Arabidopsis protoplasts. Taken together, these results suggest that combinatorial interactions among LBD proteins may be important for their function in pollen development in Arabidopsis.

  14. WPA guidance on the protection and promotion of mental health in children of persons with severe mental disorders

    PubMed Central

    BROCKINGTON, IAN; CHANDRA, PRABHA; DUBOWITZ, HOWARD; JONES, DAVID; MOUSSA, SUAAD; NAKKU, JULIET; QUADROS FERRE, ISABEL

    2011-01-01

    This guidance details the needs of children, and the qualities of parenting that meet those needs. Parental mental disorders can damage the foetus during pregnancy through the action of drugs, prescribed or abused. Pregnancy and the puerperium can exacerbate or initiate mental illness in susceptible women. After their birth, the children may suffer from the social disadvantage associated with severe mental illness. The parents (depending on the disorder, its severity and its persistence) may have intermittent or prolonged difficulties with parenting, which may sometimes result in childhood psychological disturbance or child maltreatment. This guidance considers ways of preventing, minimizing and remedying these effects. Our recommendations include: education of psychiatrists and related professions about the effect of parental mental illness on children; revision of psychiatric training to increase awareness of patients as caregivers, and to incorporate relevant assessment and intervention into their treatment and rehabilitation; the optimum use of pharmacological treatment during pregnancy; pre-birth planning when women with severe mental illness become pregnant; development of specialist services for pregnant and puerperal women, with assessment of their efficacy; community support for parenting by mothers and fathers with severe mental disorders; standards of good practice for the management of child maltreatment when parents suffer from mental illness; the importance of multi-disciplinary teamwork when helping these families, supporting their children and ensuring child protection; the development of child and adolescent mental health services worldwide. PMID:21633678

  15. WPA guidance on the protection and promotion of mental health in children of persons with severe mental disorders.

    PubMed

    Brockington, Ian; Chandra, Prabha; Dubowitz, Howard; Jones, David; Moussa, Suaad; Nakku, Juliet; Quadros Ferre, Isabel

    2011-06-01

    This guidance details the needs of children, and the qualities of parenting that meet those needs. Parental mental disorders can damage the foetus during pregnancy through the action of drugs, prescribed or abused. Pregnancy and the puerperium can exacerbate or initiate mental illness in susceptible women. After their birth, the children may suffer from the social disadvantage associated with severe mental illness. The parents (depending on the disorder, its severity and its persistence) may have intermittent or prolonged difficulties with parenting, which may sometimes result in childhood psychological disturbance or child maltreatment. This guidance considers ways of preventing, minimizing and remedying these effects. Our recommendations include: education of psychiatrists and related professions about the effect of parental mental illness on children; revision of psychiatric training to increase awareness of patients as caregivers, and to incorporate relevant assessment and intervention into their treatment and rehabilitation; the optimum use of pharmacological treatment during pregnancy; pre-birth planning when women with severe mental illness become pregnant; development of specialist services for pregnant and puerperal women, with assessment of their efficacy; community support for parenting by mothers and fathers with severe mental disorders; standards of good practice for the management of child maltreatment when parents suffer from mental illness; the importance of multi-disciplinary teamwork when helping these families, supporting their children and ensuring child protection; the development of child and adolescent mental health services worldwide.

  16. Using Shared Stories and Individual Response Modes to Promote Comprehension and Engagement in Literacy for Students with Multiple, Severe Disabilities

    ERIC Educational Resources Information Center

    Browder, Diane M.; Lee, Angela; Mims, Pam

    2011-01-01

    This study investigated the effects of scripted task analytic lessons with systematic prompting on engagement and comprehension of students with a multiple, severe disability using a multiple probe single case design. Three teachers followed the scripts to include a target student in a story based lesson to increase comprehension and engagement.…

  17. Compound Pollen Protein Nutrient Increases Serum Albumin in Cirrhotic Rats

    PubMed Central

    Shi, Hong Bo; Kong, Ming; Chen, Gong; Zhao, Jun; Shi, Hong Lin; Chen, Yu; Rowan, Frank G

    2010-01-01

    group were 101.55 ± 0.87, 94.62 ± 8.80, 98.94 ± 3.68, 78.77 ± 21.79, 39.52 ± 14.03 (pg/ml), respectively, the differences among the groups were significant (F = 11.12, P = 0.002); the levels of HGF in low dose Noveliver group, high dose Noveliver group and the compound protein pollen group were higher than that in spontaneous recovery group (P = 0.001, 0.000, 0.005). Histological results showed that the fibrosis in spontaneous recovery group was severer than those in low dose Noveliver group, high dose Noveliver group and compound protein pollen group. Conclusions Our data show that the both the Noveliver and the compound pollen protein nutrient increase the serum albumin and ameliorate malnutrition in cirrhotic rats; the recovery of serum albumin might be related to the hepatic damage repair and liver regeneration. PMID:27942305

  18. Quantitative Reconstruction of Holocene Climates of Canadian Arctic and Greenland from pollen assemblages

    NASA Astrophysics Data System (ADS)

    Whitmore, J.; Gajewski, K.

    2004-05-01

    Ice cores have provided key records of the late-Quaternary climates of the North American Arctic. However, these are spatially restricted and are available only in the glaciated eastern Arctic and Greenland. Ten pollen diagrams are available from Banks, Prince of Wales, Somerset, Ellesmere and Baffin Island describe the changes in the postglacial vegetation. These pollen assemblages, along with other proxy-climate data, have been interpreted as indicating a relatively warm early Holocene with a cooling in the past several 1000 years. However, quantitative reconstructions of the magnitude of temperature change have been hampered by lack of a sufficiently extensive modern calibration dataset. A new modern pollen dataset has recently been prepared, permitting the quantitative reconstructions of summer conditions across the Arctic. We use the modern pollen dataset, along with high-resolution estimates of July temperatures to estimate the magnitude of the Holocene climate changes across the Arctic and compare these results to the ice core records.

  19. A Temporal Dimension to the Influence of Pollen Rewards on Bee Behaviour and Fecundity in Aloe tenuior

    PubMed Central

    Duffy, Karl J.; Johnson, Steven D.; Peter, Craig I.

    2014-01-01

    The net effect of pollen production on fecundity in plants can range from negative – when self-pollen interferes with fecundity due to incompatibility mechanisms, to positive – when pollen availability is associated with increased pollinator visitation and fecundity due to its utilization as a reward. We investigated the responses of bees to pollen and nectar rewards, and the effects of these rewards on pollen deposition and fecundity in the hermaphroditic succulent shrub Aloe tenuior. Self-pollinated plants failed to set fruit, but their ovules were regularly penetrated by self-pollen tubes, which uniformly failed to develop into seeds as expected from ovarian self-incompatibility (or strong early inbreeding depression). Bees consistently foraged for pollen during the morning and early afternoon, but switched to nectar in the late afternoon. As a consequence of this differential foraging, we were able to test the relative contribution to fecundity of pollen- versus nectar-collecting flower visitors. We exposed emasculated and intact flowers in either the morning or late afternoon to foraging bees and showed that emasculation reduced pollen deposition by insects in the morning, but had little effect in the afternoon. Despite the potential for self-pollination to result in ovule discounting due to late-acting self-sterility, fecundity was severely reduced in artificially emasculated plants. Although there were temporal fluctuations in reward preference, most bee visits were for pollen rewards. Therefore the benefit of providing pollen that is accessible to bee foragers outweighs any potential costs to fitness in terms of gender interference in this species. PMID:24755611

  20. Pyrrolizidine alkaloids in food: downstream contamination in the food chain caused by honey and pollen.

    PubMed

    Kempf, M; Wittig, M; Schönfeld, K; Cramer, L; Schreier, P; Beuerle, T

    2011-03-01

    In recent years, there has been a steadily growing number of published data on pyrrolizidine alkaloids (PAs) in honey and pollen. This raises the question whether honey and/or pollen used as ingredients in food processing might provoke a downstream contamination in the food chain. Here we addressed two different facets in connection with PAs in honey and pollen. First, we analysed the PA content of several food types such as mead (n = 19), candy (n = 10), fennel honey (n = 9), soft drinks (n = 5), power bars and cereals (n = 7), jelly babies (n = 3), baby food (n = 3), supplements (n = 3) and fruit sauce (n = 1) that contained honey as an ingredient in the range of 5% to approximately 37%. Eight out of 60 retail samples were tested as being PA-positive, corresponding to 13%. Positive samples were found in mead, candy and fennel honey, and the average PA content was calculated to be 0.10 µg g(-1) retronecine equivalents (ranging from 0.010 to 0.484 µg g(-1)). Furthermore, we investigated the question whether and how PAs from PA pollen are transferred from pollen into honey. We conducted model experiments with floral pollen of Senecio vernalis and PA free honey and tested the influence of the quantity of PA pollen, contact time and a simulated honey filtration on the final PA content of honey. It could clearly be demonstrated that the PA content of honey was directly proportional to the amount of PA pollen in honey and that the transfer of PAs from pollen to honey was a rather quick process. Consequently, PA pollen represents a major source for the observed PA content in honey. On the other hand, a good portion remains in the pollen. This fraction is not detected by the common analytical methods, but will be ingested, and it represents an unknown amount of 'hidden' PAs. In addition, the results showed that a technically and legally possible honey filtration (including the removal of all pollen) would not be an option to reduce the PA level of the final product

  1. Region-specific sensitivity of anemophilous pollen deposition to temperature and precipitation.

    PubMed

    Donders, Timme H; Hagemans, Kimberley; Dekker, Stefan C; de Weger, Letty A; de Klerk, Pim; Wagner-Cremer, Friederike

    2014-01-01

    Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values), and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1), as well as in the growing season (T), are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001]) in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001). The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural archives reflect

  2. Region-Specific Sensitivity of Anemophilous Pollen Deposition to Temperature and Precipitation

    PubMed Central

    Donders, Timme H.; Hagemans, Kimberley; Dekker, Stefan C.; de Weger, Letty A.; de Klerk, Pim; Wagner-Cremer, Friederike

    2014-01-01

    Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values), and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1), as well as in the growing season (T), are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001]) in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001). The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural archives reflect

  3. Multiple Developmental Pathways Leading to a Single Morph: Monosulcate Pollen (Examples From the Asparagales)

    PubMed Central

    PENET, L.; NADOT, S.; RESSAYRE, A.; FORCHIONI, A.; DREYER, L.; GOUYON, P. H.

    2004-01-01

    • Background and Aims Early developmental events in microsporogenesis are known to play a role in pollen morphology: variation in cytokinesis type, cell wall formation, tetrad shape and aperture polarity are responsible for pollen aperture patterning. Despite the existence of other morphologies, monosulcate pollen is one of the most common aperture types in monocots, and is also considered as the ancestral condition in this group. It is known to occur from either a successive or a simultaneous cytokinesis. In the present study, the developmental sequence of microsporogenesis is investigated in several species of Asparagales that produce such monosulcate pollen, representing most families of this important monocot clade. • Methods The developmental pathway of microsporogenesis was investigated using light transmission and epifluorescence microscopy for all species studied. Confocal microscopy was used to confirm centripetal cell plate formation. • Key Results Microsporogenesis is diverse in Asparagales, and most variation is generally found between families. It is confirmed that the whole higher Asparagales clade has a very conserved microsporogenesis, with a successive cytokinesis and centrifugal cell plate formation. Centripetal cell wall formation is described in Tecophilaeaceae and Iridaceae, a feature that had so far only been reported for eudicots. • Conclusions Monosulcate pollen can be obtained from several developmental pathways, leading thus to homoplasy in the monosulcate character state. Monosulcate pollen should not therefore be considered as the ancestral state unless it is produced through the ancestral developmental pathway. The question about the ancestral developmental pathway leading to monosulcy remains open. PMID:15567807

  4. Cupressaceae pollen grains modulate dendritic cell response and exhibit IgE-inducing adjuvant activity in vivo.

    PubMed

    Kamijo, Seiji; Takai, Toshiro; Kuhara, Takatoshi; Tokura, Tomoko; Ushio, Hiroko; Ota, Mikiko; Harada, Norihiro; Ogawa, Hideoki; Okumura, Ko

    2009-11-15

    Pollen is considered a source of not only allergens but also immunomodulatory substances, which could play crucial roles in sensitization and/or the exacerbation of allergies. We investigated how allergenic pollens from different plant species (Japanese cedar and Japanese cypress, which belong to the Cupressaceae family, and birch, ragweed, and grass) modulate murine bone marrow-derived dendritic cell (DC) responses and examined the effect of Cupressaceae pollen in vivo using mice. DCs were stimulated with pollen extracts or grains in the presence or absence of LPS. Cell maturation and cytokine production in DCs were analyzed by flow cytometry, ELISA, and/or quantitative PCR. Pollen extracts suppressed LPS-induced IL-12 production and the effect was greatest for birch and grass. Without LPS, pollen grains induced DC maturation and cytokine production without IL-12 secretion and the response, for which TLR 4 was dispensable, was greatest for the Cupressaceae family. Intranasal administration of Cupressaceae pollen in mice induced an elevation of serum IgE levels and airway eosinophil infiltration. Coadministration of ovalbumin with Cupressaceae pollen grains induced ovalbumin-specific IgE responses associated with eosinophil infiltration. The results suggest that modulation of DC responses by pollen differs among the plant families via (1) the promotion of DC maturation and cytokine production by direct contact and/or (2) the inhibition of IL-12 production by soluble factors. The strong DC stimulatory activity in vitro and IgE-inducing activity in mice support the clinical relevance of Cupressaceae pollen to allergies in humans.

  5. The involvement of nitric oxide in ultraviolet-B-inhibited pollen germination and tube growth of Paulownia tomentosa in vitro.

    PubMed

    He, Jun-Min; Bai, Xiao-Ling; Wang, Rui-Bin; Cao, Bing; She, Xiao-Ping

    2007-10-01

    The role of nitric oxide (NO) in the ultraviolet-B radiation (UV-B)-induced reduction of in vitro pollen germination and tube growth of Paulownia tomentosa Steud. was studied. Results showed that exposure of the pollen to 0.4 and 0.8 W m(-2) UV-B radiation for 2 h resulted in not only the reduction of pollen germination and tube growth but also the enhancement of NO synthase (NOS, EC 1.14.13.39) activity and NO production in pollen grain and tube. Also, exogenous NO donors sodium nitroprusside and S-nitrosoglutathione inhibited both pollen germination and tube growth in a dose-dependence manner. NOS inhibitor N(G)-nitro-l-Arg-methyl eater (l-NAME) and NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) not only largely prevented the NO generation but also partly reversed the UV-B-inhibited pollen germination and tube growth. These results indicate that UV-B radiation inhibits pollen germination and tube growth partly via promoting NO production in pollen grain and tube by a NOS-like enzyme. Additionally, a guanylyl cyclase inhibitor 6-anilino-5,8-quinolinequinone (LY-83583) prevented both the UV-B- and NO donors-inhibited pollen germination and tube growth, suggesting that the NO function is mediated by cyclic guanosine 5'-monophosphate. However, the effects of c-PTIO, l-NAME and LY-83583 on the UV-B-inhibited pollen germination and tube growth were only partial, suggesting that there are NO-independent pathways in UV-B signal networks.

  6. Antioxidant Activity of Sonoran Desert Bee Pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee products have been consumed by mankind since antiquity and their health benefits are becoming more apparent. Bee pollen (pollen collected by honey bees) was collected in the high intensity ultraviolet (UV) Sonoran desert and was analyzed by the anti-2,2-diphenyl-1-picryhydrazyl (DPPH) assay and...

  7. Endogenous Gibberellins of Pine Pollen

    PubMed Central

    Kamienska, Aniela; Durley, Richard C.; Pharis, Richard P.

    1976-01-01

    Gibberellins A1 and A34 (possibly A2) were found as products of metabolism of 1,2-[3H]GA4 during germination of Pinus attenuata pollen. The conversion from GA4 to GA1 and GA34 occurred as hydroxylations at atoms C-13 and C-2 of the ent-gibberellane skeleton, respectively. Percentage interconversion of the GA4 absorbed was in the range of 0.15 to 0.43% for GA1 and 1.54 to 3.22% for GA34. Identifications were made on a gas-liquid chromatograph with radioactive monitoring by comparison with standards. PMID:16659622

  8. The Conserved Coronavirus Macrodomain Promotes Virulence and Suppresses the Innate Immune Response during Severe Acute Respiratory Syndrome Coronavirus Infection

    PubMed Central

    Fehr, Anthony R.; Channappanavar, Rudragouda; Jankevicius, Gytis; Fett, Craig; Zhao, Jincun; Athmer, Jeremiah; Meyerholz, David K.; Ahel, Ivan

    2016-01-01

    ABSTRACT ADP-ribosylation is a common posttranslational modification that may have antiviral properties and impact innate immunity. To regulate this activity, macrodomain proteins enzymatically remove covalently attached ADP-ribose from protein targets. All members of the Coronavirinae, a subfamily of positive-sense RNA viruses, contain a highly conserved macrodomain within nonstructural protein 3 (nsp3). However, its function or targets during infection remain unknown. We identified several macrodomain mutations that greatly reduced nsp3’s de-ADP-ribosylation activity in vitro. Next, we created recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) strains with these mutations. These mutations led to virus attenuation and a modest reduction of viral loads in infected mice, despite normal replication in cell culture. Further, macrodomain mutant virus elicited an early, enhanced interferon (IFN), interferon-stimulated gene (ISG), and proinflammatory cytokine response in mice and in a human bronchial epithelial cell line. Using a coinfection assay, we found that inclusion of mutant virus in the inoculum protected mice from an otherwise lethal SARS-CoV infection without reducing virus loads, indicating that the changes in innate immune response were physiologically significant. In conclusion, we have established a novel function for the SARS-CoV macrodomain that implicates ADP-ribose in the regulation of the innate immune response and helps to demonstrate why this domain is conserved in CoVs. PMID:27965448

  9. The Arabidopsis general transcription factor TFIIB1 (AtTFIIB1) is required for pollen tube growth and endosperm development.

    PubMed

    Zhou, Jing-Jing; Liang, Yan; Niu, Qian-Kun; Chen, Li-Qun; Zhang, Xue-Qin; Ye, De

    2013-05-01

    Pollen tube growth and endosperm development are important for fertilization and seed formation. The genetic mechanism of the processes remains poorly understood. This study reports the functional characterization of AtTFIIB1 in pollen tube growth and endosperm development. AtTFIIB1 shares 86% and 44% similarity with AtTFIIB2 and AtTFIIB3/AtpBRP2, respectively. It is expressed in many tissues including vegetative nuclei and generative cells of pollen grains and pollen tubes, endosperm, and embryos. It is thus different from AtTFIIB2, whose expression is not found in the endosperm and vegetative nucleus of mature pollen, and AtTFIIB3/AtpBRP2, which is expressed mostly in male gametophytes and weakly in seeds. Mutations in AtTFIIB1 caused a drastic retardation of pollen tube growth and endosperm development, as well as impaired pollen tube guidance and reception, leading to disruption of fertilization and seed development. Expression of AtTFIIB2 driven by the AtTFIIB1 promoter could restore the defective pollen tube growth, guidance, and reception completely, but only partially recovered the seed development in attfiib1, whilst expression of AtTFIIB3/AtpBRP2 driven by the AtTFIIB1 promoter could rescue only the defective attfiib1 seeds. All these results suggest that AtTFIIB1 plays important roles in pollen tube growth, guidance, and reception as well as endosperm development and is partially functionally different from AtTFIIB2 and AtTFIIB3/AtpBRP2.

  10. Pollen tube guidance by attractant molecules: LUREs.

    PubMed

    Okuda, Satohiro; Higashiyama, Tetsuya

    2010-01-01

    Sexual reproduction in flowering plants requires pollen-tube guidance, which is thought to be mediated by chemoattractants derived from target ovules. To date, however, no convincing evidence has been reported of a particular molecule being the true attractant. Emerging data indicate that two synergid cells, which are on either side of the egg cell, emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen-tube guidance. Recently, it was demonstrated that LUREs (LURE1 and LURE2), cysteine-rich polypeptides secreted from the synergid cell, are the key molecules in pollen-tube guidance. In this review, we summarize the mechanism of pollen-tube guidance, with special focus on gametophytic guidance and the attractants.

  11. 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.

  12. Pollen, vegetation, and climate relationships along the Dalton Highway, Alaska, USA: a basis for holocene paleoecological and paleoclimatic studies

    SciTech Connect

    Short, S.K.; Andrews, J.T.; Webber, P.J.

    1986-01-01

    The Dalton Highway extends from Fairbanks, in the interior of Alaska, to Prudhoe Bay on the Arctic Coastal Plain. Over this 600-km transect, July temperatures vary from 17 to 5/sup 0/C. Studies of vegetation along the Dalton Highway identified nine major zones. During the vegetation survey moss polsters were collected within the survey quadrats. Two hundred and nineteen individual moss polsters document regional variations in the modern pollen spectra along this vegetation/climate transect. Treeline is distinguished by a change from dominance by spruce and shrub (especially alder) pollen to the south to herb and shrub (especially willow) pollen dominance to the north; a shift from high modern pollen concentration values to very low values is also noted. Discriminant analysis indicated that the vegetation zones are also defined by different pollen assemblages, suggesting that former changes in vegetation during the Holocene, as recorded in peat deposits, could be interpreted from pollen diagrams. Transfer functions were developed to examine the statistical association between the modern pollen rain and several climatic parameters. The correlation between pollen taxa and mean July temperature was r = 0.84. The most important taxa in the equation are Picea, Alnus, Pinus, Sphagnum, and Betula. 59 references, 7 figures, 4 tables.

