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Sample records for floral organ abnormalities

  1. MOSAIC FLORAL ORGANS1, an AGL6-Like MADS Box Gene, Regulates Floral Organ Identity and Meristem Fate in Rice[W

    PubMed Central

    Ohmori, Shinnosuke; Kimizu, Mayumi; Sugita, Maiko; Miyao, Akio; Hirochika, Hirohiko; Uchida, Eiji; Nagato, Yasuo; Yoshida, Hitoshi

    2009-01-01

    Floral organ identity and meristem determinacy in plants are controlled by combinations of activities mediated by MADS box genes. AGAMOUS-LIKE6 (AGL6)-like genes are MADS box genes expressed in floral tissues, but their biological functions are mostly unknown. Here, we describe an AGL6-like gene in rice (Oryza sativa), MOSAIC FLORAL ORGANS1 (MFO1/MADS6), that regulates floral organ identity and floral meristem determinacy. In the flower of mfo1 mutants, the identities of palea and lodicule are disturbed, and mosaic organs were observed. Furthermore, the determinacy of the floral meristem was lost, and extra carpels or spikelets developed in mfo1 florets. The expression patterns of floral MADS box genes were disturbed in the mutant florets. Suppression of another rice AGL6-like gene, MADS17, caused no morphological abnormalities in the wild-type background, but it enhanced the phenotype in the mfo1 background, indicating that MADS17 has a minor but redundant function with that of MFO1. Whereas single mutants in either MFO1 or the SEPALLATA-like gene LHS1 showed moderate phenotypes, the mfo1 lhs1 double mutant showed a severe phenotype, including the loss of spikelet meristem determinacy. We propose that rice AGL6-like genes help to control floral organ identity and the establishment and determinacy of the floral meristem redundantly with LHS1. PMID:19820190

  2. Down-regulation of a LBD-like gene, OsIG1, leads to occurrence of unusual double ovules and developmental abnormalities of various floral organs and megagametophyte in rice

    PubMed Central

    Zhang, Jingrong; Tang, Wei; Huang, Yulan; Niu, Xiangli; Zhao, Yu; Han, Yi; Liu, Yongsheng

    2015-01-01

    The indeterminate gametophyte1 (ig1) mutation was first characterized to modulate female gametophyte development in maize (Zea mays). However, the function of its rice orthologue, OsIG1, remains unknown. For this, we first analysed OsIG1 localization from differential tissues in rice. Real-time quantitative PCR (qRT-PCR) and histochemical staining results demonstrated that the expression signal of OsIG1 was strongly detected in young inflorescence, moderately in mature flower and weakly in leaf. Furthermore, RNA in situ hybridization analyses exhibited that OsIG1 was strongly expressed in inflorescence meristems, floral meristems, empty-glume- and floret- primordia, especially in the primordia of stamens and immature ovules, and the micropylar side of the mature ovary. In OsIG1-RNAi lines, wrinkled blade formation was accompanied by increased leaf inclination angle. Cross-section further showed that the number of bulliform cells located between the vasculatures was significantly increased, indicating that OsIG1 is involved in division and differentiation of bulliform cell and lateral growth during leaf development. OsIG1-RNAi suppression lines showed pleiotropic phenotypes, including degenerated palea, glume-like features and open hull. In addition, a single OsIG1-RNAi floret is characterized by frequently developing double ovules with abnormal embryo sac development. Additionally, down-regulation of OsIG1 differentially affected the expression of genes associated with the floral organ development including EG1, OsMADS6 and OsMADS1. Taken together, these results demonstrate that OsIG1 plays an essential role in the regulation of empty-glume identity, floral organ number control and female gametophyte development in rice. PMID:25324400

  3. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice.

    PubMed

    Ren, Deyong; Rao, Yuchun; Wu, Liwen; Xu, Qiankun; Li, Zizhuang; Yu, Haiping; Zhang, Yu; Leng, Yujia; Hu, Jiang; Zhu, Li; Gao, Zhenyu; Dong, Guojun; Zhang, Guangheng; Guo, Longbiao; Zeng, Dali; Qian, Qian

    2016-06-01

    Moderate plant height and successful establishment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull-like lodicules. AFD1 encoded a DUF640 domain protein and was expressed in all tested tissues and organs. Subcellular localization showed AFD1-green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes. PMID:26486996

  4. Four shades of detachment: Regulation of floral organ abscission

    PubMed Central

    Kim, Joonyup

    2014-01-01

    Abscission of floral organs from the main body of a plant is a dynamic process that is developmentally and environmentally regulated. In the past decade, genetic studies in Arabidopsis have identified key signaling components and revealed their interactions in the regulation of floral organ abscission. The phytohormones jasmonic acid (JA) and ethylene play critical roles in flower development and floral organ abscission. These hormones regulate the timing of floral organ abscission both independently and inter-dependently. Although significant progress has been made in understanding abscission signaling, there are still many unanswered questions. These include considering abscission in the context of reproductive development and interplay between hormones embedded in the developmental processes. This review summarizes recent advances in the identification of molecular components in Arabidopsis and discusses their relationship with reproductive development. The emerging roles of hormones in the regulation of floral organ abscission, particularly by JA and ethylene, are examined. PMID:25482787

  5. A developmental basis for stochasticity in floral organ numbers

    PubMed Central

    Kitazawa, Miho S.; Fujimoto, Koichi

    2014-01-01

    Stochasticity ubiquitously inevitably appears at all levels from molecular traits to multicellular, morphological traits. Intrinsic stochasticity in biochemical reactions underlies the typical intercellular distributions of chemical concentrations, e.g., morphogen gradients, which can give rise to stochastic morphogenesis. While the universal statistics and mechanisms underlying the stochasticity at the biochemical level have been widely analyzed, those at the morphological level have not. Such morphological stochasticity is found in foral organ numbers. Although the floral organ number is a hallmark of floral species, it can distribute stochastically even within an individual plant. The probability distribution of the floral organ number within a population is usually asymmetric, i.e., it is more likely to increase rather than decrease from the modal value, or vice versa. We combined field observations, statistical analysis, and mathematical modeling to study the developmental basis of the variation in floral organ numbers among 50 species mainly from Ranunculaceae and several other families from core eudicots. We compared six hypothetical mechanisms and found that a modified error function reproduced much of the asymmetric variation found in eudicot floral organ numbers. The error function is derived from mathematical modeling of floral organ positioning, and its parameters represent measurable distances in the floral bud morphologies. The model predicts two developmental sources of the organ-number distributions: stochastic shifts in the expression boundaries of homeotic genes and a semi-concentric (whorled-type) organ arrangement. Other models species- or organ-specifically reproduced different types of distributions that reflect different developmental processes. The organ-number variation could be an indicator of stochasticity in organ fate determination and organ positioning. PMID:25404932

  6. Epigenetic imbalance and the floral developmental abnormality of the in vitro-regenerated oil palm Elaeis guineensis

    PubMed Central

    Jaligot, Estelle; Adler, Sophie; Debladis, Émilie; Beulé, Thierry; Richaud, Frédérique; Ilbert, Pascal; Finnegan, E. Jean; Rival, Alain

    2011-01-01

    Background The large-scale clonal propagation of oil palm (Elaeis guineensis) is being stalled by the occurrence of the mantled somaclonal variation. Indeed, this abnormality which presents a homeotic-like conversion of male floral organs into carpelloid structures, hampers oil production since the supernumerary female organs are either sterile or produce fruits with poor oil yields. Scope In the last 15 years, the prevailing point of view on the origin of the mantled floral phenotype has evolved from a random mutation event triggered by in vitro culture to a hormone-dependent dysfunction of gene regulation processes. In this review, we retrace the history of the research on the mantled variation in the light of the parallel advances made in the understanding of plant development regulation in model systems and more specifically in the role of epigenetic mechanisms. An overview of the current state of oil palm genomic and transcriptomic resources, which are key to any comparison with model organisms, is given. We show that, while displaying original characteristics, the mantled phenotype of oil palm is morphologically, and possibly molecularly, related to MADS-box genes mutants described in model plants. We also discuss the occurrence of comparable floral phenotypes in other palm species. Conclusions Beyond its primary interest in the search for discriminating markers against an economically crippling phenotype, the study of the mantled abnormality also provides a unique opportunity to investigate the regulation of reproductive development in a perennial tropical palm. On the basis of recent results, we propose that future efforts should concentrate on the epigenetic regulation targeting MADS-box genes and transposable elements of oil palm, since both types of sequences are most likely to be involved in the mantled variant phenotype. PMID:21224269

  7. A dynamical phyllotaxis model to determine floral organ number.

    PubMed

    Kitazawa, Miho S; Fujimoto, Koichi

    2015-05-01

    How organisms determine particular organ numbers is a fundamental key to the development of precise body structures; however, the developmental mechanisms underlying organ-number determination are unclear. In many eudicot plants, the primordia of sepals and petals (the floral organs) first arise sequentially at the edge of a circular, undifferentiated region called the floral meristem, and later transition into a concentric arrangement called a whorl, which includes four or five organs. The properties controlling the transition to whorls comprising particular numbers of organs is little explored. We propose a development-based model of floral organ-number determination, improving upon earlier models of plant phyllotaxis that assumed two developmental processes: the sequential initiation of primordia in the least crowded space around the meristem and the constant growth of the tip of the stem. By introducing mutual repulsion among primordia into the growth process, we numerically and analytically show that the whorled arrangement emerges spontaneously from the sequential initiation of primordia. Moreover, by allowing the strength of the inhibition exerted by each primordium to decrease as the primordium ages, we show that pentamerous whorls, in which the angular and radial positions of the primordia are consistent with those observed in sepal and petal primordia in Silene coeli-rosa, Caryophyllaceae, become the dominant arrangement. The organ number within the outmost whorl, corresponding to the sepals, takes a value of four or five in a much wider parameter space than that in which it takes a value of six or seven. These results suggest that mutual repulsion among primordia during growth and a temporal decrease in the strength of the inhibition during initiation are required for the development of the tetramerous and pentamerous whorls common in eudicots. PMID:25950739

  8. A Dynamical Phyllotaxis Model to Determine Floral Organ Number

    PubMed Central

    Kitazawa, Miho S.; Fujimoto, Koichi

    2015-01-01

    How organisms determine particular organ numbers is a fundamental key to the development of precise body structures; however, the developmental mechanisms underlying organ-number determination are unclear. In many eudicot plants, the primordia of sepals and petals (the floral organs) first arise sequentially at the edge of a circular, undifferentiated region called the floral meristem, and later transition into a concentric arrangement called a whorl, which includes four or five organs. The properties controlling the transition to whorls comprising particular numbers of organs is little explored. We propose a development-based model of floral organ-number determination, improving upon earlier models of plant phyllotaxis that assumed two developmental processes: the sequential initiation of primordia in the least crowded space around the meristem and the constant growth of the tip of the stem. By introducing mutual repulsion among primordia into the growth process, we numerically and analytically show that the whorled arrangement emerges spontaneously from the sequential initiation of primordia. Moreover, by allowing the strength of the inhibition exerted by each primordium to decrease as the primordium ages, we show that pentamerous whorls, in which the angular and radial positions of the primordia are consistent with those observed in sepal and petal primordia in Silene coeli-rosa, Caryophyllaceae, become the dominant arrangement. The organ number within the outmost whorl, corresponding to the sepals, takes a value of four or five in a much wider parameter space than that in which it takes a value of six or seven. These results suggest that mutual repulsion among primordia during growth and a temporal decrease in the strength of the inhibition during initiation are required for the development of the tetramerous and pentamerous whorls common in eudicots. PMID:25950739

  9. FON2 SPARE1 Redundantly Regulates Floral Meristem Maintenance with FLORAL ORGAN NUMBER2 in Rice

    PubMed Central

    Suzaki, Takuya; Ohneda, Masako; Toriba, Taiyo; Yoshida, Akiko; Hirano, Hiro-Yuki

    2009-01-01

    CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM) in Arabidopsis thaliana. In rice (Oryza sativa), FLORAL ORGAN NUMBER2 (FON2), closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM). Here we show that the FON2 SPARE1 (FOS1) gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP) at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems. PMID:19834537

  10. Generation of Novel Floral Traits Using a Combination of Floral Organ-Specific Promoters and a Chimeric Repressor in Torenia fournieri Lind.

    PubMed

    Sasaki, Katsutomo; Yamaguchi, Hiroyasu; Kasajima, Ichiro; Narumi, Takako; Ohtsubo, Norihiro

    2016-06-01

    In this study, we attempted to develop a new biotechnological method for the efficient modification of floral traits. Because transcription factors play an important role in determining floral traits, chimeric repressors, which are generated by attaching a short transcriptional repressor domain to transcription factors, have been widely used as effective tools for modifying floral traits in many plant species. However, the overexpression of these chimeric repressors by the Cauliflower mosaic virus 35S promoter sometimes causes undesirable morphological alterations to other organs. We attempted simultaneously to generate new floral traits and avoid such quality loss by examining five additional floral organ-specific promoters, one Arabidopsis thaliana promoter and four Torenia fournieri promoters, for the expression of the chimeric repressor of Arabidopsis TCP3 (AtTCP3), whose overexpression drastically alters floral traits but also generates dwarf phenotypes and deformed leaves. We found that the four torenia promoters exhibited particularly strong activity in the petals but not in the leaves, and that the combination of these floral organ-specific promoters with the chimeric repressor of AtTCP3 caused changes in the color, color patterns and cell shapes of petals, whilst avoiding other unfavorable phenotypes. Interestingly, each promoter that we used in this study generated characteristic and distinguishable floral traits. Thus, the use of different floral organ-specific promoters with different properties enables us to generate diverse floral traits using a single chimeric repressor without changing the phenotypes of other organs. PMID:27107289

  11. Novel functional roles for PERIANTHIA and SEUSS during floral organ identity specification, floral meristem termination, and gynoecial development

    PubMed Central

    Wynn, April N.; Seaman, Andrew A.; Jones, Ashley L.; Franks, Robert G.

    2014-01-01

    The gynoecium is the female reproductive structure of angiosperm flowers. In Arabidopsis thaliana the gynoecium is composed of two carpels that are fused into a tube-like structure. As the gynoecial primordium arises from the floral meristem, a specialized meristematic structure, the carpel margin meristem (CMM), develops from portions of the medial gynoecial domain. The CMM is critical for reproductive competence because it gives rise to the ovules, the precursors of the seeds. Here we report a functional role for the transcription factor PERIANTHIA (PAN) in the development of the gynoecial medial domain and the formation of ovule primordia. This function of PAN is revealed in pan aintegumenta (ant) as well as seuss (seu) pan double mutants that form reduced numbers of ovules. Previously, PAN was identified as a regulator of perianth organ number and as a direct activator of AGAMOUS (AG) expression in floral whorl four. However, the seu pan double mutants display enhanced ectopic AG expression in developing sepals and the partial transformation of sepals to petals indicating a novel role for PAN in the repression of AG in floral whorl one. These results indicate that PAN functions as an activator or repressor of AG expression in a whorl-specific fashion. The seu pan double mutants also display enhanced floral indeterminacy, resulting in the formation of “fifth whorl” structures and disruption of WUSCHEL (WUS) expression patterns revealing a novel role for SEU in floral meristem termination. PMID:24778638

  12. Unique morphological changes in plant pathogenic phytoplasma-infected petunia flowers are related to transcriptional regulation of floral homeotic genes in an organ-specific manner.

    PubMed

    Himeno, Misako; Neriya, Yutaro; Minato, Nami; Miura, Chihiro; Sugawara, Kyoko; Ishii, Yoshiko; Yamaji, Yasuyuki; Kakizawa, Shigeyuki; Oshima, Kenro; Namba, Shigetou

    2011-09-01

    Abnormal flowers are often induced by infection of certain plant pathogens, e.g. phytoplasma, but the molecular mechanisms underlying these malformations have remained poorly understood. Here, we show that infection with OY-W phytoplasma (Candidatus Phytoplasma asteris, onion yellows phytoplasma strain, line OY-W) affects the expression of the floral homeotic genes of petunia plants in an organ-specific manner. Upon infection with OY-W phytoplasma, floral morphological changes, including conversion to leaf-like structures, were observed in sepals, petals and pistils, but not in stamens. As the expression levels of homeotic genes differ greatly between floral organs, we examined the expression levels of homeotic genes in each floral organ infected by OY-W phytoplasma, compared with healthy plants. The expression levels of several homeotic genes required for organ development, such as PFG, PhGLO1 and FBP7, were significantly downregulated by the phytoplasma infection in floral organs, except the stamens, suggesting that the unique morphological changes caused by the phytoplasma infection might result from the significant decrease in expression of some crucial homeotic genes. Moreover, the expression levels of TER, ALF and DOT genes, which are known to participate in floral meristem identity, were significantly downregulated in the phytoplasma-infected petunia meristems, implying that phytoplasma would affect an upstream signaling pathway of floral meristem identity. Our results suggest that phytoplasma infection may have complex effects on floral development, resulting in the unique phenotypes that were clearly distinct from the mutant flower phenotypes produced by the knock-out or the overexpression of certain homeotic genes. PMID:21605209

  13. Control of patterning, growth, and differentiation by floral organ identity genes.

    PubMed

    Sablowski, Robert

    2015-02-01

    In spite of the different morphologies of sepals, petals, stamens, and carpels, all these floral organs are believed to be modified versions of a ground-state organ similar to the leaf. Modifications of the ground-state developmental programme are orchestrated by different combinations of MADS-domain transcription factors encoded by floral organ identity genes. In recent years, much has been revealed about the gene regulatory networks controlled by the floral organ identity genes and about the genetic pathways that control leaf development. This review examines how floral organ identity is connected with the control of morphogenesis and differentiation of shoot organs, focusing on the model species Arabidopsis thaliana. Direct links have emerged between floral organ identity genes and genes involved in abaxial-adaxial patterning, organ boundary formation, tissue growth, and cell differentiation. In parallel, predictive models have been developed to explain how the activity of regulatory genes can be coordinated by intercellular signalling and constrained by tissue mechanics. When combined, these advances provide a unique opportunity for revealing exactly how leaf-like organs have been 'metamorphosed' into floral organs during evolution and showing crucial regulatory points in the generation of plant form. PMID:25609826

  14. The expression of floral organ identity genes in contrasting water lily cultivars.

    PubMed

    Luo, Huolin; Chen, Sumei; Jiang, Jiafu; Chen, Yu; Chen, Fadi; Teng, Nianjun; Yin, Dongmei; Huang, Changbing

    2011-10-01

    The floral organs of typical eudicots such as Arabidopsis thaliana are arranged in four characteristic whorls, namely the sepal, petal, stamen and carpel, and the "ABC" floral organ identity model has been based on this arrangement. However, the floral organs in most basal angiosperms are spirally arranged with a gradual transition from the inside to outside, and an alternative model referred to as "fading borders" was developed to take account of this. The flower morphology of the water lily was tested against the "fading borders" model by determining the expression profile of the six primary floral organ identity genes AP2, AGL6, AP3, PI, AG and SEP1 in two cultivars showing contrasting floral morphology. In addition, to get accurate floatation of the genes expression level from outer to inner, we divided the floral organs into eight whorls according to morphological features. All these genes were expressed throughout all whorls of the flower, but their expression level changed gradually from the outside of the flower to its inside. This pattern was consistent with the "fading borders" model. PMID:21660548

  15. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach

    PubMed Central

    Xie, Wenchuan; Huang, Junfeng; Liu, Yang; Rao, Jianan; Luo, Da; He, Miao

    2015-01-01

    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-protein interactions (PPIs). We still don't know much about several important aspects of flower development. So we need to discriminate even more genes involving in the flower development. In this study, we identified seven differentially modules through integrating the weighted gene co-expression network analysis (WGCNA) and Support Vector Machine (SVM) method to analyze co-expression network and PPIs using the public floral and non-floral expression profiles data of Arabidopsis thaliana. Gene set enrichment analysis was used for the functional annotation of the related genes, and some of the hub genes were identified in each module. The potential floral organ morphogenesis genes of two significant modules were integrated with PPI information in order to detail the inherent regulation mechanisms. Finally, the functions of the floral patterning genes were elucidated by combining the PPI and evolutionary information. It was indicated that the sub-networks or complexes, rather than the genes, were the regulation unit of flower development. We found that the most possible potential new genes underlining the floral pattern formation in A. thaliana were FY, CBL2, ZFN3, and AT1G77370; among them, FY, CBL2 acted as an upstream regulator of AP2; ZFN3 activated the flower primordial determining gene AP1 and AP2 by HY5/HYH gene via photo induction possibly. And AT1G77370 exhibited similar function in floral morphogenesis, same as ELF3. It possibly formed a complex between RFC3 and RPS15 in

  16. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach.

    PubMed

    Xie, Wenchuan; Huang, Junfeng; Liu, Yang; Rao, Jianan; Luo, Da; He, Miao

    2015-01-01

    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-protein interactions (PPIs). We still don't know much about several important aspects of flower development. So we need to discriminate even more genes involving in the flower development. In this study, we identified seven differentially modules through integrating the weighted gene co-expression network analysis (WGCNA) and Support Vector Machine (SVM) method to analyze co-expression network and PPIs using the public floral and non-floral expression profiles data of Arabidopsis thaliana. Gene set enrichment analysis was used for the functional annotation of the related genes, and some of the hub genes were identified in each module. The potential floral organ morphogenesis genes of two significant modules were integrated with PPI information in order to detail the inherent regulation mechanisms. Finally, the functions of the floral patterning genes were elucidated by combining the PPI and evolutionary information. It was indicated that the sub-networks or complexes, rather than the genes, were the regulation unit of flower development. We found that the most possible potential new genes underlining the floral pattern formation in A. thaliana were FY, CBL2, ZFN3, and AT1G77370; among them, FY, CBL2 acted as an upstream regulator of AP2; ZFN3 activated the flower primordial determining gene AP1 and AP2 by HY5/HYH gene via photo induction possibly. And AT1G77370 exhibited similar function in floral morphogenesis, same as ELF3. It possibly formed a complex between RFC3 and RPS15 in

  17. AINTEGUMENTA, an APETALA2-like gene of Arabidopsis with pleiotropic roles in ovule development and floral organ growth.

    PubMed Central

    Elliott, R C; Betzner, A S; Huttner, E; Oakes, M P; Tucker, W Q; Gerentes, D; Perez, P; Smyth, D R

    1996-01-01

    To understand better the role of genes in controlling ovule development, a female-sterile mutant, aintegumenta (ant), was isolated from Arabidopsis. In ovules of this mutant, integuments do not develop and megasporogenesis is blocked at the tetrad stage. As a pleiotropic effect, narrower floral organs arise in reduced numbers. More complete loss of floral organs occurs when the ant mutant is combined with the floral homeotic mutant apetala2, suggesting that the two genes share functions in initiating floral organ development. The ANT gene was cloned by transposon tagging, and sequence analysis showed that it is a member of the APETALA2-like family of transcription factor genes. The expression pattern of ANT in floral and vegetative tissues indicates that it is involved not only in the initiation of integuments but also in the initiation and early growth of all primorida except roots. PMID:8742707

  18. Identification of class B and class C floral organ identity genes from rice plants.

    PubMed

    Kang, H G; Jeon, J S; Lee, S; An, G

    1998-12-01

    The functions of two rice MADS-box genes were studied by the loss-of-function approach. The first gene, OsMADS4, shows a significant homology to members in the PISTILLATA (PI) family, which is required to specify petal and stamen identity. The second gene, OsMADS3, is highly homologous to the members in the AGAMOUS (AG) family that is essential for the normal development of the internal two whorls, the stamen and carpel, of the flower. These two rice MADS box cDNA clones were connected to the maize ubiquitin promoter in an antisense orientation and the fusion molecules were introduced to rice plants by the Agrobacterium-mediated transformation method. Transgenic plants expressing antisense OsMADS4 displayed alterations of the second and third whorls. The second-whorl lodicules, which are equivalent to the petals of dicot plants in grasses, were altered into palea/lemma-like organs, and the third whorl stamens were changed to carpel-like organs. Loss-of-function analysis of OsMADS3 showed alterations in the third and fourth whorls. In the third whorl, the filaments of the transgenic plants were changed into thick and fleshy bodies, similar to lodicules. Rather than making a carpel, the fourth whorl produced several abnormal flowers. These phenotypes are similar to those of the agamous and plena mutants in Arabidopsis and Antirrhinum, respectively. These results suggest that OsMADS4 belongs to the class B gene family and OsMADS3 belongs to the class C gene family of floral organ identity determination. PMID:9869408

  19. Initiation patterns of flower and floral organ development in Arabidopsis thaliana.

    PubMed

    Bossinger, G; Smyth, D R

    1996-04-01

    Sector boundary analysis has been used to deduce the number and orientation of cells initiating flower and floral organ development in Arabidopsis thaliana. Sectors were produced in transgenic plants carrying the Ac transposon from maize inserted between the constitutive 35S promoter and the GUS reporter gene. Excision of the transposon results in a blue-staining sector. Plants were chosen in which an early arising sector passed from vegetative regions into the inflorescence and through a mature flower. The range of sector boundary positions seen in mature flowers indicated that flower primordia usually arise from a group of four cells on the inflorescence flank. The radial axes of the mature flower are apparently set by these cells, supporting the concept that they act as a structural template. Floral organs show two patterns of initiation, a leaf-like pattern with eight cells in a row (sepals and carpels), or a shoot-like pattern with four cells in a block (stamens). The petal initiation pattern involved too few cells to allow assignment. The numbers of initiating cells were close to those seen when organ growth commenced in each case, indicating that earlier specification of floral organ development does not occur. By examining sector boundaries in homeotic mutant flowers in which second whorl organs develop as sepal-like organs rather than petals, we have shown that their pattern of origin is position dependent rather than identity dependent. PMID:8620836

  20. Ligand-induced receptor-like kinase complex regulates floral organ abscission in Arabidopsis

    PubMed Central

    Meng, Xiangzong; Zhou, Jinggeng; Tang, Jiao; Li, Bo; de Oliveira, Marcos V. V.; Chai, Jijie; He, Ping; Shan, Libo

    2016-01-01

    SUMMARY Abscission is a developmental process that enables plants to shed unwanted organs. In Arabidopsis, the floral organ abscission is regulated by a signaling pathway consisting of the peptide ligand IDA, the receptor-like kinases (RLKs) HAE and HSL2, and a downstream MAP kinase (MAPK) cascade. However, little is known about the molecular link between ligand-receptor pairs and intracellular signaling. Here, we report that the SERK family RLKs function redundantly in regulating floral organ abscission downstream of IDA and upstream of the MAPK cascade. IDA induces heterodimerization of HAE/HSL2 and SERKs, which transphosphorylate each other. The SERK3 residues mediating its interaction with the immune receptor FLS2 and the brassinosteroid receptor BRI1 are also required for IDA-induced HAE/HSL2-SERK3 interaction, suggesting SERKs serve as co-receptors of HAE/HSL2 in perceiving IDA. Thus, our study reveals the signaling activation mechanism in floral organ abscission by IDA-induced HAE/HSL2-SERK complex formation accompanied by transphosphorylation. PMID:26854226

  1. Cloning and expression of floral organ development-related genes in herbaceous peony (Paeonia lactiflora Pall.).

    PubMed

    Ge, Jintao; Zhao, Daqiu; Han, Chenxia; Wang, Jing; Hao, Zhaojun; Tao, Jun

    2014-10-01

    Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental plant that has different flower types. However, the molecular mechanism underlying its floral organ development has not been fully investigated. This study isolated six floral organ development-related genes in P. lactiflora, namely, APETALA1 (PlAP1), APETALA2 (PlAP2), APETALA3-1 (PlAP3-1), APETALA3-2 (PlAP3-2), PISTILLATA (PlPI) and SEPALLATA3 (PlSEP3). The expression patterns of these genes were also investigated in the three cultivars 'Hangshao', 'Xiangyangqihua' and 'Dafugui'. Furthermore, gene expression during floral development was also analyzed in different organs. The results showed that PlAP1 was mainly expressed in the sepals, and PlAP2 was mainly expressed in the carpels and sepals. PlAP3-2 and PlPI had the highest expression levels in the stamens, followed by the petals. The expression levels of PlAP3-1 (from highest to lowest) were in the following order: petals, stamens, carpels and sepals. PlSEP3 was mainly expressed in sepals and carpels. With the depth of stamen petaloidy, the expression levels of PlAP1, PlAP2 and PlSEP3 increased, whereas those of PlAP3-1, PlAP3-2 and PlPI decreased, which showed that PlAP1 mainly determined sepals and petals of P. lactiflora. The PlAP2 not only determined the sepals and petals, and it participated in carpel formation. PlAP3-1, PlAP3-2 and PlPI mainly determined stamens and petals. PlSEP3 determined the identities of sepals and petals. This study would help determine the molecular mechanism underlying floral organ development in P. lactiflora. PMID:24972572

  2. Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission.