  13. IAA stimulates pollen tube growth and mediates the modification of its wall composition and structure in Torenia fournieri

    PubMed Central

    Wu, Juan-Zi; Lin, Yi; Zhang, Xue-Lian; Pang, Dai-Wen; Zhao, Jie

    2008-01-01

    The effects of several hormones on pollen tube growth were compared in Torenia fournieri and it was found that IAA was the most effective, stimulating pollen tube growth and causing the shank part of pollen tubes to be slender and straighter. The role of IAA was investigated by studying the changes in ultrastructure and PM H+-ATPase distribution in the pollen tubes and the modification of the tube wall. Using the fluorescent marker FM4-64, together with transmission electron microscopy, it was shown that secretory vesicles and mitochondria increased in IAA-treated tubes. Immunolocalization and fluorescence labelling, together with Fourier-transform infrared analysis, detected that IAA enhanced the level of PM H+-ATPase and the synthesis of pectins, and reduced the cellulose density in pollen tubes. Importantly, to observe the orientation of cellulose microfibrils in pollen tubes in situ, atomic force microscopy was used to examine the ‘intact’ tube wall. Atomic force microscopy images showed that cellulose microfibrils were parallel to each other in the subapical region of IAA-treated tubes, but disorganized in control tubes. All results provided new insights into the functions of cellulose microfibrils in pollen tube growth and direction, and revealed that the IAA-induced changes of pollen tubes were attributed to the increase in secretory vesicles, mitochondria, and PM H+-ATPase, and the modification of pectin and cellulose microfibrils in the tube wall. PMID:18544613

  14. Fish oil promotes survival and protects against cognitive decline in severely undernourished mice by normalizing satiety signals

    PubMed Central

    Avraham, Yosefa; Saidian, Mayer; Burston, James J.; Mevorach, Raphael; Vorobiev, Lia; Magen, Iddo; Kunkes, Eithan; Borges, Beatriz; Lichtman, Aron H.; Berry, Elliot M.

    2010-01-01

    Severe malnutrition resulting from anorexia nervosa or involuntary starvation leads to low weight, cognitive deficits, and increased mortality rates. In the present study, we examined whether fish oil supplementation, compared with canola oil, would ameliorate the morbidity and mortality associated with these conditions by normalizing endocannabinoid and monoaminergeric systems as well as other systems involved in satiety and cognitive function within the hypothalamus and hippocampus. Female Sabra mice restricted to 40% of their daily food intake exhibited decreased body weight, were sickly in appearance, displayed cognitive deficits, and had increased mortality rates. Strikingly, fish oil supplementation that contains high omega-3 fatty acids levels decreased mortality and morbidity, and normalized the expression of genes and neurotransmitters in the hippocampus and hypothalamus. Fish oil supplementation, but not canola oil, increased survival rates, improved general appearance, and prevented cognitive decline, despite the facts that both diets contained an equivalent number of calories and that there were no differences in weight between mice maintained on the two diets in 100% but decrease in the 40%. In the hypothalamus, the beneficial effects of fish oil supplementation were related to normalization of the endocannabinoid 2-arachidonylglycerol (2-AG), serotonin (5-HT) (p<0.056), dopamine (DA), neuropeptide Y (NPY), and Ca2+/calmodulin (CaM)-dependent protein kinase (Camkk2). In the hippocampus, fish oil supplementation normalized 5-HT, Camkk2, silent mating type information regulation 1 (SIRT-1), and brain-derived neurotrophic factor (BDNF). In conclusion, dietary supplements of fish oil, as source of omega-3 fatty acids, may alleviate cognitive impairments associated with severe diet restriction and prolong survival independently of weight gain by normalizing neurochemical systems. PMID:21109417

  15. 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.

  16. Rhizobium Promotes Non-Legumes Growth and Quality in Several Production Steps: Towards a Biofertilization of Edible Raw Vegetables Healthy for Humans

    PubMed Central

    García-Fraile, Paula; Carro, Lorena; Robledo, Marta; Ramírez-Bahena, Martha-Helena; Flores-Félix, José-David; Fernández, María Teresa; Mateos, Pedro F.; Rivas, Raúl; Igual, José Mariano; Martínez-Molina, Eustoquio; Peix, Álvaro; Velázquez, Encarna

    2012-01-01

    The biofertilization of crops with plant-growth-promoting microorganisms is currently considered as a healthy alternative to chemical fertilization. However, only microorganisms safe for humans can be used as biofertilizers, particularly in vegetables that are raw consumed, in order to avoid sanitary problems derived from the presence of pathogenic bacteria in the final products. In the present work we showed that Rhizobium strains colonize the roots of tomato and pepper plants promoting their growth in different production stages increasing yield and quality of seedlings and fruits. Our results confirmed those obtained in cereals and alimentary oil producing plants extending the number of non-legumes susceptible to be biofertilized with rhizobia to those whose fruits are raw consumed. This is a relevant conclusion since safety of rhizobia for human health has been demonstrated after several decades of legume inoculation ensuring that they are optimal bacteria for biofertilization. PMID:22675441

  17. Pollen competition between two sympatric Orchis species (Orchidaceae): the overtaking of conspecific of heterospecific pollen as a reproductive barrier.

    PubMed

    Luca, A; Palermo, A M; Bellusci, F; Pellegrino, G

    2015-01-01

    The frequency of hybrid formation in angiosperms depends on how and when heterospecific pollen is transferred to the stigma, and on the success of that heterospecific pollen at fertilising ovules. We applied pollen mixtures to stigmas to determine how pollen interactions affect siring success and the frequency of hybrid formation between two species of Mediterranean deceptive orchid. Plants of Orchis italica and O. anthropophora were pollinated with conspecific and heterospecific pollen (first conspecific pollen then heterospecific pollen and vice versa) and molecular analysis was used to check the paternity of the seeds produced. In this pair of Mediterranean orchids, competition between conspecific and heterospecific pollen functions as a post-pollination pre-zygotic barrier limiting the frequency of the formation of hybrids in nature. Flowers pollinated with heterospecific pollen can remain receptive for the arrival of conspecific pollen for a long time. There is always an advantage of conspecific pollen for fruit formation, whether it comes before or after heterospecific pollen, because it overtakes the heterospecific pollen. The conspecific pollen advantage exhibited in O. italica and O. anthropophora is likely to result from the reduced germination of heterospecific pollen or retarded growth of heterospecific pollen tubes in the stigma and ovary. Overall, the results indicate that our hybrid zone represents a phenomenon of little evolutionary consequence, and the conspecific pollen advantage maintains the genetic integrity of the parental species.

  18. Ultrastructural studies on pollen embryogenesis in maize (Zea mays L.).

    PubMed

    Barnabas, B; Fransz, P F; Schel, J H

    1987-06-01

    Maize anthers have been induced on modified N6 medium to produce embryoids. Different stages from the cultures were sampled and prepared for microscopical examination. The microspores at the onset of culture were in an early developmental stage, with the nucleus and numerous organelles centred in the middle, surrounded by many small vacuoles with a lipid content. The binuclear pollen grains contained small vesicles and much starch. The partially condensed vegetative nucleus indicated participation of the vegetative component in the formation of multicellular pollen grains (MPGs). Several MPGs have been observed which differed in morphology. We suggest, on the basis of these ultrastructural observations, that in maize mainly the vegetative cell contributes to the MPG which further develops directly into embryoids.

  19. Pollen grains for oral vaccination.

    PubMed

    Atwe, Shashwati U; Ma, Yunzhe; Gill, Harvinder Singh

    2014-11-28

    Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to 7 months. Confocal microscopy revealed that LSs can translocate into mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination.

  20. Pollen dispersal in sugar beet production fields.

    PubMed

    Darmency, Henri; Klein, Etienne K; De Garanbé, Thierry Gestat; Gouyon, Pierre-Henri; Richard-Molard, Marc; Muchembled, Claude

    2009-04-01

    Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers' activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power-law) dependent on the distance from the pollen source. A literature survey confirmed that power-law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild

  1. Comparison of Pollen Transfer Dynamics by Multiple Floral Visitors: Experiments with Pollen and Fluorescent Dye

    PubMed Central

    ADLER, LYNN S.; IRWIN, REBECCA E.

    2006-01-01

    • Background and Aims Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared. • Methods Naturally occurring pollen loads carried by the common floral visitor species of G. sempervirens were compared. In addition, dyed pollen donor flowers and sequences of four emasculated recipient flowers in field cages were used to estimate pollen transfer, and the utility of fluorescent dye powder as an analogue for pollen transfer was determined. • Key Results Xylocopa virginica, Osmia lignaria and Habropoda laboriosa carried the most G. sempervirens pollen on their bodies, followed by Bombus bimaculatus and Apis mellifera. However, B. bimaculatus, O. lignaria and H. laboriosa transferred significantly more pollen than A. mellifera. Nectar-robbing X. virginica transferred the least pollen, even when visiting legitimately. Dye particles were strongly correlated with pollen grains on a stigma, and therefore provide a good analogue for pollen in this system. The ratio of pollen : dye across stigmas was not affected by bee species or interactions between bee species and floral morphology. However, dye transfer was more sensitive than pollen transfer to differences in floral morphology. • Conclusions The results from this study add to a growing body of literature highlighting that floral visitors vary in pollination effectiveness, and that visitors carrying the most pollen on their bodies may not always be the most efficient at depositing pollen on stigmas. Understanding the magnitude of variability in pollinator quality is one important factor for predicting how different pollinator taxa may influence the evolution of floral traits. PMID:16299005

  2. Acute cardiac support with intravenous milrinone promotes recovery from early brain injury in a murine model of severe subarachnoid hemorrhage.

    PubMed

    Mutoh, Tomoko; Mutoh, Tatsushi; Nakamura, Kazuhiro; Yamamoto, Yukiko; Tsuru, Yoshiharu; Tsubone, Hirokazu; Ishikawa, Tatsuya; Taki, Yasuyuki

    2016-12-23

    Early brain injury/ischemia (EBI) is a serious complication early after subarachnoid hemorrhage (SAH) that contributes to development of delayed cerebral ischemia (DCI). This study aimed to determine the role of inotropic cardiac support using milrinone (MIL) on restoring acute cerebral hypoperfusion attributable to EBI and improving outcomes after experimental SAH. Forty-three male C57BL/6 mice were assigned to either sham surgery (SAH-sham), SAH induced by endovascular perforation plus postconditioning with 2% isoflurane (Control), or SAH plus isoflurane combined with MIL with and without hypoxia-inducible factor inhibitor (HIF-I) pretreatment. Cardiac output (CO) during intravenous MIL infusion (0.25-0.75 μg/kg/min) between 1.5 and 2.5h after SAH induction was monitored with Doppler-echocardiography. MRI-continuous arterial spin labeling was used for quantitative CBF measurements. Neurobehavioral function was assessed daily by neurological score and open field test. DCI was analyzed 3 days later by determining infarction on MRI. Mild reduction of cardiac output (CO) and global cerebral blood flow (CBF) depression were notable early after SAH. MIL increased CO in a dose-dependent manner (P <0.001), which was accompanied by improved hypoperfusion, incidence of DCI and functional recovery than Control (P <0.05). The neuroprotective effects afforded by MIL or Control were attenuated by HIF inhibition (P <0.05). These results suggest that MIL improves acute hypoperfusion by its inotropic effect, leading to neurobehavioral improvement in mice after severe SAH, in which HIF may be acting as a critical mediator. This article is protected by copyright. All rights reserved.

  3. Trypanosoma cruzi Infection through the Oral Route Promotes a Severe Infection in Mice: New Disease Form from an Old Infection?

    PubMed Central

    Barreto-de-Albuquerque, Juliana; Silva-dos-Santos, Danielle; Pérez, Ana Rosa; Berbert, Luiz Ricardo; de Santana-van-Vliet, Eliane; Farias-de-Oliveira, Désio Aurélio; Moreira, Otacilio C.; Roggero, Eduardo; de Carvalho-Pinto, Carla Eponina; Jurberg, José; Cotta-de-Almeida, Vinícius; Bottasso, Oscar; Savino, Wilson; de Meis, Juliana

    2015-01-01

    Oral transmission of Chagas disease has been documented in Latin American countries. Nevertheless, significant studies on the pathophysiology of this form of infection are largely lacking. The few studies investigating oral route infection disregard that inoculation in the oral cavity (Oral infection, OI) or by gavage (Gastrointestinal infection, GI) represent different infection routes, yet both show clear-cut parasitemia and heart parasitism during the acute infection. Herein, BALB/c mice were subjected to acute OI or GI infection using 5x104 culture-derived Trypanosoma cruzi trypomastigotes. OI mice displayed higher parasitemia and mortality rates than their GI counterparts. Heart histopathology showed larger areas of infiltration in the GI mice, whereas liver lesions were more severe in the OI animals, accompanied by higher Alanine Transaminase and Aspartate Transaminase serum contents. A differential cytokine pattern was also observed because OI mice presented higher pro-inflammatory cytokine (IFN-γ, TNF) serum levels than GI animals. Real-time PCR confirmed a higher TNF, IFN-γ, as well as IL-10 expression in the cardiac tissue from the OI group compared with GI. Conversely, TGF-β and IL-17 serum levels were greater in the GI animals. Immunolabeling revealed macrophages as the main tissue source of TNF in infected mice. The high mortality rate observed in the OI mice paralleled the TNF serum rise, with its inhibition by an anti-TNF treatment. Moreover, differences in susceptibility between GI versus OI mice were more clearly related to the host response than to the effect of gastric pH on parasites, since infection in magnesium hydroxide-treated mice showed similar results. Overall, the present study provides conclusive evidence that the initial site of parasite entrance critically affects host immune response and disease outcome. In light of the occurrence of oral Chagas disease outbreaks, our results raise important implications in terms of the current

  4. Influence of Electric Fields and Conductivity on Pollen Tube Growth assessed via Electrical Lab-on-Chip

    PubMed Central

    Agudelo, Carlos; Packirisamy, Muthukumaran; Geitmann, Anja

    2016-01-01

    Pollen tubes are polarly growing plant cells that are able to rapidly respond to a combination of chemical, mechanical, and electrical cues. This behavioural feature allows them to invade the flower pistil and deliver the sperm cells in highly targeted manner to receptive ovules in order to accomplish fertilization. How signals are perceived and processed in the pollen tube is still poorly understood. Evidence for electrical guidance in particular is vague and highly contradictory. To generate reproducible experimental conditions for the investigation of the effect of electric fields on pollen tube growth we developed an Electrical Lab-on-Chip (ELoC). Pollen from the species Camellia displayed differential sensitivity to electric fields depending on whether the entire cell or only its growing tip was exposed. The response to DC fields was dramatically higher than that to AC fields of the same strength. However, AC fields were found to restore and even promote pollen growth. Surprisingly, the pollen tube response correlated with the conductivity of the growth medium under different AC frequencies—consistent with the notion that the effect of the field on pollen tube growth may be mediated via its effect on the motion of ions. PMID:26804186

  5. Somatic cytokinesis and pollen maturation in Arabidopsis depend on TPLATE, which has domains similar to coat proteins.

    PubMed

    Van Damme, Daniël; Coutuer, Silvie; De Rycke, Riet; Bouget, Francois-Yves; Inzé, Dirk; Geelen, Danny

    2006-12-01

    TPLATE was previously identified as a potential cytokinesis protein targeted to the cell plate. Disruption of TPLATE in Arabidopsis thaliana leads to the production of shriveled pollen unable to germinate. Vesicular compartmentalization of the mature pollen is dramatically altered, and large callose deposits accumulate near the intine cell wall layer. Green fluorescent protein (GFP)-tagged TPLATE expression under the control of the pollen promoter Lat52 complements the phenotype. Downregulation of TPLATE in Arabidopsis seedlings and tobacco (Nicotiana tabacum) BY-2 suspension cells results in crooked cell walls and cell plates that fail to insert into the mother wall. Besides accumulating at the cell plate, GFP-fused TPLATE is temporally targeted to a narrow zone at the cell cortex where the cell plate connects to the mother wall. TPLATE-GFP also localizes to subcellular structures that accumulate at the pollen tube exit site in germinating pollen. Ectopic callose depositions observed in mutant pollen also occur in RNA interference plants, suggesting that TPLATE is implicated in cell wall modification. TPLATE contains domains similar to adaptin and beta-COP coat proteins. These data suggest that TPLATE functions in vesicle-trafficking events required for site-specific cell wall modifications during pollen germination and for anchoring of the cell plate to the mother wall at the correct cortical position.

  6. Influence of Electric Fields and Conductivity on Pollen Tube Growth assessed via Electrical Lab-on-Chip.

    PubMed

    Agudelo, Carlos; Packirisamy, Muthukumaran; Geitmann, Anja

    2016-01-25

    Pollen tubes are polarly growing plant cells that are able to rapidly respond to a combination of chemical, mechanical, and electrical cues. This behavioural feature allows them to invade the flower pistil and deliver the sperm cells in highly targeted manner to receptive ovules in order to accomplish fertilization. How signals are perceived and processed in the pollen tube is still poorly understood. Evidence for electrical guidance in particular is vague and highly contradictory. To generate reproducible experimental conditions for the investigation of the effect of electric fields on pollen tube growth we developed an Electrical Lab-on-Chip (ELoC). Pollen from the species Camellia displayed differential sensitivity to electric fields depending on whether the entire cell or only its growing tip was exposed. The response to DC fields was dramatically higher than that to AC fields of the same strength. However, AC fields were found to restore and even promote pollen growth. Surprisingly, the pollen tube response correlated with the conductivity of the growth medium under different AC frequencies--consistent with the notion that the effect of the field on pollen tube growth may be mediated via its effect on the motion of ions.

  7. 5-Aminolevulinic Acid Thins Pear Fruits by Inhibiting Pollen Tube Growth via Ca2+-ATPase-Mediated Ca2+ Efflux

    PubMed Central

    An, Yuyan; Li, Jie; Duan, Chunhui; Liu, Longbo; Sun, Yongping; Cao, Rongxiang; Wang, Liangju

    2016-01-01

    Chemical fruit thinning has become a popular practice in modern fruit orchards for achieving high quality fruits, reducing costs of hand thinning and promoting return bloom. However, most of the suggested chemical thinners are often concerned for their detrimental effects and environmental problems. 5-Aminolevulic acid (ALA) is a natural, nontoxic, biodegradable, and environment-friendly plant growth regulator. One of its outstanding roles is improving plant photosynthesis and fruit quality. Here, results showed that applying 100–200 mg/L ALA at full bloom stage significantly reduced pear fruit set. Both in vivo and in vitro studies showed that ALA significantly inhibited pollen germination and tube growth. ALA decreased not only cytosolic Ca2+ concentration ([Ca2+]cyt) but also “tip-focused” [Ca2+]cyt gradient, indicating that ALA inhibited pollen tube growth by down-regulating calcium signaling. ALA drastically enhanced pollen Ca2+-ATPase activity, suggesting that ALA-induced decrease of calcium signaling probably resulted from activating calcium pump. The significant negative correlations between Ca2+-ATPase activity and pollen germination or pollen tube length further demonstrated the critical role of calcium pump in ALA's negative effect on pollen germination. Taken together, our results suggest that ALA at low concentrations is a potential biochemical thinner, and it inhibits pollen germination and tube growth via Ca2+ efflux by activating Ca2+-ATPase, thereby thinning fruits by preventing fertilization. PMID:26904082

  8. Increasing allergy potency of Zinnia pollen grains in polluted areas.

    PubMed

    Chehregani, Abdolkarim; Majde, Ahmad; Moin, Mostafa; Gholami, Mansour; Ali Shariatzadeh, Mohammad; Nassiri, Hosein

    2004-06-01

    There is much evidence that allergic symptoms represent a major health problem in polluted cities. The aim of this research is to elucidate some microscopic effects of air pollutants on pollen structure, proteins, and allergenicity. A scanning electron microscopy study of pollen grains indicated that in polluted areas, airborne particles accumulate on the surface of pollen grains and change the shape and tectum of pollen. Also, many vesicles are released from polluted pollen grains and the pollen material agglomerates on the surface of pollen grains. SDS-PAGE revealed that different proteins exist in mature and immature pollen grains. There were no significant differences between protein bands of polluted and nonpolluted pollen grains, but in polluted pollen, protein content decreases in response to air pollution, causing the release of pollen proteins. The results indicate that mature pollen have more allergenicity than immature pollen. According to the experiments polluted pollen grains are more effective than nonpolluted pollen grains in inducing allergic symptoms. Air pollutants can cause allergic symptoms, but when associated with allergen pollen grains, their allergenicity power is increased.

  9. Natural Sunflower Pollen as a Drug Delivery Vehicle.

    PubMed

    Mundargi, Raghavendra C; Potroz, Michael G; Park, Soohyun; Shirahama, Hitomi; Lee, Jae Ho; Seo, Jeongeun; Cho, Nam-Joon

    2016-03-02

    In nature, pollen grains play a vital role for encapsulation. Many pollen species exist which are often used as human food supplements. Dynamic image particle analysis, scanning electron microscopy, and confocal microscopy analysis confirmed the size, structural uniformity, and macromolecular encapsulation in sunflower pollen, paving the way to explore natural pollen grains for the encapsulation of therapeutic molecules.

  10. Chapter 25: Collecting pollen for genetic resources conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection of pollen as a conservation target allows for the preservation of many diverse alleles within a genepool. Although it is possible to generate haploid plants from pollen grains, pollen is more commonly conserved as a gamete for gene conservation. The ease of pollen storage, shipment, and po...

  11. Exploitation of pollen by mycorrhizal mycelial systems with special reference to nutrient recycling in boreal forests.

    PubMed Central

    Perez-Moreno, J.; Read, D. J.