    PubMed

    Santiago, Julia; Brandt, Benjamin; Wildhagen, Mari; Hohmann, Ulrich; Hothorn, Ludwig A; Butenko, Melinka A; Hothorn, Michael

    2016-01-01

    Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the HAESA ectodomain. Crystal structures of HAESA in complex with IDA reveal a hormone binding pocket that accommodates an active dodecamer peptide. A central hydroxyproline residue anchors IDA to the receptor. The HAESA co-receptor SERK1, a positive regulator of the floral abscission pathway, allows for high-affinity sensing of the peptide hormone by binding to an Arg-His-Asn motif in IDA. This sequence pattern is conserved among diverse plant peptides, suggesting that plant peptide hormone receptors may share a common ligand binding mode and activation mechanism. PMID:27058169

  3. A common miRNA160-based mechanism regulates ovary patterning, floral organ abscission and lamina outgrowth in tomato.

    PubMed

    Damodharan, Subha; Zhao, Dazhong; Arazi, Tzahi

    2016-06-01

    Plant microRNAs play vital roles in auxin signaling via the negative regulation of auxin response factors (ARFs). Studies have shown that targeting of ARF10/16/17 by miR160 is indispensable for various aspects of development, but its functions in the model crop tomato (Solanum lycopersicum) are unknown. Here we knocked down miR160 (sly-miR160) using a short tandem target mimic (STTM160), and investigated its roles in tomato development. Northern blot analysis showed that miR160 is abundant in developing ovaries. In line with this, its down-regulation perturbed ovary patterning as indicated by the excessive elongation of the proximal ends of mutant ovaries and thinning of the placenta. Following fertilization, these morphological changes led to formation of elongated, pear-shaped fruits reminiscent of those of the tomato ovate mutant. In addition, STTM160-expressing plants displayed abnormal floral organ abscission, and produced leaves, sepals and petals with diminished blades, indicating a requirement for sly-miR160 for these auxin-mediated processes. We found that sly-miR160 depletion was always associated with the up-regulation of SlARF10A, SlARF10B and SlARF17, of which the expression of SlARF10A increased the most. Despite the sly-miR160 legitimate site of SlARF16A, its mRNA levels did not change in response to sly-miR160 down-regulation, suggesting that it may be regulated by a mechanism other than mRNA cleavage. SlARF10A and SlARF17 were previously suggested to function as inhibiting ARFs. We propose that by adjusting the expression of a group of ARF repressors, of which SlARF10A is a primary target, sly-miR160 regulates auxin-mediated ovary patterning as well as floral organ abscission and lateral organ lamina outgrowth. PMID:26800988

  4. K-homology Nuclear Ribonucleoproteins Regulate Floral Organ Identity and Determinacy in Arabidopsis

    PubMed Central

    Rodríguez-Cazorla, Encarnación; Ripoll, Juan José; Andújar, Alfonso; Bailey, Lindsay J.; Martínez-Laborda, Antonio; Yanofsky, Martin F.; Vera, Antonio

    2015-01-01

    Post-transcriptional control is nowadays considered a main checking point for correct gene regulation during development, and RNA binding proteins actively participate in this process. Arabidopsis thaliana FLOWERING LOCUS WITH KH DOMAINS (FLK) and PEPPER (PEP) genes encode RNA-binding proteins that contain three K-homology (KH)-domain, the typical configuration of Poly(C)-binding ribonucleoproteins (PCBPs). We previously demonstrated that FLK and PEP interact to regulate FLOWERING LOCUS C (FLC), a central repressor of flowering time. Now we show that FLK and PEP also play an important role in the maintenance of the C-function during floral organ identity by post-transcriptionally regulating the MADS-box floral homeotic gene AGAMOUS (AG). Previous studies have indicated that the KH-domain containing protein HEN4, in concert with the CCCH-type RNA binding protein HUA1 and the RPR-type protein HUA2, facilitates maturation of the AG pre-mRNA. In this report we show that FLK and PEP genetically interact with HEN4, HUA1, and HUA2, and that the FLK and PEP proteins physically associate with HUA1 and HEN4. Taken together, these data suggest that HUA1, HEN4, PEP and FLK are components of the same post-transcriptional regulatory module that ensures normal processing of the AG pre-mRNA. Our data better delineates the roles of PEP in plant development and, for the first time, links FLK to a morphogenetic process. PMID:25658099

  5. Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission

    PubMed Central

    Santiago, Julia; Brandt, Benjamin; Wildhagen, Mari; Hohmann, Ulrich; Hothorn, Ludwig A; Butenko, Melinka A; Hothorn, Michael

    2016-01-01

    Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the HAESA ectodomain. Crystal structures of HAESA in complex with IDA reveal a hormone binding pocket that accommodates an active dodecamer peptide. A central hydroxyproline residue anchors IDA to the receptor. The HAESA co-receptor SERK1, a positive regulator of the floral abscission pathway, allows for high-affinity sensing of the peptide hormone by binding to an Arg-His-Asn motif in IDA. This sequence pattern is conserved among diverse plant peptides, suggesting that plant peptide hormone receptors may share a common ligand binding mode and activation mechanism. DOI: http://dx.doi.org/10.7554/eLife.15075.001 PMID:27058169

  6. UFO in the Arabidopsis inflorescence apex is required for floral-meristem identity and bract suppression.

    PubMed

    Hepworth, Shelley R; Klenz, Jennifer E; Haughn, George W

    2006-03-01

    The UNUSUAL FLORAL ORGANS (UFO) gene of Arabidopsis encodes an F-box protein required for the determination of floral-organ and floral-meristem identity. Mutation of UFO leads to dramatic changes in floral-organ type which are well-characterized whereas inflorescence defects are more subtle and less understood. These defects include an increase in the number of secondary inflorescences, nodes that alternate between forming flowers and secondary inflorescences, and nodes in which a single flower is subtended by a bract. Here, we show how inflorescence defects correlate with the abnormal development of floral primordia and establish a temporal requirement for UFO in this process. At the inflorescence apex of ufo mutants, newly formed primordia are initially bract-like. Expression of the floral-meristem identity genes LFY and AP1 are confined to a relatively small adaxial region of these primordia with expression of the bract-identity marker FIL observed in cells that comprise the balance of the primordia. Proliferation of cells in the adaxial region of these early primordia is delayed by several nodes such that primordia appear "chimeric" at several nodes, having visible floral and bract components. However, by late stage 2 of floral development, growth of the bract generally ceases and is overtaken by development of the floral primordium. This abnormal pattern of floral meristem development is not rescued by expression of UFO from the AP1 promoter, indicating that UFO is required prior to AP1 activation for normal development of floral primordia. We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract. PMID:16244866

  7. A gain-of-function mutation in IAA8 alters Arabidopsis floral organ development by change of jasmonic acid level.

    PubMed

    Wang, Jing; Yan, Da-Wei; Yuan, Ting-Ting; Gao, Xiang; Lu, Ying-Tang

    2013-05-01

    Auxin regulates a variety of physiological processes via its downstream factors included Aux/IAAs. In this study, one of these Aux/IAAs, IAA8 is shown to play its role in Arabidopsis development with transgenic plants expressing GFP-mIAA8 under the control of IAA8 promoter, in which IAA8 protein was mutated by changing Pro170 to Leu170 in its conserved domain II. These transgenic dwarfed plants had more lateral branches, short primary inflorescence stems, decreased shoot apical dominance, curled leaves and abnormal flower organs (short petal and stamen, and bent stigmas). Further experiments revealed that IAA8::GFP-mIAA8 plants functioned as gain-of-function mutation to increase GFP-mIAA8 amount probably by stabilizing IAA8 protein against proteasome-mediated protein degradation with IAA8::GFP-IAA8 plants as control. The searching for its downstream factors indicated its interaction with both ARF6 and ARF8, suggesting that IAA8 may involve in flower organ development. This was further evidenced by analyzing the expression of jasmonic acid (JA) biosynthetic genes and JA levels because ARF6 and ARF8 are required for normal JA production. These results indicated that in IAA8::GFP-mIAA8 plants, JA biosynthetic genes including DAD1 (AT2G44810), AOS (AT5G42650) and ORP3 (AT2G06050) were dramatically down-regulated and JA level in the flowers was reduced to 70 % of that in wild-type. Furthermore, exogenous JA application can partially rescue short petal and stamen observed IAA8::GFP-mIAA8 plants. Thus, IAA8 plays its role in floral organ development by changes in JA levels probably via its interaction with ARF6/8 proteins. PMID:23483289

  8. Digital Gene Expression Analysis Based on De Novo Transcriptome Assembly Reveals New Genes Associated with Floral Organ Differentiation of the Orchid Plant Cymbidium ensifolium.

    PubMed

    Yang, Fengxi; Zhu, Genfa

    2015-01-01

    Cymbidium ensifolium belongs to the genus Cymbidium of the orchid family. Owing to its spectacular flower morphology, C. ensifolium has considerable ecological and cultural value. However, limited genetic data is available for this non-model plant, and the molecular mechanism underlying floral organ identity is still poorly understood. In this study, we characterize the floral transcriptome of C. ensifolium and present, for the first time, extensive sequence and transcript abundance data of individual floral organs. After sequencing, over 10 Gb clean sequence data were generated and assembled into 111,892 unigenes with an average length of 932.03 base pairs, including 1,227 clusters and 110,665 singletons. Assembled sequences were annotated with gene descriptions, gene ontology, clusters of orthologous group terms, the Kyoto Encyclopedia of Genes and Genomes, and the plant transcription factor database. From these annotations, 131 flowering-associated unigenes, 61 CONSTANS-LIKE (COL) unigenes and 90 floral homeotic genes were identified. In addition, four digital gene expression libraries were constructed for the sepal, petal, labellum and gynostemium, and 1,058 genes corresponding to individual floral organ development were identified. Among them, eight MADS-box genes were further investigated by full-length cDNA sequence analysis and expression validation, which revealed two APETALA1/AGL9-like MADS-box genes preferentially expressed in the sepal and petal, two AGAMOUS-like genes particularly restricted to the gynostemium, and four DEF-like genes distinctively expressed in different floral organs. The spatial expression of these genes varied distinctly in different floral mutant corresponding to different floral morphogenesis, which validated the specialized roles of them in floral patterning and further supported the effectiveness of our in silico analysis. This dataset generated in our study provides new insights into the molecular mechanisms underlying floral

  9. Digital Gene Expression Analysis Based on De Novo Transcriptome Assembly Reveals New Genes Associated with Floral Organ Differentiation of the Orchid Plant Cymbidium ensifolium

    PubMed Central

    Yang, Fengxi; Zhu, Genfa

    2015-01-01

    Cymbidium ensifolium belongs to the genus Cymbidium of the orchid family. Owing to its spectacular flower morphology, C. ensifolium has considerable ecological and cultural value. However, limited genetic data is available for this non-model plant, and the molecular mechanism underlying floral organ identity is still poorly understood. In this study, we characterize the floral transcriptome of C. ensifolium and present, for the first time, extensive sequence and transcript abundance data of individual floral organs. After sequencing, over 10 Gb clean sequence data were generated and assembled into 111,892 unigenes with an average length of 932.03 base pairs, including 1,227 clusters and 110,665 singletons. Assembled sequences were annotated with gene descriptions, gene ontology, clusters of orthologous group terms, the Kyoto Encyclopedia of Genes and Genomes, and the plant transcription factor database. From these annotations, 131 flowering-associated unigenes, 61 CONSTANS-LIKE (COL) unigenes and 90 floral homeotic genes were identified. In addition, four digital gene expression libraries were constructed for the sepal, petal, labellum and gynostemium, and 1,058 genes corresponding to individual floral organ development were identified. Among them, eight MADS-box genes were further investigated by full-length cDNA sequence analysis and expression validation, which revealed two APETALA1/AGL9-like MADS-box genes preferentially expressed in the sepal and petal, two AGAMOUS-like genes particularly restricted to the gynostemium, and four DEF-like genes distinctively expressed in different floral organs. The spatial expression of these genes varied distinctly in different floral mutant corresponding to different floral morphogenesis, which validated the specialized roles of them in floral patterning and further supported the effectiveness of our in silico analysis. This dataset generated in our study provides new insights into the molecular mechanisms underlying floral

  10. THE GLYCINE MAX FLORAL NECTARY: A SMALL BUT FASCINATING SECRETORY ORGAN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soybean floral nectary, as seen by light and scanning electron microscopy, is a small discoid mound that forms between the bases of the central hairy gynoecium and the stamen ring. The nectary exists for a very short time, forming just before flower opening and collapsing after flower opening. ...

  11. Functional analysis of B and C class floral organ genes in spinach demonstrates their role in sexual dimorphism

    PubMed Central

    2010-01-01

    Background Evolution of unisexual flowers entails one of the most extreme changes in plant development. Cultivated spinach, Spinacia oleracea L., is uniquely suited for the study of unisexual flower development as it is dioecious and it achieves unisexually by the absence of organ development, rather than by organ abortion or suppression. Male staminate flowers lack fourth whorl primordia and female pistillate flowers lack third whorl primordia. Based on theoretical considerations, early inflorescence or floral organ identity genes would likely be directly involved in sex-determination in those species in which organ initiation rather than organ maturation is regulated. In this study, we tested the hypothesis that sexual dimorphism occurs through the regulation of B class floral organ gene expression by experimentally knocking down gene expression by viral induced gene silencing. Results Suppression of B class genes in spinach resulted in the expected homeotic transformation of stamens into carpels but also affected the number of perianth parts and the presence of fourth whorl. Phenotypically normal female flowers developed on SpPI-silenced male plants. Suppression of the spinach C class floral organ identity gene, SpAG, resulted in loss of reproductive organ identity, and indeterminate flowers, but did not result in additional sex-specific characteristics or structures. Analysis of the genomic sequences of both SpAP3 and SpPI did not reveal any allelic differences between males and females. Conclusion Sexual dimorphism in spinach is not the result of homeotic transformation of established organs, but rather is the result of differential initiation and development of the third and fourth whorl primordia. SpAG is inferred to have organ identity and meristem termination functions similar to other angiosperm C class genes. In contrast, while SpPI and SpAP3 resemble other angiosperms in their essential functions in establishing stamen identity, they also appear to have

  12. Plant regeneration and floral bud formation from intact floral parts of African violet (Saintpaulia ionantha H. Wendl.) cultured in vitro.

    PubMed

    Daud, N; Taha, R M

    2008-04-01

    Intact immature flower buds of African violet (Saintpaulia ionantha H. Wendl.) were used as explant sources for in vitro studies. The effect of exogenous hormones, NAA and BAP on the indirect organogenesis of this species was observed. Callus was formed on the cut end (base) of pedicels of floral buds where they were in contact with the medium. When maintained on the same medium, callus was differentiated into adventitious shoots after 10 weeks in culture. MS media supplemented with 2.0 mg L(-1) NAA and 1.0 mg L(-1) BAP gave the highest number of sterile or vegetative floral buds from the surface of callus of the explants, but these buds failed to develop further. The floral buds were expanded as abnormal flowers. The floral structures were smaller in size compared to intact flowers. Petals (corolla) were white to purple in colour but did not form any reproductive organs, i.e., stamens or pistils. All sterile or vegetative floral buds and abnormal flowers survived for 3 months in culture but failed to reach anthesis. PMID:18810979

  13. Absence of cytoglobin promotes multiple organ abnormalities in aged mice

    PubMed Central

    Thuy, Le Thi Thanh; Van Thuy, Tuong Thi; Matsumoto, Yoshinari; Hai, Hoang; Ikura, Yoshihiro; Yoshizato, Katsutoshi; Kawada, Norifumi

    2016-01-01

    Cytoglobin (Cygb) was identified in hepatic stellate cells (HSCs) and pericytes of all organs; however, the effects of Cygb on cellular functions remain unclear. Here, we report spontaneous and age-dependent malformations in multiple organs of Cygb−/− mice. Twenty-six percent of young Cygb−/− mice (<1 year old) showed heart hypertrophy, cystic disease in the kidney or ovary, loss of balance, liver fibrosis and lymphoma. Furthermore, 71.3% (82/115) of aged Cygb−/− mice (1–2 years old) exhibited abnormalities, such as heart hypertrophy and cancer development in multiple organs; by contrast, 5.8% (4/68) of aged wild-type (WT) mice had abnormalities (p < 0.0001). Interestingly, serum and urine analysis demonstrated that the concentration of nitric oxide metabolites increased significantly in Cygb−/− mice, resulting in an imbalance in the oxidative stress and antioxidant defence system that was reversed by NG-monomethyl-L-arginine treatment. A senescent phenotype and evidence of DNA damage were found in primary HSCs and the liver of aged Cygb−/− mice. Moreover, compared with HSC+/+, HSC−/− showed high expression of Il-6 and chemokine mRNA when cocultured with mouse Hepa 1–6 cells. Thus, the absence of Cygb in pericytes provokes organ abnormalities, possibly via derangement of the nitric oxide and antioxidant defence system and through accelerated cellular senescence. PMID:27146058

  14. Five pectinase gene expressions highly responding to heat stress in rice floral organs revealed by RNA-seq analysis.

    PubMed

    Wu, Liquan; Taohua, Zhou; Gui, Wenbin; Xu, Lisen; Li, Juan; Ding, YanFeng

    2015-07-31

    Heat stress hurts rice, and floral organs are mostly sensitive to heat stress. We aimed to unravel molecular responses to heat stress in rice floral organs using Illumina/Solexa sequencing technology for addressing the increasing concern of globle warming. At meiophase of the pollen mother cell (pulvinus flat), the plants were stressed for 3 d at 38 C, and RNA was extracted from the stressed pistil and stamen for RNA-Seq sequencing to build the heat stress transcriptom library. A total of 7178 defferentially expressed genes (DEGs) between the normal and heat stress libraries were significant, 61% up-regulated and 39% down-regulated. The 7178 DEGs were significantly classified to 34 gene ontology (GO) categories, and 11 of the GO categories were significantly enriched. The GO:0016787 for hydrolase activity of molecular function was mostly enriched with the least probability, and included 11 DEGs named Hy1 - Hy11. Expression levels of five DEGs, Hy4 - Hy6 and Hy9 - Hy10 for starch and sucrose metablism via pectinase, increased 12 - 14 times in response to the heat stress. Further investigation of the five DEGs for pectin metabolism and association with reported heat responsive genes may help develop a molecular strategy to remedy heat damage in rice. PMID:26032497

  15. ROSINA (RSI), a novel protein with DNA-binding capacity, acts during floral organ development in Antirrhinum majus.

    PubMed

    Roccaro, Mario; Li, Yubin; Masiero, Simona; Saedler, Heinz; Sommer, Hans

    2005-07-01

    Petal and stamen identity of the Antirrhinum majus flower is under the genetic control of the floral homeotic gene DEFICIENS (DEF). To isolate factors involved in the regulation of DEF gene activity, a promoter segment of this B-function gene, containing cis-acting regulatory elements, was used to identify the novel trans-acting factor ROSINA (RSI). RSI does not show an extended similarity with any gene product present in the database. Rather RSI constitutes a protein that contains domains similar to known proteins from organisms of different phyla. The capacity of RSI to bind a sequence element of the DEF promoter, its spatial and temporal expression pattern together with the phenotype of RSI-RNAi interference plants as well as RSI over-expression in Arabidopsis thaliana suggest that RSI is a putative regulator of DEF gene activity in A. majus. PMID:15998310

  16. Transport of sup 14 C-IAA and sup 14 C-ACC within floral organs of Ipomoea nil

    SciTech Connect

    Kiss, H.G. ); Maurice, H.R. ); Koning, R.E. ); Daie, J. )

    1989-04-01

    The transport of {sup 14}C-IAA {sup 14}C-ACC from agarose donor blocks applied to I. nil filaments their recovery as {sup 14}C-accumulation into floral organs was examined. The accumulation of the isotopes in the corolla tissue was greater when {sup 14}C-ACC was applied than {sup 14}C-IAA in intact isolated flower buds. Greater levels of the isotopes accumulated in the pistil, with minimal levels in receptacle and calyx tissues from isolated buds. With intact buds, greater levels of the isotopes were recovered in pistil, calyx receptacle tissues. This study provides further evidence for the role of the filaments as transport vectors for IAA ACC for the production of ethylene.

  17. [Abnormal floral meristem development in transgenic tomato plants do not depend on the expression of genes encoding defense-related PR-proteins and antimicrobial peptides].

    PubMed

    Khaliluev, M R; Chaban, I A; Kononenko, N V; Baranova, E N; Dolgov, S V; Kharchenko, P N; Poliakov, V Iu

    2014-01-01

    In this study, the morphological and cytoembryological analyses of the tomato plants transformed with the genes encoding chitin-binding proteins (ac and RS-intron-Shir) from Amaranthus caudatus L. andA. retroflexus L., respectively, as well as the gene amp2 encoding hevein-like antimicrobial peptides from Stellaria media L., have been performed. The transgenic lines were adapted to soil and grown the greenhouse. The analysis of putative transgenic tomato plants revealed several lines that did not differ phenotypically from the wild type plants and three lines with disruption in differentiation of the inflorescence shoot and the flower, as well as the fruit formation (modified plants of each line were transformed with a single gene as noted before). Abnormalities in the development of the generative organs were maintained for at least six vegetative generations. These transgenic plants were shown to be defective in the mail gametophyte formation, fertilization, and, consequently, led to parthenocarpic fruits. The detailed analysis of growing ovules in the abnormal transgenic plants showed that the replacement tissue was formed and proliferated instead of unfertilized embryo sac. The structure of the replacement tissue differed from both embryonic and endosperm tissue of the normal ovule. The formation of the replacement tissue occurred due to continuing proliferation of the endothelial cells that lost their ability for differentiation. The final step in the development of the replacement tissue was its death, which resulted in the cell lysis. The expression of the genes used was confirmed by RT-PCR in all three lines with abnormal phenotype, as well as in several lines that did not phenotypically differ from the untransformed control. This suggests that abnormalities in the organs of the generative sphere in the transgenic plants do not depend on the expression of the foreign genes that were introduced in the tomato genome. Here, we argue that agrobacterial

  18. A new family of zinc finger proteins in petunia: structure, DNA sequence recognition, and floral organ-specific expression.

    PubMed

    Takatsuji, H; Nakamura, N; Katsumoto, Y

    1994-07-01

    We have previously cloned a gene for a zinc finger protein (EPF1) that is expressed specifically in petals and interacts with the promoter region of the 5-enolpyruvylshikimate-3-phosphate synthase gene in petunia. In an attempt to isolate genes encoding additional factors that interact with this promoter, we cloned four novel genes encoding zinc finger proteins (EPF2-5a, EPF2-5b, EPF2-4, and EPF2-7). Sequence analyses revealed that overall similarity between the EPF1 and the EPF2 protein family, except in the zinc finger motifs and the basic amino acid cluster, was very low, suggesting that the two groups belong to different subfamilies. DNA binding specificities of EPF1, EPF2-5, and EPF2-4 were very similar, as expected from the conserved zinc finger motifs. However, EPF2-7 showed no binding to the probes tested in spite of having the conserved motifs. DNA binding studies using a series of spacing mutant probes suggested a binding mechanism in which the EPF proteins recognize spacings in target DNA. RNA gel blot analyses and histochemical analyses with a promoter and beta-glucuronidase fusion revealed that expression of the EPF2-5 gene (EPF2-5) was petal and stamen specific. Expression of the EPF2-7 gene (EPF2-7) was sepal and petal specific and localized in vascular tissues. The preferential expression in two adjacent floral organs raises the possibility that these genes are downstream transcription factors of floral homeotic genes. PMID:8069106

  19. Genetic analysis of floral organ size in broccoli × cabbage via a mixed inheritance model of a major gene plus polygene.

    PubMed

    Shu, J S; Liu, Y M; Li, Z S; Zhang, L L; Fang, Z Y; Yang, L M; Zhuang, M; Zhang, Y Y; Lv, H H

    2016-01-01

    Broccoli and cabbage are important vegetable crops that produce hybrid seeds after insect pollination; the size of floral organs is crucial for this process. To investigate the genetic characteristics of floral organ sizes (corolla width, petal length and width, and lengths of stamen, anther, style, and stigma) and to improve the flower size and breeding efficiency of broccoli, we used multi-generation analysis of a major gene plus polygene model. Six populations obtained from a broccoli inbred line 93219 (small floral organs) and cabbage inbred line 195 (large floral organs) were used for the analysis. Corolla and petal width and stamen and anther length were controlled by the additive-dominance-epistasis polygene model. The heritability of these traits in BC1, BC2, and F2 generations was high (72.80-93.76%). Petal and stigma length were governed by the two major genes of additive-dominance-epistasis effects plus additive-dominance polygene model; the major gene heritability in the F2 generation were 79.17 and 65.77%, respectively. Style length was controlled by one major gene of additive-dominance effects plus additive-dominance-epistasis polygene model; the major gene heritability in BC1, BC2, and F2 were 40.60, 10.35, and 38.44%, respectively; the polygene heritability varied from 41.85 to 68.44%. Our results provide important genetic information for breeding, which could guide improvement of flower-related traits and lay the foundation for quantitative trait loci mapping of the flower-size traits in Brassica. PMID:27173214

  20. Metabolic and transcriptomic signatures of rice floral organs reveal sugar starvation as a factor in reproductive failure under heat and drought stress.

    PubMed

    Li, Xia; Lawas, Lovely M F; Malo, Richard; Glaubitz, Ulrike; Erban, Alexander; Mauleon, Ramil; Heuer, Sigrid; Zuther, Ellen; Kopka, Joachim; Hincha, Dirk K; Jagadish, Krishna S V

    2015-10-01

    Heat and drought stress are projected to become major challenges to sustain rice (Oryza sativa L.) yields with global climate change. Both stresses lead to yield losses when they coincide with flowering. A significant knowledge gap exists in the mechanistic understanding of the responses of rice floral organs that determine reproductive success under stress. Our work connects the metabolomic and transcriptomic changes in anthers, pistils before pollination and pollinated pistils in a heat-tolerant (N22) and a heat-sensitive (Moroberekan) cultivar. Systematic analysis of the floral organs revealed contrasts in metabolic profiles across anthers and pistils. Constitutive metabolic markers were identified that can define reproductive success in rice under stress. Six out of nine candidate metabolites identified by intersection analysis of stressed anthers were differentially accumulated in N22 compared with Moroberekan under non-stress conditions. Sugar metabolism was identified to be the crucial metabolic and transcriptional component that differentiated floral organ tolerance or susceptibility to stress. While susceptible Moroberekan specifically showed high expression of the Carbon Starved Anthers (CSA) gene under combined heat and drought, tolerant N22 responded with high expression of genes encoding a sugar transporter (MST8) and a cell wall invertase (INV4) as markers of high sink strength. PMID:25828772

  1. Floral volatiles: from biosynthesis to function.

    PubMed

    Muhlemann, Joëlle K; Klempien, Antje; Dudareva, Natalia

    2014-08-01

    Floral volatiles have attracted humans' attention since antiquity and have since then permeated many aspects of our lives. Indeed, they are heavily used in perfumes, cosmetics, flavourings and medicinal applications. However, their primary function is to mediate ecological interactions between flowers and a diverse array of visitors, including pollinators, florivores and pathogens. As such, they ultimately ensure the plants' reproductive and evolutionary success. To date, over 1700 floral volatile organic compounds (VOCs) have been identified. Interestingly, they are derived from only a few biochemical networks, which include the terpenoid, phenylpropanoid/benzenoid and fatty acid biosynthetic pathways. These pathways are intricately regulated by endogenous and external factors to enable spatially and temporally controlled emission of floral volatiles, thereby fine-tuning the ecological interactions facilitated by floral volatiles. In this review, we will focus on describing the biosynthetic pathways leading to floral VOCs, the regulation of floral volatile emission, as well as biological functions of emitted volatiles. PMID:24588567

  2. LOOSE FLOWER, a WUSCHEL-like Homeobox gene, is required for lateral fusion of floral organs in Medicago truncatula.

    PubMed

    Niu, Lifang; Lin, Hao; Zhang, Fei; Watira, Tezera W; Li, Guifen; Tang, Yuhong; Wen, Jiangqi; Ratet, Pascal; Mysore, Kirankumar S; Tadege, Million

    2015-02-01

    The Medicago truncatula WOX gene, STENOFOLIA (STF), and its orthologs in Petunia, pea, and Nicotiana sylvestris are required for leaf blade outgrowth and floral organ development as demonstrated by severe phenotypes in single mutants. But the Arabidopsis wox1 mutant displays a narrow leaf phenotype only when combined with the prs/wox3 mutant. In maize and rice, WOX3 homologs are major regulators of leaf blade development. Here we investigated the role of WOX3 in M. truncatula development by isolating the lfl/wox3 loss-of-function mutant and performing genetic crosses with the stf mutant. Lack of WOX3 function in M. truncatula leads to a loose-flower (lfl) phenotype, where defects are observed in sepal and petal development, but leaf blades are apparently normal. The stf lfl double mutant analysis revealed that STF and LFL act mainly independently with minor redundant functions in flower development, but LFL has no obvious role in leaf blade outgrowth in M. truncatula on its own or in combination with STF. Interestingly, LFL acts as a transcriptional repressor by recruiting TOPLESS in the same manner as STF does, and can substitute for STF function in leaf blade and flower development if expressed under the STF promoter. STF also complements the lfl mutant phenotype in the flower if expressed under the LFL promoter. Our data suggest that the STF/WOX1 and LFL/WOX3 genes of M. truncatula employ a similar mechanism of action in organizing cell proliferation for lateral outgrowth but may have evolved different cis elements to acquire distinct functions. PMID:25492397

  3. Nickel accumulation in leaves, floral organs and rewards varies by serpentine soil affinity

    PubMed Central

    Meindl, George A.; Bain, Daniel J.; Ashman, Tia-Lynn

    2014-01-01

    Serpentine soils are edaphically stressful environments that host many endemic plant species. In particular, serpentine soils are high in several heavy metals (e.g. nickel, cobalt and chromium) and these high heavy metal concentrations are thought, in part, to lead to varying levels of plant adaptation and soil affinities (i.e. endemic vs. non-endemic plant species). It is unclear, however, whether serpentine endemics vs. non-endemics differ with respect to heavy metal uptake into either vegetative or reproductive organs. Here, we use nickel as a model to determine whether plant heavy metal uptake varies with the level of endemism in several non-hyperaccumulating species. Under controlled greenhouse conditions, we grew seven plant species from the Brassicaceae family that vary in their degrees of affinity to serpentine soil from low (indifferent) to medium (indicator) and high (endemic) in soil that was nickel supplemented or not. We quantified nickel concentrations in leaves, pistils, anthers, pollen and nectar. While nickel concentrations did not vary across organs or affinities when grown in control soils, under conditions of nickel supplementation endemic species had the lowest tissue concentrations of nickel, particularly when considering leaves and pistils, compared with indifferent/indicator species. Species indifferent to serpentines incorporated higher concentrations of nickel into reproductive organs relative to leaves, but this was not the case for indicator species and endemics where nickel concentration was similar in these organs. Our findings suggest that endemic species possess the ability to limit nickel uptake into above-ground tissues, particularly in reproductive organs where it may interfere with survival and reproduction. Indifferent species accumulated significantly more nickel into reproductive organs compared with leaves, which may limit their reproductive potential relative to endemic species when growing on serpentine soils. Additional

  4. Micro-organisms behind the pollination scenes: microbial imprint on floral nectar sugar variation in a tropical plant community

    PubMed Central

    Canto, A.; Herrera, C. M.

    2012-01-01

    Background and Aims Variation in the composition of floral nectar reflects intrinsic plant characteristics as well as the action of extrinsic factors. Micro-organisms, particularly yeasts, represent one extrinsic factor that inhabit the nectar of animal-pollinated flowers worldwide. In this study a ‘microbial imprint hypothesis’ is formulated and tested, in which it is proposed that natural community-wide variation in nectar sugar composition will partly depend on the presence of yeasts in flowers. Methods Occurrence and density of yeasts were studied microscopically in single-flower nectar samples of 22 animal-pollinated species from coastal xeric and sub-humid tropical habitats of the Yucatán Peninsula, Mexico. Nectar sugar concentration and composition were concurrently determined on the same samples using high-performance liquid chromatography (HPLC) methods. Key Results Microscopical examination of nectar samples revealed the presence of yeasts in nearly all plant species (21 out of 22 species) and in about half of the samples examined (51·8 % of total, all species combined). Plant species and individuals differed significantly in nectar sugar concentration and composition, and also in the incidence of nectar yeasts. After statistically controlling for differences between plant species and individuals, nectar yeasts still accounted for a significant fraction of community-wide variance in all nectar sugar parameters considered. Significant yeast × species interactions on sugar parameters revealed that plant species differed in the nectar sugar correlates of variation in yeast incidence. Conclusions The results support the hypothesis that nectar yeasts impose a detectable imprint on community-wide variation in nectar sugar composition and concentration. Since nectar sugar features influence pollinator attraction and plant reproduction, future nectar studies should control for yeast presence and examine the extent to which microbial signatures on nectar

  5. NEVERSHED and INFLORESCENCE DEFICIENT IN ABSCISSION are differentially required for cell expansion and cell separation during floral organ abscission in Arabidopsis thaliana.

    PubMed

    Liu, Bin; Butenko, Melinka A; Shi, Chun-Lin; Bolivar, Jenny L; Winge, Per; Stenvik, Grethe-Elisabeth; Vie, Ane Kjersti; Leslie, Michelle E; Brembu, Tore; Kristiansen, Wenche; Bones, Atle M; Patterson, Sara E; Liljegren, Sarah J; Aalen, Reidunn B

    2013-12-01

    Floral organ shedding is a cell separation event preceded by cell-wall loosening and generally accompanied by cell expansion. Mutations in NEVERSHED (NEV) or INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) block floral organ abscission in Arabidopsis thaliana. NEV encodes an ADP-ribosylation factor GTPase-activating protein, and cells of nev mutant flowers display membrane-trafficking defects. IDA encodes a secreted peptide that signals through the receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2). Analyses of single and double mutants revealed unique features of the nev and ida phenotypes. Cell-wall loosening was delayed in ida flowers. In contrast, nev and nev ida mutants displayed ectopic enlargement of abscission zone (AZ) cells, indicating that cell expansion alone is not sufficient to trigger organ loss. These results suggest that NEV initially prevents precocious cell expansion but is later integral for cell separation. IDA is involved primarily in the final cell separation step. A mutation in KNOTTED-LIKE FROM ARABIDOPSIS THALIANA1 (KNAT1), a suppressor of the ida mutant, could not rescue the abscission defects of nev mutant flowers, indicating that NEV-dependent activity downstream of KNAT1 is required. Transcriptional profiling of mutant AZs identified gene clusters regulated by IDA-HAE/HSL2. Several genes were more strongly downregulated in nev-7 compared with ida and hae hsl2 mutants, consistent with the rapid inhibition of organ loosening in nev mutants, and the overlapping roles of NEV and IDA in cell separation. A model of the crosstalk between the IDA signalling pathway and NEV-mediated membrane traffic during floral organ abscission is presented. PMID:23963677

  6. Floral Genetic Architecture: An Examination of QTL Architecture Underlying Floral (Co)Variation Across Environments

    PubMed Central

    Brock, Marcus T.; Dechaine, Jennifer M.; Iniguez-Luy, Federico L.; Maloof, Julin N.; Stinchcombe, John R.; Weinig, Cynthia

    2010-01-01

    Genetic correlations are expected to be high among functionally related traits and lower between groups of traits with distinct functions (e.g., reproductive vs. resource-acquisition traits). Here, we explore the quantitative-genetic and QTL architecture of floral organ sizes, vegetative traits, and life history in a set of Brassica rapa recombinant inbred lines within and across field and greenhouse environments. Floral organ lengths were strongly positively correlated within both environments, and analysis of standardized G-matrices indicates that the structure of genetic correlations is ∼80% conserved across environments. Consistent with these correlations, we detected a total of 19 and 21 additive-effect floral QTL in the field and the greenhouse, respectively, and individual QTL typically affected multiple organ types. Interestingly, QTL × QTL epistasis also appeared to contribute to observed genetic correlations; i.e., interactions between two QTL had similar effects on filament length and two estimates of petal size. Although floral and nonfloral traits are hypothesized to be genetically decoupled, correlations between floral organ size and both vegetative and life-history traits were highly significant in the greenhouse; G-matrices of floral and vegetative traits as well as floral and life-history traits differed across environments. Correspondingly, many QTL (45% of those mapped in the greenhouse) showed environmental interactions, including approximately even numbers of floral and nonfloral QTL. Most instances of QTL × QTL epistasis for floral traits were environment dependent. PMID:20837996

  7. Epidermal control of floral organ identity by class B homeotic genes in Antirrhinum and Arabidopsis.

    PubMed

    Efremova, N; Perbal, M C; Yephremov, A; Hofmann, W A; Saedler, H; Schwarz-Sommer, Z

    2001-07-01

    To assess the contribution of the epidermis to the control of petal and stamen organ identity, we have used transgenic Antirrhinum and Arabidopsis plants that expressed the Antirrhinum class B homeotic transcription factors DEFICIENS (DEF) and GLOBOSA (GLO) in the epidermis. Transgene expression was controlled by the ANTIRRHINUM FIDDLEHEAD (AFI) promoter, which directs gene expression to the L1 meristematic layer and, later, to the epidermis of differentiating organs. Transgenic epidermal DEF and GLO chimeras display similar phenotypes, suggesting similar epidermal contributions by the two class B genes in ANTIRRHINUM: Epidermal B function autonomously controls the differentiation of Antirrhinum petal epidermal cell types, but cannot fully control the pattern of cell divisions and the specification of sub-epidermal petal cell-identity by epidermal signalling. This non-autonomous control is enhanced if the endogenous class B genes can be activated from the epidermis. The developmental influence of epidermal B function in Antirrhinum stamen development is very limited. In contrast, epidermal B function in Arabidopsis can control most if not all epidermal and sub-epidermal differentiation events in petals and stamens, without any contribution from the endogenous class B genes. Possible reasons for differences in the efficacy of B-function-mediated cell communication between the two species are discussed. Interestingly, our experiments uncovered partial incompatibility between class B functional homologues. Although the DEFICIENS/PISTILLATA heterodimer is functional in transgenic Arabidopsis plants, the APETALA3/GLOBOSA heterodimer is not. PMID:11526073

  8. A GLYCINE MAX FLORAL NECTARY: A FASCINATING SECRETORY ORGAN WITH UNUSUAL SUBCELLULAR STRUCTURES AND MANNER OF SECRETION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The floral nectary is a short-lived discoid gland around the base of the gynoecium. It consists of an epidermis, with prominent guard cells, that covers a mound of special parenchyma innervated by fingers of phloem. When the nectary reaches its maximum size, special parenchyma around the phloem fi...

  9. The genome and transcriptome of Phalaenopsis yield insights into floral organ development and flowering regulation

    PubMed Central

    Cheng, Ting-Chi; Huang, Ya-Wen; Tsai, Yi-Jung; Chen, Yi-Wen; Lee, Chueh-Pai; Chung, Wan-Chia

    2016-01-01

    The Phalaenopsis orchid is an important potted flower of high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis ‘KHM190’ cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima ‘B8802,’ a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal that the key role of PhAGL6b in the regulation of labellum organ development involves alternative splicing in the big lip mutant. Petal or sepal overexpressing PhAGL6b leads to the conversion into a lip-like structure. We also discovered that the gibberellin pathway that regulates the expression of flowering time genes during the reproductive phase change is induced by cool temperature. Our work thus depicted a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids. PMID:27190718

  10. The genome and transcriptome of Phalaenopsis yield insights into floral organ development and flowering regulation.

    PubMed

    Huang, Jian-Zhi; Lin, Chih-Peng; Cheng, Ting-Chi; Huang, Ya-Wen; Tsai, Yi-Jung; Cheng, Shu-Yun; Chen, Yi-Wen; Lee, Chueh-Pai; Chung, Wan-Chia; Chang, Bill Chia-Han; Chin, Shih-Wen; Lee, Chen-Yu; Chen, Fure-Chyi

    2016-01-01

    The Phalaenopsis orchid is an important potted flower of high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis 'KHM190' cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima 'B8802,' a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal that the key role of PhAGL6b in the regulation of labellum organ development involves alternative splicing in the big lip mutant. Petal or sepal overexpressing PhAGL6b leads to the conversion into a lip-like structure. We also discovered that the gibberellin pathway that regulates the expression of flowering time genes during the reproductive phase change is induced by cool temperature. Our work thus depicted a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids. PMID:27190718

  11. The Arabidopsis nectary is an ABC-independent floral structure.

    PubMed

    Baum, S F; Eshed, Y; Bowman, J L

    2001-11-01

    In contrast to the conservation of floral organ order in angiosperm flowers, nectary glands can be found in various floral and extrafloral positions. Since in Arabidopsis, the nectary develops only at the base of stamens, its specification was assayed with regard to the floral homeotic ABC selector genes. We show that the nectary can form independently of any floral organ identity gene but is restricted to the 'third whorl' domain in the flower. This domain is, in part, specified redundantly by LEAFY and UNUSUAL FLORAL ORGANS. Even though nectary glands arise from cells previously expressing the B class genes, their proper development requires the down-regulation of B class gene activity. While CRABS CLAW is essential for nectary gland formation, its ectopic expression is not sufficient to induce ectopic nectary formation. We show that in Arabidopsis multiple factors act to restrict the nectary to the flower, and surprisingly, some of these factors are LEAFY and UNUSUAL FLORAL ORGANS. PMID:11714690

  12. Pattern formation during early floral development.

    PubMed

    Vaddepalli, Prasad; Scholz, Sebastian; Schneitz, Kay

    2015-06-01

    Flowers are central to sexual reproduction in plants. The study of floral development proved tremendously successful in obtaining key insight into processes, such as fate determination, pattern formation, and growth regulation. Recent advances relate to the complex mechanisms underlying the crosstalk between phytohormone signaling, cell and tissue mechanics, and regulatory gene networks that positions floral buds at the apex and directs floral specification, initiation and outgrowth. Furthermore, progress has been made in elucidating the intercellular communication and temporal coordination necessary to organize the behavior of the various functional subdomains within the young flower. PMID:25687790

  13. Stamen abscission zone transcriptome profiling reveals new candidates for abscission control: enhanced retention of floral organs in transgenic plants overexpressing Arabidopsis ZINC FINGER PROTEIN2.

    PubMed

    Cai, Suqin; Lashbrook, Coralie C

    2008-03-01

    Organ detachment requires cell separation within abscission zones (AZs). Physiological studies have established that ethylene and auxin contribute to cell separation control. Genetic analyses of abscission mutants have defined ethylene-independent detachment regulators. Functional genomic strategies leading to global understandings of abscission have awaited methods for isolating AZ cells of low abundance and very small size. Here, we couple laser capture microdissection of Arabidopsis thaliana stamen AZs and GeneChip profiling to reveal the AZ transcriptome responding to a developmental shedding cue. Analyses focus on 551 AZ genes (AZ(551)) regulated at the highest statistical significance (P < or = 0.0001) over five floral stages linking prepollination to stamen shed. AZ(551) includes mediators of ethylene and auxin signaling as well as receptor-like kinases and extracellular ligands thought to act independent of ethylene. We hypothesized that novel abscission regulators might reside in disproportionately represented Gene Ontology Consortium functional categories for cell wall modifying proteins, extracellular regulators, and nuclear-residing transcription factors. Promoter-beta-glucuronidase expression of one transcription factor candidate, ZINC FINGER PROTEIN2 (AtZFP2), was elevated in stamen, petal, and sepal AZs. Flower parts of transgenic lines overexpressing AtZFP2 exhibited asynchronous and delayed abscission. Abscission defects were accompanied by altered floral morphology limiting pollination and fertility. Hand-pollination restored transgenic fruit development but not the rapid abscission seen in wild-type plants, demonstrating that pollination does not assure normal rates of detachment. In wild-type stamen AZs, AtZFP2 is significantly up-regulated postanthesis. Phenotype data from transgene overexpression studies suggest that AtZFP2 participates in processes that directly or indirectly influence organ shed. PMID:18192438

  14. Molecular Mechanisms of Floral Boundary Formation in Arabidopsis

    PubMed Central

    Yu, Hongyang; Huang, Tengbo

    2016-01-01

    Boundary formation is a crucial developmental process in plant organogenesis. Boundaries separate cells with distinct identities and act as organizing centers to control the development of adjacent organs. In flower development, initiation of floral primordia requires the formation of the meristem-to-organ (M–O) boundaries and floral organ development depends on the establishment of organ-to-organ (O–O) boundaries. Studies in this field have revealed a suite of genes and regulatory pathways controlling floral boundary formation. Many of these genes are transcription factors that interact with phytohormone pathways. This review will focus on the functions and interactions of the genes that play important roles in the floral boundaries and discuss the molecular mechanisms that integrate these regulatory pathways to control the floral boundary formation. PMID:26950117

  15. Sub- and neo-functionalization of APETALA3 paralogs have contributed to the evolution of novel floral organ identity in Aquilegia (columbine, Ranunculaceae).

    PubMed

    Sharma, Bharti; Kramer, Elena

    2013-02-01

    Previous studies of the lower eudicot model Aquilegia have revealed differential expression patterns of two APETALA3 (AP3) paralogs that appear to coincide with the development of a distinct fifth floral organ type, the staminodium. The AqAP3-1 locus quickly becomes limited to the staminodia while AqAP3-2 becomes stamen-specific. We used transient RNAi-based methods to silence each of these loci individually and in combination, followed by detailed studies of the resultant morphologies and the effects on gene expression patterns. Silencing of AqAP3-1 had a strong effect on the staminodia, causing transformation into carpeloid organs, while silencing of AqAP3-2 only affected the stamens, resulting in sterility, stunting or weak transformation towards carpel identity. Much more dramatic phenotypes were obtained in the doubly silenced flowers, where all stamens and staminodia were transformed into carpels. Quantitative reverse-transcription polymerase chain reaction analyses of B gene homolog expression in these flowers are consistent with complex patterns of regulatory feedback among the loci. These findings suggest that the presence of ancient AP3 paralogs in the Ranunculaceae has facilitated the recent evolution of a novel organ identity program in Aquilegia. Specifically, it appears that downregulation of AqAP3-2 in the innermost whorl of stamens was a critical step in the evolution of elaborated sterile organs in this position. PMID:23278258

  16. Building beauty: the genetic control of floral patterning

    SciTech Connect

    Lohmann, J. U., and Weigel, D.

    2002-02-01

    OAK-B135 Floral organ identity is controlled by combinatorial action of homeotic genes expressed in different territories within the emerging flower. This review discusses recent progress in our understanding of floral homeotic genes, with an emphasis on how their region-specific expression is regulated.

  17. Echocardiographic abnormalities in the assessment of cardiac organ damage in never-treated hypertensive patients.

    PubMed

    Milan, Alberto; Avenatti, Eleonora; Puglisi, Elisabetta; Abram, Sara; Magnino, Corrado; Naso, Diego; Tosello, Francesco; Fabbri, Ambra; Vairo, Alessandro; Mulatero, Paolo; Rabbia, Franco; Veglio, Franco

    2012-01-01

    Hypertension-related cardiac organ damage, other than left ventricular (LV) hypertrophy (LVH), has been described: in particular, concentric remodeling, LV diastolic dysfunction (DD), and left atrial (LA) enlargement are significantly associated with cardiovascular morbility and mortality in different populations. This study evaluated the prevalence of these latter morphofunctional abnormalities, in never-treated essential hypertensive patients and the role of such a serial assessment of hypertensive cardiac damage in improving cardiovascular risk stratification in these patients. A total of 100 never-treated essential hypertensive subjects underwent a complete clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function, and LA dimension (linear and volume) were evaluated by echocardiography. Left ventricular hypertrophy was present in 14% of the patients, whereas concentric remodeling was present in 25% of the subjects. Among patients free from LV morphology abnormalities, the most frequent abnormality was LA enlargement (global prevalence 57%); the percentage of patients with at least one parameter consistent with DD was 22% in the entire population, but DD was present as the only cardiac abnormality in 1% of our patient. Left atrial volume indexed for body surface area was the most sensitive parameter in identifying hypertension-related cardiac modification. The global prevalence of cardiac alteration reached 73% in never-treated hypertensive patients. Left ventricular remodeling and LA enlargement evaluation may grant a better assessment of cardiac organ damage and cardiovascular risk stratification of hypertensive patients without evidence of LVH after routine examination. PMID:22738434

  18. Deficiency in a Very-Long-Chain Fatty Acid β-Ketoacyl-Coenzyme A Synthase of Tomato Impairs Microgametogenesis and Causes Floral Organ Fusion1[W

    PubMed Central

    Smirnova, Anna; Leide, Jana; Riederer, Markus

    2013-01-01

    Previously, it was shown that β-ketoacyl-coenzyme A synthase ECERIFERUM6 (CER6) is necessary for the biosynthesis of very-long-chain fatty acids with chain lengths beyond C28 in tomato (Solanum lycopersicum) fruits and C26 in Arabidopsis (Arabidopsis thaliana) leaves and the pollen coat. CER6 loss of function in Arabidopsis resulted in conditional male sterility, since pollen coat lipids are responsible for contact-mediated pollen hydration. In tomato, on the contrary, pollen hydration does not rely on pollen coat lipids. Nevertheless, mutation in SlCER6 impairs fertility and floral morphology. Here, the contribution of SlCER6 to the sexual reproduction and flower development of tomato was addressed. Cytological analysis and cross-pollination experiments revealed that the slcer6 mutant has male sterility caused by (1) hampered pollen dispersal and (2) abnormal tapetum development. SlCER6 loss of function provokes a decrease of n- and iso-alkanes with chain lengths of C27 or greater and of anteiso-alkanes with chain lengths of C28 or greater in flower cuticular waxes, but it has no impact on flower cuticle ultrastructure and cutin content. Expression analysis confirmed high transcription levels of SlCER6 in the anther and the petal, preferentially in sites subject to epidermal fusion. Hence, wax deficiency was proposed to be the primary reason for the flower fusion phenomenon in tomato. The SlCER6 substrate specificity was revisited. It might be involved in elongation of not only linear but also branched very-long-chain fatty acids, leading to production of the corresponding alkanes. SlCER6 implements a function in the sexual reproduction of tomato that is different from the one in Arabidopsis: SlCER6 is essential for the regulation of timely tapetum degradation and, consequently, microgametogenesis. PMID:23144186

  19. Virus-induced gene silencing of PEAM4 affects floral morphology by altering the expression pattern of PsSOC1a and PsPVP in pea.

    PubMed

    Chen, Zhe-Hao; Jia, Fei-Fei; Hu, Jiang-Qin; Pang, Ji-Liang; Xu, Lei; Wang, Li-Lin

    2014-01-15

    pea-MADS4 (PEAM4) regulates floral morphology in Pisum sativum L., however, its molecular mechanisms still remain unclear. Virus-induced gene silencing (VIGS) is a recently developed reverse genetic approach that facilities an easier and more rapid study of gene functions. In this study, the PEAM4 gene was effectively silenced by VIGS using a pea early browning virus (PEBV) in wild type pea JI992. The infected plants showed abnormal phenotypes, as the floral organs, especially the sepals and petals changed in both size and shape, which made the corolla less closed. The petals changed in morphology and internal symmetry with, the stamens reduced and carpel dehisced. Larger sepals and longer tendrils with small cauline leaves appeared, with some sepals turning into bracts, and secondary inflorescences with fused floral organs were formed, indicating a flower-to-inflorescence change. The infected plants also displayed a delayed and prolonged flowering time. The PEAM4-VIGS plants with altered floral morphology were similar to the pim (proliferating inflorescence meristem) mutant and also mimicked the phenotypes of ap1 mutants in Arabidopsis. The expression pattern of the homologous genes PsSOC1a and PsSVP, which were involved in flowering time and florescence morphological control downstream of PEAM4, were analyzed by real-time RT-PCR and mRNA in situ hybridization. PsSOC1a and PsSVP were ectopically expressed and enhanced in the floral meristems from PEAM4-silenced plants. Our data suggests that PEAM4 may have a similar molecular mechanism as AtAP1, which inhibits the expression of PsSOC1a and PsSVP in the floral meristem from the early stages of flower development. As such, in this way PEAM4 plays a crucial role in maintaining floral organ identity and flower development in pea. PMID:24331430

  20. Overexpression of AtAP1M3 regulates flowering time and floral development in Arabidopsis and effects key flowering-related genes in poplar.

    PubMed

    Chen, Zhong; Ye, Meixia; Su, Xiaoxing; Liao, Weihua; Ma, Huandi; Gao, Kai; Lei, Bingqi; An, Xinmin

    2015-08-01

    APETALA1 plays a crucial role in the transition from vegetative to reproductive phase and in floral development. In this study, to determine the effect of AP1 expression on flowering time and floral organ development, transgenic Arabidopsis and poplar overexpressing of AtAP1M3 (Arabidopsis AP1 mutant by dominant negative mutation) were generated. Transgenic Arabidopsis with e35Spro::AtAP1M3 displayed phenotypes with delayed-flowering compared to wild-type and flowers with abnormal sepals, petals and stamens. In addition, transgenic Arabidopsis plants exhibited reduced growth vigor compared to the wild-type plants. Ectopic expression of AtAP1M3 in poplar resulted in up- or down-regulation of some endogenous key flowering-related genes, including floral meristems identity gene LFY, B-class floral organ identity genes AP3 and PI, flowering pathway integrator FT1 and flower repressors TFL1 and SVP. These results suggest that AtAP1M3 regulates flowering time and floral development in plants. PMID:25820621

  1. Toward the Analysis of the Petunia MADS Box Gene Family by Reverse and Forward Transposon Insertion Mutagenesis Approaches: B, C, and D Floral Organ Identity Functions Require SEPALLATA-Like MADS Box Genes in Petunia

    PubMed Central

    Vandenbussche, Michiel; Zethof, Jan; Souer, Erik; Koes, Ronald; Tornielli, Giovanni B.; Pezzotti, Mario; Ferrario, Silvia; Angenent, Gerco C.; Gerats, Tom

    2003-01-01

    We have initiated a systematic functional analysis of the MADS box, intervening region, K domain, C domain-type MADS box gene family in petunia. The starting point for this has been a reverse-genetics approach, aiming to select for transposon insertions into any MADS box gene. We have developed and applied a family signature insertion screening protocol that is highly suited for this purpose, resulting in the isolation of 32 insertion mutants in 20 different MADS box genes. In addition, we identified three more MADS box gene insertion mutants using a candidate-gene approach. The defined insertion lines provide a sound foundation for a systematic functional analysis of the MADS box gene family in petunia. Here, we focus on the analysis of Floral Binding Protein2 (FBP2) and FBP5 genes that encode the E-function, which in Arabidopsis has been shown to be required for B and C floral organ identity functions. fbp2 mutants display sepaloid petals and ectopic inflorescences originating from the third floral whorl, whereas fbp5 mutants appear as wild type. In fbp2 fbp5 double mutants, reversion of floral organs to leaf-like organs is increased further. Strikingly, ovules are replaced by leaf-like structures in the carpel, indicating that in addition to the B- and C-functions, the D-function, which specifies ovule development, requires E-function activity. Finally, we compare our data with results obtained using cosuppression approaches and conclude that the latter might be less suited for assigning functions to individual members of the MADS box gene family. PMID:14576291

  2. Use of the self-organizing feature map to diagnose abnormal engineering change

    NASA Astrophysics Data System (ADS)

    Lu, Ruei-Shan; Wu, Zhi-Ting; Peng, Kuo-Wei; Yu, Tai-Yi

    2015-07-01

    This study established identification manners with self-organizing feature map (SOM) to achieve the goal of monitoring Engineering Change (EC) based on historical data of a company that specializes in computers and peripherals. The product life cycle of this company is 3-6 months. The historical data were divided into three parts, each covering four months. The first part, comprising 2,343 records from January to April (the training period), comprise the Control Group. The second and third parts comprise Experimental Groups (EG) 1 and 2, respectively. For EG 1 and 2, the successful rate of recognizing information on abnormal ECs was approximately 96% and 95%, respectively. This paper shows the importance and screening procedures of abnormal engineering change for a particular company specializing in computers and peripherals.

  3. The ERECTA receptor kinase regulates Arabidopsis shoot apical meristem size, phyllotaxy and floral meristem identity

    PubMed Central

    Mandel, Tali; Moreau, Fanny; Kutsher, Yaarit; Fletcher, Jennifer C.; Carles, Cristel C.; Williams, Leor Eshed

    2014-01-01

    In plants, the shoot apical meristem (SAM) serves as a reservoir of pluripotent stem cells from which all above ground organs originate. To sustain proper growth, the SAM must maintain homeostasis between the self-renewal of pluripotent stem cells and cell recruitment for lateral organ formation. At the core of the network that regulates this homeostasis in Arabidopsis are the WUSCHEL (WUS) transcription factor specifying stem cell fate and the CLAVATA (CLV) ligand-receptor system limiting WUS expression. In this study, we identified the ERECTA (ER) pathway as a second receptor kinase signaling pathway that regulates WUS expression, and therefore shoot apical and floral meristem size, independently of the CLV pathway. We demonstrate that reduction in class III HD-ZIP and ER function together leads to a significant increase in WUS expression, resulting in extremely enlarged shoot meristems and a switch from spiral to whorled vegetative phyllotaxy. We further show that strong upregulation of WUS in the inflorescence meristem leads to ectopic expression of the AGAMOUS homeotic gene to a level that switches cell fate from floral meristem founder cell to carpel founder cell, suggesting an indirect role for ER in regulating floral meristem identity. This work illustrates the delicate balance between stem cell specification and differentiation in the meristem and shows that a shift in this balance leads to abnormal phyllotaxy and to altered reproductive cell fate. PMID:24496620

  4. The floral transcriptome of ylang ylang (Cananga odorata var. fruticosa) uncovers biosynthetic pathways for volatile organic compounds and a multifunctional and novel sesquiterpene synthase

    PubMed Central

    Jin, Jingjing; Kim, Mi Jung; Dhandapani, Savitha; Tjhang, Jessica Gambino; Yin, Jun-Lin; Wong, Limsoon; Sarojam, Rajani; Chua, Nam-Hai; Jang, In-Cheol

    2015-01-01

    The pleasant fragrance of ylang ylang varieties (Cananga odorata) is mainly due to volatile organic compounds (VOCs) produced by the flowers. Floral scents are a key factor in plant–insect interactions and are vital for successful pollination. C. odorata var. fruticosa, or dwarf ylang ylang, is a variety of ylang ylang that is popularly grown in Southeast Asia as a small shrub with aromatic flowers. Here, we describe the combined use of bioinformatics and chemical analysis to discover genes for the VOC biosynthesis pathways and related genes. The scented flowers of C. odorata var. fruticosa were analysed by gas chromatography/mass spectrometry and a total of 49 VOCs were identified at four different stages of flower development. The bulk of these VOCs were terpenes, mainly sesquiterpenes. To identify the various terpene synthases (TPSs) involved in the production of these essential oils, we performed RNA sequencing on mature flowers. From the RNA sequencing data, four full-length TPSs were functionally characterized. In vitro assays showed that two of these TPSs were mono-TPSs. CoTPS1 synthesized four products corresponding to β-thujene, sabinene, β-pinene, and α-terpinene from geranyl pyrophosphate and CoTPS4 produced geraniol from geranyl pyrophosphate. The other two TPSs were identified as sesqui-TPSs. CoTPS3 catalysed the conversion of farnesyl pyrophosphate to α-bergamotene, whereas CoTPS2 was found to be a multifunctional and novel TPS that could catalyse the synthesis of three sesquiterpenes, β-ylangene, β-copaene, and β-cubebene. Additionally, the activities of the two sesqui-TPSs were confirmed in planta by transient expression of these TPS genes in Nicotiana benthamiana leaves by Agrobacterium-mediated infiltration. PMID:25956881

  5. The OCL3 promoter from Sorghum bicolor directs gene expression to abscission and nutrient-transfer zones at the bases of floral organs

    PubMed Central

    Dwivedi, Krishna K.; Roche, Dominique J.; Clemente, Tom E.; Ge, Zhengxiang; Carman, John G.

    2014-01-01

    Background and Aims During seed fill in cereals, nutrients are symplasmically unloaded to vascular parenchyma in ovules, but thereafter nutrient transport is less certain. In Zea mays, two mechanisms of nutrient passage through the chalaza and nucellus have been hypothesized, apoplasmic and symplasmic. In a recent study, nutrients first passed non-selectively to the chalazal apoplasm and were then selectively absorbed by the nucellus before being released to the endosperm apoplasm. This study reports that the promoter of OUTER CELL LAYER3 (PSbOCL3) from Sorghum bicolor (sorghum) directs gene expression to chalazal cells where the apoplasmic barrier is thought to form. The aims were to elucidate PSbOCL3 expression patterns in sorghum and relate them to processes of nutrient pathway development in kernels and to recognized functions of the homeodomain-leucine zipper (HD-Zip) IV transcription factor family to which the promoter belongs. Methods PSbOCL3 was cloned and transformed into sorghum as a promoter–GUS (β-glucuronidase) construct. Plant tissues from control and transformed plants were then stained for GUS, and kernels were cleared and characterized using differential interference contrast microscopy. Key Results A symplasmic disconnect between the chalaza and nucellus during seed fill is inferred by the combination of two phenomena: differentiation of a distinct nucellar epidermis adjacent to the chalaza, and lysis of GUS-stained chalazal cells immediately proximal to the nucellar epidermis. Compression of the GUS-stained chalazal cells during kernel maturation produced the kernel abscission zone (closing layer). Conclusions The results suggest that the HD-Zip IV transcription factor SbOCL3 regulates kernel nutrition and abscission. The latter is consistent with evidence that members of this transcription factor group regulate silique abscission and dehiscence in Arabidopsis thaliana. Collectively, the findings suggest that processes of floral organ

  6. The floral transcriptome of ylang ylang (Cananga odorata var. fruticosa) uncovers biosynthetic pathways for volatile organic compounds and a multifunctional and novel sesquiterpene synthase.

    PubMed

    Jin, Jingjing; Kim, Mi Jung; Dhandapani, Savitha; Tjhang, Jessica Gambino; Yin, Jun-Lin; Wong, Limsoon; Sarojam, Rajani; Chua, Nam-Hai; Jang, In-Cheol

    2015-07-01

    The pleasant fragrance of ylang ylang varieties (Cananga odorata) is mainly due to volatile organic compounds (VOCs) produced by the flowers. Floral scents are a key factor in plant-insect interactions and are vital for successful pollination. C. odorata var. fruticosa, or dwarf ylang ylang, is a variety of ylang ylang that is popularly grown in Southeast Asia as a small shrub with aromatic flowers. Here, we describe the combined use of bioinformatics and chemical analysis to discover genes for the VOC biosynthesis pathways and related genes. The scented flowers of C. odorata var. fruticosa were analysed by gas chromatography/mass spectrometry and a total of 49 VOCs were identified at four different stages of flower development. The bulk of these VOCs were terpenes, mainly sesquiterpenes. To identify the various terpene synthases (TPSs) involved in the production of these essential oils, we performed RNA sequencing on mature flowers. From the RNA sequencing data, four full-length TPSs were functionally characterized. In vitro assays showed that two of these TPSs were mono-TPSs. CoTPS1 synthesized four products corresponding to β-thujene, sabinene, β-pinene, and α-terpinene from geranyl pyrophosphate and CoTPS4 produced geraniol from geranyl pyrophosphate. The other two TPSs were identified as sesqui-TPSs. CoTPS3 catalysed the conversion of farnesyl pyrophosphate to α-bergamotene, whereas CoTPS2 was found to be a multifunctional and novel TPS that could catalyse the synthesis of three sesquiterpenes, β-ylangene, β-copaene, and β-cubebene. Additionally, the activities of the two sesqui-TPSs were confirmed in planta by transient expression of these TPS genes in Nicotiana benthamiana leaves by Agrobacterium-mediated infiltration. PMID:25956881

  7. Yeasts in floral nectar: a quantitative survey

    PubMed Central

    Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, María I.

    2009-01-01

    Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm−3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm−3 were commonplace, and densities >105 cells mm−3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm−3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence

  8. Abscission of flowers and floral organs is closely associated with alkalization of the cytosol in abscission zone cells

    PubMed Central

    Sundaresan, Srivignesh; Philosoph-Hadas, Sonia; Riov, Joseph; Belausov, Eduard; Kochanek, Betina; Tucker, Mark L.; Meir, Shimon

    2015-01-01

    In vivo changes in the cytosolic pH of abscission zone (AZ) cells were visualized using confocal microscopic detection of the fluorescent pH-sensitive and intracellularly trapped dye, 2’,7’-bis-(2-carboxyethyl)-5(and-6)-carboxyfluorescein (BCECF), driven by its acetoxymethyl ester. A specific and gradual increase in the cytosolic pH of AZ cells was observed during natural abscission of flower organs in Arabidopsis thaliana and wild rocket (Diplotaxis tenuifolia), and during flower pedicel abscission induced by flower removal in tomato (Solanum lycopersicum Mill). The alkalization pattern in the first two species paralleled the acceleration or inhibition of flower organ abscission induced by ethylene or its inhibitor 1-methylcyclopropene (1-MCP), respectively. Similarly, 1-MCP pre-treatment of tomato inflorescence explants abolished the pH increase in AZ cells and pedicel abscission induced by flower removal. Examination of the pH changes in the AZ cells of Arabidopsis mutants defective in both ethylene-induced (ctr1, ein2, eto4) and ethylene-independent (ida, nev7, dab5) abscission pathways confirmed these results. The data indicate that the pH changes in the AZ cells are part of both the ethylene-sensitive and -insensitive abscission pathways, and occur concomitantly with the execution of organ abscission. pH can affect enzymatic activities and/or act as a signal for gene expression. Changes in pH during abscission could occur via regulation of transporters in AZ cells, which might affect cytosolic pH. Indeed, four genes associated with pH regulation, vacuolar H+-ATPase, putative high-affinity nitrate transporter, and two GTP-binding proteins, were specifically up-regulated in tomato flower AZ following abscission induction, and 1-MCP reduced or abolished the increased expression. PMID:25504336

  9. Abscission of flowers and floral organs is closely associated with alkalization of the cytosol in abscission zone cells.

    PubMed

    Sundaresan, Srivignesh; Philosoph-Hadas, Sonia; Riov, Joseph; Belausov, Eduard; Kochanek, Betina; Tucker, Mark L; Meir, Shimon

    2015-03-01

    In vivo changes in the cytosolic pH of abscission zone (AZ) cells were visualized using confocal microscopic detection of the fluorescent pH-sensitive and intracellularly trapped dye, 2',7'-bis-(2-carboxyethyl)-5(and-6)-carboxyfluorescein (BCECF), driven by its acetoxymethyl ester. A specific and gradual increase in the cytosolic pH of AZ cells was observed during natural abscission of flower organs in Arabidopsis thaliana and wild rocket (Diplotaxis tenuifolia), and during flower pedicel abscission induced by flower removal in tomato (Solanum lycopersicum Mill). The alkalization pattern in the first two species paralleled the acceleration or inhibition of flower organ abscission induced by ethylene or its inhibitor 1-methylcyclopropene (1-MCP), respectively. Similarly, 1-MCP pre-treatment of tomato inflorescence explants abolished the pH increase in AZ cells and pedicel abscission induced by flower removal. Examination of the pH changes in the AZ cells of Arabidopsis mutants defective in both ethylene-induced (ctr1, ein2, eto4) and ethylene-independent (ida, nev7, dab5) abscission pathways confirmed these results. The data indicate that the pH changes in the AZ cells are part of both the ethylene-sensitive and -insensitive abscission pathways, and occur concomitantly with the execution of organ abscission. pH can affect enzymatic activities and/or act as a signal for gene expression. Changes in pH during abscission could occur via regulation of transporters in AZ cells, which might affect cytosolic pH. Indeed, four genes associated with pH regulation, vacuolar H(+)-ATPase, putative high-affinity nitrate transporter, and two GTP-binding proteins, were specifically up-regulated in tomato flower AZ following abscission induction, and 1-MCP reduced or abolished the increased expression. PMID:25504336

  10. Removal of floral microbiota reduces floral terpene emissions

    NASA Astrophysics Data System (ADS)

    Peñuelas, Josep; Farré-Armengol, Gerard; Llusia, Joan; Gargallo-Garriga, Albert; Rico, Laura; Sardans, Jordi; Terradas, Jaume; Filella, Iolanda

    2014-10-01

    The emission of floral terpenes plays a key role in pollination in many plant species. We hypothesized that the floral phyllospheric microbiota could significantly influence these floral terpene emissions because microorganisms also produce and emit terpenes. We tested this hypothesis by analyzing the effect of removing the microbiota from flowers. We fumigated Sambucus nigra L. plants, including their flowers, with a combination of three broad-spectrum antibiotics and measured the floral emissions and tissular concentrations in both antibiotic-fumigated and non-fumigated plants. Floral terpene emissions decreased by ca. two thirds after fumigation. The concentration of terpenes in floral tissues did not decrease, and floral respiration rates did not change, indicating an absence of damage to the floral tissues. The suppression of the phyllospheric microbial communities also changed the composition and proportion of terpenes in the volatile blend. One week after fumigation, the flowers were not emitting β-ocimene, linalool, epoxylinalool, and linalool oxide. These results show a key role of the floral phyllospheric microbiota in the quantity and quality of floral terpene emissions and therefore a possible key role in pollination.