    2001-01-01

    Very large quantities of pollen are released annually by wind-pollinated trees, which dominate northern forest ecosystems. Since pollen is enriched in both nitrogen and phosphorus, this recurrent pulse of deposition constitutes a significant potential source of these elements in what are known to be severely nutrient-limited systems. Here, we demonstrate for the first time, to our knowledge, that an ectomycorrhizal fungus, Paxillus involutus, is able to scavenge effectively for nitrogen and phosphorus in pollen and to return a significant proportion of each nutrient to its autotrophic host, Betula pendula. More than 75 and 96%, respectively, of the nitrogen and phosphorus were removed from pollen in microcosms containing the mycorrhizal fungus, 29 and 25%, respectively, being transferred to the plants. In contrast, in microcosms without the mycorrhizal fungus only 42 and 35%, respectively, of nitrogen and phosphorus were lost from the pollen, presumably as a result of export by saprotrophs, and only 12 and 7%, respectively, were transferred to the plants. We hypothesize that this process of resource recapture, by contributing significantly to the ability of the trees to sustain the necessary annual investment in pollen production, will have a major impact upon their reproductive capabilities and hence 'fitness'. PMID:11429131

  12. An immunoblotting analysis of cross-reactivity between melon, and plantago and grass pollens.

    PubMed

    García Ortiz, J C; Ventas, P; Cosmes, P; López-Asunsolo, A

    1996-01-01

    It is known that most patients with type I allergy to pollens also suffer intolerance to fruits. Recently, an epidemiological and CAP-inhibition study has shown a new clustering of allergy between melon and Plantago and grass pollens. The aim of the present study was to confirm these results by immunoblotting analysis and inhibition of immunoblotting. Sera from 3 patients with confirmed allergy to melon, and Dactylis glomerata and Plantago lanceolata pollens were used for the in vitro studies. SDS-PAGE and immunoblotting analysis with a pool of sera revealed that several distinct protein bands were shared by the three extracts at 14, 31, and a spectrum between 40 and 70 kDa, approximately. Immunoblotting inhibition experiments, performed with extracts of melon, Plantago and Dactylis, showed that all allergens of melon blotting were almost completely inhibited by grass and Plantago pollen extracts. Inversely, the melon extract was capable of inhibiting IgE-binding to various allergens of Dactylis at high mol mass and partially to the band at 14 kDa. Moreover, the melon almost totally inhibited the IgE-binding capacity to the proteins of Plantago extract. Taken together, the results support the presence of structurally similar allergens in melon, Plantago and grass pollens, and that all allergenic epitopes of the melon are present in these pollens.

  13. Effect of temperature on pollen tube kinetics and dynamics in sweet cherry, Prunus avium (Rosaceae).

    PubMed

    Hedhly, A; Hormaza, J I; Herrero, M

    2004-04-01

    Prevailing ambient temperature during the reproductive phase is one of several important factors for seed and fruit set in different plant species, and its consequences on reproductive success may increase with global warming. The effect of temperature on pollen performance was evaluated in sweet cherry (Prunus avium L.), comparing as pollen donors two cultivars that differ in their adaptation to temperature. 'Sunburst' is a cultivar that originated in Canada with a pedigree of cultivars from Northern Europe, while 'Cristobalina' is a cultivar native to southeast Spain, adapted to warmer conditions. Temperature effects were tested either in controlled-temperature chambers or in the field in a plastic cage. In both genotypes, an increase in temperature reduced pollen germination, but accelerated pollen tube growth. However, a different genotypic response, which reflected the overall adaptation of the pollen donor, was obtained for pollen tube dynamics, expressed as the census of the microgametophyte population that successfully reached the base of the style. While both cultivars performed similarly at 20°C, the microgametophyte population was reduced at 30°C for Sunburst and at 10°C for Cristobalina. These results indicate a differential genotypic response to temperature during the reproductive phase, which could be important in terms of the time needed for a plant species to adapt to rapid temperature changes.

  14. The influence from synoptic weather on the variation of air pollution and pollen exposure

    NASA Astrophysics Data System (ADS)

    Grundström, Maria; Dahl, Åslög; Chen, Deliang; Pleijel, Håkan

    2014-05-01

    Exposure to elevated air pollution levels can make people more susceptible to allergies or result in more severe allergic reactions for people with an already pronounced sensitivity to pollen. The aim of this study was to investigate the relationships between urban air pollution (nitrogen oxides, ozone and particles) and airborne Betula pollen in Gothenburg, Sweden, during the pollen seasons for the years 2001-2012. Further, the influence from atmospheric weather pattern on pollen/pollution related risk, using Lamb Weather Types (LWT), was also considered. Daily LWTs were obtained by comparing the variation in atmospheric pressure from a 16 point grid over a given region on earth (scale ~1000km) and essentially describe the air mass movement for the region. They include two non-directional types, cyclonic (C) and anticyclonic (A) and eight directional types depending on the wind direction (N, NE, E... etc.). LWTs with dry and calm meteorological character e.g. limited precipitation and low to moderate wind speeds (A, NE, E, SE) were associated with strongly elevated air pollution and pollen levels where Betula was exceptionally high in LWTs NE and E. The co-variation between Betula pollen and ozone was strong and significant during situations with LWTs A, NE, E and SE. The most important conclusion from this study was that LWTs A, NE, E and SE were associated with high pollen and air pollution levels and can therefore be classified as high risk weather situations for combined air pollution and pollen exposure. Our study shows that LWTs have the potential to be developed into an objective tool for integrated air quality forecasting and a warning system for risk of high exposure situations.

  15. Qualitative and quantitative comparison of pollen calendars for plain and mountain areas.

    PubMed

    Michel, F B; Cour, P; Quet, L; Marty, J P

    1976-07-01

    A comparison of the quantity and the quality of pollen content in the atmosphere of two regions, one of the plains bordering the Mediterranean sea (altitude 40 m), the other of the mountains of the Pyrenees (altitude 1550 m), was made during the climatological year 1974-1975. The method which was used intercepts the pollen flux of the atmosphere with a vertical filtering unit, which is exposed facing the direction of wind on the filtering door of the weather-vane and collects much larger quantities of pollen than the other techniques of collection. The atmospheric currents displace from one region to another numerous spores and pollens, the trajectories of which are directly influenced by the general circulation of the atmosphere. The density of these fluxes can be very large, reaching 2500 grains/m3 of air at M.T.P.R. in the last week of January; the taxons collected are very numerous (more than 700). The atmospheric transfer of pollen modifies largely the pollen content of the atmosphere of different flowering domains. These interferences manifest themselves in the simplest cases by the presence of two peaks of concentration, the principal corresponding to the local efflorescence, the second to the pollen transferred from other regions. The pollen concentrations in the mountains are one-third of those in the plains. Pollination in the mountains is several weeks late in comparison to the plain during the first semester, whereas during the second semester, it is the plains that show a certain delay. These findings show why some allergic patients who go to the mountains during summer are affected twice by pollination.

  16. Autofluorescence of atmospheric bioaerosols - spectral fingerprints and taxonomic trends of native pollen

    NASA Astrophysics Data System (ADS)

    Pöhlker, C.; Huffman, J. A.; Förster, J.-D.; Pöschl, U.

    2013-06-01

    Primary biological aerosol particles (PBAP) are important factors in atmospheric cycling, climate, and public health. Pollen is a major fraction of PBAP and is receiving increasing attention due to its high allergenic potential and the associated severe impacts on personal life quality and economy. Recently, autofluorescence-based techniques have proven to be valuable tools for real-time, in-situ quantification and classification of PBAP. First studies suggest that the autofluorescence of pollen may be sufficiently selective to be utilized for an automated and real-time monitoring of pollen in ambient air. However, the degree of selectivity autofluorescence can provide is still in question and actively debated. This study addresses the origin, properties, and selectivity of autofluorescence from native pollen (undamaged and chemically untreated) by providing fluorescence microscopy and spectroscopy measurements along with a systematic synthesis of related literature. We show that dry, native pollen reveals characteristic and reproducible autofluorescence signatures which are shaped by cell wall associated fluorophores, such as phenolic compounds and carotenoid pigments. In addition, fluorescence signals from proteins and chlorophyll a were observed occasionally. The abundance and intensity of the individual fluorescence signals show certain taxonomic trends and allow systematic differentiation from bacteria and fungal spores due to the lack of protein fluorescence from the grain surface. Principal component analysis was used to explore the discrimination potential of pollen autofluorescence and revealed a differentiation of pollen on family level. Our results help explore the levels of selectivity that autofluorescence-based techniques can provide to PBAP analysis and will support the development and application of autofluorescence-based detectors for monitoring of allergenic pollen in the atmosphere.

  17. 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

  18. Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS) gene expression patterns

    PubMed Central

    2011-01-01

    Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan) walls and septae (callose plugs) of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS). Of 12 CalS gene family members in Arabidopsis, only one (CalS5) has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms) and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5) (Nymphaeales). Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression and pollen

  19. A pollen-specific novel calmodulin-binding protein with tetratricopeptide repeats

    NASA Technical Reports Server (NTRS)

    Safadi, F.; Reddy, V. S.; Reddy, A. S.

    2000-01-01

    Calcium is essential for pollen germination and pollen tube growth. A large body of information has established a link between elevation of cytosolic Ca(2+) at the pollen tube tip and its growth. Since the action of Ca(2+) is primarily mediated by Ca(2+)-binding proteins such as calmodulin (CaM), identification of CaM-binding proteins in pollen should provide insights into the mechanisms by which Ca(2+) regulates pollen germination and tube growth. In this study, a CaM-binding protein from maize pollen (maize pollen calmodulin-binding protein, MPCBP) was isolated in a protein-protein interaction-based screening using (35)S-labeled CaM as a probe. MPCBP has a molecular mass of about 72 kDa and contains three tetratricopeptide repeats (TPR) suggesting that it is a member of the TPR family of proteins. MPCBP protein shares a high sequence identity with two hypothetical TPR-containing proteins from Arabidopsis. Using gel overlay assays and CaM-Sepharose binding, we show that the bacterially expressed MPCBP binds to bovine CaM and three CaM isoforms from Arabidopsis in a Ca(2+)-dependent manner. To map the CaM-binding domain several truncated versions of the MPCBP were expressed in bacteria and tested for their ability to bind CaM. Based on these studies, the CaM-binding domain was mapped to an 18-amino acid stretch between the first and second TPR regions. Gel and fluorescence shift assays performed with CaM and a CaM-binding synthetic peptide further confirmed MPCBP binding to CaM. Western, Northern, and reverse transcriptase-polymerase chain reaction analysis have shown that MPCBP expression is specific to pollen. MPCBP was detected in both soluble and microsomal proteins. Immunoblots showed the presence of MPCBP in mature and germinating pollen. Pollen-specific expression of MPCBP, its CaM-binding properties, and the presence of TPR motifs suggest a role for this protein in Ca(2+)-regulated events during pollen germination and growth.

  20. 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.

  1. Pollen

    MedlinePlus

    ... palm maple (red) maple (silver) Phoenix palm poplar willow Some people, though, do show cross-reactivity among ... ash, box elder, cottonwood, maple, palm, poplar or willow trees. Avoid the outdoors between 5:00 a. ...

  2. 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.

  3. Bee Pollen: Chemical Composition and Therapeutic Application

    PubMed Central

    Komosinska-Vassev, Katarzyna; Olczyk, Pawel; Kaźmierczak, Justyna; Olczyk, Krystyna

    2015-01-01

    Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process. PMID:25861358

  4. Development of inhibitory antibodies to therapeutic factor VIII in severe hemophilia A is associated with microsatellite polymorphisms in the HMOX1 promoter.

    PubMed

    Repessé, Yohann; Peyron, Ivan; Dimitrov, Jordan D; Dasgupta, Suryasarathi; Moshai, Elika Farrokhi; Costa, Catherine; Borel-Derlon, Annie; Guillet, Benoit; D'Oiron, Roseline; Aouba, Achille; Rothschild, Chantal; Oldenburg, Johannes; Pavlova, Anna; Kaveri, Srinivas V; Lacroix-Desmazes, Sébastien

    2013-10-01

    Induction of heme oxygenase-1, a stress-inducible enzyme with anti-inflammatory activity, reduces the immunogenicity of therapeutic factor VIII in experimental hemophilia A. In humans, heme oxygenase-1 expression is modulated by polymorphisms in the promoter of the heme oxygenase-1-encoding gene (HMOX1). We investigated the relationship between polymorphisms in the HMOX1 promoter and factor VIII inhibitor development in severe hemophilia A. We performed a case-control study on 99 inhibitor-positive patients and 263 patients who did not develop inhibitors within the first 150 cumulative days of exposure to therapeutic factor VIII. Direct sequencing and DNA fragment analysis were used to study (GT)n polymorphism and single nucleotide polymorphisms located at -1135 and -413 in the promoter of HMOX1. We assessed associations between the individual allele frequencies or genotypes, and inhibitor development. Our results demonstrate that inhibitor-positive patients had a higher frequency of alleles with large (GT)n repeats (L: n≥30), which are associated with lesser heme oxygenase-1 expression (odds ratio 2.31; 95% confidence interval 1.46-3.66; P<0.001]. Six genotypes (L/L, L/M, L/S, M/M, M/S and S/S) of (GT)n repeats were identified (S: n<21; M: 21≤n<30). The genotype group including L alleles (L/L, L/M and L/S) was statistically more frequent among inhibitor-positive than inhibitor-negative patients, as compared to the other genotypes (33.3% versus 17.1%) (odds ratio 2.21, 95% confidence interval 1.30-3.76; P<0.01). To our knowledge, this is the first association identified between HMOX1 promoter polymorphism and development of anti-drug antibodies. Our study paves the way towards modulation of the endogenous anti-inflammatory machinery of hemophilia patients to reduce the risk of inhibitor development.

  5. Meta-analysis identified the TNFA -308G > A promoter polymorphism as a risk factor for disease severity in patients with rheumatoid arthritis

    PubMed Central

    2012-01-01

    Introduction The goal of this study is to investigate whether the -308G > A promoter polymorphism in the tumor necrosis factor alpha (TNFA) gene is associated with disease severity and radiologic joint damage in a large cohort of patients with rheumatoid arthritis (RA). Methods A long-term observational early RA inception cohort (n = 208) with detailed information about disease activity and radiologic damage after 3, 6 and 9 years of disease was genotyped for the TNFA -308G > A promoter polymorphism (rs1800629). A longitudinal regression analysis was performed to assess the effect of genotype on RA disease severity and joint damage. Subsequently, a meta-analysis, including all publically available data, was performed to further test the association between joint erosions and the TNFA polymorphism. To learn more about the mechanism behind the effect of the polymorphism, RNA isolated from peripheral blood from RA patients (n = 66) was used for TNFA gene expression analysis by quantitative PCR. Results Longitudinal regression analysis with correction for gender and disease activity showed a significant difference in total joint damage between GG and GA+AA genotype groups (P = 0.002), which was stable over time. The meta-analysis, which included 2,053 patients, confirmed an association of the genetic variant with the development of erosions (odds ratio 0.78, 95% CI 0.62, 0.98). No significant differences in TNFA gene expression were observed for the different genotypes, confirming earlier findings in healthy individuals. Conclusions Our data confirm that the TNFA -308G > A promoter polymorphism is associated with joint damage in patients with RA. This is not mediated by differences in TNFA gene expression between genotypes. PMID:23217265

  6. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic–Jurassic transition

    PubMed Central

    Kürschner, Wolfram M.; Batenburg, Sietske J.; Mander, Luke

    2013-01-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic–Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  7. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic-Jurassic transition.

    PubMed

    Kürschner, Wolfram M; Batenburg, Sietske J; Mander, Luke

    2013-10-07

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic-Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis.

  8. Evolutionary stasis in pollen morphogenesis due to natural selection.

    PubMed

    Matamoro-Vidal, Alexis; Prieu, Charlotte; Furness, Carol A; Albert, Béatrice; Gouyon, Pierre-Henri

    2016-01-01

    The contribution of developmental constraints and selective forces to the determination of evolutionary patterns is an important and unsolved question. We test whether the long-term evolutionary stasis observed for pollen morphogenesis (microsporogenesis) in eudicots is due to developmental constraints or to selection on a morphological trait shaped by microsporogenesis: the equatorial aperture pattern. Most eudicots have three equatorial apertures but several taxa have independently lost the equatorial pattern and have microsporogenesis decoupled from aperture pattern determination. If selection on the equatorial pattern limits variation, we expect to see increased variation in microsporogenesis in the nonequatorial clades. Variation of microsporogenesis was studied using phylogenetic comparative analyses in 83 species dispersed throughout eudicots including species with and without equatorial apertures. The species that have lost the equatorial pattern have highly variable microsporogenesis at the intra-individual and inter-specific levels regardless of their pollen morphology, whereas microsporogenesis remains stable in species with the equatorial pattern. The observed burst of variation upon loss of equatorial apertures shows that there are no strong developmental constraints precluding variation in microsporogenesis, and that the stasis is likely to be due principally to selective pressure acting on pollen morphogenesis because of its implication in the determination of the equatorial aperture pattern.

  9. Models to predict the start of the airborne pollen season.

    PubMed

    Siniscalco, Consolata; Caramiello, Rosanna; Migliavacca, Mirco; Busetto, Lorenzo; Mercalli, Luca; Colombo, Roberto; Richardson, Andrew D

    2015-07-01

    Aerobiological data can be used as indirect but reliable measures of flowering phenology to analyze the response of plant species to ongoing climate changes. The aims of this study are to evaluate the performance of several phenological models for predicting the pollen start of season (PSS) in seven spring-flowering trees (Alnus glutinosa, Acer negundo, Carpinus betulus, Platanus occidentalis, Juglans nigra, Alnus viridis, and Castanea sativa) and in two summer-flowering herbaceous species (Artemisia vulgaris and Ambrosia artemisiifolia) by using a 26-year aerobiological data set collected in Turin (Northern Italy). Data showed a reduced interannual variability of the PSS in the summer-flowering species compared to the spring-flowering ones. Spring warming models with photoperiod limitation performed best for the greater majority of the studied species, while chilling class models were selected only for the early spring flowering species. For Ambrosia and Artemisia, spring warming models were also selected as the best models, indicating that temperature sums are positively related to flowering. However, the poor variance explained by the models suggests that further analyses have to be carried out in order to develop better models for predicting the PSS in these two species. Modeling the pollen season start on a very wide data set provided a new opportunity to highlight the limits of models in elucidating the environmental factors driving the pollen season start when some factors are always fulfilled, as chilling or photoperiod or when the variance is very poor and is not explained by the models.

  10. Models to predict the start of the airborne pollen season

    NASA Astrophysics Data System (ADS)

    Siniscalco, Consolata; Caramiello, Rosanna; Migliavacca, Mirco; Busetto, Lorenzo; Mercalli, Luca; Colombo, Roberto; Richardson, Andrew D.

    2015-07-01

    Aerobiological data can be used as indirect but reliable measures of flowering phenology to analyze the response of plant species to ongoing climate changes. The aims of this study are to evaluate the performance of several phenological models for predicting the pollen start of season (PSS) in seven spring-flowering trees ( Alnus glutinosa, Acer negundo, Carpinus betulus, Platanus occidentalis, Juglans nigra, Alnus viridis, and Castanea sativa) and in two summer-flowering herbaceous species ( Artemisia vulgaris and Ambrosia artemisiifolia) by using a 26-year aerobiological data set collected in Turin (Northern Italy). Data showed a reduced interannual variability of the PSS in the summer-flowering species compared to the spring-flowering ones. Spring warming models with photoperiod limitation performed best for the greater majority of the studied species, while chilling class models were selected only for the early spring flowering species. For Ambrosia and Artemisia, spring warming models were also selected as the best models, indicating that temperature sums are positively related to flowering. However, the poor variance explained by the models suggests that further analyses have to be carried out in order to develop better models for predicting the PSS in these two species. Modeling the pollen season start on a very wide data set provided a new opportunity to highlight the limits of models in elucidating the environmental factors driving the pollen season start when some factors are always fulfilled, as chilling or photoperiod or when the variance is very poor and is not explained by the models.

  11. Conservation biological control in strawberry: effect of different pollen on development, survival, and reproduction of Neoseiulus californicus (Acari: Phytoseiidae).

    PubMed

    Gugole Ottaviano, María F; Cédola, Claudia V; Sánchez, Norma E; Greco, Nancy M

    2015-12-01

    Wild vegetation surrounding crops may provide temporary habitat and potential food sources for phytoseiids in different seasons. Monthly vegetation samples of wild plants adjacent to strawberry plants and wild plants in a vegetation strip close to the crop were taken. The frequency of Neoseiulus californicus, Tetranychus urticae and other mites and insects was recorded. In addition, in a laboratory assay, the survival, developmental time and fecundity of females fed on pollen of strawberry and pollen of wild plants where N. californicus was recorded during their flowering, were estimated. Pollen from Urtica urens, Lamium amplexicaule, Convolvulus arvensis, Sonchus oleraceous, Galega officinalis, and Fragaria x ananassa (strawberry) allowed development of N. californicus to adult, but not reproduction. Survival was 70-80 % when fed on pollen from S. oleraceus, G. officinalis and C. arvensis, 80-90 % when fed on pollen from U. urens and F. x ananassa, and more than 90 % when fed on T. urticae and on pollen from L. amplexicaule. In autumn and winter, U. urens, L. amplexicaule and S. oleraceous could promote the persistence of N. californicus when prey density in strawberry is low, offering T. urticae, thrips and pollen. In summer, pollen of C. arvensis and G. officinalis would contribute to the persistence of N. californicus when the strawberry crop is ending and offers scarce food resources. Although the pollen of these plants would not enable the predator population to increase, the presence of these plants in the vicinity of strawberry could contribute to the persistence of N. californicus population and help to limit T. urticae growth when this pest begins to colonize the crop.

  12. 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.

  13. 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.

  14. Pollen limitation and Allee effect related to population size and sex ratio in the endangered Ottelia acuminata (Hydrocharitaceae): implications for conservation and reintroduction.

    PubMed

    Xia, J; Lu, J; Wang, Z X; Hao, B B; Wang, H B; Liu, G H

    2013-03-01

    Small populations may suffer more severe pollen limitation and result in Allee effects. Sex ratio may also affect pollination and reproduction success in dioecious species, which is always overlooked when performing conservation and reintroduction tasks. In this study, we investigated whether and how population size and sex ratio affected pollen limitation and reproduction in the endangered Ottelia acuminata, a dioecious submerged species. We established experimental plots with increasing population size and male sex ratio. We observed insect visitation, estimated pollen limitation by hand-pollinations and counted fruit set and seed production per fruit. Fruit set and seed production decreased significantly in small populations due to pollinator scarcity and thus suffered more severe pollen limitation. Although frequently visited, female-biased larger populations also suffered severe pollen limitation due to few effective visits and insufficient pollen availability. Rising male ratio enhanced pollination service and hence reproduction. Unexpectedly, pollinator preferences did not cause reduced reproduction in male-biased populations because of high pollen availability. However, reproductive outputs showed more variability in severe male-biased populations. Our results revealed two component Allee effects in fruit set and seed production, mediated by pollen limitation in O. acuminata. Moreover, reproduction decreased significantly in larger female-biased populations, increasing the risk of an Allee effect.

  15. AUXIN RESPONSE FACTOR17 is essential for pollen wall pattern formation in Arabidopsis.

    PubMed

    Yang, Jun; Tian, Lei; Sun, Ming-Xi; Huang, Xue-Yong; Zhu, Jun; Guan, Yue-Feng; Jia, Qi-Shi; Yang, Zhong-Nan

    2013-06-01

    In angiosperms, pollen wall pattern formation is determined by primexine deposition on the microspores. Here, we show that AUXIN RESPONSE FACTOR17 (ARF17) is essential for primexine formation and pollen development in Arabidopsis (Arabidopsis thaliana). The arf17 mutant exhibited a male-sterile phenotype with normal vegetative growth. ARF17 was expressed in microsporocytes and microgametophytes from meiosis to the bicellular microspore stage. Transmission electron microscopy analysis showed that primexine was absent in the arf17 mutant, which leads to pollen wall-patterning defects and pollen degradation. Callose deposition was also significantly reduced in the arf17 mutant, and the expression of CALLOSE SYNTHASE5 (CalS5), the major gene for callose biosynthesis, was approximately 10% that of the wild type. Chromatin immunoprecipitation and electrophoretic mobility shift assays showed that ARF17 can directly bind to the CalS5 promoter. As indicated by the expression of DR5-driven green fluorescent protein, which is an synthetic auxin response reporter, auxin signaling appeared to be specifically impaired in arf17 anthers. Taken together, our results suggest that ARF17 is essential for pollen wall patterning in Arabidopsis by modulating primexine formation at least partially through direct regulation of CalS5 gene expression.

  16. Interleukin-21 is associated with the severity of psoriasis vulgaris through promoting CD4+ T cells to differentiate into Th17 cells

    PubMed Central

    Wang, Ying; Wang, Li-Li; Yang, Hao-Yu; Wang, Fei-Fei; Zhang, Xue-Xiu; Bai, Yan-Ping

    2016-01-01

    Interleukin-21 (IL-21) and T helper 17 (Th17) cells are known to be involved in the pathogenesis of psoriasis, but little is known about their relationship in psoriasis. Herein, we investigated whether IL-21 could regulate Th17 cell induction in patients with psoriasis vulgaris. 32 patients with psoriasis vulgaris and 13 healthy controls were recruited. Flow cytometry was used to detect the frequencies of cells mainly secreting IL-21 (including IL-21+CD4+ T and IL-21+ Th17 cells) and Th17 cells. An enzyme-linked immunosorbent assay (ELISA) was used to determine the serum content of IL-21. Severity of the psoriasis was evaluated by a Psoriasis Area and Severity Index (PASI) score. In addition, the differentiation of CD4+ T cells with IL-21 and the different frequencies of IL-21+CD4+ T cells, IL-21+ Th17 cells and Th17 cells were assessed, as were serum levels of IL-21 in patients with moderate to severe psoriasis before and after treatment. Our results showed that the levels of IL-21, IL-21+CD4+ T cells, IL-21+ Th17 cells and Th17 cells were significantly increased in patients and positively associated with PASI score (P < 0.01). Moreover, the levels of IL-21, IL-21+CD4+ T cells and IL-21+ Th17 cells were positively correlated with the frequency of Th17 cells (P < 0.01). In vitro experiments demonstrated that IL-21 could promote CD4+ T cells to differentiate into Th17 cells. After a 4-week treatment of acitretin and a topical therapy, all the immune markers observed in patients decreased significantly (P < 0.01), but the levels remained higher than those in healthy controls (P < 0.01). These findings indicate that IL-21 might promote Th17 cell induction in psoriasis and might be a potential immune marker for targeting this disease. PMID:27508040

  17. Molecular biomarkers for grass pollen immunotherapy

    PubMed Central

    Popescu, Florin-Dan

    2014-01-01

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines. PMID:25237628

  18. Quarternary Pollen Analysis in Secondary School Ecology

    ERIC Educational Resources Information Center

    Slater, F. M.

    1972-01-01

    Describes techniques for studying historic changes in climate by analysis of pollen preserved in peat bogs. Illustrates the methodology and data analysis techniques by reference to results from English research. (AL)

  19. 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.

  20. In vitro inhibition of incompatible pollen tubes in Nicotiana alata involves the uncoupling of the F-actin cytoskeleton and the endomembrane trafficking system.

    PubMed

    Roldán, Juan A; Rojas, Hernán J; Goldraij, Ariel

    2015-01-01

    In the S-RNase-based self-incompatibility system, subcellular events occurring in the apical region of incompatible pollen tubes during the pollen rejection process are poorly understood. F-actin dynamics and endomembrane trafficking are crucial for polar growth, which is temporally and spatially controlled in the tip region of pollen tubes. Thus, we developed a simple in vitro assay to study the changes in the F-actin cytoskeleton and the endomembrane system at the apical region of incompatible pollen tubes in Nicotiana alata. Growth but not germination of pollen tubes of S c₁₀-, S₇₀-, and S₇₅-haplotypes was selectively inhibited by style extracts carrying the same haplotypes. Pollen F-actin cytoskeleton and endomembrane system, visualized by fluorescent markers, were normal during the initial 60 min of pollen culture in the presence of compatible and incompatible style extracts. Additional culture resulted in complete growth arrest and critical alterations in the integrity of the F-actin cytoskeleton and the endomembrane system of incompatible pollen tubes. The F-actin ring and the V-shaped zone disappeared from the apical region, while distorted F-actin cables and progressive formation of membrane aggregates evolved in the subapical region and the shank. The vacuolar network of incompatible pollen tubes invaded the tip region, but vacuolar membrane integrity remained mostly unaffected. The polar growth machinery of incompatible pollen tubes was uncoupled, as evidenced by the severe disruption of colocalization between the F-actin cytoskeleton and the endomembrane compartments. A model of pollen rejection integrating the main subcellular events occurring in incompatible pollen is discussed.

  1. AMS radiocarbon dating of pollen concentrates in a karstic lake system

    NASA Astrophysics Data System (ADS)

    Fletcher, William; Zielhofer, Christoph; Mischke, Steffen; Campbell, Jennifer; Bryant, Charlotte; Fink, David; Xu, Xiaomei

    2016-04-01

    In lake sediments where terrestrial macrofossils are rare or absent, AMS radiocarbon dating of pollen concentrates represents an important alternative solution for developing a robust and high resolution chronology suitable for Bayesian modelling of age-depth relationships. Here we report an application of the dense media separation approach (Vandergoes and Prior, Radiocarbon 45:479-492, 2003) to Holocene lake sediments from karstic Lake Sidi Ali, Morocco (33° 03'N, 05° 00'W; 2,080 m a.s.l.). Paired dates on terrestrial (macrofossil) and aquatic (ostracod) samples, and dating of bulk sediment surface material at the site indicate varying reservoir effects of up to 900 yr and highlight the need to date terrestrial carbon sources. Dating of pollen concentrates is a viable approach at Lake Sidi Ali, as pollen concentrations are high (~200,000 grains/cc), and pollen assemblages typically contain only minor percentages (<1%) of aquatic pollen. Following laboratory trials, 23 pollen concentrates alongside laboratory standards (anthracite, IAEA C5 wood) were prepared and dated following the heavy liquid (sodium polytungstate, SPT) density separation protocol. A series of SPT solutions of progressively decreasing density (1.9-1.15 s.g.) were used to divide the samples into several fractions. The pollen purity of these fractions was evaluated by microscopic analysis of smear slides, and the richest fraction(s) were selected for dating. Sieving at 10 μm and at 50/125 μm (depending on the size of predominant pollen grains) was used to further concentrate the pollen grains, and the samples were freeze dried to determine the dry weight of material. The results show that the highest purity of pollen is sample dependent and may typically be achieved in the fractions precipitating at 1.4-1.2 s.g. With sieving, terrestrial pollen purity of ~50-80% can be achieved, offering a considerable improvement in terms of terrestrial carbon content over bulk sediment. These values reflect

  2. 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 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. PMID:23940803

  3. 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.

  4. Pollen as atmospheric cloud condensation nuclei

    NASA Astrophysics Data System (ADS)

    Steiner, Allison L.; Brooks, Sarah D.; Deng, Chunhua; Thornton, Daniel C. O.; Pendleton, Michael W.; Bryant, Vaughn

    2015-05-01

    Anemophilous (wind-dispersed) pollen grains are emitted in large quantities by vegetation in the midlatitudes for reproduction. Pollen grains are coarse particles (5-150 µm) that can rupture when wet to form submicron subpollen particles (SPP) that may have a climatic role. Laboratory CCN experiments of six fresh pollen samples show that SPP activate as CCN at a range of sizes, requiring supersaturations from 0.81 (± 0.07)% for 50 nm particles, 0.26 (± 0.03)% for 100 nm particles, and 0.12 (± 0.00)% for 200 nm particles. Compositional analyses indicate that SPP contain carbohydrates and proteins. The SPP contribution to global CCN is uncertain but could be important depending on pollen concentrations outside the surface layer and the number of SPP generated from a single pollen grain. The production of hygroscopic SPP from pollen represents a novel, biologically driven cloud formation pathway that may influence cloud optical properties and lifetimes, thereby influencing climate.

  5. Thunderstorm asthma due to grass pollen.

    PubMed

    Suphioglu, C

    1998-08-01

    It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. Moreover, grass pollen is also responsible for triggering allergic asthma, gaining impetus as a result of the 1987/1989 Melbourne and 1994 London thunderstorm-associated asthma epidemics. However, grass pollen is too large to gain access into the lower airways to trigger the asthmatic response and micronic particles <5 micro m are required to trigger the response. We have successfully shown that ryegrass pollen ruptures upon contact with water, releasing about 700 starch granules which not only contain the major allergen Lol p 5, but have been shown to trigger both in vitro and in vivo IgE-mediated responses. Furthermore, starch granules have been isolated from the Melbourne atmosphere with 50-fold increase following rainfall. Free grass pollen allergen molecules have been recently shown to interact with other particles including diesel exhaust carbon particles, providing a further transport mechanism for allergens to gain access into lower airways. In this review, implication and evidence for grass pollen as a trigger of thunderstorm-associated asthma is presented. Such information is critical and mandatory for patient education and training in their allergen avoidance programs. More importantly, patients with serum IgE to group 5 allergens are at high risk of allergic asthma, especially those not protected by medication. Therefore, a system to determine the total atmospheric allergen load and devising of an effective asthma risk forecast is urgently needed and is subject to current investigation.

  6. Gametophytic Pollen Tube Guidance: Attractant Peptides, Gametic Controls, and Receptors.

    PubMed

    Higashiyama, Tetsuya; Yang, Wei-Cai

    2017-01-01

    Pollen tube guidance in flowering plants is a unique and critical process for successful sexual reproduction. The pollen tube that grows from pollen, which is the male gametophyte, precisely navigates to the embryo sac, which is the female gametophyte, within the pistil. Recent advances have clarified the molecular framework of gametophytic pollen tube guidance. Multiple species-specific attractant peptides are secreted from synergid cells, the proper development and function of which are regulated by female gametes. Multiple receptor-like kinases on the pollen tube tip are involved in sensing species-specific attractant peptides. In this Update article, recent progress in our understanding of the mechanism of gametophytic pollen tube guidance is reviewed, including attraction by synergid cells, control of pollen tube guidance by female gametes, and directional growth of the pollen tube by directional cue sensing. Future directions in the study of pollen tube guidance also are discussed.

  7. The ADH7 Promoter of Saccharomyces cerevisiae is Vanillin-Inducible and Enables mRNA Translation Under Severe Vanillin Stress.

    PubMed

    Nguyen, Trinh T M; Iwaki, Aya; Izawa, Shingo

    2015-01-01

    Vanillin is one of the major phenolic aldehyde compounds derived from lignocellulosic biomass and acts as a potent fermentation inhibitor to repress the growth and fermentative ability of yeast. Vanillin can be reduced to its less toxic form, vanillyl alcohol, by the yeast NADPH-dependent medium chain alcohol dehydrogenases, Adh6 and Adh7. However, there is little information available regarding the regulation of their gene expression upon severe vanillin stress, which has been shown to repress the bulk translation activity in yeast cells. Therefore, in this study, we investigated expression patterns of the ADH6 and ADH7 genes in the presence of high concentrations of vanillin. We found that although both genes were transcriptionally upregulated by vanillin stress, they showed different protein expression patterns in response to vanillin. Expression of Adh6 was constitutive and gradually decreased under vanillin stress, whereas expression of Adh7 was inducible, and, importantly, occurred under severe vanillin stress. The null mutants of ADH6 or ADH7 genes were hypersensitive to vanillin and reduced vanillin less efficiently than the wild type, confirming the importance of Adh6 and Adh7 in vanillin detoxification. Additionally, we demonstrate that the ADH7 promoter is vanillin-inducible and enables effective protein synthesis even under severe vanillin stress, and it may be useful for the improvement of vanillin-tolerance and biofuel production efficiency via modification of yeast gene expression in the presence of high concentrations of vanillin.

  8. Toll-like receptor 4 agonistic antibody promotes innate immunity against severe pneumonia induced by coinfection with influenza virus and Streptococcus pneumoniae.

    PubMed

    Tanaka, Akitaka; Nakamura, Shigeki; Seki, Masafumi; Fukudome, Kenji; Iwanaga, Naoki; Imamura, Yoshifumi; Miyazaki, Taiga; Izumikawa, Koichi; Kakeya, Hiroshi; Yanagihara, Katsunori; Kohno, Shigeru

    2013-07-01

    Coinfection with bacteria is a major cause of mortality during influenza epidemics. Recently, Toll-like receptor (TLR) agonists were shown to have immunomodulatory functions. In the present study, we investigated the effectiveness and mechanisms of the new TLR4 agonistic monoclonal antibody UT12 against secondary pneumococcal pneumonia induced by coinfection with influenza virus in a mouse model. Mice were intranasally inoculated with Streptococcus pneumoniae 2 days after influenza virus inoculation. UT12 was intraperitoneally administered 2 h before each inoculation. Survival rates were significantly increased and body weight loss was significantly decreased by UT12 administration. Additionally, the production of inflammatory mediators was significantly suppressed by the administration of UT12. In a histopathological study, pneumonia in UT12-treated mice was very mild compared to that in control mice. UT12 increased antimicrobial defense through the acceleration of macrophage recruitment into the lower respiratory tract induced by c-Jun N-terminal kinase (JNK) and nuclear factor kappaB (NF-κB) pathway-dependent monocyte chemoattractant protein 1 (MCP-1) production. Collectively, these findings indicate that UT12 promoted pulmonary innate immunity and may reduce the severity of severe pneumonia induced by coinfection with influenza virus and S. pneumoniae. This immunomodulatory effect of UT12 improves the prognosis of secondary pneumococcal pneumonia and makes UT12 an attractive candidate for treating severe infectious diseases.

  9. An internal promoter underlies the difference in disease severity between N- and C-terminal truncation mutations of Titin in zebrafish

    PubMed Central

    Zou, Jun; Tran, Diana; Baalbaki, Mai; Tang, Ling Fung; Poon, Annie; Pelonero, Angelo; Titus, Erron W; Yuan, Christiana; Shi, Chenxu; Patchava, Shruthi; Halper, Elizabeth; Garg, Jasmine; Movsesyan, Irina; Yin, Chaoying; Wu, Roland; Wilsbacher, Lisa D; Liu, Jiandong; Hager, Ronald L; Coughlin, Shaun R; Jinek, Martin; Pullinger, Clive R; Kane, John P; Hart, Daniel O; Kwok, Pui-Yan; Deo, Rahul C

    2015-01-01

    Truncating mutations in the giant sarcomeric protein Titin result in dilated cardiomyopathy and skeletal myopathy. The most severely affected dilated cardiomyopathy patients harbor Titin truncations in the C-terminal two-thirds of the protein, suggesting that mutation position might influence disease mechanism. Using CRISPR/Cas9 technology, we generated six zebrafish lines with Titin truncations in the N-terminal and C-terminal regions. Although all exons were constitutive, C-terminal mutations caused severe myopathy whereas N-terminal mutations demonstrated mild phenotypes. Surprisingly, neither mutation type acted as a dominant negative. Instead, we found a conserved internal promoter at the precise position where divergence in disease severity occurs, with the resulting protein product partially rescuing N-terminal truncations. In addition to its clinical implications, our work may shed light on a long-standing mystery regarding the architecture of the sarcomere. DOI: http://dx.doi.org/10.7554/eLife.09406.001 PMID:26473617

  10. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    PubMed Central

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-01-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content. PMID:27457754

  11. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    NASA Astrophysics Data System (ADS)

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-07-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content.

  12. Ovine HSP90AA1 Expression Rate Is Affected by Several SNPs at the Promoter under Both Basal and Heat Stress Conditions

    PubMed Central

    Salces-Ortiz, Judit; González, Carmen; Moreno-Sánchez, Natalia; Calvo, Jorge H.; Pérez-Guzmán, M. Dolores; Serrano, Magdalena M.

    2013-01-01

    The aim of this work was to investigate the association between polymorphisms located at the HSP90AA1 ovine gene promoter and gene expression rate under different environmental conditions, using a mixed model approach. Blood samples from 120 unrelated rams of the Manchega sheep breed were collected at three time points differing in environmental conditions. Rams were selected on the basis of their genotype for the transversion G/C located 660 base pairs upstream the gene transcription initiation site. Animals were also genotyped for another set of 6 SNPs located at the gene promoter. Two SNPs, G/C−660 and A/G−444, were associated with gene overexpression resulting from heat stress. The composed genotype CC−660-AG−444 was the genotype having the highest expression rates with fold changes ranging from 2.2 to 3.0. The genotype AG−522 showed the highest expression levels under control conditions with a fold change of 1.4. Under these conditions, the composed genotype CC−601-TT−524-AG−522-TT−468 is expected to be correlated with higher basal expression of the gene according to genotype frequencies and linkage disequilibrium values. Some putative transcription factors were predicted for binding sites where the SNPs considered are located. Since the expression rate of the gene under alternative environmental conditions seems to depend on the composed genotype of several SNPs located at its promoter, a cooperative regulation of the transcription of the HSP90AA1 gene could be hypothesized. Nevertheless epigenetic regulation mechanisms cannot be discarded. PMID:23826107

  13. Marking live conifer pollen for long-distance dispersal experiments.

    PubMed

    Williams, Claire G; von Aderkas, Patrick

    2011-01-01

    Long-distance dispersal (LDD) theory requires a method for marking live LDD pollen. Such a method must complement more intensive sampling methods inclusive of molecular cytogenetics, proteomics and genomics. We developed a new method for marking live Pinus taeda pollen using two dyes, rhodamine 123 and aniline blue, dissolved in a sucrose solution. Marked and unmarked pollen were compared with respect to in vitro germination, storage, terminal velocity, and in vivo pollen tube penetration of ovules. We found that: (1) both types of marked pollen retained their capacity for germination, (2) both types of marked pollen had similar aerodynamic properties when compared to unmarked pollen controls, (3) marked pollen retained its germination capacity for 48 h, and (4) of the marked pollen, only the aniline-marked pollen penetrated ovules during pollination. Germination declined rapidly for both types of marked pollen after 48 h and before 37 days at -20°C storage, while unmarked pollen lots retained 93% germination at all stages. This method for marking live P. taeda pollen is feasible for tracing LDD pollen only if released and deposited within 48 h of dye treatment.

  14. Marking live conifer pollen for long-distance dispersal experiments.

    PubMed

    Williams, Claire G; von Aderkas, Patrick

    2011-01-01

    Study of long-distance dispersal (LDD) theory requires a method for marking live LDD pollen. Such a method must complement the more intensive sampling methods involving molecular cytogenetics, proteomics, and genomics. We have developed a new method for marking live Pinus taeda pollen using two dyes, rhodamine 123 and aniline blue, dissolved in a sucrose solution. Marked and unmarked pollen were compared with respect to in vitro germination, storage, terminal velocity and in vivo pollen-tube penetration of ovules. We found that: (1) both types of marked pollen retained their capacity for germination, (2) both types of marked pollen had similar aerodynamic properties as unmarked pollen controls, (3) marked pollen retained its germination capacity for 48 h, and (4) of the marked pollen, only the aniline-marked pollen penetrated ovules during pollination. Germination declined rapidly for both types of marked pollen after 48 h and before 37 days at -20°C storage, while the unmarked pollen lots retained 93% germination at all stages. Our method for marking live P. taeda pollen is feasible for tracing LDD pollen if released and deposited within 48 h of dye treatment.

  15. Does an 'oversupply' of ovules cause pollen limitation?

    PubMed

    Rosenheim, Jay A; Schreiber, Sebastian J; Williams, Neal M

    2016-04-01

    Lifetime seed production can be constrained by shortfalls of pollen receipt ('pollen limitation'). The ovule oversupply hypothesis states that, in response to unpredictable pollen availability, plants evolve to produce more ovules than they expect to be fertilized, and that this results in pollen limitation of seed production. Here, we present a cartoon model and a model of optimal plant reproductive allocations under stochastic pollen receipt to evaluate the hypothesis that an oversupply of ovules leads to increased pollen limitation. We show that an oversupply of ovules has two opposing influences on pollen limitation of whole-plant seed production. First, ovule oversupply increases the likelihood that pollen receipt limits the number of ovules that can be fertilized ('prezygotic pollen limitation'). Second, ovule oversupply increases the proportion of pollen grains received that are used to fertilize ovules ('pollen use efficiency'). As a result of these opposing influences, ovule oversupply has only a modest effect on the degree to which lifetime seed production is constrained by pollen receipt, producing a small decrease in the incidence of pollen limitation. Ovule oversupply is not the cause of the pollen limitation problem, but rather is part of the evolutionary solution to that problem.