  11. Removal of floral microbiota reduces floral terpene emissions

    PubMed Central

    Peñuelas, Josep; Farré-Armengol, Gerard; Llusia, Joan; Gargallo-Garriga, Albert; Rico, Laura; Sardans, Jordi; Terradas, Jaume; Filella, Iolanda

    2014-01-01

    The emission of floral terpenes plays a key role in pollination in many plant species. We hypothesized that the floral phyllospheric microbiota could significantly influence these floral terpene emissions because microorganisms also produce and emit terpenes. We tested this hypothesis by analyzing the effect of removing the microbiota from flowers. We fumigated Sambucus nigra L. plants, including their flowers, with a combination of three broad-spectrum antibiotics and measured the floral emissions and tissular concentrations in both antibiotic-fumigated and non-fumigated plants. Floral terpene emissions decreased by ca. two thirds after fumigation. The concentration of terpenes in floral tissues did not decrease, and floral respiration rates did not change, indicating an absence of damage to the floral tissues. The suppression of the phyllospheric microbial communities also changed the composition and proportion of terpenes in the volatile blend. One week after fumigation, the flowers were not emitting β-ocimene, linalool, epoxylinalool, and linalool oxide. These results show a key role of the floral phyllospheric microbiota in the quantity and quality of floral terpene emissions and therefore a possible key role in pollination. PMID:25335793

  12. Evolutionarily conserved repressive activity of WOX proteins mediates leaf blade outgrowth and floral organ development in plants

    PubMed Central

    Lin, Hao; Niu, Lifang; McHale, Neil A.; Ohme-Takagi, Masaru; Mysore, Kirankumar S.; Tadege, Million

    2013-01-01

    The WUSCHEL related homeobox (WOX) genes play key roles in stem cell maintenance, embryonic patterning, and lateral organ development. WOX genes have been categorized into three clades—ancient, intermediate, and modern/WUS—based on phylogenetic analysis, but a functional basis for this classification has not been established. Using the classical bladeless lam1 mutant of Nicotiana sylvestris as a genetic tool, we examined the function of the Medicago truncatula WOX gene, STENOFOLIA (STF), in controlling leaf blade outgrowth. STF and LAM1 are functional orthologs. We found that the introduction of mutations into the WUS-box of STF (STFm1) reduces its ability to complement the lam1 mutant. Fusion of an exogenous repressor domain to STFm1 restores complementation, whereas fusion of an exogenous activator domain to STFm1 enhances the narrow leaf phenotype. These results indicate that transcriptional repressor activity mediated by the WUS-box of STF acts to promote blade outgrowth. With the exception of WOX7, the WUS-box is conserved in the modern clade WOX genes, but is not found in members of the intermediate or ancient clades. Consistent with this, all members of the modern clade except WOX7 can complement the lam1 mutant when expressed using the STF promoter, but members of the intermediate and ancient clades cannot. Furthermore, we found that fusion of either the WUS-box or an exogenous repressor domain to WOX7 or to members of intermediate and ancient WOX clades results in a gain-of-function ability to complement lam1 blade outgrowth. These results suggest that modern clade WOX genes have evolved for repressor activity through acquisition of the WUS-box. PMID:23248305

  13. The tomato floral homeotic protein FBP1-like gene, SlGLO1, plays key roles in petal and stamen development.

    PubMed

    Guo, Xuhu; Hu, Zongli; Yin, Wencheng; Yu, Xiaohui; Zhu, Zhiguo; Zhang, Jianling; Chen, Guoping

    2016-01-01

    MADS-box transcription factors play important role in plant growth and development, especially floral organ identities. In our study, a MADS-box gene SlGLO1- tomato floral homeotic protein FBP1-like gene was isolated. Its tissue-specific expression profile analysis showed that SlGLO1 was highly expressed in petals and stamens. RNAi (RNA interference) repression of SlGLO1 resulted in floral organ abnormal phenotypes, including green petals with shorter size, and aberrant carpelloid stamens. SlGLO1-silenced lines are male sterile. Total chlorophyll content was increased and chlorophyll biosynthetic genes were significantly up-regulated in SlGLO1-silenced petals and stamens. Furthermore, B-class genes expression analysis indicated that the repressed function of SlGLO1 led to the enhanced expression of TAP3 and the down-regulation of TPI in the petals and stamens, while the expression of TM6 was reduced in petals and increased in stamens and carpels of SlGLO1-RNAi plants. Additionally, pollen grains of transgenic lines were aberrant and failed to germinate and tomato pollen-specific genes were down-regulated by more than 90% in SlGLO1-silenced lines. These results suggest that SlGLO1 plays important role in regulating plant floral organ and pollen development in tomato. PMID:26842499

  14. The tomato floral homeotic protein FBP1-like gene, SlGLO1, plays key roles in petal and stamen development

    PubMed Central

    Guo, Xuhu; Hu, Zongli; Yin, Wencheng; Yu, Xiaohui; Zhu, Zhiguo; Zhang, Jianling; Chen, Guoping

    2016-01-01

    MADS-box transcription factors play important role in plant growth and development, especially floral organ identities. In our study, a MADS-box gene SlGLO1- tomato floral homeotic protein FBP1-like gene was isolated. Its tissue-specific expression profile analysis showed that SlGLO1 was highly expressed in petals and stamens. RNAi (RNA interference) repression of SlGLO1 resulted in floral organ abnormal phenotypes, including green petals with shorter size, and aberrant carpelloid stamens. SlGLO1-silenced lines are male sterile. Total chlorophyll content was increased and chlorophyll biosynthetic genes were significantly up-regulated in SlGLO1-silenced petals and stamens. Furthermore, B-class genes expression analysis indicated that the repressed function of SlGLO1 led to the enhanced expression of TAP3 and the down-regulation of TPI in the petals and stamens, while the expression of TM6 was reduced in petals and increased in stamens and carpels of SlGLO1-RNAi plants. Additionally, pollen grains of transgenic lines were aberrant and failed to germinate and tomato pollen-specific genes were down-regulated by more than 90% in SlGLO1-silenced lines. These results suggest that SlGLO1 plays important role in regulating plant floral organ and pollen development in tomato. PMID:26842499

  15. Abnormal organization of keratin intermediate filaments in cultured keratinocytes of epidermolysis bullosa simplex.

    PubMed

    Kitajima, Y; Inoue, S; Yaoita, H

    1989-01-01

    Distinctive abnormality in the organization of keratin intermediate filaments (KIFs) was found for the first time in cultured epidermal keratinocytes from two patients with hereditary epidermolysis bullosa simplex (EBS), which showed cleavages above the basement membrane zone due to the fragility of basal cells. KIFs in EBS keratinocytes revealed an irregular radial arrangement composed of sparse but thick KIF bundles. Furthermore, these KIF bundles in many cells changed into numerous ball-like keratin aggregates and disappeared beyond these keratin aggregates in the peripheral cytoplasm. Electron microscopy of cultured EBS keratinocytes showed that many ball-like structures consisting of fine filaments or granules or homogeneous substances were scattered in the peripheral regions of the cell attaching to the dish, and intermediate filaments appeared to be emanating from or surrounding the structures. These ball-like keratin aggregates have never been observed in normal human keratinocytes. PMID:2471468

  16. Eya1-deficient mice lack ears and kidneys and show abnormal apoptosis of organ primordia.

    PubMed

    Xu, P X; Adams, J; Peters, H; Brown, M C; Heaney, S; Maas, R

    1999-09-01

    Haploinsufficiency for human EYA1, a homologue of the Drosophila melanogaster gene eyes absent (eya), results in the dominantly inherited disorders branchio-oto-renal (BOR) syndrome and branchio-oto (BO) syndrome, which are characterized by craniofacial abnormalities and hearing loss with (BOR) or without (BO) kidney defects. To understand the developmental pathogenesis of organs affected in these syndromes, we inactivated the gene Eya1 in mice. Eya1 heterozygotes show renal abnormalities and a conductive hearing loss similar to BOR syndrome, whereas Eya1 homozygotes lack ears and kidneys due to defective inductive tissue interactions and apoptotic regression of the organ primordia. Inner ear development in Eya1 homozygotes arrests at the otic vesicle stage and all components of the inner ear and specific cranial sensory ganglia fail to form. In the kidney, Eya1 homozygosity results in an absence of ureteric bud outgrowth and a subsequent failure of metanephric induction. Gdnf expression, which is required to direct ureteric bud outgrowth via activation of the c-ret Rtk (refs 5, 6, 7, 8), is not detected in Eya1-/- metanephric mesenchyme. In Eya1-/- ear and kidney development, Six but not Pax expression is Eya1 dependent, similar to a genetic pathway elucidated in the Drosophila eye imaginal disc. Our results indicate that Eya1 controls critical early inductive signalling events involved in ear and kidney formation and integrate Eya1 into the genetic regulatory cascade controlling kidney formation upstream of Gdnf. In addition, our results suggest that an evolutionarily conserved Pax-Eya-Six regulatory hierarchy is used in mammalian ear and kidney development. PMID:10471511

  17. Congenital hydrocephalus and abnormal subcommissural organ development in Sox3 transgenic mice.

    PubMed

    Lee, Kristie; Tan, Jacqueline; Morris, Michael B; Rizzoti, Karine; Hughes, James; Cheah, Pike See; Felquer, Fernando; Liu, Xuan; Piltz, Sandra; Lovell-Badge, Robin; Thomas, Paul Q

    2012-01-01

    Congenital hydrocephalus (CH) is a life-threatening medical condition in which excessive accumulation of CSF leads to ventricular expansion and increased intracranial pressure. Stenosis (blockage) of the Sylvian aqueduct (Aq; the narrow passageway that connects the third and fourth ventricles) is a common form of CH in humans, although the genetic basis of this condition is unknown. Mouse models of CH indicate that Aq stenosis is associated with abnormal development of the subcommmissural organ (SCO) a small secretory organ located at the dorsal midline of the caudal diencephalon. Glycoproteins secreted by the SCO generate Reissner's fibre (RF), a thread-like structure that descends into the Aq and is thought to maintain its patency. However, despite the importance of SCO function in CSF homeostasis, the genetic program that controls SCO development is poorly understood. Here, we show that the X-linked transcription factor SOX3 is expressed in the murine SCO throughout its development and in the mature organ. Importantly, overexpression of Sox3 in the dorsal diencephalic midline of transgenic mice induces CH via a dose-dependent mechanism. Histological, gene expression and cellular proliferation studies indicate that Sox3 overexpression disrupts the development of the SCO primordium through inhibition of diencephalic roof plate identity without inducing programmed cell death. This study provides further evidence that SCO function is essential for the prevention of hydrocephalus and indicates that overexpression of Sox3 in the dorsal midline alters progenitor cell differentiation in a dose-dependent manner. PMID:22291885

  18. Congenital Hydrocephalus and Abnormal Subcommissural Organ Development in Sox3 Transgenic Mice

    PubMed Central

    Lee, Kristie; Tan, Jacqueline; Morris, Michael B.; Rizzoti, Karine; Hughes, James; Cheah, Pike See; Felquer, Fernando; Liu, Xuan; Piltz, Sandra; Lovell-Badge, Robin; Thomas, Paul Q.

    2012-01-01

    Congenital hydrocephalus (CH) is a life-threatening medical condition in which excessive accumulation of CSF leads to ventricular expansion and increased intracranial pressure. Stenosis (blockage) of the Sylvian aqueduct (Aq; the narrow passageway that connects the third and fourth ventricles) is a common form of CH in humans, although the genetic basis of this condition is unknown. Mouse models of CH indicate that Aq stenosis is associated with abnormal development of the subcommmissural organ (SCO) a small secretory organ located at the dorsal midline of the caudal diencephalon. Glycoproteins secreted by the SCO generate Reissner's fibre (RF), a thread-like structure that descends into the Aq and is thought to maintain its patency. However, despite the importance of SCO function in CSF homeostasis, the genetic program that controls SCO development is poorly understood. Here, we show that the X-linked transcription factor SOX3 is expressed in the murine SCO throughout its development and in the mature organ. Importantly, overexpression of Sox3 in the dorsal diencephalic midline of transgenic mice induces CH via a dose-dependent mechanism. Histological, gene expression and cellular proliferation studies indicate that Sox3 overexpression disrupts the development of the SCO primordium through inhibition of diencephalic roof plate identity without inducing programmed cell death. This study provides further evidence that SCO function is essential for the prevention of hydrocephalus and indicates that overexpression of Sox3 in the dorsal midline alters progenitor cell differentiation in a dose-dependent manner. PMID:22291885

  19. MADS-domain transcription factors and the floral quartet model of flower development: linking plant development and evolution.

    PubMed

    Theißen, Günter; Melzer, Rainer; Rümpler, Florian

    2016-09-15

    The floral quartet model of floral organ specification poses that different tetramers of MIKC-type MADS-domain transcription factors control gene expression and hence the identity of floral organs during development. Here, we provide a brief history of the floral quartet model and review several lines of recent evidence that support the model. We also describe how the model has been used in contemporary developmental and evolutionary biology to shed light on enigmatic topics such as the origin of land and flowering plants. Finally, we suggest a novel hypothesis describing how floral quartet-like complexes may interact with chromatin during target gene activation and repression. PMID:27624831

  20. Positron Emission Tomography Reveals Abnormal Topological Organization in Functional Brain Network in Diabetic Patients

    PubMed Central

    Qiu, Xiangzhe; Zhang, Yanjun; Feng, Hongbo; Jiang, Donglang

    2016-01-01

    Recent studies have demonstrated alterations in the topological organization of structural brain networks in diabetes mellitus (DM). However, the DM-related changes in the topological properties in functional brain networks are unexplored so far. We therefore used fluoro-D-glucose positron emission tomography (FDG-PET) data to construct functional brain networks of 73 DM patients and 91 sex- and age-matched normal controls (NCs), followed by a graph theoretical analysis. We found that both DM patients and NCs had a small-world topology in functional brain network. In comparison to the NC group, the DM group was found to have significantly lower small-world index, lower normalized clustering coefficients and higher normalized characteristic path length. Moreover, for diabetic patients, the nodal centrality was significantly reduced in the right rectus, the right cuneus, the left middle occipital gyrus, and the left postcentral gyrus, and it was significantly increased in the orbitofrontal region of the left middle frontal gyrus, the left olfactory region, and the right paracentral lobule. Our results demonstrated that the diabetic brain was associated with disrupted topological organization in the functional PET network, thus providing functional evidence for the abnormalities of brain networks in DM. PMID:27303259

  1. Positron Emission Tomography Reveals Abnormal Topological Organization in Functional Brain Network in Diabetic Patients.

    PubMed

    Qiu, Xiangzhe; Zhang, Yanjun; Feng, Hongbo; Jiang, Donglang

    2016-01-01

    Recent studies have demonstrated alterations in the topological organization of structural brain networks in diabetes mellitus (DM). However, the DM-related changes in the topological properties in functional brain networks are unexplored so far. We therefore used fluoro-D-glucose positron emission tomography (FDG-PET) data to construct functional brain networks of 73 DM patients and 91 sex- and age-matched normal controls (NCs), followed by a graph theoretical analysis. We found that both DM patients and NCs had a small-world topology in functional brain network. In comparison to the NC group, the DM group was found to have significantly lower small-world index, lower normalized clustering coefficients and higher normalized characteristic path length. Moreover, for diabetic patients, the nodal centrality was significantly reduced in the right rectus, the right cuneus, the left middle occipital gyrus, and the left postcentral gyrus, and it was significantly increased in the orbitofrontal region of the left middle frontal gyrus, the left olfactory region, and the right paracentral lobule. Our results demonstrated that the diabetic brain was associated with disrupted topological organization in the functional PET network, thus providing functional evidence for the abnormalities of brain networks in DM. PMID:27303259

  2. Dermatoses among floral shop workers.

    PubMed

    Thiboutot, D M; Hamory, B H; Marks, J G

    1990-01-01

    Concern about the increasing incidence of hand dermatitis in floral shop workers in the United States and its possible association to the plant Alstroemeria, a flower that has become popular since its introduction in 1981, prompted investigation of the prevalence and cause of hand dermatitis in a sample of floral workers. Fifty-seven floral workers were surveyed, and 15 (26%) reported hand dermatitis within the previous 12 months. Sixteen floral workers (eight with dermatitis) volunteered to be patch tested to the North American Contact Dermatitis Group Standard and Perfume Trays, a series of eight pesticides and 20 plant allergens. Of four of seven floral designers and arrangers who reported hand dermatitis, three reacted positively to patch tests to tuliposide A, the allergen in Alstroemeria. Patch test readings for all other plant extracts were negative. A positive reading for a test to one pesticide, difolatan (Captafol), was noted, the relevance of which is unknown. PMID:2137139

  3. Floral Transformation of Wheat

    NASA Astrophysics Data System (ADS)

    Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

    A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

  4. Proteomic insights into floral biology.

    PubMed

    Li, Xiaobai; Jackson, Aaron; Xie, Ming; Wu, Dianxing; Tsai, Wen-Chieh; Zhang, Sheng

    2016-08-01

    The flower is the most important biological structure for ensuring angiosperms reproductive success. Not only does the flower contain critical reproductive organs, but the wide variation in morphology, color, and scent has evolved to entice specialized pollinators, and arguably mankind in many cases, to ensure the successful propagation of its species. Recent proteomic approaches have identified protein candidates related to these flower traits, which has shed light on a number of previously unknown mechanisms underlying these traits. This review article provides a comprehensive overview of the latest advances in proteomic research in floral biology according to the order of flower structure, from corolla to male and female reproductive organs. It summarizes mainstream proteomic methods for plant research and recent improvements on two dimensional gel electrophoresis and gel-free workflows for both peptide level and protein level analysis. The recent advances in sequencing technologies provide a new paradigm for the ever-increasing genome and transcriptome information on many organisms. It is now possible to integrate genomic and transcriptomic data with proteomic results for large-scale protein characterization, so that a global understanding of the complex molecular networks in flower biology can be readily achieved. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. PMID:26945514

  5. Stamen Abscission Zone Transcriptome Profiling Reveals New Candidates for Abscission Control: Enhanced Retention of Floral Organs in Transgenic Plants Overexpressing Arabidopsis ZINC FINGER PROTEIN21[C][W][OA

    PubMed Central

    Cai, Suqin; Lashbrook, Coralie C.

    2008-01-01

    Organ detachment requires cell separation within abscission zones (AZs). Physiological studies have established that ethylene and auxin contribute to cell separation control. Genetic analyses of abscission mutants have defined ethylene-independent detachment regulators. Functional genomic strategies leading to global understandings of abscission have awaited methods for isolating AZ cells of low abundance and very small size. Here, we couple laser capture microdissection of Arabidopsis thaliana stamen AZs and GeneChip profiling to reveal the AZ transcriptome responding to a developmental shedding cue. Analyses focus on 551 AZ genes (AZ551) regulated at the highest statistical significance (P ≤ 0.0001) over five floral stages linking prepollination to stamen shed. AZ551 includes mediators of ethylene and auxin signaling as well as receptor-like kinases and extracellular ligands thought to act independent of ethylene. We hypothesized that novel abscission regulators might reside in disproportionately represented Gene Ontology Consortium functional categories for cell wall modifying proteins, extracellular regulators, and nuclear-residing transcription factors. Promoter-β-glucuronidase expression of one transcription factor candidate, ZINC FINGER PROTEIN2 (AtZFP2), was elevated in stamen, petal, and sepal AZs. Flower parts of transgenic lines overexpressing AtZFP2 exhibited asynchronous and delayed abscission. Abscission defects were accompanied by altered floral morphology limiting pollination and fertility. Hand-pollination restored transgenic fruit development but not the rapid abscission seen in wild-type plants, demonstrating that pollination does not assure normal rates of detachment. In wild-type stamen AZs, AtZFP2 is significantly up-regulated postanthesis. Phenotype data from transgene overexpression studies suggest that AtZFP2 participates in processes that directly or indirectly influence organ shed. PMID:18192438

  6. Floral visitation and reproductive traits of Stamenoid petals, a naturally occurring floral homeotic variant of Capsella bursa-pastoris (Brassicaceae).

    PubMed

    Ziermann, Janine; Ritz, Markus S; Hameister, Steffen; Abel, Christian; Hoffmann, Matthias H; Neuffer, Barbara; Theissen, Günter

    2009-11-01

    Homeotic changes played a considerable role during the evolution of flowers, but how floral homeotic mutants initially survive in nature has remained enigmatic. To better understand the evolutionary potential of floral homeotic mutants, we established as a model system Stamenoid petals (Spe), a natural variant of Capsella bursa-pastoris (Brassicaceae). In the flowers of Spe plants, petals are transformed into stamens, whereas all other floral organs are unaffected. In contrast with most other homeotic mutants, the Spe variant occurs in relatively stable populations in the wild. In order to determine how the profound change in floral architecture influences plant performance in the wild, we performed common garden experiments running over 3 years. Here, we show that Spe and wild-type plants attract the same assemblage of floral visitors: mainly hoverflies, wild bees and thrips. However, floral visitation is about twice as frequent in wild-type plants as in Spe plants. Nevertheless, the numbers of seeds per fruit were about the same in both variants. Wild-type plants produced more flowers, fruits and seeds per plant than Spe plants, whereas the germination capacity of Spe seeds was higher than that of the wild-type. Determination of volatile composition revealed monoterpenes and 3,4-dimethylbenzaldehyde, which were detected only in wild-type flowers, presumably because they are produced only by petals. Our data indicate that the similar fitness of Spe and wild-type C. bursa-pastoris in the field results from complex compensation between plant architecture and germination capacity. In contrast, flower structure and floral visitation are only of minor importance, possibly because C. bursa-pastoris is mainly self-pollinating. PMID:19784670

  7. Abnormal topological organization of the white matter network in Mandarin speakers with congenital amusia

    PubMed Central

    Zhao, Yanxin; Chen, Xizhuo; Zhong, Suyu; Cui, Zaixu; Gong, Gaolang; Dong, Qi; Nan, Yun

    2016-01-01

    Congenital amusia is a neurogenetic disorder that mainly affects the processing of musical pitch. Brain imaging evidence indicates that it is associated with abnormal structural and functional connections in the fronto-temporal region. However, a holistic understanding of the anatomical topology underlying amusia is still lacking. Here, we used probabilistic diffusion tensor imaging tractography and graph theory to examine whole brain white matter structural connectivity in 31 Mandarin-speaking amusics and 24 age- and IQ-matched controls. Amusics showed significantly reduced global connectivity, as indicated by the abnormally decreased clustering coefficient (Cp) and increased normalized shortest path length (λ) compared to the controls. Moreover, amusics exhibited enhanced nodal strength in the right inferior parietal lobule relative to controls. The co-existence of the lexical tone deficits was associated with even more deteriorated global network efficiency in amusics, as suggested by the significant correlation between the increments in normalized shortest path length (λ) and the insensitivity in lexical tone perception. Our study is the first to reveal reduced global connectivity efficiency in amusics as well as an increase in the global connectivity cost due to the co-existed lexical tone deficits. Taken together these results provide a holistic perspective on the anatomical substrates underlying congenital amusia. PMID:27211239

  8. Abnormal topological organization of the white matter network in Mandarin speakers with congenital amusia.

    PubMed

    Zhao, Yanxin; Chen, Xizhuo; Zhong, Suyu; Cui, Zaixu; Gong, Gaolang; Dong, Qi; Nan, Yun

    2016-01-01

    Congenital amusia is a neurogenetic disorder that mainly affects the processing of musical pitch. Brain imaging evidence indicates that it is associated with abnormal structural and functional connections in the fronto-temporal region. However, a holistic understanding of the anatomical topology underlying amusia is still lacking. Here, we used probabilistic diffusion tensor imaging tractography and graph theory to examine whole brain white matter structural connectivity in 31 Mandarin-speaking amusics and 24 age- and IQ-matched controls. Amusics showed significantly reduced global connectivity, as indicated by the abnormally decreased clustering coefficient (Cp) and increased normalized shortest path length (λ) compared to the controls. Moreover, amusics exhibited enhanced nodal strength in the right inferior parietal lobule relative to controls. The co-existence of the lexical tone deficits was associated with even more deteriorated global network efficiency in amusics, as suggested by the significant correlation between the increments in normalized shortest path length (λ) and the insensitivity in lexical tone perception. Our study is the first to reveal reduced global connectivity efficiency in amusics as well as an increase in the global connectivity cost due to the co-existed lexical tone deficits. Taken together these results provide a holistic perspective on the anatomical substrates underlying congenital amusia. PMID:27211239

  9. Evolutionary trends in the floral transcriptome: insights from one of the basalmost angiosperms, the water lily Nuphar advena (Nymphaeaceae).

    PubMed

    Yoo, Mi-Jeong; Chanderbali, André S; Altman, Naomi S; Soltis, Pamela S; Soltis, Douglas E

    2010-11-01

    Current understanding of floral developmental genetics comes primarily from the core eudicot model Arabidopsis thaliana. Here, we explore the floral transcriptome of the basal angiosperm, Nuphar advena (water lily), for insights into the ancestral developmental program of flowers. We identify several thousand Nuphar genes with significantly upregulated floral expression, including homologs of the well-known ABCE floral regulators, deployed in broadly overlapping transcriptional programs across floral organ categories. Strong similarities in the expression profiles of different organ categories in Nuphar flowers are shared with the magnoliid Persea americana (avocado), in contrast to the largely organ-specific transcriptional cascades evident in Arabidopsis, supporting the inference that this is the ancestral condition in angiosperms. In contrast to most eudicots, floral organs are weakly differentiated in Nuphar and Persea, with staminodial intermediates between stamens and perianth in Nuphar, and between stamens and carpels in Persea. Consequently, the predominantly organ-specific transcriptional programs that characterize Arabidopsis flowers (and perhaps other eudicots) are derived, and correlate with a shift towards morphologically distinct floral organs, including differentiated sepals and petals, and a perianth distinct from stamens and carpels. Our findings suggest that the genetic regulation of more spatially discrete transcriptional programs underlies the evolution of floral morphology. PMID:21070420

  10. [Floral essences, a fascinating world].

    PubMed

    Llonch, María

    2005-05-01

    Floral essences were discovered in the decade of the thirties by the English doctor, bacteriologist and homeopath Dr. Edward Bach. He described 38 remedies elaborated with flowers and shoots; each one correspondeds to an emotional pattern or a typical personality. Furthermore, he describes a remedy developed for emergency situations. PMID:15981972

  11. Identification of major quantitative trait loci underlying floral pollination syndrome divergence in Penstemon.

    PubMed

    Wessinger, Carolyn A; Hileman, Lena C; Rausher, Mark D

    2014-08-01

    Distinct floral pollination syndromes have emerged multiple times during the diversification of flowering plants. For example, in western North America, a hummingbird pollination syndrome has evolved more than 100 times, generally from within insect-pollinated lineages. The hummingbird syndrome is characterized by a suite of floral traits that attracts and facilitates pollen movement by hummingbirds, while at the same time discourages bee visitation. These floral traits generally include large nectar volume, red flower colour, elongated and narrow corolla tubes and reproductive organs that are exerted from the corolla. A handful of studies have examined the genetic architecture of hummingbird pollination syndrome evolution. These studies find that mutations of relatively large effect often explain increased nectar volume and transition to red flower colour. In addition, they suggest that adaptive suites of floral traits may often exhibit a high degree of genetic linkage, which could facilitate their fixation during pollination syndrome evolution. Here, we explore these emerging generalities by investigating the genetic basis of floral pollination syndrome divergence between two related Penstemon species with different pollination syndromes--bee-pollinated P. neomexicanus and closely related hummingbird-pollinated P. barbatus. In an F2 mapping population derived from a cross between these two species, we characterized the effect size of genetic loci underlying floral trait divergence associated with the transition to bird pollination, as well as correlation structure of floral trait variation. We find the effect sizes of quantitative trait loci for adaptive floral traits are in line with patterns observed in previous studies, and find strong evidence that suites of floral traits are genetically linked. This linkage may be due to genetic proximity or pleiotropic effects of single causative loci. Interestingly, our data suggest that the evolution of floral traits

  12. Heterozygous Mutation of Drosophila Opa1 Causes the Development of Multiple Organ Abnormalities in an Age-Dependent and Organ-Specific Manner

    PubMed Central

    Le, Phung Khanh; Pak, William L.; Tse, Stephanie; Ocorr, Karen; Huang, Taosheng

    2009-01-01

    Optic Atrophy 1 (OPA1) is a ubiquitously expressed dynamin-like GTPase in the inner mitochondrial membrane. It plays important roles in mitochondrial fusion, apoptosis, reactive oxygen species (ROS) and ATP production. Mutations of OPA1 result in autosomal dominant optic atrophy (DOA). The molecular mechanisms by which link OPA1 mutations and DOA are not fully understood. Recently, we created a Drosophila model to study the pathogenesis of optic atrophy. Heterozygous mutation of Drosophila OPA1 (dOpa1) by P-element insertion results in no obvious morphological abnormalities, whereas homozygous mutation is embryonic lethal. In eye-specific somatic clones, homozygous mutation of dOpa1 causes rough (mispatterning) and glossy (decreased lens deposition) eye phenotypes in adult Drosophila. In humans, heterozygous mutations in OPA1 have been associated with mitochondrial dysfunction, which is predicted to affect multiple organs. In this study, we demonstrated that heterozygous dOpa1 mutation perturbs the visual function and an ERG profile of the Drosophila compound eye. We independently showed that antioxidants delayed the onset of mutant phenotypes in ERG and improved larval vision function in phototaxis assay. Furthermore, heterozygous dOpa1 mutation also caused decreased heart rate, increased heart arrhythmia, and poor tolerance to stress induced by electrical pacing. However, antioxidants had no effects on the dysfunctional heart of heterozygous dOpa1 mutants. Under stress, heterozygous dOpa1 mutations caused reduced escape response, suggesting abnormal function of the skeletal muscles. Our results suggest that heterozygous mutation of dOpa1 shows organ-specific pathogenesis and is associated with multiple organ abnormalities in an age-dependent and organ-specific manner. PMID:19718456

  13. A putative miR172-targeted CeAPETALA2-like gene is involved in floral patterning regulation of the orchid Cymbidium ensifolium.

    PubMed

    Yang, F X; Zhu, G F; Wang, Z; Liu, H L; Huang, D

    2015-01-01

    APETALA2 plays critical roles in establishing meristem and organ identity during plant floral development. In this study, we obtained a CeAP2-like gene by using the mRNA differential display technique to analyze the wild type and a multitepal mutant of the orchid Cymbidium ensifolium. The full-length cDNA encoding the CeAP2-like transcription factor shows significant similarity to the cDNA of AP2 from Erycina pusilla and contains nucleotides complementary to miR172. Using a transient gene expression system of Arabidopsis protoplasts, we found that the accumulation of CeAP2-like protein and transcripts was negatively regulated by miR172, indicating this gene as a putative target of miR172. Northern blotting revealed that CeAP2-like is dominantly expressed in the sepals and petals of the wild-type flower, and shows low expression in the gynostemium. In contrast, the accumulation of CeAP2-like transcripts decreased significantly, especially in the central part of the mutant flower, corresponding to its abnormal petals and the absence of the gynostemium. Furthermore, we found an antagonistic expression pattern between CeAP2-like and AGAMOUS in the wild type, representing A- and C-class genes that specify floral organ fate. However, this antagonistic distribution was modified in the multitepal mutant, and both genes showed lower expression than that in the wild type. This result suggested that the balance between CeAP2-like and AGAMOUS activity was important for the regulation of floral patterning in C. ensifolium. This study represents the first report on a class A gene and its regulatory role for floral development in the orchid C. ensifolium. PMID:26505352

  14. Spontaneous autoimmune thyroiditis in obese strain chickens: a genetic analysis of target organ abnormalities

    SciTech Connect

    Neu, N.; Hala, K.; Dietrich, H.; Wick, G.