  16. The airborne pollen calendar for Lublin, central-eastern Poland.

    PubMed

    Piotrowska-Weryszko, Krystyna; Weryszko-Chmielewska, Elżbieta

    2014-01-01

    An aerobiological study was conducted to investigate the quantity and quality of pollen in the atmosphere of Lublin in central-eastern Poland. Pollen monitoring was carried out in the period 2001-2012 using a Hirst-type volumetric spore trap. The atmospheric pollen season in Lublin lasted, on average, from the end of January to the beginning of October. The mean air temperature during the study period was found to be higher by 1.1 °C than the mean temperature in the period 1951-2000. 56 types of pollen of plants belonging to 41 families were identified. 28 types represented woody plants and 28 represented herbaceous plants. The study distinguished 5 plant taxa the pollen of which was present most abundantly in the air of Lublin, which altogether accounted for 73.4%: Betula, Urtica, Pinus, Poaceae, and Alnus. The mean annual pollen index was 68 706; the largest amount of pollen was recorded in April and accounted for 33.3% of the annual pollen index. The pollen calendar included 28 allergenic plant taxa. The pollen of woody plants had the highest percentage in the pollen spectrum, on average 58.4%. The parameters of the pollen calendar for Lublin were compared with the calendar for central-eastern Europe with regard to the start of the pollen season of particular taxa. The pollen calendar for Lublin was demonstrated to show greater similarity to the calendar for Münster (Germany) than to the calendar for Bratislava (Slovakia).

  17. Recombinant Mal d 1 facilitates sublingual challenge tests of birch pollen-allergic patients with apple allergy.

    PubMed

    Kinaciyan, T; Nagl, B; Faustmann, S; Kopp, S; Wolkersdorfer, M; Bohle, B

    2016-02-01

    It is still unclear whether allergen-specific immunotherapy (AIT) with birch pollen improves birch pollen-related food allergy. One reason for this may be the lack of standardized tests to assess clinical reactions to birch pollen-related foods, for example apple. We tested the applicability of recombinant (r) Mal d 1, the Bet v 1-homolog in apple, for oral challenge tests. Increasing concentrations of rMal d 1 in 0.9% NaCl were sublingually administered to 72 birch pollen-allergic patients with apple allergy. The dose of 1.6 μg induced oral allergy syndromes in 26.4%, 3.2 μg in 15.3%, 6.3 μg in 27.8%, 12.5 μg in 8.3%, 25 μg in 11.1%, and 50 μg in 4.2% of the patients. No severe reactions occurred. None of the patients reacted to 0.9% NaCl alone. Sublingual administration of 50 μg of rMal d 1 induced no reactions in three nonallergic individuals. Our approach allows straight forward, dose-defined sublingual challenge tests in a high number of birch pollen-allergic patients that inter alia can be applied to evaluate the therapeutic efficacy of birch pollen AIT on birch pollen-related food allergy.

  18. 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.

  19. Protocol for a double-blind randomised controlled trial of low dose intradermal grass pollen immunotherapy versus a histamine control on symptoms and medication use in adults with seasonal allergic rhinitis (PollenLITE)

    PubMed Central

    2013-01-01

    Background Subcutaneous immunotherapy with high dose grass pollen (typically microgram quantities) was first described over 100 years ago. This treatment suppresses allergen-induced cutaneous late responses, with lesser effects on early responses. We previously reported that repeated 2-weekly intradermal injections of grass pollen - containing approximately 7 ng of major allergen Phl p 5 – led to a progressive suppression of the allergen-induced cutaneous response, and that by the sixth injection, this was inhibited by over 90%. The purpose of this trial is to investigate the clinical efficacy of intradermal desensitisation with low doses (i.e. nanogram quantities) of grass pollen allergen for seasonal allergic rhinitis. Methods/design The Pollen Low dose Intradermal therapy Evaluation (PollenLITE) is a single centre double-blind randomised parallel group controlled trial of the efficacy and safety of intradermal grass pollen injections plus standard treatment, versus histamine injections plus standard treatment, in adults with moderate-severe grass pollen-induced allergic rhinitis (‘summer hay fever’). A minimum of ninety adults with a history of moderate-severe persistent allergic rhinitis during the UK grass pollen season will be randomised into two equal groups to receive 7 or 8 intradermal injections of grass pollen extract (containing approximately 7 ng of major allergen Phl p 5) or histamine, before the grass pollen season. In the summer, participants will score their symptoms, medication requirements, visual analogue scores, and complete EuroQOL (EQ-5D-5 L) and mini Rhinoconjunctivitis Quality of Life Questionnaires. Global assessments will also be recorded at the end of the pollen season. Blood samples will be collected from all participants for mechanistic immune assays. Skin punch biopsies will also be collected in 40 participants selected at random from intradermal injection sites after the grass pollen season for mechanistic assays. Finally

  20. Early onset of Chanarin-Dorfman syndrome with severe liver involvement in a patient with a complex rearrangement of ABHD5 promoter

    PubMed Central

    2014-01-01

    Background α/β-hydrolase domain-containing protein 5 (ABHD5) plays an important role in the triacylglycerols (TAG) hydrolysis. Indeed, ABHD5 is the co-activator of adipose triglyceride lipase (ATGL), that catalyses the initial step of TAG hydrolysis. Mutations in ABHD5 gene are associated with the onset of Chanarin-Dorfman syndrome (CDS), a rare autosomal recessive lipid storage disorder, characterized by non-bullous congenital ichthyosiform erythroderma (NCIE), hepatomegaly and liver steatosis. Case presentation We describe here a 5-years-old Brazilian child who presented with NCIE at birth and diffuse micro and macro-vesicular steatosis on liver biopsy since she was 2 years old. Molecular analysis of coding sequence and putative 5′ regulatory region of ABHD5 gene was performed. A homozygous novel deletion, affecting the promoter region and the exon 1, was identified, confirming the suspected diagnosis of CDS for this patient. RT-PCR analysis showed that the genomic rearrangement completely abolished the ABHD5 gene expression in the patient, while only a partial loss of expression was detected in her parents. This is the first report describing the identification of a large deletion encompassing the promoter region of ABHD5 gene. The total loss of ABHD5 expression may explain the early onset of CDS and the severe liver involvement. After molecular diagnosis, the patient started a special diet, poor in fatty acids with medium chain triglycerides (MCT), and showed hepatic and dermatologic improvement in spite of severe molecular defect. Conclusions This case report extends the spectrum of disease-causing ABHD5 mutations in CDS providing evidence for a novel pathogenic mechanism for this rare disorder. Moreover, our preliminary data show that early diagnosis and prompt treatment of neutral lipid accumulation might be useful for CD patients. PMID:24628803

  1. Ultraviolet radiation environment of pollen and its effect on pollen germination. Final report

    SciTech Connect

    Not Available

    1981-12-01

    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.

  2. Exposure to grass pollen--but not birch pollen--affects lung function in Swedish children.

    PubMed

    Gruzieva, O; Pershagen, G; Wickman, M; Melén, E; Hallberg, J; Bellander, T; Lõhmus, M

    2015-09-01

    Allergic response to pollen is increasing worldwide, leading to high medical and social costs. However, the effect of pollen exposure on lung function has rarely been investigated. Over 1800 children in the Swedish birth cohort BAMSE were lung-function- and IgE-tested at the age of 8 and 16 years old. Daily concentrations for 9 pollen types together with measurements for ozone, NO2 , PM10 , PM2.5 were estimated for the index day as well as up to 6 days before the testing. Exposure to grass pollen during the preceding day was associated with a reduced forced expiratory volume in 8-yr-olds; -32.4 ml; 95% CI: -50.6 to -14.2, for an increase in three pollen counts/m³. Associations appeared stronger in children sensitized to pollen allergens. As the grass species flower late in the pollen season, the allergy care routines might be weakened during this period. Therefore, allergy information may need to be updated to increase awareness among grass pollen-sensitized individuals.

  3. 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.

  4. Development and validation of a 5-day-ahead hay fever forecast for patients with grass-pollen-induced allergic rhinitis.

    PubMed

    de Weger, Letty A; Beerthuizen, Thijs; Hiemstra, Pieter S; Sont, Jacob K

    2014-08-01

    One-third of the Dutch population suffers from allergic rhinitis, including hay fever. In this study, a 5-day-ahead hay fever forecast was developed and validated for grass pollen allergic patients in the Netherlands. Using multiple regression analysis, a two-step pollen and hay fever symptom prediction model was developed using actual and forecasted weather parameters, grass pollen data and patient symptom diaries. Therefore, 80 patients with a grass pollen allergy rated the severity of their hay fever symptoms during the grass pollen season in 2007 and 2008. First, a grass pollen forecast model was developed using the following predictors: (1) daily means of grass pollen counts of the previous 10 years; (2) grass pollen counts of the previous 2-week period of the current year; and (3) maximum, minimum and mean temperature (R (2)=0.76). The second modeling step concerned the forecasting of hay fever symptom severity and included the following predictors: (1) forecasted grass pollen counts; (2) day number of the year; (3) moving average of the grass pollen counts of the previous 2 week-periods; and (4) maximum and mean temperatures (R (2)=0.81). Since the daily hay fever forecast is reported in three categories (low-, medium- and high symptom risk), we assessed the agreement between the observed and the 1- to 5-day-ahead predicted risk categories by kappa, which ranged from 65 % to 77 %. These results indicate that a model based on forecasted temperature and grass pollen counts performs well in predicting symptoms of hay fever up to 5 days ahead.

  5. Development and validation of a 5-day-ahead hay fever forecast for patients with grass-pollen-induced allergic rhinitis

    NASA Astrophysics Data System (ADS)

    de Weger, Letty A.; Beerthuizen, Thijs; Hiemstra, Pieter S.; Sont, Jacob K.

    2014-08-01

    One-third of the Dutch population suffers from allergic rhinitis, including hay fever. In this study, a 5-day-ahead hay fever forecast was developed and validated for grass pollen allergic patients in the Netherlands. Using multiple regression analysis, a two-step pollen and hay fever symptom prediction model was developed using actual and forecasted weather parameters, grass pollen data and patient symptom diaries. Therefore, 80 patients with a grass pollen allergy rated the severity of their hay fever symptoms during the grass pollen season in 2007 and 2008. First, a grass pollen forecast model was developed using the following predictors: (1) daily means of grass pollen counts of the previous 10 years; (2) grass pollen counts of the previous 2-week period of the current year; and (3) maximum, minimum and mean temperature ( R 2 = 0.76). The second modeling step concerned the forecasting of hay fever symptom severity and included the following predictors: (1) forecasted grass pollen counts; (2) day number of the year; (3) moving average of the grass pollen counts of the previous 2 week-periods; and (4) maximum and mean temperatures ( R 2 = 0.81). Since the daily hay fever forecast is reported in three categories (low-, medium- and high symptom risk), we assessed the agreement between the observed and the 1- to 5-day-ahead predicted risk categories by kappa, which ranged from 65 % to 77 %. These results indicate that a model based on forecasted temperature and grass pollen counts performs well in predicting symptoms of hay fever up to 5 days ahead.

  6. Pollen feeding proteomics: Salivary proteins of the passion flower butterfly, Heliconius melpomene.

    PubMed

    Harpel, Desiree; Cullen, Darron A; Ott, Swidbert R; Jiggins, Chris D; Walters, James R

    2015-08-01

    While most adult Lepidoptera use flower nectar as their primary food source, butterflies in the genus Heliconius have evolved the novel ability to acquire amino acids from consuming pollen. Heliconius butterflies collect pollen on their proboscis, moisten the pollen with saliva, and use a combination of mechanical disruption and chemical degradation to release free amino acids that are subsequently re-ingested in the saliva. Little is known about the molecular mechanisms of this complex pollen feeding adaptation. Here we report an initial shotgun proteomic analysis of saliva from Heliconius melpomene. Results from liquid-chromatography tandem mass-spectrometry confidently identified 31 salivary proteins, most of which contained predicted signal peptides, consistent with extracellular secretion. Further bioinformatic annotation of these salivary proteins indicated the presence of four distinct functional classes: proteolysis (10 proteins), carbohydrate hydrolysis (5), immunity (6), and "housekeeping" (4). Additionally, six proteins could not be functionally annotated beyond containing a predicted signal sequence. The presence of several salivary proteases is consistent with previous demonstrations that Heliconius saliva has proteolytic capacity. It is likely that these proteins play a key role in generating free amino acids during pollen digestion. The identification of proteins functioning in carbohydrate hydrolysis is consistent with Heliconius butterflies consuming nectar, like other lepidopterans, as well as pollen. Immune-related proteins in saliva are also expected, given that ingestion of pathogens is a likely route to infection. The few "housekeeping" proteins are likely not true salivary proteins and reflect a modest level of contamination that occurred during saliva collection. Among the unannotated proteins were two sets of paralogs, each seemingly the result of a relatively recent tandem duplication. These results offer a first glimpse into the

  7. Biosynthesis of anther cuticle and pollen exine in rice

    PubMed Central

    Li, Hui

    2010-01-01

    The lipidic structures, anther cuticle (outer anther surface) and pollen exine (outer pollen wall), play a key protective role for the male gametophyte and pollen grain development. We recently identified ancient cytochrome P450 family member CYP704B2 in rice and proposed a common fatty acid ω-hydroxylation pathway for synthesizing anther cuticle and pollen exine during plant male reproductive development. Here, we propose developmental model of pollen exine formation and discuss key genes required for pollen exine synthesis in the important crop plant rice. PMID:20930527

  8. 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

  9. Enzyme activities of Arabidopsis inositol polyphosphate kinases AtIPK2α and AtIPK2β are involved in pollen development, pollen tube guidance and embryogenesis.

    PubMed

    Zhan, Huadong; Zhong, Yujiao; Yang, Zhongnan; Xia, Huijun

    2015-06-01

    Inositol polyphosphate kinase (IPK2) is a key component of inositol polyphosphate signaling. There are two highly homologous inositol polyphosphate kinases (AtIPK2α and AtIPK2β) in Arabidopsis. Previous studies that overexpressed or reduced the expression of AtIPK2α and AtIPK2β revealed their roles in auxiliary shoot branching, abiotic stress responses and root growth. Here, we report that AtIPK2α and AtIPK2β act redundantly during pollen development, pollen tube guidance and embryogenesis. Single knock-out mutants of atipk2α and atipk2β were indistinguishable from the wild type, whereas the atipk2α atipk2β double mutant could not be obtained. Detailed genetic and cytological investigations showed that the mutation of AtIPK2α and AtIPK2β resulted in severely reduced transmission of male gametophyte as a result of abnormal pollen development and defective pollen tube guidance. In addition, the early embryo development of the atipk2α atipk2β double mutant was also aborted. Expressing either catalytically inactive or substrate specificity-altered variants of AtIPK2β could not rescue the male gametophyte and embryogenesis defects of the atipk2α atipk2β double mutant, implying that the kinase activity of AtIPK2 is required for pollen development, pollen tube guidance and embryogenesis. Taken together, our results provide genetic evidence for the requirement of inositol polyphosphate signaling in plant sexual reproduction.

  10. 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.

  11. The Abundance and Pollen Foraging Behaviour of Bumble Bees in Relation to Population Size of Whortleberry (Vaccinium uliginosum)

    PubMed Central

    Mayer, Carolin; Michez, Denis; Chyzy, Alban; Brédat, Elise; Jacquemart, Anne-Laure

    2012-01-01

    Habitat fragmentation can have severe effects on plant pollinator interactions, for example changing the foraging behaviour of pollinators. To date, the impact of plant population size on pollen collection by pollinators has not yet been investigated. From 2008 to 2010, we monitored nine bumble bee species (Bombus campestris, Bombus hortorum s.l., Bombus hypnorum, Bombus lapidarius, Bombus pascuorum, Bombus pratorum, Bombus soroensis, Bombus terrestris s.l., Bombus vestalis s.l.) on Vaccinium uliginosum (Ericaceae) in up to nine populations in Belgium ranging in size from 80 m2 to over 3.1 ha. Bumble bee abundance declined with decreasing plant population size, and especially the proportion of individuals of large bumble bee species diminished in smaller populations. The most remarkable and novel observation was that bumble bees seemed to switch foraging behaviour according to population size: while they collected both pollen and nectar in large populations, they largely neglected pollen collection in small populations. This pattern was due to large bumble bee species, which seem thus to be more likely to suffer from pollen shortages in smaller habitat fragments. Comparing pollen loads of bumble bees we found that fidelity to V. uliginosum pollen did not depend on plant population size but rather on the extent shrub cover and/or openness of the site. Bumble bees collected pollen only from three plant species (V. uliginosum, Sorbus aucuparia and Cytisus scoparius). We also did not discover any pollination limitation of V. uliginosum in small populations. We conclude that habitat fragmentation might not immediately threaten the pollination of V. uliginosum, nevertheless, it provides important nectar and pollen resources for bumble bees and declining populations of this plant could have negative effects for its pollinators. The finding that large bumble bee species abandon pollen collection when plant populations become small is of interest when considering plant and

  12. The abundance and pollen foraging behaviour of bumble bees in relation to population size of whortleberry (Vaccinium uliginosum).

    PubMed

    Mayer, Carolin; Michez, Denis; Chyzy, Alban; Brédat, Elise; Jacquemart, Anne-Laure

    2012-01-01

    Habitat fragmentation can have severe effects on plant pollinator interactions, for example changing the foraging behaviour of pollinators. To date, the impact of plant population size on pollen collection by pollinators has not yet been investigated. From 2008 to 2010, we monitored nine bumble bee species (Bombus campestris, Bombus hortorum s.l., Bombus hypnorum, Bombus lapidarius, Bombus pascuorum, Bombus pratorum, Bombus soroensis, Bombus terrestris s.l., Bombus vestalis s.l.) on Vaccinium uliginosum (Ericaceae) in up to nine populations in Belgium ranging in size from 80 m(2) to over 3.1 ha. Bumble bee abundance declined with decreasing plant population size, and especially the proportion of individuals of large bumble bee species diminished in smaller populations. The most remarkable and novel observation was that bumble bees seemed to switch foraging behaviour according to population size: while they collected both pollen and nectar in large populations, they largely neglected pollen collection in small populations. This pattern was due to large bumble bee species, which seem thus to be more likely to suffer from pollen shortages in smaller habitat fragments. Comparing pollen loads of bumble bees we found that fidelity to V. uliginosum pollen did not depend on plant population size but rather on the extent shrub cover and/or openness of the site. Bumble bees collected pollen only from three plant species (V.uliginosum, Sorbus aucuparia and Cytisus scoparius). We also did not discover any pollination limitation of V. uliginosum in small populations. We conclude that habitat fragmentation might not immediately threaten the pollination of V. uliginosum, nevertheless, it provides important nectar and pollen resources for bumble bees and declining populations of this plant could have negative effects for its pollinators. The finding that large bumble bee species abandon pollen collection when plant populations become small is of interest when considering plant and

  13. Analysis of Allergenic Pollen by FTIR Microspectroscopy.

    PubMed

    Zimmerman, B; Tafintseva, V; Bağcıoğlu, M; Høegh Berdahl, M; Kohler, A

    2016-01-05

    Fourier transform infrared (FTIR) spectroscopy is a powerful tool for the identification and characterization of pollen and spores. However, interpretation and multivariate analysis of infrared microscopy spectra of single pollen grains are hampered by Mie-type scattering. In this paper, we introduce a novel sampling setup for infrared microspectroscopy of pollens preventing strong Mie-type scattering. Pollen samples were embedded in a soft paraffin layer between two sheets of polyethylene foils without any further sample pretreatment. Single-grain infrared spectra of 13 different pollen samples, belonging to 11 species, were obtained and analyzed by the new approach and classified by sparse partial least-squares regression (PLSR). For the classification, chemical and physical information were separated by extended multiplicative signal correction and used together to build a classification model. A training set of 260 spectra and an independent test set of 130 spectra were used. Robust sparse classification models allowing the biochemical interpretation of the classification were obtained by the sparse PLSR, because only a subset of variables was retained for the analysis. With accuracy values of 95% and 98%, for the independent test set and full cross-validation respectively, the method is outperforming the previously published studies on development of an automated pollen analysis. Since the method is compatible with standard air-samplers, it can be employed with minimal modification in regular aerobiology studies. When compared with optical microscopy, which is the benchmark method in pollen analysis, the infrared microspectroscopy method offers better taxonomic resolution, as well as faster, more economical, and bias-free measurement.

  14. Arabidopsis AtVPS15 plays essential roles in pollen germination possibly by interacting with AtVPS34.

    PubMed

    Wang, Wei-Ying; Zhang, Li; Xing, Shufan; Ma, Zhiqiang; Liu, Jingjing; Gu, Hongya; Qin, Genji; Qu, Li-Jia

    2012-02-01

    VPS15 protein is a component of the phosphatidylinositol 3-kinase complex which plays a pivotal role in the development of yeast and mammalian cells. The knowledge about the function of its homologue in plants remains limited. Here we report that AtVPS15, a homologue of yeast VPS15p in Arabidopsis, plays an essential role in pollen germination. Homozygous T-DNA insertion mutants of AtVPS15 could not be obtained from the progenies of self-pollinated heterozygous mutants. Reciprocal crosses between atvps15 mutants and wild-type Arabidopsis revealed that the T-DNA insertion was not able to be transmitted by male gametophytes. DAPI staining, Alexander's stain and scanning electron microscopic analysis showed that atvps15 heterozygous plants produced pollen grains that were morphologically indistinguishable from wild-type pollen, whereas in vitro germination experiments revealed that germination of the pollen grains was defective. GUS staining analysis of transgenic plants expressing the GUS reporter gene driven by the AtVPS15 promoter showed that AtVPS15 was mainly expressed in pollen grains. Finally, DUALmembrane yeast two-hybrid analysis demonstrated that AtVPS15 might interact directly with AtVPS34. These results suggest that AtVPS15 is very important for pollen germination, possibly through modulation of the activity of PI3-kinase.

  15. Bees associate colour cues with differences in pollen rewards.

    PubMed

    Nicholls, Elizabeth; de Ibarra, Natalie Hempel

    2014-08-01

    In contrast to the wealth of knowledge concerning sucrose-rewarded learning, the question of whether bees learn when they collect pollen from flowers has been little addressed. The nutritional value of pollen varies considerably between species, and it may be that bees learn the features of flowers that produce pollen best suited to the dietary requirements of their larvae. It is still unknown, however, whether a non-ingestive reward pathway for pollen learning exists, and how foraging bees sense differences between pollen types. Here we adopt a novel experimental approach testing the learning ability of bees with pollen rewards. Bumblebees were reared under controlled laboratory conditions. To establish which pollen rewards are distinguishable, individual bees were given the choice of collecting two types of pollen, diluted to varying degrees with indigestible α-cellulose. Bees preferentially collected a particular pollen type, but this was not always the most concentrated sample. Preferences were influenced by the degree of similarity between samples and also by the period of exposure, with bees more readily collecting samples of lower pollen concentration after five trials. When trained differentially, bees were able to associate an initially less-preferred contextual colour with the more concentrated sample, whilst their pollen preferences did not change. Successful learning of contextual cues seems to maintain pollen foraging preferences over repeated exposures, suggesting that fast learning of floral cues may preclude continuous sampling and evaluation of alternative reward sources, leading to constancy in pollen foraging.

  16. Surface Pollen Distribution from Alpine Vegetation in Eastern Tibet, China.

    PubMed

    Zhang, Yun; Kong, Zhaochen; Yang, Zhenjing; Wang, Li; Duan, Xiaohong

    2017-04-03

    We explore the relationship between modern pollen spectra and vegetation patterns in the Eastern Tibet, China in order to provide information on the representation of pollen taxa and improve the general knowledge of vertical pollen transport. Forty-two modern pollen samples collected in surface soil along two altitudinal transects allowed conclusions on vertical pollen dispersal from the alpine region of Dingqing County, Changdu district in Tibet. Discriminant analyses and detrended correspondence analysis (DCA) of 24 pollen taxa were used to further discuss the difference of modern pollen spectra in these alpine vegetation zones. The surface pollen assemblage is divided into three pollen zones, such as subalpine shrub meadow, montane coniferous forest and shrub steppe with sparse trees. Altitude and precipitation are two primary factors contributing to changes in surface pollen assemblage from alpine vegetation in the eastern Tibet. Large amounts of spruce pollen at higher elevations above the timberline might be introduced from lower elevations by upslope winds. Therefore, the interpretation of spruce pollen in the fossil record must take into account long distance upward wind transport. Moreover, the destruction of coniferous forest in the study area is well illustrated in the modern pollen rain.

  17. Recent pollen spectra and zonal vegetation in the western USSR

    NASA Astrophysics Data System (ADS)

    Peterson, G. M.

    The relationship of modern pollen spectra to present-day vegetation is critical to the reconstruction of vegetation and climate from fossil pollen spectra. This study uses isopoll maps to illustrate the pollen-vegetation relationships in the Soviet Union west of 100°E and presents descriptive statistics for 544 modern samples of arboreal pollen and for 370 samples of herb pollen obtained from the Soviet palynological literature. Data are assembled from this large geographic region and presented in a standardized form on a scale which can be used to relate quantitative pollen data to zonal vegetation and climatic variables and to make comparisons with other regions. In order to show the relationship between pollen types and major ecotones in forested and non-forested areas, the pollen data are presented as percentages of a sum including both arboreal and non-arboreal pollen. Major pollen types which attain values of 10% or more in at least one vegetation zone include Betula (birch), Cyperaceae (sedges), Picea (spruce), Pinus (total pine), Pinus sibirica, Ericaceae (heath family), Gramineae (grasses), Artemisia (sage), and Chenopodiaceae (i.e., saltbush, Russian thistle, pigweed family). Samples from the tundra and forest-tundra have high values of Ericaceae (heath family), birch, alder, and sedge pollen. In the boreal forest, pine, spruce, and birch pollen predominate. In the mixed and deciduous forests, Tilia (linden), Quercus (oak), Ulmus (elm), and Corylus (hazel) pollen attain maximum values. In the forest-steppe and steppe zones, arboreal pollen decreases in importance and is replaced by non-arboreal pollen types. Pollen of Artemisia and Chenopodiaceae predominates in the semi-desert zones. In spite of variation in the pollen spectra arising from the use of different sediment types (soil, peat, and river sediments), and human disturbance of vegetation, the pollen spectra are clearly related to zonal vegetation. Pollen spectra from the western USSR show

  18. Pollen-stigma adhesion in Brassica spp involves SLG and SLR1 glycoproteins.

    PubMed Central

    Luu, D T; Marty-Mazars, D; Trick, M; Dumas, C; Heizmann, P

    1999-01-01

    The adhesion of pollen grains to the stigma is the first step of pollination in flowering plants. During this step, stigmas discriminate between pollen grains that can and cannot be permitted to effect fertilization. This selection is operated by various constituents of the cell walls of both partners. Several genes structurally related to the self-incompatibility system that prevents self-pollination in Brassica spp are known to target their products into the stigma cell wall. We proposed previously that one of these genes, the one encoding the S locus glycoprotein (SLG)-like receptor 1 (SLR1), which is coexpressed with that encoding SLG, may participate in pollen-stigma adhesion. Here, we exploit a biomechanical assay to measure the pollen adhesion force and show that it is reduced both by transgenic suppression of SLR1 expression and by pretreatment of wild-type stigmas with anti-SLR1 antibodies, anti-SLG antibodies, or pollen coat-protein extracts. Our results indicate a common adhesive function for the SLR1 and SLG proteins in the pollination process. PMID:9927642

  19. Differential characteristics of olive pollen from different cultivars: biological and clinical implications.

    PubMed

    Alché, J D; Castro, A J; Jiménez-López, J C; Morales, S; Zafra, A; Hamman-Khalifa, A M; Rodríguez-García, M I

    2007-01-01

    The olive tree is grown in many parts of the world. Its germplasm is very broad, with 250 varieties in Spain alone. Variations in the ability of pollen to germinate have been studied in detail and show conspicuous differences between varieties. However, commercial olive pollen from cultivars whose origin is unknown is the material that is commonly used for clinical and biological studies. We aim to assess the putative heterogeneity of olive cultivars with regard to the presence of several pollen allergens and to determine whether these differences have biological and clinical relevance. Previous studies show that most allergens isolated and characterized to date are highly polymorphic. Olive cultivars display wide differences in the expression levels of many allergens and in the number and molecular characteristics of the allergen isoforms expressed. These differences are maintained over the years, and are intrinsic to the genetics of each cultivar. Such broad polymorphism seems to be involved in the physiology of the olive reproductive system, which might include the adaptation of the plant to different environmental conditions, the establishment of the compatibility system, and pollen performance. The differences in allergen composition in cultivars, particularly in the Ole e 1 allergen, are responsible for the important differences in the allergenic potency of the extracts. These findings could have a number of implications for the diagnosis and therapy of olive pollen allergy. We discuss how cultivar differences affect extract quality, diagnostic and therapeutic efficacy and safety, and the development of new vaccines based on the use of recombinant allergens.

  20. Spatial variability in airborne pollen concentrations.

    PubMed

    Raynor, G S; Ogden, E C; Hayes, J V

    1975-03-01

    Tests were conducted to determine the relationship between airborne pollen concentrations and distance. Simultaneous samples were taken in 171 tests with sets of eight rotoslide samplers spaced from one to 486 M. apart in straight lines. Use of all possible pairs gave 28 separation distances. Tests were conducted over a 2-year period in urban and rural locations distant from major pollen sources during both tree and ragweed pollen seasons. Samples were taken at a height of 1.5 M. during 5-to 20-minute periods. Tests were grouped by pollen type, location, year, and direction of the wind relative to the line. Data were analyzed to evaluate variability without regard to sampler spacing and variability as a function of separation distance. The mean, standard deviation, coefficient of variation, ratio of maximum to the mean, and ratio of minimum to the mean were calculated for each test, each group of tests, and all cases. The average coefficient of variation is 0.21, the maximum over the mean, 1.39 and the minimum over the mean, 0.69. No relationship was found with experimental conditions. Samples taken at the minimum separation distance had a mean difference of 18 per cent. Differences between pairs of samples increased with distance in 10 of 13 groups. These results suggest that airborne pollens are not always well mixed in the lower atmosphere and that a sample becomes less representative with increasing distance from the sampling location.

  1. Regulation of Pollen Tube Growth by Transglutaminase

    PubMed Central

    Cai, Giampiero; Serafini-Fracassini, Donatella; Del Duca, Stefano

    2013-01-01

    In pollen tubes, cytoskeleton proteins are involved in many aspects of pollen germination and growth, from the transport of sperm cells to the asymmetrical distribution of organelles to the deposition of cell wall material. These activities are based on the dynamics of the cytoskeleton. Changes to both actin filaments and microtubules are triggered by specific proteins, resulting in different organization levels suitable for the different functions of the cytoskeleton. Transglutaminases are enzymes ubiquitous in all plant organs and cell compartments. They catalyze the post-translational conjugation of polyamines to different protein targets, such as the cytoskeleton. Transglutaminases are suggested to have a general role in the interaction between pollen tubes and the extracellular matrix during fertilization and a specific role during the self-incompatibility response. In such processes, the activity of transglutaminases is enhanced, leading to the formation of cross-linked products (including aggregates of tubulin and actin). Consequently, transglutaminases are suggested to act as regulators of cytoskeleton dynamics. The distribution of transglutaminases in pollen tubes is affected by both membrane dynamics and the cytoskeleton. Transglutaminases are also secreted in the extracellular matrix, where they may take part in the assembly and/or strengthening of the pollen tube cell wall. PMID:27137368

  2. Effect of water absorption on pollen adhesion.

    PubMed

    Lin, Haisheng; Lizarraga, Leonardo; Bottomley, Lawrence A; Carson Meredith, J

    2015-03-15

    Pollens possess a thin liquid coating, pollenkitt, which plays a major role in adhesion by forming capillary menisci at interfaces. Unfortunately, the influence of humidity on pollenkitt properties and capillary adhesion is unknown. Because humidity varies widely in the environment, the answers have important implications for better understanding plant reproduction, allergy and asthma, and pollen as atmospheric condensation nuclei. Here, pollenkitt-mediated adhesion of sunflower pollen to hydrophilic and hydrophobic surfaces was measured as a function of humidity. The results quantify for the first time the significant water absorption of pollenkitt and the resulting complex dependence of adhesion on humidity. On hydrophilic Si, adhesion increased with increasing RH for pollens with or without pollenkitt, up to 200nN at 70% RH. In contrast, on hydrophobic PS, adhesion of pollenkitt-free pollen is independent of RH. Surprisingly, when pollenkitt was present adhesion forces on hydrophobic PS first increased with RH up to a maximum value at 35% RH (∼160nN), and then decreased with further increases in RH. Independent measurement of pollenkitt properties is used with models of capillary adhesion to show that humidity-dependent changes in pollenkitt wetting and viscosity are responsible for this complex adhesion behavior.

  3. Upper Paleocene and lowermost Eocene angiosperm pollen biostratigraphy of the eastern Gulf Coast and Virginia

    USGS Publications Warehouse

    Frederiksen, N.O.

    1998-01-01

    Strata comprising most of the upper Paleocene in eastern North America are divided into two new pollen zones, the Carya and Platycarya platycaryoides Interval Zones. Pollen data have proven to be important for correlations between Alabama-western Georgia and eastern Mississippi and between the eastern Gulf Coast and Virginia. Migration of tropical plant taxa from the Caribbean to the Gulf Coast began at least 4 m.y. before the end of the Paleocene. The Terminal Paleocene Extinction Event, accompanied by a distinct pulse of plant immigration from Europe, began several hundred thousand years before the end of the Paleocene.

  4. Occupational Allergy to Peach (Prunus persica) Tree Pollen and Potential Cross-Reactivity between Rosaceae Family Pollens.

    PubMed

    Jiang, Nannan; Yin, Jia; Mak, Philip; Wen, Liping

    2015-10-01

    Orchard workers in north China are highly exposed to orchard pollens, especially peach and other Rosaceae family pollens during pollination season. The aim of this study was to investigate whether occupational allergy to peach tree pollen as a member of Rosaceae family is IgE-mediated and to evaluate the cross-reactivity among Rosaceae family pollens. Allergen skin test and conjunctival challenge test were performed; enzyme linked immune-sorbent assay (ELISA), inhibiting ELISA, western immunoblotting and inhibiting western immunoblotting were done with Rosaceae family orchard pollens, including peach, apricot, cherry, apple and pear tree pollens. Mass spectrometry was also performed to probe the main allergen component and cross-reactive protein. Sensitizations to peach pollen were found in both skin test and conjunctival challenge in the patients. Serum specific IgE to three pollens (peach, apricot and cherry) were detected through ELISA. When peach pollen used as solid phase, ELISA inhibition revealed other four kinds of pollens capable of inducing partial to strong inhibitions (45% to 87%), with the strongest inhibition belonging to apricot pollen (87%). Western blotting showed predominant IgE binding to a 20 KD protein among these pollens, which appeared to be a cross-reactive allergen component through western blotting inhibition. It was recognized as a protein homologous to glutathione s-transferase 16 from Arabidopsis thaliana. Peach and other Rosaceae family tree pollen may serve as a potential cause of IgE mediated occupational respiratory disease in orchard workers in north China.

  5. Safety of Grass Pollen Sublingual Immunotherapy for Allergic Rhinitis in Concomitant Asthma.

    PubMed

    Sahadevan, A; Cusack, R; Lane, S J

    2015-01-01

    Seasonal allergic rhinitis (AR) occurs predominantly as a result of grass pollen allergy. Grass pollen sublingual immunotherapy (SLIT) has been proven effective in treating AR1. SLIT is currently licensed for use in AR with concomitant stable mild asthma. There is evidence that SLIT improves asthma control when primarily used to treat AR2. The aim was to assess the safety of SLIT in patients with severe seasonal allergic rhinitis who have co-existing stable mild asthma. The secondary aim was to determine whether asthma control improved post SLIT. There was no deterioration in asthma control after 6-36 months of SLIT. 27/30 (90%) patients' asthma control remained stable or indeed improved (p < 0.021). Of this 15 (50%) patients' asthma improved. There was no statistically significant change in their asthma pharmacotherapy after SLIT (p = 0.059). In conclusion, grass pollen SLIT is safe and can potentially treat dual allergic rhinitis- mild asthmatic patients.

  6. Late holocene climate changes in eastern North America estimated from pollen data

    SciTech Connect

    Gajewski, K.

    1988-01-01

    Well-dated pollen profiles from six sites from Maine to Minnesota record vegetation changes indicative of summer temperature and annual precipitation variations over the past 2000 yr. Laminations in the sediment provide accurate time control. Multiple regression techniques were used to calculate calibration functions from a spatial network of modern pollen and climate data. When applied to the six pollen diagrams, these calibration functions yielded estimates that show a long-term trend toward lower summer temperature. Superimposed on this long-term trend are short-term fluctuations that are frequently in phase at the sites. Departures from the long-term cooling trend are positive around 1500 yr ago (indicating relative warmth) and negative between 200 and 500 yr ago (indicating relative cold). Annual precipitation showed a slight increase at several sites during the past 1000 yr relative to the previous 1000 yr.

  7. 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

  8. Pollen Grain Size, Density, and Settling Velocity for Palmer Amaranth (Amaranthus palmeri)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Palmer amaranth has known resistance to several herbicides, including glyphosate, and there is concern that the resistance traits are being transferred between spatially segregated populations via pollen movement. The objective of this study was to describe the physical properties of Palmer amarant...

  9. [Hypersensitivity to pollen of Olea europea in patients with pollen allergy in Zadar County, Croatia].

    PubMed

    Skitarelić, Natasa; Mazzi, Antun; Skitarelić, Neven; Misulić, Josko; Vuletić, Ana

    2010-06-01

    Olive pollen is one of the most common respiratory allergens in the Mediterranean countries. The aim of this study was to establish the frequency of hypersensitivity to the pollen of Olea europea in pollen allergic patients in the County of Zadar. The study included 671 patients with pollen allergy; 61 % were male and 39 % female. 53.5 % were children aged from 4 to 14 years and 46.5 % adolescents and adults from 15 to 59 years. We took their case history, clinically examined them, and tested using the skin prick test and enzymo-immunologic UniCAP test for specific IgE antibodies. For statistical analysis we used the chi-square test. Hypersensitivity to Olea europea pollen was confirmed in 8.8 % patients with pollen allergy. Among them, the most prevalent symptom was rhinitis (58 %). Most hypersensitive patients were urban residents. Only 3 % patients lived on an island. Judging by available data, our findings show the lowest hypersensitivity to olive pollen in the Mediterranean. A comparison with our two earlier studies did not show any fluctuation in this kind of hypersensitivity.

  10. The revised edition of korean calendar for allergenic pollens.

    PubMed

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

    2012-01-01

    The old calendar of pollens did not reflect current pollen distribution and concentrations that can be influenced by changes of weather and environment of each region in South Korea. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in eight regions nationwide between 1997 and 2009. The distribution of pollen was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) for 12 years between July 1, 1997 and June 30, 2009. Pollens were collected by using Burkard 7-day sampler (Burkard Manufacturing Co Ltd, UK). Pollens which were stained with Calberla's fuchsin staining solution were identified and counted. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. 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. In Kangneung, birch appeared earlier, pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja and alder 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 ragweed. In Busan the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among all areas. In Kwangju, Oriental thuja and hazelnut appeared in early February. Japanese cedar showed the highest pollen concentration in March in Jeju. In conclusion, update information on pollen calendar in South Korea should be provided for allergic patients through the website to manage and prevent the pollinosis.

  11. Modern pollen deposition in Long Island Sound

    USGS Publications Warehouse

    Beuning, Kristina R.M.; Fransen, Lindsey; Nakityo, Berna; Mecray, Ellen L.; Bucholtz 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.

  12. Pollen Biology of Ornamental Ginger (Hedychium spp. J. Koenig)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An improved in vitro pollen germination assay was developed to assess the viability of stored Hedychium pollen. The effect of polyethylene glycol (PEG) (10, 15, and 20% w/v) on pollen germination and tube growth was evaluated for H. longicornutum and two commercial Hedychium cultivars, ‘Orange Brush...

  13. Hygroscopic weight gain of pollen grains from Juniperus species

    NASA Astrophysics Data System (ADS)

    Bunderson, Landon D.; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %.

  14. Hygroscopic weight gain of pollen grains from Juniperus species.

    PubMed

    Bunderson, Landon D; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %.

  15. 7 CFR 201.78 - Pollen control for hybrids.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Pollen control for hybrids. 201.78 Section 201.78... REGULATIONS Additional Requirements for the Certification of Plant Materials of Certain Crops § 201.78 Pollen... branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any...

  16. 7 CFR 201.78 - Pollen control for hybrids.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Pollen control for hybrids. 201.78 Section 201.78... REGULATIONS Additional Requirements for the Certification of Plant Materials of Certain Crops § 201.78 Pollen... branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any...

  17. 7 CFR 201.78 - Pollen control for hybrids.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Pollen control for hybrids. 201.78 Section 201.78... REGULATIONS Additional Requirements for the Certification of Plant Materials of Certain Crops § 201.78 Pollen... branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any...

  18. 7 CFR 201.78 - Pollen control for hybrids.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Pollen control for hybrids. 201.78 Section 201.78... REGULATIONS Additional Requirements for the Certification of Plant Materials of Certain Crops § 201.78 Pollen... branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any...

  19. 7 CFR 201.78 - Pollen control for hybrids.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Pollen control for hybrids. 201.78 Section 201.78... REGULATIONS Additional Requirements for the Certification of Plant Materials of Certain Crops § 201.78 Pollen... branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any...

  20. Effects of NO2 and Ozone on Pollen Allergenicity

    PubMed Central

    Frank, Ulrike; Ernst, Dieter

    2016-01-01

    This mini-review summarizes the available data of the air pollutants NO2 and ozone on allergenic pollen from different plant species, focusing on potentially allergenic components of the pollen, such as allergen content, protein release, IgE-binding, or protein modification. Various in vivo and in vitro studies on allergenic pollen are shown and discussed. PMID:26870080

  1. 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

  2. Diversity and conservation in maize pollen: Phenotypes and transcripts

    EPA Science Inventory

    In addition to its crucial role in seed production, pollen serves as a vector for gene flow between plant populations. Recently, pollen was identified as a mechanism for introduction of transgenes into non-transgenic populations. To investigate the genetic basis for pollen fitn...

  3. Pollen Germination--A Challenging and Educational Experiment.

    ERIC Educational Resources Information Center

    Tse, H. L. H.; Chan, G. Y. S.

    2001-01-01

    Summarizes the recent research on pollen germination and introduces some basic studies on pollen tube growth that can be conducted in a secondary school laboratory. Discusses the use of a light microscope and refrigerator to study pollen. (Contains 13 references.) (Author/YDS)

  4. Unexpected severe consequences of Pikfyve deletion by aP2- or Aq-promoter-driven Cre expression for glucose homeostasis and mammary gland development.

    PubMed

    Ikonomov, Ognian C; Sbrissa, Diego; Delvecchio, Khortnal; Rillema, James A; Shisheva, Assia

    2016-06-01

    Systemic deficiency of PIKfyve, the evolutionarily conserved phosphoinositide kinase synthesizing cellular PtdIns5P and PtdIns(3,5)P2 and implicated in insulin signaling, causes early embryonic death in mice. In contrast, mice with muscle-specific Pikfyve disruption have normal lifespan but exhibit early-age whole-body glucose intolerance and muscle insulin resistance, thus establishing the key role of muscle PIKfyve in glucose homeostasis. Fat and muscle tissues control postprandial glucose clearance through different mechanisms, raising questions as to whether adipose Pikfyve disruption will also trigger whole-body metabolic abnormalities, and if so, what the mechanism might be. To clarify these issues, here we have characterized two new mouse models with adipose tissue disruption of Pikfyve through Cre recombinase expression driven by adipose-specific aP2- or adiponectin (Aq) promoters. Whereas both mouse lines were ostensibly normal until adulthood, their glucose homeostasis and systemic insulin sensitivity were severely dysregulated. These abnormalities stemmed in part from accelerated fat-cell lipolysis and elevated serum FFA Intriguingly, aP2-Cre-PIKfyve(fl/fl) but not Aq-Cre-PIKfyve(fl/fl) females had severely impaired pregnancy-induced mammary gland differentiation and lactogenesis, consistent with aP2-Cre-mediated Pikfyve excision in nonadipogenic tissues underlying this defect. Intriguingly, whereas mammary glands from postpartum control and Aq-Cre-PIKfyve(fl/fl) mice or ex vivo mammary gland explants showed profound upregulation of PIKfyve protein levels subsequent to prolactin receptor activation, such increases were not apparent in aP2-Cre-PIKfyve(fl/fl) females. Collectively, our data identify for the first time that adipose tissue Pikfyve plays a key role in the mechanisms regulating glucose homeostasis and that the PIKfyve pathway is critical in mammary epithelial differentiation during pregnancy and lactogenesis downstream of prolactin receptor

  5. Pollen rain and subfossil pollen spectra of the Mongun-Taiga mountain massif (South-Eastern Altai)

    NASA Astrophysics Data System (ADS)

    Kolunchukova, M.; Savelieva, L. A.