    1985-12-01

    In this study the authors investigated the genetic background of primary abnormalities found in the thyroid gland of Obese strain (OS) chickens with spontaneous autoimmune thyroiditis (SAT), i.e., susceptibility to passively transferred antibodies to thyroglobulin (TgAb) and incomplete suppression of iodine uptake by thyroxine (T4). Several crosses between the B15/B15 subline of OS chickens and the inbred CB line (B12/B12) were done and the progeny was analyzed for thyroiditis after injection of OS serum containing high titers of TgAb. It was found that passive transfer of TgAb increased the lymphoid infiltration in the thyroids of OS chickens, but had no effect on CB birds. A genetic analysis of backcrosses revealed that this trait is, in the case of simple Mendelian inheritance, encoded by at least three recessive genes. The thyroidal T I uptake of these crosses under T4 was also determined and they found that this trait is most probably encoded by only one recessive gene.

  15. Floral meristem initiation and meristem cell fate are regulated by the maize AP2 genes ids1 and sid1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grass flowers are organized on small branches known as spikelets. In maize, the spikelet meristem is determinate, producing one floral meristem and then converting into a second floral meristem. The APETALA2 (AP2)-like gene indeterminate spikelet1 (ids1) is required for the timely conversion of the ...

  16. Reduced transcription of a LEAFY-like gene in Alstroemeria sp. cultivar Green Coral that cannot develop floral meristems.

    PubMed

    Hirai, Masayo; Yamagishi, Masumi; Kanno, Akira

    2012-04-01

    Alstroemeria sp. cv. Green Coral has numerous bracts instead of flowers, and its cyme structures are repeated eternally. Observations of the development and morphology of inflorescence in cv. Green Coral revealed that transition from inflorescence to floral meristem was restricted. We isolated and characterized floral meristem identity genes LEAFY-like (AlsLFY) and SQUAMOSA-like (AlsSQa and AlsSQb) genes from Alstroemeria ligtu. In situ hybridization results indicated that AlsSQa and AlsSQb were expressed in the dome-shaped floral meristems and all floral organ primordia in A. ligtu. Transcripts of AlsLFY accumulated early in the dome-shaped floral meristems; the signals were restricted later to the outer region of the floral meristem. These results indicate that AlsLFY, AlsSQa, and AlsSQb function as floral meristem identity genes. Expression profiles of AlsLFY, AlsSQa, AlsSQb, and other MADS-box genes were compared between A. ligtu and cv. Green Coral. AlsLFY, AlsDEFa, and AlsAGL6 transcripts were not detected at the shoot apices of cv. Green Coral but were detected in A. ligtu. The early induction and accumulation of AlsLFY transcripts in the inflorescence meristem of A. ligtu prior to development of the floral meristem suggest that downregulation of AlsLFY is likely to restrict the inflorescence-to-floral meristem transition in cv. Green Coral. PMID:22325893

  17. Drought and leaf herbivory influence floral volatiles and pollinator attraction.

    PubMed

    Burkle, Laura A; Runyon, Justin B

    2016-04-01

    The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic compounds (VOCs) and, in turn, plant-pollinator interactions. In this study, we experimentally manipulated drought and herbivory for four forb species to determine effects of these treatments and their interactions on (1) visual plant traits traditionally associated with pollinator attraction, (2) floral VOCs, and (3) the visitation rates and community composition of pollinators. For all forbs tested, experimental drought universally reduced flower size and floral display, but there were species-specific effects of drought on volatile emissions per flower, the composition of compounds produced, and subsequent pollinator visitation rates. Moreover, the community of pollinating visitors was influenced by drought across forb species (i.e. some pollinator species were deterred by drought while others were attracted). Together, these results indicate that VOCs may provide more nuanced information to potential floral visitors and may be relatively more important than visual traits for pollinator attraction, particularly under shifting environmental conditions. PMID:26546275

  18. Floral trait variation and integration as a function of sexual deception in Gorteria diffusa

    PubMed Central

    Ellis, Allan G.; Brockington, Samuel F.; de Jager, Marinus L.; Mellers, Gregory; Walker, Rachel H.; Glover, Beverley J.

    2014-01-01

    Phenotypic integration, the coordinated covariance of suites of morphological traits, is critical for proper functioning of organisms. Angiosperm flowers are complex structures comprising suites of traits that function together to achieve effective pollen transfer. Floral integration could reflect shared genetic and developmental control of these traits, or could arise through pollinator-imposed stabilizing correlational selection on traits. We sought to expose mechanisms underlying floral trait integration in the sexually deceptive daisy, Gorteria diffusa, by testing the hypothesis that stabilizing selection imposed by male pollinators on floral traits involved in mimicry has resulted in tighter integration. To do this, we quantified patterns of floral trait variance and covariance in morphologically divergent G. diffusa floral forms representing a continuum in the levels of sexual deception. We show that integration of traits functioning in visual attraction of male pollinators increases with pollinator deception, and is stronger than integration of non-mimicry trait modules. Consistent patterns of within-population trait variance and covariance across floral forms suggest that integration has not been built by stabilizing correlational selection on genetically independent traits. Instead pollinator specialization has selected for tightened integration within modules of linked traits. Despite potentially strong constraint on morphological evolution imposed by developmental genetic linkages between traits, we demonstrate substantial divergence in traits across G. diffusa floral forms and show that divergence has often occurred without altering within-population patterns of trait correlations. PMID:25002705

  19. Floral trait variation and integration as a function of sexual deception in Gorteria diffusa.

    PubMed

    Ellis, Allan G; Brockington, Samuel F; de Jager, Marinus L; Mellers, Gregory; Walker, Rachel H; Glover, Beverley J

    2014-08-19

    Phenotypic integration, the coordinated covariance of suites of morphological traits, is critical for proper functioning of organisms. Angiosperm flowers are complex structures comprising suites of traits that function together to achieve effective pollen transfer. Floral integration could reflect shared genetic and developmental control of these traits, or could arise through pollinator-imposed stabilizing correlational selection on traits. We sought to expose mechanisms underlying floral trait integration in the sexually deceptive daisy, Gorteria diffusa, by testing the hypothesis that stabilizing selection imposed by male pollinators on floral traits involved in mimicry has resulted in tighter integration. To do this, we quantified patterns of floral trait variance and covariance in morphologically divergent G. diffusa floral forms representing a continuum in the levels of sexual deception. We show that integration of traits functioning in visual attraction of male pollinators increases with pollinator deception, and is stronger than integration of non-mimicry trait modules. Consistent patterns of within-population trait variance and covariance across floral forms suggest that integration has not been built by stabilizing correlational selection on genetically independent traits. Instead pollinator specialization has selected for tightened integration within modules of linked traits. Despite potentially strong constraint on morphological evolution imposed by developmental genetic linkages between traits, we demonstrate substantial divergence in traits across G. diffusa floral forms and show that divergence has often occurred without altering within-population patterns of trait correlations. PMID:25002705

  20. Abnormal intermediate filament organization alters mitochondrial motility in giant axonal neuropathy fibroblasts

    PubMed Central

    Lowery, Jason; Jain, Nikhil; Kuczmarski, Edward R.; Mahammad, Saleemulla; Goldman, Anne; Gelfand, Vladimir I.; Opal, Puneet; Goldman, Robert D.

    2016-01-01

    Giant axonal neuropathy (GAN) is a rare disease caused by mutations in the GAN gene, which encodes gigaxonin, an E3 ligase adapter that targets intermediate filament (IF) proteins for degradation in numerous cell types, including neurons and fibroblasts. The cellular hallmark of GAN pathology is the formation of large aggregates and bundles of IFs. In this study, we show that both the distribution and motility of mitochondria are altered in GAN fibroblasts and this is attributable to their association with vimentin IF aggregates and bundles. Transient expression of wild-type gigaxonin in GAN fibroblasts reduces the number of IF aggregates and bundles, restoring mitochondrial motility. Conversely, silencing the expression of gigaxonin in control fibroblasts leads to changes in IF organization similar to that of GAN patient fibroblasts and a coincident loss of mitochondrial motility. The inhibition of mitochondrial motility in GAN fibroblasts is not due to a global inhibition of organelle translocation, as lysosome motility is normal. Our findings demonstrate that it is the pathological changes in IF organization that cause the loss of mitochondrial motility. PMID:26700320

  1. The floral transcriptome of Eucalyptus grandis.

    PubMed

    Vining, Kelly J; Romanel, Elisson; Jones, Rebecca C; Klocko, Amy; Alves-Ferreira, Marcio; Hefer, Charles A; Amarasinghe, Vindhya; Dharmawardhana, Palitha; Naithani, Sushma; Ranik, Martin; Wesley-Smith, James; Solomon, Luke; Jaiswal, Pankaj; Myburg, Alexander A; Strauss, Steven H

    2015-06-01

    As a step toward functional annotation of genes required for floral initiation and development within the Eucalyptus genome, we used short read sequencing to analyze transcriptomes of floral buds from early and late developmental stages, and compared these with transcriptomes of diverse vegetative tissues, including leaves, roots, and stems. A subset of 4807 genes (13% of protein-coding genes) were differentially expressed between floral buds of either stage and vegetative tissues. A similar proportion of genes were differentially expressed among all tissues. A total of 479 genes were differentially expressed between early and late stages of floral development. Gene function enrichment identified 158 gene ontology classes that were overrepresented in floral tissues, including 'pollen development' and 'aromatic compound biosynthetic process'. At least 40 floral-dominant genes lacked functional annotations and thus may be novel floral transcripts. We analyzed several genes and gene families in depth, including 49 putative biomarkers of floral development, the MADS-box transcription factors, 'S-domain'-receptor-like kinases, and selected gene family members with phosphatidylethanolamine-binding protein domains. Expanded MADS-box gene subfamilies in Eucalyptus grandis included SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), SEPALLATA (SEP) and SHORT VEGETATIVE PHASE (SVP) Arabidopsis thaliana homologs. These data provide a rich resource for functional and evolutionary analysis of genes controlling eucalypt floral development, and new tools for breeding and biotechnology. PMID:25353719

  2. Unique and redundant functional domains of APETALA1 and CAULIFLOWER, two recently duplicated Arabidopsis thaliana floral MADS-box genes.

    PubMed

    Alvarez-Buylla, Elena R; García-Ponce, Berenice; Garay-Arroyo, Adriana

    2006-01-01

    APETALA1 (AP1) and CAULIFLOWER (CAL) are closely related MADS box genes that are partially redundant during Arabidopsis thaliana floral meristem determination. AP1 is able to fully substitute for CAL functions, but not vice versa, and AP1 has unique sepal and petal identity specification functions. In this study, the unique and redundant functions of these two genes has been mapped to the four protein domains that characterize type-II MADS-domain proteins by expressing all 15 chimeric combinations of AP1 and CAL cDNA regions under control of the AP1 promoter in ap1-1 loss-of-function plants. The "in vivo" function of these chimeric genes was analysed in Arabidopsis plants by expressing the chimeras. Rescue of flower meristem and sepal/petal identities was scored in single and multiple insert homozygous transgenic lines. Using these chimeric lines, it was found that distinct residues of the AP1 K domain not shared by the same CAL domain are necessary and sufficient for complete recovery of floral meristem identity, in the context of the CAL protein sequence, while both AP1 COOH and K domains are indispensable for complete rescue of sepal identity. By contrast, either one of these two AP1 domains is necessary and sufficient for complete petal identity recovery. It was also found that there were positive and negative synergies among protein domains and their combinations, and that multiple-insert lines showed relatively better rescue than equivalent single-insert lines. Finally, several lines had flowers with extra sepals and petals suggesting that chimeric proteins yield abnormal transcriptional complexes that may alter the expression or regulation of genes that control floral organ number under normal conditions. PMID:16893974

  3. Genome-wide transcriptome profiling provides insights into floral bud development of summer-flowering Camellia azalea

    PubMed Central

    Fan, Zhengqi; Li, Jiyuan; Li, Xinlei; Wu, Bin; Wang, Jiangying; Liu, Zhongchi; Yin, Hengfu

    2015-01-01

    The transition from vegetative to reproductive growth in woody perennials involves pathways controlling flowering timing, bud dormancy and outgrowth in responses to seasonal cues. However little is known about the mechanism governing the adaptation of signaling pathways to environmental conditions in trees. Camellia azalea is a rare species in this genus flowering during summer, which provides a unique resource for floral timing breeding. Here we reported a comprehensive transcriptomics study to capture the global gene profiles during floral bud development in C. azalea. We examined the genome-wide gene expression between three developmental stages including floral bud initiation, floral organ differentiation and bud outgrowth, and identified nine co-expression clusters with distinctive patterns. Further, we identified the differential expressed genes (DEGs) during development and characterized the functional properties of DEGs by Gene Ontology analysis. We showed that transition from floral bud initiation to floral organ differentiation required changes of genes in flowering timing regulation, while transition to floral bud outgrowth was regulated by various pathways such as cold and light signaling, phytohormone pathways and plant metabolisms. Further analyses of dormancy associated MADS-box genes revealed that SVP- and AGL24- like genes displayed distinct expression patterns suggesting divergent roles during floral bud development. PMID:25978548

  4. Microcystin-LR induces abnormal root development by altering microtubule organization in tissue-cultured common reed (Phragmites australis) plantlets.

    PubMed

    Máthé, Csaba; Beyer, Dániel; Erdodi, Ferenc; Serfozo, Zoltán; Székvölgyi, Lóránt; Vasas, Gábor; M-Hamvas, Márta; Jámbrik, Katalin; Gonda, Sándor; Kiss, Andrea; Szigeti, Zsuzsa M; Surányi, Gyula

    2009-05-01

    Microcystin-LR (MC-LR) is a heptapeptide cyanotoxin, known to be a potent inhibitor of type 1 and 2A protein phosphatases in eukaryotes. Our aim was to investigate the effect of MC-LR on the organization of microtubules and mitotic chromatin in relation to its possible effects on cell and whole organ morphology in roots of common reed (Phragmites australis). P. australis is a widespread freshwater and brackish water aquatic macrophyte, frequently exposed to phytotoxins in eutrophic waters. Reed plantlets regenerated from embryogenic calli were treated with 0.001-40 microg ml(-1) (0.001-40.2 microM) MC-LR for 2-20 days. At 0.5 microg ml(-1) MC-LR and at higher cyanotoxin concentrations, the inhibition of protein phosphatase activity by MC-LR induced alterations in reed root growth and morphology, including abnormal lateral root development and the radial swelling of cells in the elongation zone of primary and lateral roots. Both short-term (2-5 days) and long-term (10-20 days) of cyanotoxin treatment induced microtubule disruption in meristems and in the elongation and differentiation zones. Microtubule disruption was accompanied by root cell shape alteration. At concentrations of 0.5-5 microg ml(-1), MC-LR increased mitotic index at long-term exposure and induced the increase of the percentage of meristematic cells in prophase as well as telophase and cytokinesis of late mitosis. High cyanotoxin concentrations (10-40 microg ml(-1)) inhibited mitosis at as short as 2 days of exposure. The alteration of microtubule organization was observed in mitotic cells at all exposure periods studied, at cyanotoxin concentrations of 0.5-40 microg ml(-1). MC-LR induced spindle anomalies at the metaphase-anaphase transition, the formation of asymmetric anaphase spindles and abnormal sister chromatid separation. This paper reports for the first time that MC-LR induces cytoskeletal changes that lead to alterations of root architecture and development in common reed and generally, in

  5. Patterns of pollen removal and deposition in Polemonium brandegeei (Polemoniaceae): the role of floral visitors, floral design and sexual interference.

    PubMed

    Kulbaba, M W; Worley, A C

    2014-11-01

    The arrangement, colour, shape and size of floral parts (collectively floral design) have evolved primarily to promote mating success via animal-mediated pollen transfer. Although numerous studies have examined variation in pollinator assemblages, relatively few have examined patterns of pollen removal and deposition in the presence of fluctuating pollinators and ineffective floral visitors; therefore, net pollen removal and deposition by entire visitor assemblages are unclear. We studied the timing (diurnal or nocturnal) and effects of floral traits on pollen removal and deposition under a dynamic visitor assemblage of Polemonium brandegeei. We quantified pollen grains remaining in anthers (pollen removal) and deposited on stigmas (pollen deposition) of plants visited during either the day (07:30-20:00 h) or night (20:30-07:30 h) in natural populations over two flowering seasons. Pollen removal and deposition occurred both diurnally and nocturnally during our study. Increased diurnal removal and deposition coincided with peak floral visitations in 2006. This increase in pollen removal and deposition may reflect increased visits by pollen consumers, effective hawkmoth pollinators and increased self-pollen deposition due to hot, dry weather. Nonlinear effects of style length significantly affected pollen removal, with less pollen remaining in flowers with intermediate style lengths. Pollen deposition was more complex, with herkogamy and anther height affecting deposition. Further, close proximity of stigmas and anthers increased the potential for sexual interference between pollen removal and deposition. Overall, flower visitations and pollen removal and deposition varied between years and populations, but sex organ placement consistently influenced the removal and deposition of pollen. PMID:24850527

  6. A Floral Transcriptome for Hippeastrum (Amaryllidaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two transcriptomes have been constructed from floral tissue of two Hippeastrum (Amaryllidaceae) species, H. brasilianum (Traub & J.L.Doran) Dutilh and H. papilio (Ravenna) Van Scheepan. The former has fragrant flowers, while flowers of the latter do not produce floral fragrance. RNA was isolated a...

  7. Air pollution modifies floral scent trails

    NASA Astrophysics Data System (ADS)

    McFrederick, Quinn S.; Kathilankal, James C.; Fuentes, Jose D.

    Floral hydrocarbons provide essential signals to attract pollinators. As soon as they are emitted to the atmosphere, however, hydrocarbons are destroyed by chemical reactions involving pollutants such as ozone. It is therefore likely that increased air pollution interferes with pollinator attracting hydrocarbon signals. To test this hypothesis, a Lagrangian diffusion model was used to determine the position of air parcels away from hydrocarbon sources and to estimate the rate of chemical destruction of hydrocarbons as air parcels moved across the landscape. The hydrocarbon compounds linalool, β-myrcene, and β-ocimene were chosen because they are known to be common scents released from flowers. The suppressed ambient abundances of volatile organic compounds were determined in response to increased regional levels of ozone, hydroxyl, and nitrate radicals. The results indicate that the documented increases in air pollution concentrations, from pre-industrial to present times, can lead to reductions in volatile compound concentrations insects detect as they pollinate flowers. For highly reactive volatiles the maximum downwind distance from the source at which pollinators can detect the scents may have changed from kilometers during pre-industrial times to <200 m during the more polluted conditions of present times. The increased destruction of floral signals in polluted air masses may have important implications for both pollinators and signaling plants. When patches of flowers are further apart than the visual range of pollinators, such as in fragmented landscapes, the loss of scent signals may mean that pollinators spend more time searching for patches and less time foraging. This decrease in pollinator foraging efficiency will simultaneously decrease the pollinator's reproductive output and the amount of pollen flow in flowering plants.

  8. Inherited phenotype instability of inflorescence and floral organ development in homeotic barley double mutants and its specific modification by auxin inhibitors and 2,4-D

    PubMed Central

    Šiukšta, Raimondas; Vaitkūnienė, Virginija; Kaselytė, Greta; Okockytė, Vaiva; Žukauskaitė, Justina; Žvingila, Donatas; Rančelis, Vytautas

    2015-01-01

    Background and Aims Barley (Hordeum vulgare) double mutants Hv-Hd/tw2, formed by hybridization, are characterized by inherited phenotypic instability and by several new features, such as bract/leaf-like structures, long naked gaps in the spike, and a wide spectrum of variations in the basic and ectopic flowers, which are absent in single mutants. Several of these features resemble those of mutations in auxin distribution, and thus the aim of this study was to determine whether auxin imbalances are related to phenotypic variations and instability. The effects of auxin inhibitors and 2,4-D (2,4-dichlorophenoxyacetic acid) on variation in basic and ectopic flowers were therefore examined, together with the effects of 2,4-D on spike structure. Methods The character of phenotypic instability and the effects of auxin inhibitors and 2,4-D were compared in callus cultures and intact plants of single homeotic Hv-tw2 and Hv-Hooded/Kap (in the BKn3 gene) mutants and alternative double mutant lines: offspring from individual plants in distal hybrid generations (F9–F10) that all had the same BKn3 allele as determined by DNA sequencing. For intact plants, two auxin inhibitors, 9-hydroxyfluorene-9-carboxylic acid (HFCA) and p-chlorophenoxyisobutyric acid (PCIB), were used. Key Results Callus growth and flower/spike structures of the Hv-tw2 mutant differed in their responses to HFCA and PCIB. An increase in normal basic flowers after exposure to auxin inhibitors and a decrease in their frequencies caused by 2,4-D were observed, and there were also modifications in the spectra of ectopic flowers, especially those with sexual organs, but the effects depended on the genotype. Exposure to 2,4-D decreased the frequency of short gaps and lodicule transformations in Hv-tw2 and of long naked gaps in double mutants. Conclusions The effects of auxin inhibitors and 2,4-D suggest that ectopic auxin maxima or deficiencies arise in various regions of the inflorescence/flower primordia. Based

  9. Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants1[OPEN

    PubMed Central

    2016-01-01

    Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. PMID:26969720

  10. Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants.

    PubMed

    Wang, Lu; Ruan, Yong-Ling

    2016-05-01

    Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. PMID:26969720

  11. Genetic ablation of petal and stamen primordia to elucidate cell interactions during floral development.

    PubMed

    Day, C D; Galgoci, B F; Irish, V F

    1995-09-01

    Two models have been proposed to explain the coordinated development of the four whorls of floral organs. The spatial model predicts that positional information defines the four whorls simultaneously, and that individual organs develop independently of surrounding tissues. The sequential model suggests that inductive events between the outer and inner whorl primordia are required for appropriate organogenesis. To test these models we have genetically ablated second and third whorl floral organ primordia to determine if organ identity, number or position are perturbed in the first or fourth whorls. We used diphtheria toxin to specifically ablate floral cells early in development in Nicotiana tabacum and in Arabidopsis thaliana. Second and third whorl expression of the diphtheria toxin A chain coding sequence (DTA) was conferred by the Arabidopsis APETALA3 (AP3) promoter. Both Nicotiana and Arabidopsis flowers that express the AP3-DTA construct lack petals and stamens; it appears that the second and third whorl cells expressing this construct arrest early in floral development. These results show that first and fourth whorl development is normal and can proceed without information from adjacent second and third whorl primordia. We propose that positional information specifies the establishment of all four whorls of organs prior to the expression of AP3 in the floral meristem. PMID:7555715

  12. Glucose Metabolism during Resting State Reveals Abnormal Brain Networks Organization in the Alzheimer’s Disease and Mild Cognitive Impairment

    PubMed Central

    Martínez-Montes, Eduardo

    2013-01-01

    This paper aims to study the abnormal patterns of brain glucose metabolism co-variations in Alzheimer disease (AD) and Mild Cognitive Impairment (MCI) patients compared to Normal healthy controls (NC) using the Alzheimer Disease Neuroimaging Initiative (ADNI) database. The local cerebral metabolic rate for glucose (CMRgl) in a set of 90 structures belonging to the AAL atlas was obtained from Fluro-Deoxyglucose Positron Emission Tomography data in resting state. It is assumed that brain regions whose CMRgl values are significantly correlated are functionally associated; therefore, when metabolism is altered in a single region, the alteration will affect the metabolism of other brain areas with which it interrelates. The glucose metabolism network (represented by the matrix of the CMRgl co-variations among all pairs of structures) was studied using the graph theory framework. The highest concurrent fluctuations in CMRgl were basically identified between homologous cortical regions in all groups. Significant differences in CMRgl co-variations in AD and MCI groups as compared to NC were found. The AD and MCI patients showed aberrant patterns in comparison to NC subjects, as detected by global and local network properties (global and local efficiency, clustering index, and others). MCI network’s attributes showed an intermediate position between NC and AD, corroborating it as a transitional stage from normal aging to Alzheimer disease. Our study is an attempt at exploring the complex association between glucose metabolism, CMRgl covariations and the attributes of the brain network organization in AD and MCI. PMID:23894356

  13. Annual Research Review: Growth connectomics – the organization and reorganization of brain networks during normal and abnormal development

    PubMed Central

    Vértes, Petra E; Bullmore, Edward T

    2015-01-01

    Background We first give a brief introduction to graph theoretical analysis and its application to the study of brain network topology or connectomics. Within this framework, we review the existing empirical data on developmental changes in brain network organization across a range of experimental modalities (including structural and functional MRI, diffusion tensor imaging, magnetoencephalography and electroencephalography in humans). Synthesis We discuss preliminary evidence and current hypotheses for how the emergence of network properties correlates with concomitant cognitive and behavioural changes associated with development. We highlight some of the technical and conceptual challenges to be addressed by future developments in this rapidly moving field. Given the parallels previously discovered between neural systems across species and over a range of spatial scales, we also review some recent advances in developmental network studies at the cellular scale. We highlight the opportunities presented by such studies and how they may complement neuroimaging in advancing our understanding of brain development. Finally, we note that many brain and mind disorders are thought to be neurodevelopmental in origin and that charting the trajectory of brain network changes associated with healthy development also sets the stage for understanding abnormal network development. Conclusions We therefore briefly review the clinical relevance of network metrics as potential diagnostic markers and some recent efforts in computational modelling of brain networks which might contribute to a more mechanistic understanding of neurodevelopmental disorders in future. PMID:25441756

  14. The N-Terminus of the Floral Arabidopsis TGA Transcription Factor PERIANTHIA Mediates Redox-Sensitive DNA-Binding

    PubMed Central

    Gutsche, Nora; Zachgo, Sabine

    2016-01-01

    The Arabidopsis TGA transcription factor (TF) PERIANTHIA (PAN) regulates the formation of the floral organ primordia as revealed by the pan mutant forming an abnormal pentamerous arrangement of the outer three floral whorls. The Arabidopsis TGA bZIP TF family comprises 10 members, of which PAN and TGA9/10 control flower developmental processes and TGA1/2/5/6 participate in stress-responses. For the TGA1 protein it was shown that several cysteines can be redox-dependently modified. TGA proteins interact in the nucleus with land plant-specific glutaredoxins, which may alter their activities posttranslationally. Here, we investigated the DNA-binding of PAN to the AAGAAT motif under different redox-conditions. The AAGAAT motif is localized in the second intron of the floral homeotic regulator AGAMOUS (AG), which controls stamen and carpel development as well as floral determinacy. Whereas PAN protein binds to this regulatory cis-element under reducing conditions, the interaction is strongly reduced under oxidizing conditions in EMSA studies. The redox-sensitive DNA-binding is mediated via a special PAN N-terminus, which is not present in other Arabidopsis TGA TFs and comprises five cysteines. Two N-terminal PAN cysteines, Cys68 and Cys87, were shown to form a disulfide bridge and Cys340, localized in a C-terminal putative transactivation domain, can be S-glutathionylated. Comparative land plant analyses revealed that the AAGAAT motif exists in asterid and rosid plant species. TGA TFs with N-terminal extensions of variable length were identified in all analyzed seed plants. However, a PAN-like N-terminus exists only in the rosids and exclusively Brassicaceae homologs comprise four to five of the PAN N-terminal cysteines. Redox-dependent modifications of TGA cysteines are known to regulate the activity of stress-related TGA TFs. Here, we show that the N-terminal PAN cysteines participate in a redox-dependent control of the PAN interaction with a highly conserved

  15. Molecular characterization and expression analysis of the critical floral genes in hickory (Carya cathayensis Sarg.).

    PubMed

    Shen, Chen; Xu, Yingwu; Huang, Jianqin; Wang, Zhengjia; Qiu, Jiani; Huang, Youjun

    2014-10-01

    The full ORFs of three floral genes in hickory (Carya cathayensis Sarg.), CcAGL24 (the AGAMOUS-LIKE24 homolog), CcSOC1 (the SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 homolog) and CcAP1 (the APETALA1 homolog) are derived using a 5' RACE PCR protocol. Through sequence alignment and phylogenetic analysis, it is demonstrated that the three genes belong to the MADS-Box family. According to the evolutionary trees of the three genes, the homologous genes from the same family cluster well together, while those from different orders doesn't match evolutionary regularity of individual organisms. The result of Quantitative RT-PCR analysis shows that the transcriptional levels of the three genes are up-regulated in early stage and down-regulated in late stage in pistillate floral development. However, it takes different time to reach respective expression peak among the three genes. In staminate floral development, the transcription trend of the three genes is up-regulated, subsequently down-regulated, and then up-regulated again. Nevertheless, those trajectories, peaks, expression levels, inflection points are different in pistillate floral development. The result suggests that their functions are different in between pistillate and staminate floral development. The probable ordinal site of the three genes in the flowering network from top down is CcAGL24, CcSOC1, and CcAP1, which is identical to that in herbaceous plants. Moreover, several adverse environmental factors trigger several negative genes and then confine the development of staminate floral buds. Our results suggest the possible relationship among the three critical floral genes and their functions throughout the floral development in hickory. PMID:25137292

  16. Spatiotemporal Floral Scent Variation of Penstemon digitalis.

    PubMed

    Burdon, Rosalie C F; Raguso, Robert A; Kessler, André; Parachnowitsch, Amy L

    2015-07-01

    Variability in floral volatile emissions can occur temporally through floral development, during diel cycles, as well as spatially within a flower. These spatiotemporal patterns are hypothesized to provide additional information to floral visitors, but they are rarely measured, and their attendant hypotheses are even more rarely tested. In Penstemon digitalis, a plant whose floral scent has been shown to be under strong phenotypic selection for seed fitness, we investigated spatiotemporal variation in floral scent by using dynamic headspace collection, respectively solid-phase microextraction, and analyzed the volatile samples by combined gas chromatography-mass spectrometry. Total volatile emission was greatest during flowering and peak pollinator activity hours, suggesting its importance in mediating ecological interactions. We also detected tissue and reward-specific compounds, consistent with the hypothesis that complexity in floral scent composition reflects several ecological functions. In particular, we found tissue-specific scents for the stigma, stamens, and staminode (a modified sterile stamen common to all Penstemons). Our findings emphasize the dynamic nature of floral scents and highlight a need for greater understanding of ecological and physiological mechanisms driving spatiotemporal patterns in scent production. PMID:26133675

  17. Floral Nectar: Pollinator Attraction or Manipulation?

    PubMed

    Pyke, Graham H

    2016-05-01

    The literature suggests that floral nectar acts principally to attract pollinator visitation (and/or revisitation), thereby enhancing plant reproductive success. However, floral nectar also manipulates pollinator behaviour during and immediately following plant visits, affecting pollen transfer, and plant reproduction. I argue that floral nectar should really be viewed as a pollinator manipulant rather than attractant, thus potentially explaining why its concentration is not generally high and why it decreases with increasing pollinator body size. Otherwise, such patterns may remain mysterious and unexplained. PMID:26987770

  18. An APETALA3 homolog controls both petal identity and floral meristem patterning in Nigella damascena L. (Ranunculaceae).