    2011-12-01

    Palynological analysis is commonly used for the vegetation and climatic reconstructions. It is known that there are many factors influenced on pollen spectra formation and it is necessary to study in detail the modern spectra from the investigated area which form interpretation base of fossil samples. In July 2010, during the expedition to the Mongun-Taiga mountain massif (South-Western Tuva, the Altai Mountains) the collections of modern surface samples from diverse plant communities were made to depict the present-day pollen rain. For this purpose a longitudinal profile at the altitudes of 2300-3100 m was laid. The detailed geobotanical descriptions on each sampling site were made. Soil samples were taken from 1.5 cm depth and catching of pollen rain was carrying out on glass plates in an area of 108 cm2. A total of 9 samples were treated for pollen analysis, pollen residues mounted in glycerin were analyzed under the microscope. The interpretation of the pollen and spores was performed using pollen atlases and pollen diagrams were made. All samples are distorted by strange pollen of arboreal. The Pinus pollen content varies between 20% and 80%. Single grains of Piceae, Alnus, Alnuster are found. Some non-arboreal pollen like Artemisia and Chenopodiaceae is presented in all spectra, their abundance varies between 1-20 %. Although this species grow within researching area, they are found not in all described vegetative associations. Connection between projective cover of local species and strange pollen's participation in spectra formation is found: low projective cover causes less pollen production and amount of strange pollen (generally arboreal) increases. Domination of some local species is not reflected by their pollen assemblages. For example abundance of Larix pollen (the main arboreal species within researching area) reaches only 2%, and grains of Dryas are not found at all. It can be explained by bad safety and volatility of their grains. So even single

  6. The Physics of Pollen and Spore Rebound from Plant Surfaces.

    NASA Astrophysics Data System (ADS)

    Paw U, Kyaw Tha

    1980-12-01

    The problem of particle rebound from plant surfaces has been examined. Particle rebound is a component of net deposition; the other components are reentrainment and impingement. I carried out several sets of wind tunnel experiments to examine the nature of rebound, reentrainment and impingement. Quantitative and qualitative analyses were carried out on the data. A simple computer model was created to predict particle deposition in wind tunnel conditions. My work confirms that rebound is an important process in the wind tunnel, and implies the existence of a process I call 'rebound/reentrainment'. I tested several major hypotheses. The first was that biological materials exhibit the same physical rebound characteristics as artificial materials. The second was that particles rebound in a manner predicted by Dahneke's (1971, 1975) theory. The third was that rebound is a dominant component of net deposition. The fourth was that surface characteristics may seriously influence rebound. I carried out my experiments in a low-speed wind tunnel. For surfaces I used glass and the leaves of tulip poplar (Liriodendron tulipifera), Coleus (Coleus blumeii) and American elm (Ulmus americana). For particles I used glass microbeads, lycopodium spores (Lycopodium spp.), and ragweed pollen (Ambrosia trifida). Four main sets of experiments were carried out. I examined rebound, as a function of particle speed, of particles impinging upon leaf surfaces, reentrainment of spores and pollen as a function of wind speed and time, net deposition, as a function of wind speed, and adhesion of pollen and spores to the leaf surfaces. From these experiments I concluded that in general, pollen and spore rebound can be described well by Dahneke's (1971, 1975) theory. Particle differences are far more significant than surface differences in the rebound process. I postulate the existence of rebound/reentrainment when particles impinge on surfaces with tangential fluid flow present. Particles will

  7. 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

  8. 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

  9. Five-grass-pollen sublingual immunotherapy tablet for the treatment of grass-pollen-induced allergic rhinoconjunctivitis: 5 years of experience.

    PubMed

    Didier, Alain; Wahn, Ulrich; Horak, Friedrich; Cox, Linda S

    2014-10-01

    Oralair(®) (OA) (Stallergenes, Antony, France) is a unique pre- and co-seasonal 5-grass-pollen sublingual immunotherapy tablet launched in 2008, and now approved in 31 countries worldwide for the treatment of grass-pollen allergic rhinitis and rhinoconjunctivitis. OA is the first oral treatment with a consistent, well-balanced allergen extract that mimics natural exposure and sensitization. A wealth of data exists from over 5 years of clinical and real-world experience demonstrating the efficacy and safety of OA for grass-pollen-allergy treatment. OA is highly effective from the first pollen season in all patient subgroups, including children and those with comorbid mild asthma, irrespective of sensitization status and symptom severity. OA also has sustained long-term benefits for symptom control and quality of life. This article provides an overview of the pharmacodynamics and pharmacology of OA; its efficacy, safety, tolerability and cost-effectiveness for the treatment of allergic rhinitis and rhinoconjunctivitis and its role in clinical practice.

  10. Climate warming and the decline of Taxus airborne pollen in urban pollen rain (Emilia Romagna, northern Italy).

    PubMed

    Mercuri, A M; Torri, P; Casini, E; Olmi, L

    2013-01-01

    Woody plant performance in a changing global environment has always been at the centre of palaeoenvironmental and long-term climate reconstructions carried out by means of pollen analysis. In Mediterranean regions, Taxus constitutes the highest percentage in past pollen diagrams from cold or cool periods, and therefore it is generally considered a good index to infer climate features from past records. However, a comparison of these inferences with the true current trends in pollen production has not been attemped until now. This study reports the decline of airborne pollen of Taxus observed in Emilia Romagna, a region of northern Italy, during the period 1990-2007. Phenological observations on four male specimens and microscopic examination of fresh pollen were made in order to check Taxus flowering time and pollen morphology. Airborne pollen was monitored through continuous sampling with a Hirst volumetric sampler. In the 18-year long period of investigation, Taxus pollen production has decreased, while total woody pollen abundance in air has increased. The trend of the Taxus pollen season shows a delay at the beginning, a shortening of the pollen period, and an advance of the end of the pollen season. This was interpreted as a response to climate warming. In particular, Taxus follows the behaviour of winter-flowering plants, and therefore earlier pollination is favoured at low autumn temperatures, while late pollination occurs more often, most likely after warm autumn temperatures.

  11. Determination of suspendable ice nuclei from various pollen species

    NASA Astrophysics Data System (ADS)

    Felgitsch, Laura; Pummer, Bernhard; Grothe, Hinrich

    2014-05-01

    Heterogeneous ice nucleation is an important process in cloud glaciation. On the one hand, ice clouds increase the albedo (Mishchenko et al. 1996), leading to a cooling effect, and on the other hand tend to a faster precipitation (Lohmann 2002) and therefore reduce the total cloud albedo, which has a direct influence on the climate and weather. However, many processes involved are still not entirely understood and only poorly described which makes it difficult to forecast these effects for climate modelling. Therefore detailed laboratory studies are inherently necessary. Only recently, Pummer et al. (2012) have shown that pollen emitted from trees originating from the Northern timberline carry active ice nuclei, which are suspendable macromolecules. So far little is known about the structures and functionalities of these molecules. Here we present several analytical strategies we use to separate the responsible species (via solid phase extraction with different columns like C18 and PH) and solve the structure including different forms of mass spectrometry (MS) like the intact cell MS and matrix assisted laser desorption/ionization (MALDI) MS, which give access to the molecules in question. For identification, the surface molecules are compared with those washed out from pores and from pollen that burst due to osmotic pressure. Lohmann U.; 'A Glaciation Indirect Aerosol Effect Caused by Soot Aerosols; J. Geoph. Res.; Vol. 24 No.4; pp 11-1 - 11-4; 2002 Mishchenko M.I., Rossow W.B., Macke A., Lacis A. A.; Sensitivity of Cirrus Cloud Albedo, Bidirectional Reflectance and Optical Thickness Retrieval Accuracy to Ice Particle Shape, J. Geoph. Res.; Vol. 101, No D12; pp. 16,973 - 16,985; 1996 Pummer B., Bauer H., Bernardi J., Bleicher S., Grothe H.; Suspendable Macromolecules are Responsible for Ice Nucleation Activity of Birch and Conifer Pollen; Atmos. Chem. Phys.; 12; pp. 2541 - 2550;

  12. Identification of Actin-Binding Proteins from Maize Pollen

    SciTech Connect

    Staiger, C.J.

    2004-01-13

    Specific Aims--The goal of this project was to gain an understanding of how actin filament organization and dynamics are controlled in flowering plants. Specifically, we proposed to identify unique proteins with novel functions by investigating biochemical strategies for the isolation and characterization of actin-binding proteins (ABPs). In particular, our hunt was designed to identify capping proteins and nucleation factors. The specific aims included: (1) to use F-actin affinity chromatography (FAAC) as a general strategy to isolate pollen ABPs (2) to produce polyclonal antisera and perform subcellular localization in pollen tubes (3) to isolate cDNA clones for the most promising ABPs (4) to further purify and characterize ABP interactions with actin in vitro. Summary of Progress By employing affinity chromatography on F-actin or DNase I columns, we have identified at least two novel ABPs from pollen, PrABP80 (gelsolin-like) and ZmABP30, We have also cloned and expressed recombinant protein, as well as generated polyclonal antisera, for 6 interesting ABPs from Arabidopsis (fimbrin AtFIM1, capping protein a/b (AtCP), adenylyl cyclase-associated protein (AtCAP), AtCapG & AtVLN1). We performed quantitative analyses of the biochemical properties for two of these previously uncharacterized ABPs (fimbrin and capping protein). Our studies provide the first evidence for fimbrin activity in plants, demonstrate the existence of barbed-end capping factors and a gelsolin-like severing activity, and provide the quantitative data necessary to establish and test models of F-actin organization and dynamics in plant cells.

  13. A distinct mechanism regulating a pollen-specific guanine nucleotide exchange factor for the small GTPase Rop in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rop/Rac small GTPases are central to diverse developmental and cellular activities in plants, playing an especially important Role in polar growth of pollen tubes. Although it is established that a class of plant-specific RopGEFs promotes the activity of Rop/Rac through the catalytic PRONE (Plant-sp...

  14. A distinct mechanism regulating a pollen-specific guanine nucleotide exchange factor for the small GTPase Rop in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rop/Rac small GTPases are central to diverse developmental and cellular activities in plants, playing an especially important role in polar growth of pollen tubes. Although it is established that a class of plant-specific RopGEFs promotes the activity of Rop/Rac through the catalytic PRONE (Plant sp...

  15. Integrating the EMPD with an Alpine altitudinal training set to reconstruct climate variables in Holocene pollen records from high-altitude peat bogs

    NASA Astrophysics Data System (ADS)

    Furlanetto, Giulia; Badino, Federica; Brunetti, Michele; Champvillair, Elena; De Amicis, Mattia; Maggi, Valter; Pini, Roberta; Ravazzi, Cesare; Vallé, Francesca

    2016-04-01

    Temperatures and precipitation are the main environmental factors influencing vegetation and pollen production. Knowing the modern climate optima and tolerances of those plants represented in fossil assemblages and assuming that the relationships between plants and climate in the past are not dissimilar from the modern ones, fossil pollen records offer many descriptors to reconstruct past climate variables. The aim of our work is to investigate the potential of high-altitude pollen records from an Alpine peat bog (TBValter, close to the Ruitor Glacier, Western Italian Alps) for quantitative paleoclimate estimates. The idea behind is that high-altitude ecosystems are more sensitive to climate changes, especially to changes in July temperatures that severely affect the timberline ecotone. Meantime, we met with difficulties when considering the factors involved in pollen dispersal over a complex altitudinal mountain pattern, such as the Alps. We used the EMPD-European Modern Pollen Database (Davis et al., 2013) as modern training set to be compared with our high-altitude fossil site. The EMPD dataset is valuable in that it provides a large geographic coverage of main ecological and climate gradients (at sub-continental scale) but lacks in sampling of altitudinal gradients and high-altitude sites in the Alps. We therefore designed an independent altitudinal training set for the alpine valley hosting our fossil site. 27 sampling plots were selected along a 1700m-elevational transect. In a first step, each plot was provided with (i) 3 moss polsters collected following the guidelines provided by Cañellas-Boltà et al. (2009) and analyzed separately to account for differences in pollen deposition at small scale, (ii) morphometrical parameters obtained through a high-resolution DEM, and (iii) temperature and precipitation were estimated by means of weighted linear regression of the meteorological variable versus elevation, locally evaluated for each site (Brunetti et al

  16. Pollen tetrads in the detection of environmental mutagenesis

    SciTech Connect

    Mulcahy, D.L.

    1981-01-01

    Although pollen is a very sensitive indicator of environmental mutagenesis, it is also sensitive to nonmutagenic environmental stress. By analyzing pollen tetrads, rather than individual pollen grains, it is possible to distinguish between mutagenic and nonmutagenic influences. Another advantage of using pollen tetrads in mutagenicity studies is that it is possible to discriminate between pre- and post-pachytene mutations. This eliminates the mutant sector problem of a single mutational event giving rise to a large number of mutant cells. Methods of analyzing pollen tetrads are described.

  17. Arabidopsis COG Complex Subunits COG3 and COG8 Modulate Golgi Morphology, Vesicle Trafficking Homeostasis and Are Essential for Pollen Tube Growth

    PubMed Central

    Li, Yingxin; Li, Pengxiang; Gao, Caiji; Ding, Yu; Lan, Zhiyi; Shi, Zhixuan; Rui, Qingchen; Feng, Yihong; Liu, Yulong; Zhao, Yanxue; Wu, Chengyun; Zhang, Qian; Li, Yan; Jiang, Liwen

    2016-01-01

    Spatially and temporally regulated membrane trafficking events incorporate membrane and cell wall materials into the pollen tube apex and are believed to underlie the rapid pollen tube growth. In plants, the molecular mechanisms and physiological functions of intra-Golgi transport and Golgi integrity maintenance remain largely unclear. The conserved oligomeric Golgi (COG) complex has been implicated in tethering of retrograde intra-Golgi vesicles in yeast and mammalian cells. Using genetic and cytologic approaches, we demonstrate that T-DNA insertions in Arabidopsis COG complex subunits, COG3 and COG8, cause an absolute, male-specific transmission defect that can be complemented by expression of COG3 and COG8 from the LAT52 pollen promoter, respectively. No obvious abnormalities in the microgametogenesis of the two mutants are observed, but in vitro and in vivo pollen tube growth are defective. COG3 or COG8 proteins fused to green fluorescent protein (GFP) label the Golgi apparatus. In pollen of both mutants, Golgi bodies exhibit altered morphology. Moreover, γ-COP and EMP12 proteins lose their tight association with the Golgi. These defects lead to the incorrect deposition of cell wall components and proteins during pollen tube growth. COG3 and COG8 interact directly with each other, and a structural model of the Arabidopsis COG complex is proposed. We believe that the COG complex helps to modulate Golgi morphology and vesicle trafficking homeostasis during pollen tube tip growth. PMID:27448097

  18. Extensive Pollen Flow but Few Pollen Donors and High Reproductive Variance in an Extremely Fragmented Landscape

    PubMed Central

    González-Martínez, Santiago C.; Aparicio, Abelardo

    2012-01-01

    Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (Nep) and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73–93%), fat-tailed dispersal kernels and large average pollination distances (δ = 229–412 m). However, they also agreed in detecting very few pollen donors (Nep = 4.3–10.2) and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14%) and strong spatial genetic structure (Sp = 0.012), probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment. PMID:23152842

  19. Floral sources to Tetragonisca angustula (Hymenoptera: Apidae) and their pollen morphology in a Southeastern Brazilian Atlantic Forest.

    PubMed

    Braga, Juliana Almeida; Sales, Erika Oliveira; Soares Neto, João; Conde, Marilena Menezes; Barth, Ortrud Monika; Maria, Cristina Lorenzon

    2012-12-01

    The stingless bees are important flowers visitors of several plant species, due to their feeding habits and foraging behavior, constituting an important group to maintain biodiversity and the dynamics of tropical communities. Among stingless bees, Tetragonisca angustula is widely distributed in tropical habitats, and has been considered an important pollinator of different plant families. To support a rational economic use of this group, there is a need to characterize the plant species that represent important sources as part of their diet, as preferred, alternative or casual food sources. The aim of this survey was to distinguish the plant species that T. angustula visited most often. The study was undertaken in four regions of the Atlantic Rainforest in Rio de Janeiro state (Brazil) over a year from March 2008 to February 2009. For this, we collected bees, flowering plants and bee pollen loads from the four sites, and evaluated pollen morphology in the laboratory. Field observations showed the presence of plants belonging to ten different families and pollen loads showed the presence of pollen types belonging to 26 plant families. There were strong differences between pollen types, especially regarding pollen grain shape. The present survey suggests a high value of these plant species as trophic resources for the T. angustula in the understory of Atlantic Rainforest. Changes in these fragments of this forest may compromise the availability of resources for Tetragonisca angustula species and other stingless bees.

  20. The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis morio.

    PubMed Central

    Johnson, Steven D.; Peter, Craig I.; Agren, Jon

    2004-01-01

    It has been suggested that the absence of floral rewards in many orchid species causes pollinators to probe fewer flowers on a plant, and thus reduces geitonogamy, i.e. self-pollination between flowers, which may result in inbreeding depression and reduced pollen export. We examined the effects of nectar addition on pollinator visitation and pollen transfer by tracking the fate of colour-labelled pollen in Anacamptis morio, a non-rewarding orchid species pollinated primarily by queen bumble-bees. Addition of nectar to spurs of A. morio significantly increased the number of flowers probed by bumble-bees, the time spent on an inflorescence, pollinarium removal and the proportion of removed pollen involved in self-pollination through geitonogamy, but did not affect pollen carryover (the fraction of a pollinarium carried over from one flower to the next). Only visits that exceeded 18 s resulted in geitonogamy, as this is the time taken for removed pollinaria to bend into a position to strike the stigma. A mutation for nectar production in A. morio would result in an initial 3.8-fold increase in pollinarium removal per visit, but also increase geitonogamous self-pollination from less than 10% of pollen depositions to ca. 40%. Greater efficiency of pollen export will favour deceptive plants when pollinators are relatively common and most pollinaria are removed from flowers or when inbreeding depression is severe. These findings provide empirical support both for Darwin's contention that pollinarium bending is an anti-selfing mechanism in orchids and for the idea that floral deception serves to maximize the efficiency of pollen export. PMID:15255098

  1. Pistillate flower development and pollen tube growth mode during the delayed fertilization stage in Corylus heterophylla Fisch.

    PubMed

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Kafkas, Salih; Güney, Murat

    2014-09-01

    Unlike most angiosperms, in which fertilization occurs within several days after pollination, fertilization in hazel (Corylus Spp.) is delayed by two to three and a half months. However, the female inflorescences or young fruits are too hard or lignified to be dissected according to regular paraffin sectioning technique. So, what the nature of development during the extended progamic phases of hazel remains unknown. The female inflorescence development and pollen tube growth mode during the delayed fertilization stage in hazel were investigated by improved paraffin sectioning and aniline blue staining of pollen tubes. The results showed ovaries and ovules of hazel were invisible at the time of blooming. Early ovary and ovule primordium began to form from 15 to 20 days after blooming, respectively. Integument and mature embryo sacs differentiated from the nucellus on 40th and 55th day after blooming, respectively. Pollen tubes were retarded in the bottom of the style or the pollen tube cavity (PTC, a specifical lignified cavity structure at the bottom of style for pollen tube to rest during progamic phase) for about 26 days. Then, the pollen tubes were observed to leave the PTC and began to enter the ovary. After that, a single pollen tube passed through the vicinity of the micropyle. Finally, pollen tubes turned a corner and penetrated the embryo sac through the tissue of the chalaza instead of micropyle on 52 and 55 days after blooming, respectively. The results of more in-depth information will be beneficial to better understanding of the delayed fertilization process in hazel.

  2. Evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens.

    PubMed

    Kernerman, S M; McCullough, J; Green, J; Ownby, D R

    1992-12-01

    In a clinical investigation, 103 Michigan residents with symptoms suggestive of allergic rhinitis or asthma were skin tested with olive (Olea europaea) pollen extract. Nineteen had positive reactions. Since the olive tree is not native to nor grown in Michigan, this study was undertaken to determine whether the skin test reactivity was the result of cross-reactivity among tree pollen allergens. ELISAs were developed to measure olive, ash (Fraxinus americana), privet (Ligustrum vulgare), and Russian olive (Elaeagnus angustifolia) specific IgE antibodies. Inhibition studies were performed to determine whether pollen extracts from each of these tree species could inhibit IgE antibody binding to olive extracts. Eleven of the 19 skin test-positive patients were olive-ELISA positive, eight either were ELISA-positive to ash, seven to privet and ten to Russian olive. There were significant correlations between the ELISA results to olive and each of the other three pollens. The inhibition studies demonstrated that all three of the tree pollens were capable of inhibiting the binding of IgE to olive extract in a dose-response fashion. IgE-immunoblot studies demonstrated several proteins common to olive, ash, and privet. Twelve of the olive skin test-positive patients were contacted and 75% were exposed to one or more of the studied trees in their yards. Five patients had traveled to areas where olive trees are grown. We conclude that there is a high degree of cross-reactivity among allergens from native Michigan trees and from olive trees. This cross-reactivity is the most likely reason for skin test reactivity to olive pollen extract in Michigan.

  3. Temporal variability in airborne pollen concentrations.

    PubMed

    Raynor, G S; Hayes, J V; Ogden, E C

    1976-06-01

    Tests were conducted to determine the relationship between concentrations of airborne pollens and sampling time, using sequential rotoslide samplers at urban and rural locations. Short-period data showed an increase in variability with time between samples. Two-hour data showed a stronger trend for the first 12 hours but better agreement as the time between samples approached one day.

  4. 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…

  5. Pollen analyses of tarnished plant bugs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild host plants play an important role for tarnished plant bug (TPB), Lygus lineolaris, especially when cultivated crops are not flowering. Knowledge of native habitats is important for managing this insect pest. Although pollen has been used to characterize dispersal and food sources of many inse...