    PubMed

    Gonçalves, Beatriz; Nougué, Odrade; Jabbour, Florian; Ridel, Céline; Morin, Halima; Laufs, Patrick; Manicacci, Domenica; Damerval, Catherine

    2013-10-01

    Flower architecture mutants provide a unique opportunity to address the genetic origin of flower diversity. Here we study a naturally occurring floral dimorphism in Nigella damascena (Ranunculaceae), involving replacement of the petals by numerous sepal-like and chimeric sepal/stamen organs. We performed a comparative study of floral morphology and floral development, and characterized the expression of APETALA3 and PISTILLATA homologs in both morphs. Segregation analyses and gene silencing were used to determine the involvement of an APETALA3 paralog (NdAP3-3) in the floral dimorphism. We demonstrate that the complex floral dimorphism is controlled by a single locus, which perfectly co-segregates with the NdAP3-3 gene. This gene is not expressed in the apetalous morph and exhibits a particular expression dynamic during early floral development in the petalous morph. NdAP3-3 silencing in petalous plants perfectly phenocopies the apetalous morph. Our results show that NdAP3-3 is fully responsible for the complex N. damascena floral dimorphism, suggesting that it plays a role not only in petal identity but also in meristem patterning, possibly through regulation of perianth organ number and the perianth/stamen boundary. PMID:23855996

  19. Floral induction in Eucalyptus nitens.

    PubMed

    Moncur, M W; Hasan, O

    1994-11-01

    Eucalyptus nitens (Deane & Maiden) Maiden takes at least five years to initiate flower buds from seed and is an infrequent and light flowerer. Because this behavior constitutes a major impediment to breeding programs, we examined the mechanisms controlling floral induction in E. nitens, with the long-term aim of reducing generation time and increasing seed yield. Application of paclobutrazol reduced the concentration of endogenous gibberellic acid (GA) in apical tissue and enhanced the reproductive activity of grafted trees maintained outside over winter in Canberra, Australia. Grafts maintained in a warm greenhouse over winter did not produce flower buds, despite the paclobutrazol-induced reduction in GA concentration of the apical tissue. Exposing untreated grafts, which had been maintained over winter in a warm greenhouse, to low temperature the following spring reduced growth but did not induce flower bud production. Addition of GA(3) to paclobutrazol-treated grafts reduced the effect of paclobutrazol on reproductive activity. PMID:14967619

  20. Separable roles of UFO during floral development revealed by conditional restoration of gene function.

    PubMed

    Laufs, Patrick; Coen, Enrico; Kronenberger, Jocelyne; Traas, Jan; Doonan, John

    2003-02-01

    The UNUSUAL FLORAL ORGANS (UFO) gene is required for several aspects of floral development in Arabidopsis including specification of organ identity in the second and third whorls and the proper pattern of primordium initiation in the inner three whorls. UFO is expressed in a dynamic pattern during the early phases of flower development. Here we dissect the role of UFO by ubiquitously expressing it in ufo loss-of-function flowers at different developmental stages and for various durations using an ethanol-inducible expression system. The previously known functions of UFO could be separated and related to its expression at specific stages of development. We show that a 24- to 48-hour period of UFO expression from floral stage 2, before any floral organs are visible, is sufficient to restore normal petal and stamen development. The earliest requirement for UFO is during stage 2, when the endogenous UFO gene is transiently expressed in the centre of the wild-type flower and is required to specify the initiation patterns of petal, stamen and carpel primordia. Petal and stamen identity is determined during stages 2 or 3, when UFO is normally expressed in the presumptive second and third whorl. Although endogenous UFO expression is absent from the stamen whorl from stage 4 onwards, stamen identity can be restored by UFO activation up to stage 6. We also observed floral phenotypes not observed in loss-of-function or constitutive gain-of-function backgrounds, revealing additional roles of UFO in outgrowth of petal primordia. PMID:12506008

  1. The AINTEGUMENTA gene of Arabidopsis required for ovule and female gametophyte development is related to the floral homeotic gene APETALA2.

    PubMed Central

    Klucher, K M; Chow, H; Reiser, L; Fischer, R L

    1996-01-01

    Ovules play a central role in plant reproduction, generating the female gametophyte within sporophytic integuments. When fertilized, the integuments differentiate into the seed coat and support the development of the embryo and endosperm. Mutations in the AINTEGUMENTA (ANT) locus of Arabidopsis have a profound effect on ovule development. Strong ant mutants have ovules that fail to form integuments or a female gametophyte. Flower development is also altered, with a random reduction of organs in the outer three whorls. In addition, organs present in the outer three floral whorls often have abnormal morphology. Ovules from a weak ant mutant contain both inner and outer integuments but generally fail to produce a functional female gametophyte. We isolated the ANT gene by using a mutation derived by T-DNA insertional mutagenesis. ANT is a member of a gene family that includes the floral homeotic gene APETALA2 (AP2). Like AP2, ANT contains two AP2 domains homologous with the DNA binding domain of ethylene response element binding proteins. ANT is expressed most highly in developing flowers but is also expressed in vegetative tissue. Taken together, these results suggest that ANT is a transcription factor that plays a critical role in regulating ovule and female gametophyte development. PMID:8742706

  2. Orchestration of the Floral Transition and Floral Development in Arabidopsis by the Bifunctional Transcription Factor APETALA2[W][OA

    PubMed Central

    Yant, Levi; Mathieu, Johannes; Dinh, Thanh Theresa; Ott, Felix; Lanz, Christa; Wollmann, Heike; Chen, Xuemei; Schmid, Markus

    2010-01-01

    The Arabidopsis thaliana transcription factor APETALA2 (AP2) has numerous functions, including roles in seed development, stem cell maintenance, and specification of floral organ identity. To understand the relationship between these different roles, we mapped direct targets of AP2 on a genome-wide scale in two tissue types. We find that AP2 binds to thousands of loci in the developing flower, many of which exhibit AP2-dependent transcription. Opposing, logical effects are evident in AP2 binding to two microRNA genes that influence AP2 expression, with AP2 positively regulating miR156 and negatively regulating miR172, forming a complex direct feedback loop, which also included all but one of the AP2-like miR172 target clade members. We compare the genome-wide direct target repertoire of AP2 with that of SCHLAFMÜTZE, a closely related transcription factor that also represses the transition to flowering. We detect clear similarities and important differences in the direct target repertoires that are also tissue specific. Finally, using an inducible expression system, we demonstrate that AP2 has dual molecular roles. It functions as both a transcriptional activator and repressor, directly inducing the expression of the floral repressor AGAMOUS-LIKE15 and directly repressing the transcription of floral activators like SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1. PMID:20675573

  3. Multimodal Floral Signals and Moth Foraging Decisions

    PubMed Central

    Riffell, Jeffrey A.; Alarcón, Ruben

    2013-01-01

    Background Combinations of floral traits – which operate as attractive signals to pollinators – act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear. Methodology/Principal Findings Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition – a contrast to many studies that have used artificial stimuli (essential oils, single odorants) that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers – a species that is not very attractive to hawkmoths – showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however – a flower that is highly attractive to naïve hawkmoths – did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays. Conclusions/Significance These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as

  4. Organic trace minerals and 25-hydroxycholecalciferol affect performance characteristics, leg abnormalities, and biomechanical properties of leg bones of turkeys.

    PubMed

    Ferket, P R; Oviedo-Rondón, E O; Mente, P L; Bohórquez, D V; Santos, A A; Grimes, J L; Richards, J D; Dibner, J J; Felts, V

    2009-01-01

    Leg problems and resulting mortality can exceed 1% per week in turkey toms starting at approximately 15 wk of age. Dietary supplementation of organic trace minerals (MIN) and 25-hydroxycholecalciferol (HyD) may improve performance, decrease incidence of leg abnormalities, and increase bone strength. Nicholas 85X700 toms were assigned to 4 treatments consisting of a factorial arrangement of 2 concentrations of MIN (0 and 0.1% of Mintrex P(Se), which adds 40, 40, 20, and 0.3 mg/kg of Zn, Mn, Cu, and Se, respectively) and 2 concentrations of HyD (0 and 92 microg/kg of HyD). Diets were formulated to be equal in nutrient content and fed ad libitum as 8 feed phases. Feed intake and BW were measured at 6, 12, 15, 17, and 20 wk of age. Valgus, varus, and shaky leg defects were determined at 12, 15, 17, and 20 wk of age. Tibia and femur biomechanical properties were evaluated by torsion and bending tests at 17 wk of age. There were no treatment effects on BW. Only MIN significantly improved feed conversion ratio through to 20 wk of age. Cumulative mortality at 3 wk of age was greater among the MIN birds, but it was lower by 20 wk (P = 0.085). The MIN decreased the incidence of varus defects at 17 wk of age; shaky leg at 12, 15, and 17 wk of age; and valgus defects at 15, 17, and 20 wk of age. There were no MIN x HyD interaction effects on individual gait problems. Maximum load and the bending stress required for tibias to break in a 4-point assay were increased with MIN supplementation, especially when HyD was also added. Maximum shear stress at failure of femoral bones in a torsion assay was increased by supplementation with both MIN and HyD together. Dietary supplementation of MIN and HyD may improve biomechanical properties of bones. Dietary MIN supplementation may improve feed conversion of turkeys, likely by decreasing leg problems. PMID:19096066

  5. NFL, the tobacco homolog of FLORICAULA and LEAFY, is transcriptionally expressed in both vegetative and floral meristems.

    PubMed Central

    Kelly, A J; Bonnlander, M B; Meeks-Wagner, D R

    1995-01-01

    The homologous genes FLORICAULA (FLO) of Antirrhinum and LEAFY (LFY) of Arabidopsis regulate the formation of determinate floral meristems. Transcripts of these single-copy genes are confined to floral meristems and some floral organs as well as to the leaflike bracts that subtend Antirrhinum flowers. Based on these observations, we hypothesized that the transcription of genes homologous to FLO and LFY in tobacco, a determinate plant in which the primary shoot apex is consumed in the production of a terminal flower, would serve as a molecular marker for floral commitment. Surprisingly, transcripts of the tobacco homologs NFL1 and NFL2 (Nicotiana FLO/LFY) were found not only in floral meristems, but also in indeterminate vegetative meristems. This implies that the transcriptional expression of the FLO/LFY homologous genes in the apical meristem is not sufficient for the initiation of floral meristem development. In addition, the transcript patterns of the NFL genes identified a previously undescribed subset of cells within the shoot apical meristem that may indicate unique functional compartmentalization. This suggests that, unlike FLO and LFY, which specify determinacy only during floral development, the NFL genes act to specify determinacy in the progenitor cells for both flowers and leaves. PMID:7756832

  6. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  7. Floral gene resources from basal angiosperms for comparative genomics research

    PubMed Central

    Albert, Victor A; Soltis, Douglas E; Carlson, John E; Farmerie, William G; Wall, P Kerr; Ilut, Daniel C; Solow, Teri M; Mueller, Lukas A; Landherr, Lena L; Hu, Yi; Buzgo, Matyas; Kim, Sangtae; Yoo, Mi-Jeong; Frohlich, Michael W; Perl-Treves, Rafael; Schlarbaum, Scott E; Bliss, Barbara J; Zhang, Xiaohong; Tanksley, Steven D; Oppenheimer, David G; Soltis, Pamela S; Ma, Hong; dePamphilis, Claude W; Leebens-Mack, James H

    2005-01-01

    Background The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. Results Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. Conclusion Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and

  8. Effects of Floral Scents and Their Dietary Experiences on the Feeding Preference in the Blowfly, Phormia regina

    PubMed Central

    Maeda, Toru; Tamotsu, Miwako; Yamaoka, Ryohei; Ozaki, Mamiko

    2015-01-01

    The flowers of different plant species have diverse scents with varied chemical compositions. Hence, every floral scent does not uniformly affect insect feeding preferences. The blowfly, Phormia regina, is a nectar feeder, and when a fly feeds on flower nectar, its olfactory organs, antennae, and maxillary palps are exposed to the scent. Generally, feeding preference is influenced by food flavor, which relies on both taste and odor. Therefore, the flies perceive the sweet taste of nectar and the particular scent of the flower simultaneously, and this olfactory information affects their feeding preference. Here, we show that the floral scents of 50 plant species have various effects on their sucrose feeding motivation, which was evaluated using the proboscis extension reflex (PER). Those floral scents were first categorized into three groups, based on their effects on the PER threshold sucrose concentration, which indicates whether a fly innately dislikes, ignores, or likes the target scent. Moreover, memory of olfactory experience with those floral scents during sugar feeding influenced the PER threshold. After feeding on sucrose solutions flavored with floral scents for 5 days, the scents did not consistently show the previously observed effects. Considering such empirical effects of scents on the PER threshold, we categorized the effects of the 50 tested floral scents on feeding preference into 16 of all possible 27 theoretical types. We then conducted the same experiments with flies whose antennae or maxillary palps were ablated prior to PER test in a fly group naïve to floral scents and prior to the olfactory experience during sugar feeding in the other fly group in order to test how these organs were involved in the effect of the floral scent. The results suggested that olfactory inputs through these organs play different roles in forming or modifying feeding preferences. Thus, our study contributes to an understanding of underlying mechanisms associated with

  9. Congenital Abnormalities

    MedlinePlus

    ... serious health problems (e.g. Down syndrome ). Single-Gene Abnormalities Sometimes the chromosomes are normal in number, ... blood flow to the fetus impair fetal growth. Alcohol consumption and certain drugs during pregnancy significantly increase ...

  10. Craniofacial Abnormalities

    MedlinePlus

    ... of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ... palate, are among the most common of all birth defects. Others are very rare. Most of them affect ...

  11. Walking abnormalities

    MedlinePlus

    ... include: Arthritis of the leg or foot joints Conversion disorder (a psychological disorder) Foot problems (such as a ... injuries. For an abnormal gait that occurs with conversion disorder, counseling and support from family members are strongly ...

  12. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  13. Nail abnormalities

    MedlinePlus

    Nail abnormalities are problems with the color, shape, texture, or thickness of the fingernails or toenails. ... Fungus or yeast cause changes in the color, texture, and shape of the nails. Bacterial infection may ...

  14. Regulation of APETALA3 floral homeotic gene expression by meristem identity genes.

    PubMed

    Lamb, Rebecca S; Hill, Theresa A; Tan, Queenie K-G; Irish, Vivian F

    2002-05-01

    The Arabidopsis APETALA3 (AP3) floral homeotic gene is required for specifying petal and stamen identities, and is expressed in a spatially limited domain of cells in the floral meristem that will give rise to these organs. Here we show that the floral meristem identity genes LEAFY (LFY) and APETALA1 (AP1) are required for the activation of AP3. The LFY transcription factor binds to a sequence, with dyad symmetry, that lies within a region of the AP3 promoter required for early expression of AP3. Mutation of this region abolishes LFY binding in vitro and in yeast one hybrid assays, but has no obvious effect on AP3 expression in planta. Experiments using a steroid-inducible form of LFY show that, in contrast to its direct transcriptional activation of other floral homeotic genes, LFY acts in both a direct and an indirect manner to regulate AP3 expression. This LFY-induced expression of AP3 depends in part on the function of the APETALA1 (AP1) floral homeotic gene, since mutations in AP1 reduce LFY-dependent induction of AP3 expression. LFY therefore appears to act through several pathways, one of which is dependent on AP1 activity, to regulate AP3 expression. PMID:11959818

  15. Herbivory and floral signaling: phenotypic plasticity and tradeoffs between reproduction and indirect defense.

    PubMed

    Schiestl, Florian P; Kirk, Heather; Bigler, Laurent; Cozzolino, Salvatore; Desurmont, Gaylord A

    2014-07-01

    Plant defense against herbivores may compromise attraction of mutualists, yet information remains limited about the mechanisms underlying such signaling tradeoffs. Here, we investigated the effects of foliar herbivory by two herbivore species on defense compounds, floral signaling, pollinator and parasitoid attraction, and seed production. Herbivory generally reduced the quantity of many floral volatile organic compounds VOCs) in Brassica rapa. By contrast, floral color, flower diameter, and plant height remained unaffected. The decreased amounts of floral volatiles led to reduced attractiveness of flowers to pollinators, but increased the attractiveness of herbivore-infested plants to parasitoids. Plants infested with the native butterfly Pieris brassicae produced more flowers during early flowering, effectively compensating for the lower olfactory attractiveness. Herbivory by the invasive Spodoptera littoralis increased the amounts of glucobrassicanapin, and led to delayed flowering. These plants tended to attract fewer pollinators and to produce fewer seeds. Our study indicates a tradeoff between pollinator attraction and indirect defense (parasitoid attraction), which can be mitigated by reduced floral VOC emission and production of more early flowers. We suggest that this compensatory mechanism is specific to plant-herbivore associations with a coevolutionary history. PMID:24684288

  16. Experimental manipulation of floral scent bouquets restructures flower-visitor interactions in the field.

    PubMed

    Larue, Anne-Amélie C; Raguso, Robert A; Junker, Robert R

    2016-03-01

    A common structural feature of natural communities is the non-random distribution of pairwise interactions between organisms of different trophic levels. For plant-animal interactions, it is predicted that both stochastic processes and functional plant traits that facilitate or prevent interactions are responsible for these patterns. However, unbiased manipulative field experiments that rigorously test the effects of individual traits on community structure are lacking. We address this gap by manipulating floral scent bouquets in the field. Manipulation of floral scent bouquets led to quantitative as well as qualitative restructuring of flower-visitor networks, making them more generalized. Olfactometer trials confirmed both positive and negative responses to scent bouquets. Our results clearly show that the distribution of insect visitors to the two abundant study plant species reflects the insects' species-specific preferences for floral scents, rather than for visual or morphological floral traits. Thus, floral scents may be of major importance in partitioning flower-visitor interactions. Integrating experimental manipulations of plant traits with field observations of interaction patterns thus represents a promising approach for revealing the processes that structure species assemblages in natural communities. PMID:26428739

  17. Serine 231 and 257 of Agamous-like 15 are phosphorylated in floral receptacles

    PubMed Central

    Patharkar, Osric Rahul; Macken, Terra A.; Walker, John C.

    2016-01-01

    ABSTRACT The large dynamic range of gene expression changes accompanying floral organ abscission can be explained by a molecular positive feedback loop that regulates the process. In short, a mitogen-activated protein kinase (MAPK) cascade, positioned genetically downstream from the abscission receptor HAESA (HAE), phosphorylates the transcription factor, AGAMOUS-like 15 (AGL15), allowing HAE to be expressed. However, it is unknown which residues of AGL15 are phosphorylated and precisely how phosphorylation alters AGL15 function. Here we report that serine 231 and 257 of AGL15 are phosphorylated in floral receptacles. Effects of phosphorylation on AGL15 are discussed. PMID:27322882

  18. Genetic screens for floral mutants in Arabidopsis thaliana: enhancers and suppressors.

    PubMed

    Dinh, Thanh Theresa; Luscher, Elizabeth; Li, Shaofang; Liu, Xigang; Won, So Youn; Chen, Xuemei

    2014-01-01

    The flower is a hallmark feature that has contributed to the evolutionary success of land plants. Diverse mutagenic agents have been employed as a tool to genetically perturb flower development and identify genes involved in floral patterning and morphogenesis. Since the initial studies to identify genes governing processes such as floral organ specification, mutagenesis in sensitized backgrounds has been used to isolate enhancers and suppressors to further probe the molecular basis of floral development. Here, we first describe two commonly employed methods for mutagenesis (using ethyl methanesulfonate (EMS) or T-DNAs as mutagens), and then describe three methods for identifying a mutation that leads to phenotypic alterations--traditional map-based cloning, TAIL-PCR, and deep sequencing in the plant model Arabidopsis thaliana. PMID:24395255

  19. Genetic Screens for Floral Mutants in Arabidopsis thaliana: Enhancers and Suppressors

    PubMed Central

    Dinh, Thanh Theresa; Luscher, Elizabeth; Li, Shaofang; Liu, Xigang; Won, So Youn; Chen, Xuemei

    2015-01-01

    The flower is a hallmark feature that has contributed to the evolutionary success of land plants. Diverse mutagenic agents have been employed as a tool to genetically perturb flower development and identify genes involved in floral patterning and morphogenesis. Since the initial studies to identify genes governing processes such as floral organ specification, mutagenesis in sensitized backgrounds has been used to isolate enhancers and suppressors to further probe the molecular basis of floral development. Here, we first describe two commonly employed methods for mutagenesis (using ethyl methanesulfonate (EMS) or T-DNAs as mutagens), and then describe three methods for identifying a mutation that leads to phenotypic alterations—traditional map-based cloning, TAIL-PCR, and deep sequencing in the plant model Arabidopsis thaliana. PMID:24395255

  20. Advertising to the enemy: enhanced floral fragrance increases beetle attraction and reduces plant reproduction.

    PubMed

    Theis, Nina; Adler, Lynn S

    2012-02-01

    Many organisms face challenges in avoiding predation while searching for mates. For plants, emitting floral fragrances to advertise reproductive structures could increase the attraction of detrimental insects along with pollinators. Very few studies have experimentally evaluated the costs and benefits of fragrance emission with explicit consideration of how plant fitness is affected by both pollinators and florivores. To determine the reproductive consequences of increasing the apparency of reproductive parts, we manipulated fragrance, pollination, and florivores in the wild Texas gourd, Cucurbita pepo var. texana. With enhanced fragrance we found an increase in the attraction of florivores, rather than pollinators, and a decrease in seed production. This study is the first to demonstrate that enhanced floral fragrance can increase the attraction of detrimental florivores and decrease plant reproduction, suggesting that florivory as well as pollination has shaped the evolution of floral scent. PMID:22624324

  1. Genetic and phenotypic analysis of shoot apical and floral meristem development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The shoot apical and floral meristems (SAM and FM, respectively) of Arabidopsis thaliana contain reservoirs of self-renewing stem cells that function as sources of progenitor cells for organ formation during development. The primary SAM produces all of the aerial structures of the adult plant, where...

  2. Appetitive floral odours prevent aggression in honeybees

    PubMed Central

    Nouvian, Morgane; Hotier, Lucie; Claudianos, Charles; Giurfa, Martin; Reinhard, Judith

    2015-01-01

    Honeybees defend their colonies aggressively against intruders and release a potent alarm pheromone to recruit nestmates into defensive tasks. The effect of floral odours on this behaviour has never been studied, despite the relevance of these olfactory cues for the biology of bees. Here we use a novel assay to investigate social and olfactory cues that drive defensive behaviour in bees. We show that social interactions are necessary to reveal the recruiting function of the alarm pheromone and that specific floral odours—linalool and 2-phenylethanol—have the surprising capacity to block recruitment by the alarm pheromone. This effect is not due to an olfactory masking of the pheromone by the floral odours, but correlates with their appetitive value. In addition to their potential applications, these findings provide new insights about how honeybees make the decision to engage into defence and how conflicting information affects this process. PMID:26694599

  3. Appetitive floral odours prevent aggression in honeybees.

    PubMed

    Nouvian, Morgane; Hotier, Lucie; Claudianos, Charles; Giurfa, Martin; Reinhard, Judith

    2015-01-01

    Honeybees defend their colonies aggressively against intruders and release a potent alarm pheromone to recruit nestmates into defensive tasks. The effect of floral odours on this behaviour has never been studied, despite the relevance of these olfactory cues for the biology of bees. Here we use a novel assay to investigate social and olfactory cues that drive defensive behaviour in bees. We show that social interactions are necessary to reveal the recruiting function of the alarm pheromone and that specific floral odours-linalool and 2-phenylethanol-have the surprising capacity to block recruitment by the alarm pheromone. This effect is not due to an olfactory masking of the pheromone by the floral odours, but correlates with their appetitive value. In addition to their potential applications, these findings provide new insights about how honeybees make the decision to engage into defence and how conflicting information affects this process. PMID:26694599

  4. Molecular control and variation in the floral transition.

    PubMed

    Battey, Nicholas H; Tooke, Fiona

    2002-02-01

    The common controls that are involved in both vegetative and floral development are becoming apparent at the molecular level. Intriguing links are also emerging between developmental events during the juvenile/adult and floral transitions. This progress has made it possible to test the annual model of floral transition in a wide range of plant species, including those that flower perennially. PMID:11788310

  5. A novel role of BELL1-like homeobox genes, PENNYWISE and POUND-FOOLISH, in floral patterning.

    PubMed

    Yu, Lifeng; Patibanda, Varun; Smith, Harley M S

    2009-02-01

    Flowers are determinate shoots comprised of perianth and reproductive organs displayed in a whorled phyllotactic pattern. Floral organ identity genes display region-specific expression patterns in the developing flower. In Arabidopsis, floral organ identity genes are activated by LEAFY (LFY), which functions with region-specific co-regulators, UNUSUAL FLORAL ORGANS (UFO) and WUSCHEL (WUS), to up-regulate homeotic genes in specific whorls of the flower. PENNYWISE (PNY) and POUND-FOOLISH (PNF) are redundant functioning BELL1-like homeodomain proteins that are expressed in shoot and floral meristems. During flower development, PNY functions with a co-repressor complex to down-regulate the homeotic gene, AGAMOUS (AG), in the outer whorls of the flower. However, the function of PNY as well as PNF in regulating floral organ identity in the central whorls of the flower is not known. In this report, we show that combining mutations in PNY and PNF enhance the floral patterning phenotypes of weak and strong alleles of lfy, indicating that these BELL1-like homeodomain proteins play a role in the specification of petals, stamens and carpels during flower development. Expression studies show that PNY and PNF positively regulate the homeotic genes, APETALA3 and AG, in the inner whorls of the flower. Moreover, PNY and PNF function in parallel with LFY, UFO and WUS to regulate homeotic gene expression. Since PNY and PNF interact with the KNOTTED1-like homeodomain proteins, SHOOTMERISTEMLESS (STM) and KNOTTED-LIKE from ARABIDOPSIS THALIANA2 (KNAT2) that regulate floral development, we propose that PNY/PNF-STM and PNY/PNF-KNAT2 complexes function in the inner whorls to regulate flower patterning events. PMID:19082619

  6. Histone acetylation accompanied with promoter sequences displaying differential expression profiles of B-class MADS-box genes for phalaenopsis floral morphogenesis.

    PubMed

    Hsu, Chia-Chi; Wu, Pei-Shan; Chen, Tien-Chih; Yu, Chun-Wei; Tsai, Wen-Chieh; Wu, Keqiang; Wu, Wen-Luan; Chen, Wen-Huei; Chen, Hong-Hwa

    2014-01-01

    Five B-class MADS-box genes, including four APETALA3 (AP3)-like PeMADS2∼5 and one PISTILLATA (PI)-like PeMADS6, specify the spectacular flower morphology in orchids. The PI-like PeMADS6 ubiquitously expresses in all floral organs. The four AP3-like genes, resulted from two duplication events, express ubiquitously at floral primordia and early floral organ stages, but show distinct expression profiles at late floral organ primordia and floral bud stages. Here, we isolated the upstream sequences of PeMADS2∼6 and studied the regulatory mechanism for their distinct gene expression. Phylogenetic footprinting analysis of the 1.3-kb upstream sequences of AP3-like PeMADS2∼5 showed that their promoter regions have sufficiently diverged and contributed to their subfunctionalization. The amplified promoter sequences of PeMADS2∼6 could drive beta-glucuronidase (GUS) gene expression in all floral organs, similar to their expression at the floral primordia stage. The promoter sequence of PeMADS4, exclusively expressed in lip and column, showed a 1.6∼3-fold higher expression in lip/column than in sepal/petal. Furthermore, we noted a 4.9-fold increase in histone acetylation (H3K9K14ac) in the translation start region of PeMADS4 in lip as compared in petal. All these results suggest that the regulation via the upstream sequences and increased H3K9K14ac level may act synergistically to display distinct expression profiles of the AP3-like genes at late floral organ primordia stage for Phalaenopsis floral morphogenesis. PMID:25501842

  7. Histone Acetylation Accompanied with Promoter Sequences Displaying Differential Expression Profiles of B-Class MADS-Box Genes for Phalaenopsis Floral Morphogenesis

    PubMed Central

    Hsu, Chia-Chi; Wu, Pei-Shan; Chen, Tien-Chih; Yu, Chun-Wei; Tsai, Wen-Chieh; Wu, Keqiang; Wu, Wen-Luan; Chen, Wen-Huei; Chen, Hong-Hwa

    2014-01-01

    Five B-class MADS-box genes, including four APETALA3 (AP3)-like PeMADS2∼5 and one PISTILLATA (PI)-like PeMADS6, specify the spectacular flower morphology in orchids. The PI-like PeMADS6 ubiquitously expresses in all floral organs. The four AP3-like genes, resulted from two duplication events, express ubiquitously at floral primordia and early floral organ stages, but show distinct expression profiles at late floral organ primordia and floral bud stages. Here, we isolated the upstream sequences of PeMADS2∼6 and studied the regulatory mechanism for their distinct gene expression. Phylogenetic footprinting analysis of the 1.3-kb upstream sequences of AP3-like PeMADS2∼5 showed that their promoter regions have sufficiently diverged and contributed to their subfunctionalization. The amplified promoter sequences of PeMADS2∼6 could drive beta-glucuronidase (GUS) gene expression in all floral organs, similar to their expression at the floral primordia stage. The promoter sequence of PeMADS4, exclusively expressed in lip and column, showed a 1.6∼3-fold higher expression in lip/column than in sepal/petal. Furthermore, we noted a 4.9-fold increase in histone acetylation (H3K9K14ac) in the translation start region of PeMADS4 in lip as compared in petal. All these results suggest that the regulation via the upstream sequences and increased H3K9K14ac level may act synergistically to display distinct expression profiles of the AP3-like genes at late floral organ primordia stage for Phalaenopsis floral morphogenesis. PMID:25501842

  8. Dosage-dependent impacts of a floral volatile compound on pollinators, larcenists, and the potential for floral evolution in the alpine skypilot Polemonium viscosum.

    PubMed

    Galen, Candace; Kaczorowski, Rainee; Todd, Sadie L; Geib, Jennifer; Raguso, Robert A

    2011-02-01

    All volatile organic compounds (VOCs) vary quantitatively, yet how such variation affects their ecological roles is unknown. Because floral VOCs are cues for both pollinators and floral antagonists, variation in emission may have major consequences for costs and benefits in plant-pollinator interactions. In Polemonium viscosum, the emission rate for the floral VOC 2-phenylethanol (2PE) spans more than two orders of magnitude. We investigated the ecological and evolutionary impacts of this immense phenotypic variation. The emission rate of 2PE varies independently of nectar rewards and thus is uninformative of profitability. Emission is elevated in flowers that are morphologically vulnerable to ant larcenists, suggesting that chemical deterrence may compensate for weak physical barriers. In nature, plants emitting more 2PE than their neighbors escape ant damage. Flower-damaging ants die when exposed to 2PE in the laboratory, and they avoid high 2PE emitters in the field. High 2PE also reduces bumblebee visitation and pollination, suggesting an ecological cost of defense in pollinator service. However, at more moderate emission rates, 2PE enhances the amount of nectar left in flowers, at no pollination cost. In conclusion, repellency of 2PE is highly sensitive to dosage, giving it a key role in shaping ecological interactions between skypilot plants and their floral visitors. PMID:21460561

  9. An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

    PubMed

    Risseeuw, Eddy; Venglat, Prakash; Xiang, Daoquan; Komendant, Kristina; Daskalchuk, Tim; Babic, Vivijan; Crosby, William; Datla, Raju

    2013-01-01

    Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants. PMID:24376756

  10. Lilium floral fragrance: A biochemical and genetic resource for aroma and flavor.

    PubMed

    Johnson, Timothy S; Schwieterman, Michael L; Kim, Joo Young; Cho, Keun H; Clark, David G; Colquhoun, Thomas A

    2016-02-01

    Hybrid Lilium (common name lily) cultivars are among the top produced domestic fresh cut flowers and potted plants in the US today. Many hybrid Lilium cultivars produce large and showy flowers that emit copious amounts of volatile molecules, which can negatively affect a consumer's appreciation or limit use of the plant product. There are few publications focused on the biochemistry, genetics, and/or molecular regulation of floral volatile biosynthesis for Lilium cultivars. In an initial pursuit to provide breeders with molecular markers for floral volatile biosynthesis, a total of five commercially available oriental and oriental-trumpet hybrid Lilium cultivars were selected for analytical characterization of floral volatile emission. In total, 66 volatile molecules were qualified and quantitated among all cultivars. Chemical classes of identified volatiles include monoterpene hydrocarbons, monoterpene alcohols and aldehydes, phenylpropanoids, benzenoids, fatty-acid-derived, nitrogen-containing, and amino-acid-derived compounds. In general, the floral volatile profiles of the three oriental-trumpet hybrids were dominated by monoterpene hydrocarbons, monoterpene alcohols and aldehydes, while the two oriental hybrids were dominated by monoterpene alcohols and aldehydes and phenylpropanoids, respectively. Tepal tissues (two petal whirls) emitted the vast majority of total volatile molecules compared to the reproductive organs of the flowers. Tepal volatile profiles were cultivar specific with a high degree of distinction, which indicates the five cultivars chosen will provide an excellent differential genetic environment for gene discovery through comparative transcriptomics in the future. Cloning and assaying transcript accumulation from four floral volatile biosynthetic candidates provided few immediate or obvious trends with floral volatile emission. PMID:26654856

  11. Micromorphology of the Labellum and Floral Spur of Cryptocentrum Benth. and Sepalosaccus Schltr. (Maxillariinae: Orchidaceae)

    PubMed Central

    Davies, Kevin L.; Stpiczyńska, Malgorzata

    2007-01-01

    Background and Aims Gross vegetative and floral morphology, as well as modern molecular techniques, indicate that Cryptocentrum Benth. and Sepalosaccus Schltr. are related to Maxillaria Ruiz & Pav. However, they differ from Maxillaria in their possession of floral spurs and, in this respect, are atypical of Maxillariinae. The labellar micromorphology of Maxillaria, unlike that of the other two genera, has been extensively studied. In the present report, the labellar micromorphology of Cryptocentrum and Sepalosaccus is compared with that of Maxillaria and, for the first time, the micromorphology of the floral spur as found in Maxillariinae is described. Methods Labella and dissected floral spurs of Cryptocentrum and Sepalosaccus were examined using light microscopy (LM) and scanning electron microscopy (SEM). Key Results In each case, the labellum consists of a papillose mid-lobe (epichile), a cymbiform region (hypochile) and, proximally, a spur, which is pronounced in Cryptocentrum but short and blunt in Sepalosaccus. The inner epidermal surface of the spur of Cryptocentrum is glabrous or pubescent, and the bicellular hairs, where present, are unlike any hitherto described for Maxillariinae. Similar but unicellular hairs also occur in the floral spur of Sepalosaccus, whereas the glabrous epidermis lining the spur of C. peruvianum contains putative nectar pores. Conclusions The labellar micromorphology of Cryptocentrum and Sepalosaccus generally resembles that of Maxillaria. The floral spur of Cryptocentrum displays two types of organization in that the epidermal lining may be glabrous (possibly with nectar pores) or pubescent. This may have taxonomic significance and perhaps reflects physiological differences relating to nectar secretion. The trichomes found within the spurs of Cryptocentrum and Sepalosaccus more closely resemble the hairs of certain unrelated, nectariferous orchid taxa than those found in the largely nectarless genus Maxillaria, and this further

  12. Chapter 6: Floral Transformation of Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hexaploid wheat is one of the world’s most important staple crops but genetic transformation is still challenging. We are developing a floral transformation protocol for wheat that does not require tissue culture. Several T-DNA transformants have been produced in the high quality, hard red germpla...

  13. Circadian Rhythms in Floral Scent Emission.

    PubMed

    Fenske, Myles P; Imaizumi, Takato

    2016-01-01

    To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the floral volatile benzenoid/phenylpropanoid (FVBP) pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT 1 (ODO1), EMISSION OF BENZENOIDS I (EOBI), and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY) have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success. PMID:27148293

  14. Circadian Rhythms in Floral Scent Emission

    PubMed Central

    Fenske, Myles P.; Imaizumi, Takato

    2016-01-01

    To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the floral volatile benzenoid/phenylpropanoid (FVBP) pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT 1 (ODO1), EMISSION OF BENZENOIDS I (EOBI), and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY) have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success. PMID:27148293

  15. Invisible floral larcenies: microbial communities degrade floral nectar of bumble bee-pollinated plants.

    PubMed

    Herrera, Carlos M; García, Isabel M; Pérez, Ricardo

    2008-09-01

    The ecology of nectarivorous microbial communities remains virtually unknown, which precludes elucidating whether these organisms play some role in plant-pollinator mutualisms beyond minor commensalism. We simultaneously assessed microbial abundance and nectar composition at the individual nectary level in flowers of three southern Spanish bumble bee-pollinated plants (Helleborus foetidus, Aquilegia vulgaris, and Aquilegia pyrenaica cazorlensis). Yeasts were frequent and abundant in nectar of all species, and variation in yeast density was correlated with drastic changes in nectar sugar concentration and composition. Yeast communities built up in nectar from early to late floral stages, at which time all nectaries contained yeasts, often at densities between 10(4) and 10(5) cells/mm3. Total sugar concentration and percentage sucrose declined, and percentage fructose increased, with increasing density of yeast cells in nectar. Among-nectary variation in microbial density accounted for 65% (H. foetidus and A. vulgaris) and 35% (A. p. cazorlensis) of intraspecific variance in nectar sugar composition, and 60% (H. foetidus) and 38% (A. vulgaris) of variance in nectar concentration. Our results provide compelling evidence that nectar microbial communities can have detrimental effects on plants and/or pollinators via extensive nectar degradation and also call for a more careful interpretation of nectar traits in the future, if uncontrolled for yeasts. PMID:18831156

  16. Diversity of floral visitors to sympatric Lithophragma species differing in floral morphology.

    PubMed

    Cuautle, Mariana; Thompson, John N

    2010-01-01

    Most coevolving relationships between pairs of species are embedded in a broader multispecific interaction network. The mutualistic interaction between Lithophragma parviflorum (Saxifragaceae) and its pollinating floral parasite Greya politella (Lepidoptera, Prodoxidae) occurs in some communities as a pairwise set apart from most other interactions in those communities. In other communities, however, this pair of species occurs with congeners and with other floral visitors to Lithophragma. We analyzed local and geographic differences in the network formed by interactions between Lithophragma plants and Greya moths in communities containing two Lithophragma species, two Greya species, and floral visitors other than Greya that visit Lithophragma flowers. Our goal was to evaluate if non-Greya visitors were common, if visitor assembly differs between Lithophragma species and populations and if these visitors act as effective pollinators. Sympatric populations of L. heterophyllum and L. parviflorum differ in floral traits that may affect assemblies of floral visitors. Visitation rates by non-Greya floral visitors were low, and the asymptotic number of visitor species was less than 20 species in all populations. Lithophragma species shared some of the visitors, with visitor assemblages differing between sites more for L. heterophyllum than for L. parviflorum. Pollination efficacy experiments showed that most visitors were poor pollinators. Single visits to flowers by this assemblage of species resulted in significantly higher seed set in Lithophragma heterophyllum (30.6 +/- 3.9 SE) than in L. parviflorum (4.7 +/- 3.4 SE). This difference was consistent between sites, suggesting that these visitors provide a better fit to the floral morphology of L. heterophyllum. Overall, none of the non-Greya visitors appears to be either sufficiently common or efficient as a pollinator to impose strong selection on any of these four Lithophragma populations in comparison with Greya

  17. In planta localisation patterns of MADS domain proteins during floral development in Arabidopsis thaliana

    PubMed Central

    Urbanus, Susan L; de Folter, Stefan; Shchennikova, Anna V; Kaufmann, Kerstin; Immink, Richard GH; Angenent, Gerco C

    2009-01-01

    Background MADS domain transcription factors play important roles in various developmental processes in flowering plants. Members of this family play a prominent role in the transition to flowering and the specification of floral organ identity. Several studies reported mRNA expression patterns of the genes encoding these MADS domain proteins, however, these studies do not provide the necessary information on the temporal and spatial localisation of the proteins. We have made GREEN FLUORESCENT PROTEIN (GFP) translational fusions with the four MADS domain proteins SEPALLATA3, AGAMOUS, FRUITFULL and APETALA1 from the model plant Arabidopsis thaliana and analysed the protein localisation patterns in living plant tissues by confocal laser scanning microscopy (CLSM). Results We unravelled the protein localisation patterns of the four MADS domain proteins at a cellular and subcellular level in inflorescence and floral meristems, during development of the early flower bud stages, and during further differentiation of the floral organs. The protein localisation patterns revealed a few deviations from known mRNA expression patterns, suggesting a non-cell autonomous action of these factors or alternative control mechanisms. In addition, we observed a change in the subcellular localisation of SEPALLATA3 from a predominantly nuclear localisation to a more cytoplasmic localisation, occurring specifically during petal and stamen development. Furthermore, we show that the down-regulation of the homeodomain transcription factor WUSCHEL in ovular tissues is preceded by the occurrence of both AGAMOUS and SEPALLATA3 proteins, supporting the hypothesis that both proteins together suppress WUSCHEL expression in the ovule. Conclusion This approach provides a highly detailed in situ map of MADS domain protein presence during early and later stages of floral development. The subcellular localisation of the transcription factors in the cytoplasm, as observed at certain stages during

  18. Semen-Like Floral Scents and Pollination Biology of a Sapromyophilous Plant Stemona japonica (Stemonaceae).

    PubMed

    Chen, Gao; Jürgens, Andreas; Shao, Lidong; Liu, Yang; Sun, Weibang; Xia, Chengfeng

    2015-03-01

    By emitting scent resembling that of organic material suitable for oviposition and/or consumption by flies, sapromyophilous flowers use these flies as pollinators. To date, intensive scent analyses of such flowers have been restricted to Apocynaceae, Annonaceae, and Araceae. Recent studies have suggested that the wide range of volatile organic compounds (VOCs) from sapromyophilous flowers play an important role in attracting saprophagous flies by mimicking different types of decomposing substrates (herbivore and carnivore feces, carrion, and the fruiting bodies of fungi, etc.). In this study, we report the flower visitors and the floral VOCs of Stemona japonica (Blume) Miquel, a species native to China. The flowers do not produce rewards, and pollinators were not observed consuming pollen, thus suggesting a deceptive pollination system. Headspace samples of the floral scent were collected via solid-phase micro-extraction and analysed by gas chromatography coupled with mass spectrometry. Main floral scent compounds were 1-pyrroline (59.2%), 2-methyl-1-butanol (27.2%), and 3-methyl-1-butanol (8.8%), and resulted in a semen-like odor of blooming flowers. The floral constituents of S. japonica were significantly different from those found in previous sapromyophilous plants. An olfaction test indicated that 1-pyrroline is responsible for the semen-like odor in S. japonica flowers. Main flower visitors were shoot flies of the genus Atherigona (Muscidae). Bioassays using a mixture of all identified floral volatiles revealed that the synthetic volatiles can attract Atherigona flies in natural habitats. Our results suggest that the foul-smelling flowers of S. japonica may represent a new type of sapromyophily through scent mimicry. PMID:25835570

  19. Multi-organ Abnormalities and mTORC1 Activation in Zebrafish Model of Multiple Acyl-CoA Dehydrogenase Deficiency

    PubMed Central

    Kim, Seok-Hyung; Scott, Sarah A.; Bennett, Michael J.; Carson, Robert P.; Fessel, Joshua; Brown, H. Alex; Ess, Kevin C.

    2013-01-01

    Multiple Acyl-CoA Dehydrogenase Deficiency (MADD) is a severe mitochondrial disorder featuring multi-organ dysfunction. Mutations in either the ETFA, ETFB, and ETFDH genes can cause MADD but very little is known about disease specific mechanisms due to a paucity of animal models. We report a novel zebrafish mutant dark xavier (dxavu463) that has an inactivating mutation in the etfa gene. dxavu463 recapitulates numerous pathological and biochemical features seen in patients with MADD including brain, liver, and kidney disease. Similar to children with MADD, homozygote mutant dxavu463 zebrafish have a spectrum of phenotypes ranging from moderate to severe. Interestingly, excessive maternal feeding significantly exacerbated the phenotype. Homozygous mutant dxavu463 zebrafish have swollen and hyperplastic neural progenitor cells, hepatocytes and kidney tubule cells as well as elevations in triacylglycerol, cerebroside sulfate and cholesterol levels. Their mitochondria were also greatly enlarged, lacked normal cristae, and were dysfunctional. We also found increased signaling of the mechanistic target of rapamycin complex 1 (mTORC1) with enlarged cell size and proliferation. Treatment with rapamycin partially reversed these abnormalities. Our results indicate that etfa gene function is remarkably conserved in zebrafish as compared to humans with highly similar pathological, biochemical abnormalities to those reported in children with MADD. Altered mTORC1 signaling and maternal nutritional status may play critical roles in MADD disease progression and suggest novel treatment approaches that may ameliorate disease severity. PMID:23785301

  20. Dependency on floral resources determines the animals' responses to floral scents.

    PubMed

    Junker, Robert R; Blüthgen, Nico

    2010-08-01

    Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination - the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including mechanisms to bypass or tolerate floral defences such as morphological barriers and repellent / deterrent secondary metabolites. Facultative flower visitors, in contrast, are supposed to lack these adaptations and are often prevented to consume floral resources by defence mechanisms. In cases where obligate flower visitors are mutualists and facultative ones are antagonists, this dichotomy provides a solution for the plants' dilemma to attract pollinators and simultaneously repel exploiters. In a meta-analysis, we recently supported this hypothesis: obligate flower visitors are attracted to floral scents, while facultative ones are repelled. Here, we add empirical evidence to these results: bumblebees and ants, obligate and facultative flower visitors, respectively, responded as predicted by the results of the meta-analysis to synthetic floral scent compounds. PMID:20671428

  1. Contributions of iridescence to floral patterning.

    PubMed

    Whitney, Heather M; Kolle, Mathias; Alvarez-Fernandez, Ruben; Steiner, Ullrich; Glover, Beverley J

    2009-05-01

    The Hibiscus trionum flower is distinctly patterned, with white petals each with a patch of red pigment at the base, producing a 'bulls-eye' pattern on the whole flower. The red pigmented patches are also iridescent, due to the presence of a series of overlying cuticular striations that act as a diffraction grating. We have previously reported that scanning electron microscopy revealed a sharply defined difference between the surface structure overlying the pigmented patch and that over the rest of the petal, with the diffraction grating only present over the pigmented region. Here we show that differences in petal surface structure overlie differences in pigment color in three other species, in a range of different patterns. Floral patterns have previously been shown to be advantageous in pollinator attraction, and we discuss whether emphasis of pigment patterns by structural color may increase floral recognition by pollinators. PMID:19641739

  2. Contributions of iridescence to floral patterning

    PubMed Central

    Whitney, Heather M; Kolle, Mathias; Alvarez-Fernandez, Ruben; Steiner, Ullrich

    2009-01-01

    The Hibiscus trionum flower is distinctly patterned, with white petals each with a patch of red pigment at the base, producing a ‘bulls-eye’ pattern on the whole flower. The red pigmented patches are also iridescent, due to the presence of a series of overlying cuticular striations that act as a diffraction grating. We have previously reported that scanning electron microscopy revealed a sharply defined difference between the surface structure overlying the pigmented patch and that over the rest of the petal, with the diffraction grating only present over the pigmented region. Here we show that differences in petal surface structure overlie differences in pigment color in three other species, in a range of different patterns. Floral patterns have previously been shown to be advantageous in pollinator attraction, and we discuss whether emphasis of pigment patterns by structural color may increase floral recognition by pollinators. PMID:19641739

  3. Floral associations of cyclocephaline scarab beetles.

    PubMed

    Moore, Matthew Robert; Jameson, Mary Liz

    2013-01-01

    The scarab beetle tribe Cyclocephalini (Coleoptera: Scarabaeidae: Dynastinae) is the second largest tribe of rhinoceros beetles, with nearly 500 described species. This diverse group is most closely associated with early diverging angiosperm groups (the family Nymphaeaceae, magnoliid clade, and monocots), where they feed, mate, and receive the benefit of thermal rewards from the host plant. Cyclocephaline floral association data have never been synthesized, and a comprehensive review of this ecological interaction was necessary to promote research by updating nomenclature, identifying inconsistencies in the data, and reporting previously unpublished data. Based on the most specific data, at least 97 cyclocephaline beetle species have been reported from the flowers of 58 plant genera representing 17 families and 15 orders. Thirteen new cyclocephaline floral associations are reported herein. Six cyclocephaline and 25 plant synonyms were reported in the literature and on beetle voucher specimen labels, and these were updated to reflect current nomenclature. The valid names of three unavailable plant host names were identified. We review the cyclocephaline floral associations with respect to inferred relationships of angiosperm orders. Ten genera of cyclocephaline beetles have been recorded from flowers of early diverging angiosperm groups. In contrast, only one genus, Cyclocephala, has been recorded from dicot flowers. Cyclocephaline visitation of dicot flowers is limited to the New World, and it is unknown whether this is evolutionary meaningful or the result of sampling bias and incomplete data. The most important areas for future research include: (1) elucidating the factors that attract cyclocephalines to flowers including floral scent chemistry and thermogenesis, (2) determining whether cyclocephaline dicot visitation is truly limited to the New World, and (3) inferring evolutionary relationships within the Cyclocephalini to rigorously test vicarance hypotheses

  4. Floral Associations of Cyclocephaline Scarab Beetles

    PubMed Central

    Moore, Matthew Robert; Jameson, Mary Liz

    2013-01-01

    The scarab beetle tribe Cyclocephalini (Coleoptera: Scarabaeidae: Dynastinae) is the second largest tribe of rhinoceros beetles, with nearly 500 described species. This diverse group is most closely associated with early diverging angiosperm groups (the family Nymphaeaceae, magnoliid clade, and monocots), where they feed, mate, and receive the benefit of thermal rewards from the host plant. Cyclocephaline floral association data have never been synthesized, and a comprehensive review of this ecological interaction was necessary to promote research by updating nomenclature, identifying inconsistencies in the data, and reporting previously unpublished data. Based on the most specific data, at least 97 cyclocephaline beetle species have been reported from the flowers of 58 plant genera representing 17 families and 15 orders. Thirteen new cyclocephaline floral associations are reported herein. Six cyclocephaline and 25 plant synonyms were reported in the literature and on beetle voucher specimen labels, and these were updated to reflect current nomenclature. The valid names of three unavailable plant host names were identified. We review the cyclocephaline floral associations with respect to inferred relationships of angiosperm orders. Ten genera of cyclocephaline beetles have been recorded from flowers of early diverging angiosperm groups. In contrast, only one genus, Cyclocephala, has been recorded from dicot flowers. Cyclocephaline visitation of dicot flowers is limited to the New World, and it is unknown whether this is evolutionary meaningful or the result of sampling bias and incomplete data. The most important areas for future research include: 1) elucidating the factors that attract cyclocephalines to flowers including floral scent chemistry and thermogenesis, 2) determining whether cyclocephaline dicot visitation is truly limited to the New World, and 3) inferring evolutionary relationships within the Cyclocephalini to rigorously test vicarance hypotheses

  5. Floral Ontogeny in Scirpus, Eriophorum and Dulichium (Cyperaceae), with Special Reference to the Perianth

    PubMed Central

    VRIJDAGHS, A.; CARIS, P.; GOETGHEBEUR, P.; SMETS, E.

    2005-01-01

    • Background and Aims Based on molecular phylogenetic analysis, it has been suggested recently that the Cyperaceae comprises only two subfamilies: the Mapanioideae and the Cyperoideae. In most flowers of the Cyperoideae, the whorl of inner stamens is reduced, resulting in tetracyclic flowers. In the more primitive (scirpoid) genera within the Cyperoideae, the perianth consists of two polysymmetric whorls, whereas the perianth parts in the more derived genera have been subject to modifications and/or reduction. Comparative studies of the many silky hairs of Eriophorum and of the eight bristles of Dulichium have given rise to much discussion about their homology. • Methods The spikelet and floral ontogeny in freshly collected inflorescences was investigated using scanning electron microscopy. • Key Results Complete floral ontogenies are presented for Scirpus sylvaticus L., Eriophorum latifolium Hoppe and Dulichium arundinaceum (L.) Britton, with special reference to the perianth. The results in S. sylvaticus confirm the trimerous monocot-like organization of the flower. It is used as a model for floral development in Cyperoideae. In the early developmental stages, the androecium of E. latifolium is surrounded by a massive perigonial primordium, from which the many hair-like bristles originate. Consequently, the stamens develop among the hair primordia, more or less simultaneously. The hairs are arranged in whorls, which develop centripetally. The development of the perianth in D. arundinaceum starts with the formation of three initial perianth primordia opposite the stamens. Subsequently, two more abaxial bristle primordia, alternating with the stamens, originate simultaneously with the appearance of three adaxial bristle primordia in the zone where an adaxial inner perianth primordium is expected. • Conclusions The floral development in E. latifolium and D. arundinaceum can be considered as variations upon the scirpoid floral ontogenetic theme. PMID:15788436

  6. Floral Morphology and Development in Quillajaceae and Surianaceae (Fabales), the Species-poor Relatives of Leguminosae and Polygalaceae

    PubMed Central

    Bello, M. A.; Hawkins, J. A.; Rudall, P. J.

    2007-01-01

    Background and Aims Molecular phylogenies have suggested a new circumscription for Fabales to include Leguminosae, Quillajaceae, Surianaceae and Polygalaceae. However, recent attempts to reconstruct the interfamilial relationships of the order have resulted in several alternative hypotheses, including a sister relationship between Quillajaceae and Surianaceae, the two species-poor families of Fabales. Here, floral morphology and ontogeny of these two families are investigated to explore evidence of a potential relationship between them. Floral traits are discussed with respect to early radiation in the order. Method Floral buds of representatives of Quillajaceae and Surianaceae were dissected and observed using light microscopy and scanning electron microscopy. Key Results Quillajaceae and Surianaceae possess some common traits, such as inflorescence morphology and perianth initiation, but development and organization of their reproductive whorls differ. In Quillaja, initiation of the diplostemonous androecium is unidirectional, overlapping with the petal primordia. In contrast, Suriana is obdiplostemonous, and floral organ initiation is simultaneous. Independent initiation of five carpels is common to both Quillaja and Suriana, but subsequent development differs; the antesepalous carpels of Quillaja become fused proximally and exhibit two rows of ovules, and in Suriana the gynoecium is apocarpous, gynobasic, with antepetalous biovulate carpels. Conclusions Differences in the reproductive development and organization of Quillajaceae and Surianaceae cast doubt on their potential sister relationship. Instead, Quillaja resembles Leguminosae in some floral traits, a hypothesis not suggested by molecular-based phylogenies. Despite implicit associations of zygomorphy with species-rich clades and actinomorphy with species-poor families in Fabales, this correlation sometimes fails due to high variation in floral symmetry. Studies considering specific derived clades and

  7. Floral biology and reproductive isolation by floral scent in three sympatric aroid species in French Guiana.

    PubMed

    Hentrich, H; Kaiser, R; Gottsberger, G

    2010-07-01

    We studied the reproductive biology of three sympatric Araceae species, Anthurium sagittatum, A. thrinax and Spathiphyllum humboldtii in French Guiana. The plants flowered simultaneously and were visited by scent-collecting male euglossine bees, which were apparently their major pollinators. In total, each species was visited by 3-7 euglossine species, and 2-3 euglossine species accounted for at least 80% of all flower visits, with visits being plant species-specific. Floral scent consisted of 6-10 main compounds, which made up 76-94% of the total amount of volatiles and were specific in these high amounts to each plant species. We suggest that the different floral scents lead to clear separation of the main pollinating euglossine species, providing a directed and efficient intraspecific pollen flow that results in high reproductive success. Since the simple floral (inflorescence) morphology of the studied plants does not support any morphological mechanisms to exclude visitors, as for example in euglossine-pollinated perfume orchids, floral scent might be of major importance for the reproductive isolation and sympatric occurrence of these plants. PMID:20636901

  8. Air pollutants degrade floral scents and increase insect foraging times

    NASA Astrophysics Data System (ADS)

    Fuentes, Jose D.; Chamecki, Marcelo; Roulston, T.'ai; Chen, Bicheng; Pratt, Kenneth R.

    2016-09-01

    Flowers emit mixtures of scents that mediate plant-insect interactions such as attracting insect pollinators. Because of their volatile nature, however, floral scents readily react with ozone, nitrate radical, and hydroxyl radical. The result of such reactions is the degradation and the chemical modification of scent plumes downwind of floral sources. Large Eddy Simulations (LES) are developed to investigate dispersion and chemical degradation and modification of floral scents due to reactions with ozone, hydroxyl radical, and nitrate radical within the atmospheric surface layer. Impacts on foraging insects are investigated by utilizing a random walk model to simulate insect search behavior. Results indicate that even moderate air pollutant levels (e.g., ozone mixing ratios greater than 60 parts per billion on a per volume basis, ppbv) substantially degrade floral volatiles and alter the chemical composition of released floral scents. As a result, insect success rates of locating plumes of floral scents were reduced and foraging times increased in polluted air masses due to considerable degradation and changes in the composition of floral scents. Results also indicate that plant-pollinator interactions could be sensitive to changes in floral scent composition, especially if insects are unable to adapt to the modified scentscape. The increase in foraging time could have severe cascading and pernicious impacts on the fitness of foraging insects by reducing the time devoted to other necessary tasks.

  9. Ozone degrades floral scent and reduces pollinator attraction to flowers.

    PubMed

    Farré-Armengol, Gerard; Peñuelas, Josep; Li, Tao; Yli-Pirilä, Pasi; Filella, Iolanda; Llusia, Joan; Blande, James D

    2016-01-01

    In this work we analyzed the degradation of floral scent volatiles from Brassica nigra by reaction with ozone along a distance gradient and the consequences for pollinator attraction. For this purpose we used a reaction system comprising three reaction tubes in which we conducted measurements of floral volatiles using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) and GC-MS. We also tested the effects of floral scent degradation on the responses of the generalist pollinator Bombus terrestris. The chemical analyses revealed that supplementing air with ozone led to an increasing reduction in the concentrations of floral volatiles in air with distance from the volatile source. The results revealed different reactivities with ozone for different floral scent constituents, which emphasized that ozone exposure not only degrades floral scents, but also changes the ratios of compounds in a scent blend. Behavioural tests revealed that floral scent was reduced in its attractiveness to pollinators after it had been exposed to 120 ppb O3 over a 4.5 m distance. The combined results of chemical analyses and behavioural responses of pollinators strongly suggest that high ozone concentrations have significant negative impacts on pollination by reducing the distance over which floral olfactory signals can be detected by pollinators. PMID:26346807

  10. 36 CFR 12.10 - Floral and commemorative tributes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Floral and commemorative tributes. 12.10 Section 12.10 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL CEMETERY REGULATIONS § 12.10 Floral and commemorative tributes. The placement on a grave of fresh cut or artificial flowers in...

  11. Novel and conserved microRNAs in soybean floral whorls.

    PubMed

    Kulcheski, F R; Molina, L G; da Fonseca, G C; de Morais, G L; de Oliveira, L F V; Margis, R

    2016-01-10

    MicroRNAs (miRNAs) correspond to a class of endogenous small non-coding RNAs (19-24 nt) that regulates the gene expression, through mRNA target cleavage or translation inhibition. In plants, miRNAs have been shown to play pivotal roles in a wide variety of metabolic and biological processes like plant growth, development, and response to biotic and abiotic stress. Soybean is one of the most important crops worldwide, due to the production of oil and its high protein content. The reproductive phase is considered the most important for soybean yield, which is mainly intended to produce the grains. The identification of miRNAs is not yet saturated in soybean, and there are no studies linking them to the different floral organs. In this study, three different mature soybean floral whorls were used in the construction of sRNA libraries. The sequencing of petal, carpel and stamen libraries generated a total of 10,165,661 sequences. Subsequent analyses identified 200 miRNAs sequences, among which, 41 were novel miRNAs, 80 were conserved soybean miRNAs, 31 were new antisense conserved soybean miRNAs and 46 were soybean miRNAs isoforms. We also found a new miRNA conserved in other plant species, and finally one miRNA-sibling of a soybean conserved miRNA. Conserved and novel miRNAs were evaluated by RT-qPCR. We observed a differential expression across the three whorls for six miRNAs. Computational predicted targets for miRNAs analyzed by RT-qPCR were identified and present functions related to reproductive process in plants. In summary, the increased accumulation of specific and novel miRNAs in different whorls indicates that miRNAs are an important part of the regulatory network in soybean flower. PMID:26341053

  12. Nickel accumulation by Streptanthus polygaloides (Brassicaceae) reduces floral visitation rate.

    PubMed

    Meindl, George A; Ashman, Tia-Lynn

    2014-02-01

    Hyperaccumulation is the phenomenon whereby plants take up and sequester in high concentrations elements that generally are excluded from above-ground tissues. It largely is unknown whether the metals taken up by these plants are transferred to floral rewards (i.e., nectar and pollen) and, if so, whether floral visitation is affected. We grew Streptanthus polygaloides, a nickel (Ni) hyperaccumulator, in short-term Ni supplemented soils and control soils to determine whether Ni is accumulated in floral rewards and whether floral visitation is affected by growth in Ni-rich soils. We found that while supplementation of soils with Ni did not alter floral morphology or reward quantity (i.e., anther size or nectar volume), Ni did accumulate in the nectar and pollen-filled anthers-providing the first demonstration that Ni is accumulated in pollinator rewards. Further, S. polygaloides grown in Ni-supplemented soils received fewer visits per flower per hour from both bees and flies (both naïve to Ni-rich floral resources in the study area) relative to plants grown in control soils, although the probability a plant was visited initially was unaffected by Ni treatment. Our findings show that while Ni-rich floral rewards decrease floral visitation, floral visitors are not completely deterred, so some floral visitors may collect and ingest potentially toxic resources from metal-hyperaccumulating plants. In addition to broadening our understanding of the effects of metal accumulation on ecological interactions in natural populations, these results have implications for the use of insect-pollinated plants in phytoremediation. PMID:24477333

  13. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

    PubMed Central

    Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

    2016-01-01

    The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

  14. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications.

    PubMed

    Tóth, Peter; Undas, Anna K; Verstappen, Francel; Bouwmeester, Harro

    2016-01-01

    The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

  15. Floral symmetry affects speciation rates in angiosperms.

    PubMed Central

    Sargent, Risa D.

    2004-01-01

    Despite much recent activity in the field of pollination biology, the extent to which animal pollinators drive the formation of new angiosperm species remains unresolved. One problem has been identifying floral adaptations that promote reproductive isolation. The evolution of a bilaterally symmetrical corolla restricts the direction of approach and movement of pollinators on and between flowers. Restricting pollinators to approaching a flower from a single direction facilitates specific placement of pollen on the pollinator. When coupled with pollinator constancy, precise pollen placement can increase the probability that pollen grains reach a compatible stigma. This has the potential to generate reproductive isolation between species, because mutations that cause changes in the placement of pollen on the pollinator may decrease gene flow between incipient species. I predict that animal-pollinated lineages that possess bilaterally symmetrical flowers should have higher speciation rates than lineages possessing radially symmetrical flowers. Using sister-group comparisons I demonstrate that bilaterally symmetric lineages tend to be more species rich than their radially symmetrical sister lineages. This study supports an important role for pollinator-mediated speciation and demonstrates that floral morphology plays a key role in angiosperm speciation. PMID:15156918

  16. Distinct regulation in inflorescence carbohydrate metabolism according to grapevine cultivars during floral development.