  6. Towards a street-level pollen concentration and exposure forecast

    NASA Astrophysics Data System (ADS)

    van der Molen, Michiel; Krol, Maarten; van Vliet, Arnold; Heuvelink, Gerard

    2015-04-01

    Atmospheric pollen are an increasing source of nuisance for people in industrialised countries and are associated with significant cost of medication and sick leave. Citizen pollen warnings are often based on emission mapping based on local temperature sum approaches or on long-range atmospheric model approaches. In practise, locally observed pollen may originate from both local sources (plants in streets and gardens) and from long-range transport. We argue that making this distinction is relevant because the diurnal and spatial variation in pollen concentrations is much larger for pollen from local sources than for pollen from long-range transport due to boundary layer processes. This may have an important impact on exposure of citizens to pollen and on mitigation strategies. However, little is known about the partitioning of pollen into local and long-range origin categories. Our objective is to study how the concentrations of pollen from different sources vary temporally and spatially, and how the source region influences exposure and mitigation strategies. We built a Hay Fever Forecast system (HFF) based on WRF-chem, Allergieradar.nl, and geo-statistical downscaling techniques. HFF distinguishes between local (individual trees) and regional sources (based on tree distribution maps). We show first results on how the diurnal variation of pollen concentrations depends on source proximity. Ultimately, we will compare the model with local pollen counts, patient nuisance scores and medicine use.

  7. Allergenic pollen in the atmosphere of Kayseri, Turkey.

    PubMed

    Ince, Ali; Kart, Levent; Demir, Ramazan; Ozyurt, M Sabri

    2004-01-01

    Airborne pollen are important allergens that cause sensitization in allergic rhinoconjunctivitis and asthma. Our aim was to detect the pollen in the atmosphere of Kayseri, to present a pollen calendar, and to detect the allergenic level of these pollen by performing skin tests on patients. Atmospheric pollen were collected by Durham gravimetric samplers in Kayseri between March and November in the years 1996 and 1997. In our study, we observed pollen belonging to 43 different taxa. The total number of pollen per cm2 was found to be 1,330.8 in 1996 and 1,182.5 in 1997. Most of the pollen were from the taxa Pinus, Poaceae, Chenopodiaceae/Amaranthaceae, Cupressaceae, Populus and Quercus in decreasing order. In the skin tests, pollen of the taxa Poaceae and Chenopodiaceae were found to give the most frequent allergic reactions. It was concluded that preparing an airborne pollen calendar could be useful for medical practice. Nevertheless the skin test data did not really correlate with the aerobiologic data, as skin test reactivity is related to the allergenicity of the pollen and not just to ambient exposure.

  8. Considerations About Pollen Used for the Production of Allergen Extracts.

    PubMed

    Codina, Rosa; Crenshaw, Rodger C; Lockey, Richard F

    2015-01-01

    Pollen is a biological product obtained to manufacture tree, weed, and grass allergen extracts, used to diagnose and treat allergies. Genetic and environmental factors affect the composition of pollen, e.g., the plant varieties from which pollen are obtained, weather, and levels of air pollution during plant growth. Therefore, appropriate guidelines and training of personnel to perform the activities associated with pollen are essential to produce appropriate allergen extracts. Various regulatory institutions, which vary in different countries, including the Food and Drug Administration (FDA) in the USA, control how such products should be produced. For example, the FDA regulates the manufacturing of pollen extracts but not the quality of the pollen used to prepare them, relying on each manufacturer to set its own standards to do so. To the contrary, European regulatory agencies, including the European Medicines Agency, control both the quality of the pollen and the manufacturing process to produce pollen extracts. Regulatory agencies, allergen manufacturers, scientific institutions, and pollen collection entities should collaborate to develop and implement guidelines appropriate for worldwide use for both the collection and processing of pollen raw materials. This article provides an overview of the subject of pollen for use in allergen extracts.

  9. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis

    PubMed Central

    Lambalk, Joep; Ottiger, Marcel

    2016-01-01

    Introduction An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a common method for cellular characterisation in microbiology and medicine during the last decade. The aim of this study is to demonstrate the potential of IFC in plant cell analysis with the focus on pollen. Method Developing and mature pollen grains were analysed during their passage through a microfluidic chip to which radio frequencies of 0.5 to 12 MHz were applied. The acquired data provided information about the developmental stage, viability, and germination capacity. The biological relevance of the acquired IFC data was confirmed by classical staining methods, inactivation controls, as well as pollen germination assays. Results Different stages of developing pollen, dead, viable and germinating pollen populations could be detected and quantified by IFC. Pollen viability analysis by classical FDA staining showed a high correlation with IFC data. In parallel, pollen with active germination potential could be discriminated from the dead and the viable but non-germinating population. Conclusion The presented data demonstrate that IFC is an efficient, label-free, reliable and non-destructive technique to analyse pollen quality in a species-independent manner. PMID:27832091

  10. Pollen processing behavior of Heliconius butterflies: a derived grooming behavior.

    PubMed

    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.

  11. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen.

    PubMed

    Ge, Weina; Song, Yun; Zhang, Cuijun; Zhang, Yafang; Burlingame, Alma L; Guo, Yi

    2011-12-01

    Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) saturation labeling techniques. One hundred and three proteins differentially expressed (p value≤0.01) in pollen germinated for 6h compared with un-germination mature pollen, and 98 spots, which represented 71 proteins, were identified by LC-MS/MS. By bioinformatics analysis, 50 proteins were identified as secreted proteins. These proteins were mainly involved in cell wall modification and remodeling, protein metabolism and signal transduction. Three of the differentially expressed proteins were randomly selected to determine their subcellular localizations by transiently expressing YFP fusion proteins. The results of subcellular localization were identical with the bioinformatics prediction. Based on these data, we proposed a model for apoplastic proteins functioning in pollen germination and pollen tube growth. These results will lead to a better understanding of the mechanisms of pollen germination and pollen tube growth.

  12. Mismatch in aeroallergens and airborne grass pollen concentrations

    NASA Astrophysics Data System (ADS)

    Plaza, M. P.; Alcázar, P.; Hernández-Ceballos, M. A.; Galán, C.

    2016-11-01

    An accurate estimation of the allergen concentration in the atmosphere is essential for allergy sufferers. The major cause of pollinosis all over Europe is due to grass pollen and Phl p 5 has the highest rates of sensitization (>50%) in patients with grass pollen-induced allergy. However, recent research has shown that airborne pollen does not always offer a clear indicator of exposure to aeroallergens. This study aims to evaluate relations between airborne grass pollen and Phl p 5 concentrations in Córdoba (southern Spain) and to study how meteorological parameters influence these atmospheric records. Monitoring was carried out from 2012 to 2014. Hirst-type volumetric spore trap was used for pollen collection, following the protocol recommended by the Spanish Aerobiology Network (REA). Aeroallergen sampling was performed using a low-volume cyclone sampler, and allergenic particles were quantified by ELISA assay. Besides, the influence of main meteorological factors on local airborne pollen and allergen concentrations was surveyed. A significant correlation was observed between grass pollen and Phl p 5 allergen concentrations during the pollen season, but with some sporadic discrepancy episodes. The cumulative annual Pollen Index also varied considerably. A significant correlation has been obtained between airborne pollen and minimum temperature, relative humidity and precipitation, during the three studied years. However, there is no clear relationship between allergens and weather variables. Our findings suggest that the correlation between grass pollen and aeroallergen Phl p 5 concentrations varies from year-to-year probably related to a complex interplay of meteorological variables.

  13. Using the pollen viability and morphology for fluoride pollution biomonitoring.

    PubMed

    Malayeri, Behrooz Eshghi; Noori, Mitra; Jafari, Mehrana

    2012-06-01

    The methods using plants for biomonitoring of air and soil quality are simple, cheap, and fast and can supplement the classical physicochemical methods. In this study, biological pollen characterization of some collected legume species from an aluminum smelter area in Iran (IRALCO) was carried out to determine the actual value of pollen as a bioindicator of the effects of soil and atmospheric pollution. Young buds and flowers of six legumes (Cercis siliquastrum L., Medicago sativa L., Robinia pseudoacacia L., Melilotus officinalis (L.) lam, Trifolium repens L., and Sophora alopecuroides L.) in polluted and control plants were removed and compared. Studies of light and electron microscopic preparation showed some abnormalities during pollen development in affect of fluoride pollution. The viability of pollen grains estimated by staining with acetocarmine shows sharp differences in smearing advanced pollen grains from abnormal ones. Except M. officinalis, the pollen grains of C. siliquastrum, M. sativa, R. pseudoacacia, T. repens, and S. alopecuroides in polluted areas showed light, partial, or no staining with acetocarmine, whereas almost all of the control ones clearly stained. Observation of the pollen grains by light microscopy and scanning electron microscopy showed the significant effect of fluoride on shapes and sizes of pollen grains. The stimulation and inhibition of these pollen characteristics depend on the pollen species as well as on the pollutant and its concentration. Therefore, pollen grains provide essential information on biological impact of pollutants and they are good candidates for biomonitoring the atmospheric and edaphic pollutions.

  14. Specific immunotherapy for common grass pollen allergies: pertinence of a five grass pollen vaccine.

    PubMed

    Moingeon, Philippe; Hrabina, Maud; Bergmann, Karl-Christian; Jaeger, Siegfried; Frati, Franco; Bordas, Véronique; Peltre, Gabriel

    2008-01-01

    Patients throughout Europe are concomitantly exposed to multiple pollens from distinct Pooideae species. Given the overlap in pollination calendars and similar grain morphology, it is not possible to identify which grass species are present in the environment from pollen counts. Furthermore, neither serum IgE reactivity nor skin prick testing allow the identification of which grass species are involved in patient sensitisation. Due to their high level of amino acid sequence homology (e.g., >90% for group 1, 55-80% for group 5), significant cross-immunogenicity is observed between allergens from Pooideae pollens. Nevertheless, pollen allergens also contain species-specific T or B cell epitopes, and substantial quantitative differences exist in allergen (e.g., groups 1 and 5) composition between pollens from distinct grass species. In this context, a mixture of pollens from common and well-characterised Pooideae such as Anthoxanthum odoratum, Dactylis glomerata, Lolium perenne, Phleum pratense and Poa pratensis is suitable for immunotherapy purposes because (1) it has been validated, both in terms of safety and efficacy, by established clinical practice; (2) it reflects natural exposure and sensitisation conditions; (3) it ensures a consistent and well-balanced composition of critical allergens, thus extending the repertoire of T and B cell epitopes present in the vaccine.

  15. 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

  16. Nitric Oxide Participates in Cold-Inhibited Camellia sinensis Pollen Germination and Tube Growth Partly via cGMP In Vitro

    PubMed Central

    Zhu-Ge, Qiang; Jiang, Xin; Wang, Wei-Dong; Fang, Wan-Ping; Chen, Xuan; Li, Xing-Hui

    2012-01-01

    Nitric oxide (NO) plays essential roles in many biotic and abiotic stresses in plant development procedures, including pollen tube growth. Here, effects of NO on cold stress inhibited pollen germination and tube growth in Camellia sinensis were investigated in vitro. The NO production, NO synthase (NOS)-like activity, cGMP content and proline (Pro) accumulation upon treatment with NO scavenger cPTIO, NOS inhibitor L-NNA, NO donor DEA NONOate, guanylate cyclase (GC) inhibitor ODQ or phosphodiesterase (PDE) inhibitor Viagra at 25°C (control) or 4°C were analyzed. Exposure to 4°C for 2 h reduced pollen germination and tube growth along with increase of NOS-like activity, NO production and cGMP content in pollen tubes. DEA NONOate treatment inhibited pollen germination and tube growth in a dose-dependent manner under control and reinforced the inhibition under cold stress, during which NO production and cGMP content promoted in pollen tubes. L-NNA and cPTIO markedly reduced the generation of NO induced by cold or NO donor along with partly reverse of cold- or NO donor-inhibited pollen germination and tube growth. Furthermore, ODQ reduced the cGMP content under cold stress and NO donor treatment in pollen tubes. Meanwhile, ODQ disrupted the reinforcement of NO donor on the inhibition of pollen germination and tube growth under cold condition. Additionally, Pro accumulation of pollen tubes was reduced by ODQ compared with that receiving NO donor under cold or control condition. Effects of cPTIO and L-NNA in improving cold-treated pollen germination and pollen tube growth could be lowered by Viagra. Moreover, the inhibitory effects of cPTIO and L-NNA on Pro accumulation were partly reversed by Viagra. These data suggest that NO production from NOS-like enzyme reaction decreased the cold-responsive pollen germination, inhibited tube growth and reduced Pro accumulation, partly via cGMP signaling pathway in C. sinensis. PMID:23272244

  17. An olive pollen protein with allergenic activity, Ole e 10, defines a novel family of carbohydrate-binding modules and is potentially implicated in pollen germination

    PubMed Central

    2005-01-01

    CBMs (carbohydrate-binding modules) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. They have been frequently identified by amino acid sequence alignments, but only a few have been experimentally established to have a carbohydrate-binding activity. A small olive pollen protein, Ole e 10 (10 kDa), has been described as a major inducer of type I allergy in humans. In the present study, the ability of Ole e 10 to bind several polysaccharides has been analysed by affinity gel electrophoresis, which demonstrated that the protein bound 1,3-β-glucans preferentially. Analytical ultracentrifugation studies confirmed binding to laminarin, at a protein/ligand ratio of 1:1. The interaction of Ole e 10 with laminarin induced a conformational change in the protein, as detected by CD and fluorescence analyses, and an increase of 3.6 °C in the thermal denaturation temperature of Ole e 10 in the presence of the glycan. These results, and the absence of alignment of the sequence of Ole e 10 with that of any classified CBM, indicate that this pollen protein defines a novel family of CBMs, which we propose to name CBM43. Immunolocalization of Ole e 10 in mature and germinating pollen by transmission electron microscopy and confocal laser scanning microscopy demonstrated the co-localization of Ole e 10 and callose (1,3-β-glucan) in the growing pollen tube, suggesting a role for this protein in the metabolism of carbohydrates and in pollen tube wall re-formation during germination. PMID:15882149

  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. Drought, pollen and nectar availability, and pollination success.

    PubMed

    Waser, Nickolas M; Price, Mary V

    2016-06-01

    Pollination success of animal-pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar "neighborhoods" of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per-flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.

  20. Pollination of Picea orientalis (Pinaceae): saccus morphology governs pollen.

    PubMed

    Runions, C J; Rensing, K H; Takaso, T; Owens, J N

    1999-02-01

    Sacci of conifer pollen do not function primarily to increase the efficiency of wind pollination as is widely thought. Rather, they are bladders and cause pollen to float upwards in a liquid drop into the ovules. This observation is seemingly unsupported in the case of oriental spruce (Picea orientalis (L.) Link), which has saccate pollen. Ovulate cones are pendant at the time of pollination, which requires that pollen sink into the ovules. Pollen of oriental spruce floats at first but within 1-2 min sinks into the ovule. As sinking does not occur in saccate pollen of other Pinaceae, a variety of techniques was used to determine anatomical differences leading to this uncharacteristic tendency. Light, scanning electron, and confocal microscopy of the pollen surface yielded no significant appearing difference between pollen of oriental spruce and white spruce. However, transmission electron microscopy of freeze-fixed/freeze-substituted hydrated pollen revealed that the ektexine of oriental spruce pollen sacci is porous compared to that of white spruce. Confocal microscopy allowed examination of pollen hydration dynamics. Water enters pollen at the distal pole between sacci, and resulting rapid expansion of the tube cell forces air out of the saccate space. White spruce pollen remains buoyant because of enclosed air pockets in the saccus ektexine. Evolutionary change in pollen wall anatomy with resultant loss of saccus function is correlated with a change in ovulate strobilus orientation at pollination in oriental spruce. A suite of characters interact in the conifer pollination mechanism, and concerted change in these characters may lead to speciation.

  1. Self-incompatibility in Papaver: identification of the pollen S-determinant PrpS.

    PubMed

    Poulter, Natalie S; Wheeler, Michael J; Bosch, Maurice; Franklin-Tong, Vernonica E

    2010-04-01

    Many flowering plants are hermaphrodite, posing the problem of self-fertilization and the subsequent loss of the genetic fitness of the offspring. To prevent this, many plants have developed a genetically controlled mechanism called self-incompatibility (SI). When the male and female S-determinants match, self (incompatible) pollen is recognized and rejected before fertilization can occur. In poppy (Papaver rhoeas), the pistil S-determinant (PrsS) is a small secreted protein that interacts with incompatible pollen, initiating a Ca(2+)-dependent signalling network. SI triggers several downstream events, including depolymerization of the cytoskeleton, phosphorylation of two soluble inorganic pyrophosphatases and an MAPK (mitogen-activated protein kinase). This culminates in PCD (programmed cell death) involving several caspase-like activities. The recent discovery of the Papaver pollen S-determinant PrpS marks a significant step forward in the understanding of the Papaver SI system. PrpS encodes a ~20 kDa predicted transmembrane protein which has no homology with known proteins. It is specifically expressed in pollen, linked to the pistil S-determinant, and displays the high polymorphism expected of an S-locus determinant. The present review focuses on the discovery and characterization of PrpS which strongly support the hypothesis that Papaver SI is triggered by the interaction of PrsS and PrpS.

  2. Phosphatidylinositol 4-phosphate 5-kinases 1 and 2 are involved in the regulation of vacuole morphology during Arabidopsis thaliana pollen development.

    PubMed

    Ugalde, José-Manuel; Rodriguez-Furlán, Cecilia; Rycke, Riet De; Norambuena, Lorena; Friml, Jiří; León, Gabriel; Tejos, Ricardo

    2016-09-01

    The pollen grains arise after meiosis of pollen mother cells within the anthers. A series of complex structural changes follows, generating mature pollen grains capable of performing the double fertilization of the female megasporophyte. Several signaling molecules, including hormones and lipids, have been involved in the regulation and appropriate control of pollen development. Phosphatidylinositol 4-phophate 5-kinases (PIP5K), which catalyze the biosynthesis of the phosphoinositide PtdIns(4,5)P2, are important for tip polar growth of root hairs and pollen tubes, embryo development, vegetative plant growth, and responses to the environment. Here, we report a role of PIP5Ks during microgametogenesis. PIP5K1 and PIP5K2 are expressed during early stages of pollen development and their transcriptional activity respond to auxin in pollen grains. Early male gametophytic lethality to certain grade was observed in both pip5k1(-/-) and pip5k2(-/-) single mutants. The number of pip5k mutant alleles is directly related to the frequency of aborted pollen grains suggesting the two genes are involved in the same function. Indeed PIP5K1 and PIP5K2 are functionally redundant since homozygous double mutants did not render viable pollen grains. The loss of function of PIP5K1 and PIP5K2results in defects in vacuole morphology in pollen at the later stages and epidermal root cells. Our results show that PIP5K1, PIP5K2 and phosphoinositide signaling are important cues for early developmental stages and vacuole formation during microgametogenesis.

  3. Transporters involved in pH and K+ homeostasis affect pollen wall formation, male fertility, and embryo development

    DOE PAGES

    Padmanaban, Senthilkumar; Czerny, Daniel D.; Levin, Kara A.; ...

    2017-02-23

    Flowering plant genomes encode multiple cation/H+ exchangers (CHXs) whose functions are largely unknown. AtCHX17, AtCHX18, and AtCHX19 are membrane transporters that modulate K+ and pH homeostasis and are localized in the dynamic endomembrane system. Loss of function reduced seed set, but the particular phase(s) of reproduction affected was not determined. Pollen tube growth and ovule targeting of chx17chx18chx19 mutant pollen appeared normal, but reciprocal cross experiments indicate a largely male defect. Although triple mutant pollen tubes reach ovules of a wild-type pistil and a synergid cell degenerated, half of those ovules were unfertilized or showed fertilization of the egg ormore » central cell, but not both female gametes. Fertility could be partially compromised by impaired pollen tube and/or sperm function as CHX19 and CHX18 are expressed in the pollen tube and sperm cell, respectively. When fertilization was successful in self-pollinated mutants, early embryo formation was retarded compared with embryos from wild-type ovules receiving mutant pollen. Thus CHX17 and CHX18 proteins may promote embryo development possibly through the endosperm where these genes are expressed. The reticulate pattern of the pollen wall was disorganized in triple mutants, indicating perturbation of wall formation during male gametophyte development. Lastly, as pH and cation homeostasis mediated by AtCHX17 affect membrane trafficking and cargo delivery, these results suggest that male fertility, sperm function, and embryo development are dependent on proper cargo sorting and secretion that remodel cell walls, plasma membranes, and extracellular factors.« less

  4. Assessment of pollen reward and pollen availability in Solanum stramoniifolium and Solanum paniculatum for buzz-pollinating carpenter bees.

    PubMed

    Burkart, A; Schlindwein, C; Lunau, K

    2014-03-01

    The two widespread tropical Solanum species S. paniculatum and S. stramoniifolium are highly dependent on the visits of large bees that pollinate the flowers while buzzing them. Both Solanum species do not offer nectar reward; the rewarding of bees is thus solely dependent on the availability of pollen. Flower visitors are unable to visually assess the amount of pollen, because the pollen is hidden in poricidal anthers. In this study we ask whether and how the amount of pollen determines the attractiveness of flowers for bees. The number of pollen grains in anthers of S. stramoniifolium was seven times higher than in S. paniculatum. By contrast, the handling time per five flowers for carpenter bees visiting S. paniculatum was 3.5 times shorter than of those visiting S. stramoniifolium. As a result foraging carpenter bees collected a similar number of pollen grains per unit time on flowers of both species. Experimental manipulation of pollen availability by gluing the anther pores showed that the carpenter bees were unable to detect the availability of pollen by means of chemical cues before landing and without buzzing. Our study shows that the efficiency of pollen collecting on S. paniculatum is based on large inflorescences with short between-flower search times and short handling time of individual flowers, whereas that of S. stramoniifolium relies on a large amount of pollen per flower. Interestingly, large carpenter bees are able to adjust their foraging behaviour to drastically different strategies of pollen reward in otherwise very similar plant species.

  5. Development of personal pollen information—the next generation of pollen information and a step forward for hay fever sufferers

    NASA Astrophysics Data System (ADS)

    Kmenta, Maximilian; Bastl, Katharin