    PubMed

    Sawicki, Mélodie; Jacquens, Lucile; Baillieul, Fabienne; Clément, Christophe; Vaillant-Gaveau, Nathalie; Jacquard, Cédric

    2015-07-01

    Carbohydrate metabolism is important in plant sexual reproduction because sugar contents are determining factors for both flower initiation and floral organ development. In woody plants, flowering represents the most energy-consuming step crucial to reproductive success. Nevertheless, in these species, the photosynthesis performed by flowers supplies the carbon required for reproduction. In grapevine (Vitis vinifera), the inflorescence has a specific status because this organ imports carbohydrates at the same time as it exports photoassimilates. In this study, fluctuations in carbohydrate metabolism were monitored by analyzing gas exchanges, photosynthetic electron transport capacity, carbohydrate contents and some activities of carbohydrate metabolism enzymes, in the inflorescences of Pinot noir and Gewurztraminer, two cultivars with a different sensitivity to coulure phenomenon. Our results showed that photosynthetic activity and carbohydrate metabolism are clearly different and differently regulated during the floral development in the two cultivars. Indeed, the regulation of the linear electron flow and the cyclic electron flow is not similar. Moreover, the regulation of PSII activity, with a higher Y(NPQ)/Y(NO) ratio in Gewurztraminer, can be correlated with the higher protection of the photosynthetic chain and consequently with the higher yield under optimal conditions of this cultivar. At least, our results showed a higher photosynthetic activity and a better protection of PSI in Pinot noir during the floral development. PMID:25585972

  17. Floral patterning defects induced by Arabidopsis APETALA2 and microRNA172 expression in Nicotiana benthamiana.

    PubMed

    Mlotshwa, Sizolwenkosi; Yang, Zhiyong; Kim, Yunju; Chen, Xuemei

    2006-07-01

    Floral patterning and morphogenesis are controlled by many transcription factors including floral homeotic proteins, by which floral organ identity is determined. Recent studies have uncovered widespread regulation of transcription factors by microRNAs (miRNAs), approximately 21-nucleotide non-coding RNAs that regulate protein-coding RNAs through transcript cleavage and/or translational inhibition. The regulation of the floral homeotic gene APETALA2 (AP2) by miR172 is crucial for normal Arabidopsis flower development and is likely to be conserved across plant species. Here we probe the activity of the AP2/miR172 regulatory circuit in a heterologous Solanaceae species, Nicotiana benthamiana. We generated transgenic N. benthamiana lines expressing Arabidopsis wild type AP2 (35S::AP2), miR172-resistant AP2 mutant (35S::AP2m3) and MIR172a-1 (35S::MIR172) under the control of the cauliflower mosaic virus 35S promoter. 35S::AP2m3 plants accumulated high levels of AP2 mRNA and protein and exhibited floral patterning defects that included proliferation of numerous petals, stamens and carpels indicating loss of floral determinacy. On the other hand, nearly all 35S::AP2 plants accumulated barely detectable levels of AP2 mRNA or protein and were essentially non-phenotypic. Overall, the data indicated that expression of the wild type Arabidopsis AP2 transgene was repressed at the mRNA level by an endogenous N. benthamiana miR172 homologue that could be detected using Arabidopsis miR172 probe. Interestingly, 35S::MIR172 plants had sepal-to-petal transformations and/or more sepals and petals, suggesting interference with N. benthamiana normal floral homeotic gene function in perianth organs. Our studies uncover the potential utility of the Arabidopsis AP2/miR172 system as a tool for manipulation of floral architecture and flowering time in non-model plants. PMID:16897492

  18. Whole-Transcriptome Analysis of Differentially Expressed Genes in the Vegetative Buds, Floral Buds and Buds of Chrysanthemum morifolium

    PubMed Central

    Liu, Hua; Sun, Ming; Du, Dongliang; Pan, Huitang; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

    2015-01-01

    Background Chrysanthemum morifolium is an important floral crop that is cultivated worldwide. However, due to a lack of genomic resources, very little information is available concerning the molecular mechanisms of flower development in chrysanthemum. Results The transcriptomes of chrysanthemum vegetative buds, floral buds and buds were sequenced using Illumina paired-end sequencing technology. A total of 15.4 Gb of reads were assembled into 91,367 unigenes with an average length of 739 bp. A total of 43,137 unigenes showed similarity to known proteins in the Swissprot or NCBI non-redundant protein databases. Additionally, 25,424, 24,321 and 13,704 unigenes were assigned to 56 gene ontology (GO) categories, 25 EuKaryotic Orthologous Groups (KOG) categories, and 285 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 1,876 differentially expressed genes (DEGs) (1,516 up-regulated, 360 down-regulated) were identified between vegetative buds and floral buds, and 3,300 DEGs (1,277 up-regulated, 1,706 down-regulated) were identified between floral buds and buds. Many genes encoding important transcription factors (e.g., AP2, MYB, MYC, WRKY, NAC and CRT) as well as proteins involved in carbohydrate metabolism, protein kinase activity, plant hormone signal transduction, and the defense responses, among others, were considerably up-regulated in floral buds. Genes involved in the photoperiod pathway and flower organ determination were also identified. These genes represent important candidate genes for molecular cloning and functional analysis to study flowering regulation in chrysanthemum. Conclusion This comparative transcriptome analysis revealed significant differences in gene expression and signaling pathway components between the vegetative buds, floral buds and buds of Chrysanthemum morifolium. A wide range of genes was implicated in regulating the phase transition from vegetative to reproductive growth. These results should aid

  19. The role of jasmonates in floral nectar secretion.

    PubMed

    Radhika, Venkatesan; Kost, Christian; Boland, Wilhelm; Heil, Martin

    2010-01-01

    Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA) endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants. PMID:20174464

  20. A de novo floral transcriptome reveals clues into Phalaenopsis orchid flower development.

    PubMed

    Huang, Jian-Zhi; Lin, Chih-Peng; Cheng, Ting-Chi; Chang, Bill Chia-Han; Cheng, Shu-Yu; Chen, Yi-Wen; Lee, Chen-Yu; Chin, Shih-Wen; Chen, Fure-Chyi

    2015-01-01

    Phalaenopsis has a zygomorphic floral structure, including three outer tepals, two lateral inner tepals and a highly modified inner median tepal called labellum or lip; however, the regulation of its organ development remains unelucidated. We generated RNA-seq reads with the Illumina platform for floral organs of the Phalaenopsis wild-type and peloric mutant with a lip-like petal. A total of 43,552 contigs were obtained after de novo assembly. We used differentially expressed gene profiling to compare the transcriptional changes in floral organs for both the wild-type and peloric mutant. Pair-wise comparison of sepals, petals and labellum between peloric mutant and its wild-type revealed 1,838, 758 and 1,147 contigs, respectively, with significant differential expression. PhAGL6a (CUFF.17763), PhAGL6b (CUFF.17763.1), PhMADS1 (CUFF.36625.1), PhMADS4 (CUFF.25909) and PhMADS5 (CUFF.39479.1) were significantly upregulated in the lip-like petal of the peloric mutant. We used real-time PCR analysis of lip-like petals, lip-like sepals and the big lip of peloric mutants to confirm the five genes' expression patterns. PhAGL6a, PhAGL6b and PhMADS4 were strongly expressed in the labellum and significantly upregulated in lip-like petals and lip-like sepals of peloric-mutant flowers. In addition, PhAGL6b was significantly downregulated in the labellum of the big lip mutant, with no change in expression of PhAGL6a. We provide a comprehensive transcript profile and functional analysis of Phalaenopsis floral organs. PhAGL6a PhAGL6b, and PhMADS4 might play crucial roles in the development of the labellum in Phalaenopsis. Our study provides new insights into how the orchid labellum differs and why the petal or sepal converts to a labellum in Phalaenopsis floral mutants. PMID:25970572

  1. A De Novo Floral Transcriptome Reveals Clues into Phalaenopsis Orchid Flower Development

    PubMed Central

    Huang, Jian-Zhi; Lin, Chih-Peng; Cheng, Ting-Chi; Chang, Bill Chia-Han; Cheng, Shu-Yu; Chen, Yi-Wen; Lee, Chen-Yu; Chin, Shih-Wen; Chen, Fure-Chyi

    2015-01-01

    Phalaenopsis has a zygomorphic floral structure, including three outer tepals, two lateral inner tepals and a highly modified inner median tepal called labellum or lip; however, the regulation of its organ development remains unelucidated. We generated RNA-seq reads with the Illumina platform for floral organs of the Phalaenopsis wild-type and peloric mutant with a lip-like petal. A total of 43,552 contigs were obtained after de novo assembly. We used differentially expressed gene profiling to compare the transcriptional changes in floral organs for both the wild-type and peloric mutant. Pair-wise comparison of sepals, petals and labellum between peloric mutant and its wild-type revealed 1,838, 758 and 1,147 contigs, respectively, with significant differential expression. PhAGL6a (CUFF.17763), PhAGL6b (CUFF.17763.1), PhMADS1 (CUFF.36625.1), PhMADS4 (CUFF.25909) and PhMADS5 (CUFF.39479.1) were significantly upregulated in the lip-like petal of the peloric mutant. We used real-time PCR analysis of lip-like petals, lip-like sepals and the big lip of peloric mutants to confirm the five genes’ expression patterns. PhAGL6a, PhAGL6b and PhMADS4 were strongly expressed in the labellum and significantly upregulated in lip-like petals and lip-like sepals of peloric-mutant flowers. In addition, PhAGL6b was significantly downregulated in the labellum of the big lip mutant, with no change in expression of PhAGL6a. We provide a comprehensive transcript profile and functional analysis of Phalaenopsis floral organs. PhAGL6a PhAGL6b, and PhMADS4 might play crucial roles in the development of the labellum in Phalaenopsis. Our study provides new insights into how the orchid labellum differs and why the petal or sepal converts to a labellum in Phalaenopsis floral mutants. PMID:25970572

  2. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts.

    PubMed

    Cane, James H

    2011-09-01

    Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar floral traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy by polyleges sometimes serves as an ethological mating barrier. More often, their foraging infidelities instead facilitate host introgression and hybridization. Many other bee species are oligolectic (taxonomic specialists for pollen). Oligoleges could be more discriminating connoisseurs than polyleges when foraging among their limited set of related floral hosts. If true, greater foraging constancy might ensue, contributing to positive assortative mating and disruptive selection, thereby facilitating speciation among their interfertile floral hosts. To test this Connoisseur Hypothesis, nesting females of two species of oligolectic Osmia bees were presented with randomized mixed arrays of flowers of two sympatric species of their pollen host, Balsamorhiza, a genus known for hybridization. In a closely spaced grid, the females of both species preferred the larger flowered B. macrophylla, evidence for discrimination. However, both species' females showed no floral constancy whatsoever during their individual foraging bouts, switching randomly between species proportional to their floral preference. In a wider spaced array in which the bouquets reflected natural plant spacing, foraging oligolectic bees often transferred pollen surrogates (fluorescent powders) both between conspecific flowers (geitonogamy and xenogamy) and between the two Balsamorhiza species. The Connoisseur Hypothesis was therefore rejected. Foraging infidelity by these oligolectic Osmia bees will contribute to

  3. Floral adaptation to local pollinator guilds in a terrestrial orchid

    PubMed Central

    Sun, Mimi; Gross, Karin; Schiestl, Florian P.

    2014-01-01

    Background and Aims Studies of local floral adaptation in response to geographically divergent pollinators are essential for understanding floral evolution. This study investigated local pollinator adaptation and variation in floral traits in the rewarding orchid Gymnadenia odoratissima, which spans a large altitudinal gradient and thus may depend on different pollinator guilds along this gradient. Methods Pollinator communities were assessed and reciprocal transfer experiments were performed between lowland and mountain populations. Differences in floral traits were characterized by measuring floral morphology traits, scent composition, colour and nectar sugar content in lowland and mountain populations. Key Results The composition of pollinator communities differed considerably between lowland and mountain populations; flies were only found as pollinators in mountain populations. The reciprocal transfer experiments showed that when lowland plants were transferred to mountain habitats, their reproductive success did not change significantly. However, when mountain plants were moved to the lowlands, their reproductive success decreased significantly. Transfers between populations of the same altitude did not lead to significant changes in reproductive success, disproving the potential for population-specific adaptations. Flower size of lowland plants was greater than for mountain flowers. Lowland plants also had significantly higher relative amounts of aromatic floral volatiles, while the mountain plants had higher relative amounts of other floral volatiles. The floral colour of mountain flowers was significantly lighter compared with the lowland flowers. Conclusions Local pollinator adaptation through pollinator attraction was shown in the mountain populations, possibly due to adaptation to pollinating flies. The mountain plants were also observed to receive pollination from a greater diversity of pollinators than the lowland plants. The different floral

  4. Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid

    PubMed Central

    Gross, Karin; Sun, Mimi; Schiestl, Florian P.

    2016-01-01

    Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling. PMID:26886766

  5. Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid.

    PubMed

    Gross, Karin; Sun, Mimi; Schiestl, Florian P

    2016-01-01

    Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling. PMID:26886766

  6. Why are orchid flowers so diverse? Reduction of evolutionary constraints by paralogues of class B floral homeotic genes

    PubMed Central

    Mondragón-Palomino, Mariana; Theißen, Günter

    2009-01-01

    Background The nearly 30 000 species of orchids produce flowers of unprecedented diversity. However, whether specific genetic mechanisms contributed to this diversity is a neglected topic and remains speculative. We recently published a theory, the ‘orchid code’, maintaining that the identity of the different perianth organs is specified by the combinatorial interaction of four DEF-like MADS-box genes with other floral homeotic genes. Scope Here the developmental and evolutionary implications of our theory are explored. Specifically, it is shown that all frequent floral terata, including all peloric types, can be explained by monogenic gain- or-loss-of-function mutants, changing either expression of a DEF-like or CYC-like gene. Supposed dominance or recessiveness of mutant alleles is correlated with the frequency of terata in both cultivation and nature. Our findings suggest that changes in DEF- and CYC-like genes not only underlie terata but also the natural diversity of orchid species. We argue, however, that true changes in organ identity are rare events in the evolution of orchid flowers, even though we review some likely cases. Conclusions The four DEF paralogues shaped floral diversity in orchids in a dramatic way by modularizing the floral perianth based on a complex series of sub- and neo-functionalization events. These genes may have eliminated constraints, so that different kinds of perianth organs could then evolve individually and thus often in dramatically different ways in response to selection by pollinators or by genetic drift. We therefore argue that floral diversity in orchids may be the result of an unprecedented developmental genetic predisposition that originated early in orchid evolution. PMID:19141602

  7. Floral volatiles in a sapromyiophilous plant and their importance in attracting house fly pollinators.

    PubMed

    Zito, Pietro; Dötterl, Stefan; Sajeva, Maurizio

    2015-04-01

    Floral scent in sapromyiophilous plants often consists of complex blends with not only fetid (e.g., sulfides) but also sweet (e.g., terpenoids) volatile organic compounds, and a recent study suggests that both groups of compounds are involved in pollinator attraction. However, little is known about the number and identity of compounds involved in pollinator attraction in these deceptive plants that mimic breeding sites of fly pollinators. In the present paper, we studied flower volatiles of sapromyiophilous Periploca laevigata and their capability to elicit biological responses in one of the pollinator species, Musca domestica. Floral volatiles were collected by dynamic headspace and analyzed by gas chromatography/mass spectrometry (GC/MS), and electrophysiological (GC/EAD) and behavioral assays (two choice olfactometer) were conducted. In the floral scent of P. laevigata, we detected 44 compounds, of which indole, β-caryophyllene, and germacrene D, as well as dimethyl trisulfide, which was present in trace amounts, were electrophysiologically active in the antennae of M. domestica. However, when we evaluated in behavioral experiments the attractiveness of the electrophysiologically active compounds (complete mixture against partial mixtures or against single compounds), we found that indole was the only attractive compound for the flies. PMID:25833217

  8. [Regulation network and biological roles of LEAFY in Arabidopsis thaliana in floral development].

    PubMed

    Wang, Li-Lin; Liang, Hai-Man; Pang, Ji-Liang; Zhu, Mu-Yuan

    2004-01-01

    Recent research progress on regulation network and biological roles of LFY gene in Arabidopsis thaliana and its homologue genes in floral development are reviewed emphatically in the present paper. LFY gene expresses widely in both vegetative and reproductive tissues in different higher plants, therefore investigation on role of LFY gene on flowering is of general significance. LFY gene plays an important role to promote flower formation by interaction and coordination with other genes,such as TFL, EMF, AP1, AP2, CAL, FWA, FT, AP3, PI, AG, UFO, CO, LD, GA1 etc, and a critical level of LFY expression is essential. LFY gene not only controls flowering-time and floral transition,but also plays an important role in inflorescence and floral organ development. It was situated at the central site in gene network of flowering regulation,positively or negatively regulates the level or activities of flowering-related genes. Some physiological factors, such as carbon sources, phytohormones, affect directly or indirectly the expression and actions of LFY gene. This indicates that level of LFY expression can also be regulated with physiological methods. It is probable that we can explain the principal mechanism of flowering by regulation network of LFY gene. PMID:15626683

  9. Floral Evolution of Philodendron Subgenus Meconostigma (Araceae)

    PubMed Central

    de Oliveira, Letícia Loss; Calazans, Luana Silva Braucks; de Morais, Érica Barroso; Mayo, Simon Joseph; Schrago, Carlos Guerra; Sakuragui, Cassia Mônica

    2014-01-01

    Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface. PMID:24586972

  10. Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

    PubMed

    Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

    2014-01-01

    In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants. PMID:24676333

  11. Floral Reward, Advertisement and Attractiveness to Honey Bees in Dioecious Salix caprea

    PubMed Central

    Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

    2014-01-01

    In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants. PMID:24676333

  12. Specialist Osmia Bees Forage Indiscriminately Among Hybridizing Balsamorhiza Floral Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Even generalist pollinators are typically taxonomic specialists during individual foraging bouts. Such floral constancy restricts pollen flow, and thereby gene flow, between otherwise inter-fertile flowering species, thus serving as an ethological mating barrier. Among incipient species, however, ...

  13. How scent and nectar influence floral antagonists and mutualists.

    PubMed

    Kessler, Danny; Kallenbach, Mario; Diezel, Celia; Rothe, Eva; Murdock, Mark; Baldwin, Ian T

    2015-01-01

    Many plants attract and reward pollinators with floral scents and nectar, respectively, but these traits can also incur fitness costs as they also attract herbivores. This dilemma, common to most flowering plants, could be solved by not producing nectar and/or scent, thereby cheating pollinators. Both nectar and scent are highly variable in native populations of coyote tobacco, Nicotiana attenuata, with some producing no nectar at all, uncorrelated with the tobacco's main floral attractant, benzylacetone. By silencing benzylacetone biosynthesis and nectar production in all combinations by RNAi, we experimentally uncouple these floral rewards/attractrants and measure their costs/benefits in the plant's native habitat and experimental tents. Both scent and nectar increase outcrossing rates for three, separately tested, pollinators and both traits increase oviposition by a hawkmoth herbivore, with nectar being more influential than scent. These results underscore that it makes little sense to study floral traits as if they only mediated pollination services. PMID:26132861

  14. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Even generalist pollinators are typically taxonomic specialists during individual foraging bouts. Such floral constancy restricts pollen flow, and thereby gene flow, between otherwise inter-fertile flowering species, thus serving as an ethological mating barrier. Among incipient species, however, ...

  15. Similar Genetic Mechanisms Underlie the Parallel Evolution of Floral Phenotypes

    PubMed Central

    Zhang, Wenheng; Kramer, Elena M.; Davis, Charles C.

    2012-01-01

    The repeated origin of similar phenotypes is invaluable for studying the underlying genetics of adaptive traits; molecular evidence, however, is lacking for most examples of such similarity. The floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to result from specialization on oil-bee pollinators. We recently demonstrated that CYCLOIDEA2–like genes (CYC2A and CYC2B) are associated with the development of the stereotypical floral zygomorphy that is critical to this plant–pollinator mutualism. Here, we build on this developmental framework to characterize floral symmetry in three clades of Malpighiaceae that have independently lost their oil bee association and experienced parallel shifts in their floral morphology, especially in regard to symmetry. We show that in each case these species exhibit a loss of CYC2B function, and a strikingly similar shift in the expression of CYC2A that is coincident with their shift in floral symmetry. These results indicate that similar floral phenotypes in this large angiosperm clade have evolved via parallel genetic changes from an otherwise highly conserved developmental program. PMID:22558314

  16. Homoeologous copy-specific expression patterns of MADS-box genes for floral formation in allopolyploid wheat.

    PubMed

    Tanaka, Miku; Tanaka, Hiroko; Shitsukawa, Naoki; Kitagawa, Satoshi; Takumi, Shigeo; Murai, Koji

    2016-01-01

    The consensus model for floral organ formation in higher plants, the so-called ABCDE model, proposes that floral whorl-specific combinations of class A, B, C, D, and E genes specify floral organ identity. Class A, B, C, D and E genes encode MADS-box transcription factors; the single exception being the class A gene APETALA2. Bread wheat (Triticum aestivum) is a hexaploid species with a genome constitution AABBDD; the hexaploid originated from a cross between tetraploid T. turgidum (AABB) and diploid Aegilops tauschii (DD). Tetraploid wheat is thought to have originated from a cross between the diploid species T. urartu (AA) and Ae. speltoides (BB). Consequently, the hexaploid wheat genome contains triplicated homoeologous copies (homoeologs) of each gene derived from the different ancestral diploid species. In this study, we examined the expression patterns of homoeologs of class B, C and D MADS-box genes during floral development. For the class B gene wheat PISTILLATA2 (WPI2), the homoeologs from the A and D genomes were expressed, while expression of the B genome homoeolog was suppressed. For the class C gene wheat AGAMOUS1 (WAG1), the homoeologs on the A and B genomes were expressed, while expression of the D genome homoeolog was suppressed. For the class D gene wheat SEEDSTICK (WSTK), the B genome homoeolog was preferentially expressed. These differential patterns of homoeolog expression were consistently observed among different hexaploid wheat varieties and synthetic hexaploid wheat lines developed by artificial crosses between tetraploid wheat and Ae. tauschii. These results suggest that homoeolog-specific regulation of the floral MADS-box genes occurs in allopolyploid wheat. PMID:26616759

  17. The corona of the daffodil Narcissus bulbocodium shares stamen-like identity and is distinct from the orthodox floral whorls.

    PubMed

    Waters, Mark T; Tiley, Anna M M; Kramer, Elena M; Meerow, Alan W; Langdale, Jane A; Scotland, Robert W

    2013-05-01

    The structural homology of the daffodil corona has remained a source of debate throughout the history of botany. Over the years it has been separately referred to as a modified petal stipule, stamen and tepal. Here we provide insights from anatomy and molecular studies to clarify the early developmental stages and position of corona initiation in Narcissus bulbocodium. We demonstrate that the corona initiates as six separate anlagen from hypanthial tissue between the stamens and perianth. Scanning electron microscope images and serial sections demonstrate that corona initiation occurs late in development, after the other floral whorls are fully developed. To define more precisely the identity of the floral structures, daffodil orthologues of the ABC floral organ identity genes were isolated and expression patterns were examined in perianth, stamens, carpel, hypanthial tube and corona tissue. Coupled with in situ hybridisation experiments, these analyses showed that the expression pattern of the C-class gene NbAGAMOUS in the corona is more similar to that of the stamens than that of the tepals. In combination, our results demonstrate that the corona of the daffodil N. bulbocodium exhibits stamen-like identity, develops independently from the orthodox floral whorls and is best interpreted as a late elaboration of the region between the petals and stamens associated with epigyny and the hypanthium. PMID:23406544

  18. Identification and Characterization of Three Orchid MADS-Box Genes of the AP1/AGL9 Subfamily during Floral Transition1

    PubMed Central

    Yu, Hao; Goh, Chong Jin

    2000-01-01

    Gene expressions associated with in vitro floral transition in an orchid hybrid (Dendrobium grex Madame Thong-In) were investigated by differential display. One clone, orchid transitional growth related gene 7 (otg7), encoding a new MADS-box gene, was identified to be specifically expressed in the transitional shoot apical meristem (TSAM). Using this clone as a probe, three orchid MADS-box genes, DOMADS1, DOMADS2, and DOMADS3, were subsequently isolated from the TSAM cDNA library. Phylogenetic analyses show that DOMADS1 and DOMADS2 are new members of the AGL2 subfamily and SQUA subfamily, respectively. DOMADS3 contains the signature amino acids as with the members in the independent OSMADS1 subfamily separated from the AGL2 subfamily. All three of the DOMADS genes were expressed in the TSAM during floral transition and later in mature flowers. DOMADS1 RNA was uniformly expressed in both of the inflorescence meristem and the floral primordium and later localized in all of the floral organs. DOMADS2 showed a novel expression pattern that has not been previously characterized for any other MADS-box genes. DOMADS2 transcript was expressed early in the 6-week-old vegetative shoot apical meristem in which the obvious morphological change to floral development had yet to occur. It was expressed throughout the process of floral transition and later in the columns of mature flowers. The onset of DOMADS3 transcription was in the early TSAM at the stage before the differentiation of the first flower primordium. Later, DOMADS3 transcript was only detectable in the pedicel tissues. Our results suggest that the DOMADS genes play important roles in the process of floral transition. PMID:10938351

  19. Validation of Aintegumenta as a gene to modify floral size in ornamental plants.

    PubMed

    Manchado-Rojo, María; Weiss, Julia; Egea-Cortines, Marcos

    2014-10-01

    The gene AINTEGUMENTA (AtANT) is an APETALA2 transcription factor in Arabidopsis activating growth downstream of auxin signalling. Lateral organ size is positively correlated with ANT expression in Arabidopsis. We tested the use of AtANT as a tool to modify floral size in two different plants used as model organisms and ornamental crops, Petunia × hybrida and Antirrhinum majus. Petunia plants expressing PhANT RNAi showed a decrease in PhANT expression correlated with smaller petal limbs. In contrast Petunia plants overexpressing AtANT had larger petal limbs. Petal tube length was less affected in down-regulation of PhANT or overexpression of AtANT. Overexpression of AtANT in Antirrhinum caused increased flower size via increased petal limb width and tube length. Down-regulation of PhANT showed an effect on cell size while overexpression of AtANT in Petunia and Antirrhinum caused significant increases in cell expansion that could explain the differences in floral organ size. The endogenous expression levels of PhANT and AmANT tended to be higher in the limb than in the tube in both Antirrhinum and Petunia. AtANT overexpression caused significant AmANT up-regulation in Antirrhinum limbs but not of PhANT in Petunia, indicating differences in the regulatory network. The differential effect of AtANT on limb and tube in Petunia and Antirrhinum correspond to phenotypic differences observed in natural variation in the corresponding genus indicating a relation between the phenotypic space of a genus and the effect of modified ANT levels, validating ANT as a gene to modify floral size. PMID:24985495

  20. Interpreting lemma and palea homologies: a point of view from rice floral mutants.

    PubMed

    Lombardo, Fabien; Yoshida, Hitoshi

    2015-01-01

    In contrast to eudicot flowers which typically exhibit sepals and petals at their periphery, the flowers of grasses are distinguished by the presence of characteristic outer organs. In place of sepals, grasses have evolved the lemma and the palea, two bract-like structures that partially or fully enclose the inner reproductive organs. With little morphological similarities to sepals, whether the lemma and palea are part of the perianth or non-floral organs has been a longstanding debate. In recent years, comparative studies of floral mutants as well as the availability of whole genome sequences in many plant species have provided strong arguments in favor of the hypothesis of lemma and palea being modified sepals. In rice, a feature of the palea is the bending of its lateral region into a hook-shaped marginal structure. This allows the palea to lock into the facing lemma region, forming a close-fitting lemma-palea enclosure. In this article, we focus on the rice lemma and palea and review some of the key transcription factors involved in their development and functional specialization. Alternative interpretations of these organs are also addressed. PMID:25741351

  1. Floral adaptation and diversification under pollen limitation

    PubMed Central

    Harder, Lawrence D.; Aizen, Marcelo A.

    2010-01-01

    Pollen limitation (PL) of seed production creates unique conditions for reproductive adaptation by angiosperms, in part because, unlike under ovule or resource limitation, floral interactions with pollen vectors can contribute to variation in female success. Although the ecological and conservation consequences of PL have received considerable attention in recent times, its evolutionary implications are poorly appreciated. To identify general influences of PL on reproductive adaptation compared with those under other seed-production limits and their implications for evolution in altered environments, we derive a model that incorporates pollination and post-pollination aspects of PL. Because PL always favours increased ovule fertilization, even when population dynamics are not seed limited, it should pervasively influence selection on reproductive traits. Significantly, under PL the intensity of inbreeding does not determine whether outcrossing or autonomous selfing can evolve, although it can affect which response is most likely. Because the causes of PL are multifaceted in both natural and anthropogenically altered environments, the possible outcrossing solutions are diverse and context dependent, which may contribute to the extensive variety of angiosperm reproductive characteristics. Finally, the increased adaptive options available under PL may be responsible for positive global associations between it and angiosperm diversity. PMID:20047878

  2. Differential expression of MYB gene (OgMYB1) determines color patterning in floral tissue of Oncidium Gower Ramsey.

    PubMed

    Chiou, Chung-Yi; Yeh, Kai-Wun

    2008-03-01

    The yellow coloration pattern in Oncidium floral lip associated with red sepal and petal tissues is an ideal model to study coordinate regulation of anthocyanin synthesis. In this study, chromatography analysis revealed that the red coloration in floral tissues was composed of malvidin-3-O-galactoside, peonidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside compounds. By contrary, these pigments were not detected in yellow lip tissue. Four key genes involved in anthocyanin biosynthetic pathway, i.e. chalcone synthase (OgCHS), chalcone isomerase (OgCHI), dihydroflavonol 4-reductase (OgDFR) and anthocyanidin synthase (OgANS) were isolated and their expression patterns were characterized. Northern blot analysis confirmed that although they are active during floral development, OgCHI and OgDFR genes are specifically down-regulated in yellow lip tissue. Bombardment with OgCHI and OgDFR genes into lip tissue driven by a flower-specific promoter, Pchrc (chromoplast-specific carotenoid-associated gene), demonstrated that transient expression of these two genes resulted in anthocyanin production in yellow lip. Further analysis of a R2R3 MYB transcription factor, OgMYB1, revealed that although it is actively expressed during floral development, it is not expressed in yellow lip tissue. Transient expression of OgMYB1 in lip tissues by bombardment can also induce formation of red pigments through the activation of OgCHI and OgDFR transcription. These results demonstrate that differential expression of OgMYB1 is critical to determine the color pattern of floral organ in Oncidium Gower Ramsey. PMID:18161007

  3. Flowering mechanisms, pollination strategies and floral scent analyses of syntopically co-flowering Homalomena spp. (Araceae) on Borneo.

    PubMed

    Hoe, Y C; Gibernau, M; Maia, A C D; Wong, S Y

    2016-07-01

    In this study, the flowering mechanisms and pollination strategies of seven species of the highly diverse genus Homalomena (Araceae) were investigated in native populations of West Sarawak, Borneo. The floral scent compositions were also recorded for six of these species. The selected taxa belong to three out of four complexes of the section Cyrtocladon (Hanneae, Giamensis and Borneensis). The species belonging to the Hanneae complex exhibited longer anthesis (53-62 h) than those of the Giamensis and Borneensis complexes (ca. 30 h). Species belonging to the Hanneae complex underwent two floral scent emission events in consecutive days, during the pistillate and staminate phases of anthesis. In species belonging to the Giamensis and Borneensis complexes, floral scent emission was only evident to the human nose during the pistillate phase. A total of 33 volatile organic compounds (VOCs) were detected in floral scent analyses of species belonging to the Hanneae complex, whereas 26 VOCs were found in samples of those belonging to the Giamensis complex. The floral scent blends contained uncommon compounds in high concentration, which could ensure pollinator discrimination. Our observations indicate that scarab beetles (Parastasia gestroi and P. nigripennis; Scarabaeidae, Rutelinae) are the pollinators of the investigated species of Homalomena, with Chaloenus schawalleri (Chrysomelidae, Galeuricinae) acting as a secondary pollinator. The pollinators utilise the inflorescence for food, mating opportunities and safe mating arena as rewards. Flower-breeding flies (Colocasiomyia nigricauda and C. aff. heterodonta; Diptera, Drosophilidae) and terrestrial hydrophilid beetles (Cycreon sp.; Coleoptera, Hydrophilidae) were also frequently recovered from inflorescences belonging to all studied species (except H. velutipedunculata), but they probably do not act as efficient pollinators. Future studies should investigate the post-mating isolating barriers among syntopically co

  4. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    PubMed Central

    Genung, Mark A.; Lessard, Jean-Philippe; Brown, Claire B.; Bunn, Windy A.; Cregger, Melissa A.; Reynolds, Wm. Nicholas; Felker-Quinn, Emmi; Stevenson, Mary L.; Hartley, Amanda S.; Crutsinger, Gregory M.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    Background In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. Methodology/Principal Findings Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot) of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1) plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2) plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. Conclusions/Significance These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems. PMID:20090850

  5. Transcriptome Analysis for Abnormal Spike Development of the Wheat Mutant dms

    PubMed Central

    Zhu, Xin-Xin; Li, Qiao-Yun; Shen, Chun-Cai; Duan, Zong-Biao; Yu, Dong-Yan; Niu, Ji-Shan; Ni, Yong-Jing; Jiang, Yu-Mei

    2016-01-01

    Background Wheat (Triticum aestivum L.) spike development is the foundation for grain yield. We obtained a novel wheat mutant, dms, characterized as dwarf, multi-pistil and sterility. Although the genetic changes are not clear, the heredity of traits suggests that a recessive gene locus controls the two traits of multi-pistil and sterility in self-pollinating populations of the medium plants (M), such that the dwarf genotype (D) and tall genotype (T) in the progeny of the mutant are ideal lines for studies regarding wheat spike development. The objective of this study was to explore the molecular basis for spike abnormalities of dwarf genotype. Results Four unigene libraries were assembled by sequencing the mRNAs of the super-bulked differentiating spikes and stem tips of the D and T plants. Using integrative analysis, we identified 419 genes highly expressed in spikes, including nine typical homeotic genes of the MADS-box family and the genes TaAP2, TaFL and TaDL. We also identified 143 genes that were significantly different between young spikes of T and D, and 26 genes that were putatively involved in spike differentiation. The result showed that the expression levels of TaAP1-2, TaAP2, and other genes involved in the majority of biological processes such as transcription, translation, cell division, photosynthesis, carbohydrate transport and metabolism, and energy production and conversion were significantly lower in D than in T. Conclusions We identified a set of genes related to wheat floral organ differentiation, including typical homeotic genes. Our results showed that the major causal factors resulting in the spike abnormalities of dms were the lower expression homeotic genes, hormonal imbalance, repressed biological processes, and deficiency of construction materials and energy. We performed a series of studies on the homeotic genes, however the other three causal factors for spike abnormal phenotype of dms need further study. PMID:26982202

  6. Floral morphogenesis: stochastic explorations of a gene network epigenetic landscape.

    PubMed

    Alvarez-Buylla, Elena R; Chaos, Alvaro; Aldana, Maximino; Benítez, Mariana; Cortes-Poza, Yuriria; Espinosa-Soto, Carlos; Hartasánchez, Diego A; Lotto, R Beau; Malkin, David; Escalera Santos, Gerardo J; Padilla-Longoria, Pablo

    2008-01-01

    In contrast to the classical view of development as a preprogrammed and deterministic process, recent studies have demonstrated that stochastic perturbations of highly non-linear systems may underlie the emergence and stability of biological patterns. Herein, we address the question of whether noise contributes to the generation of the stereotypical temporal pattern in gene expression during flower development. We modeled the regulatory network of organ identity genes in the Arabidopsis thaliana flower as a stochastic system. This network has previously been shown to converge to ten fixed-point attractors, each with gene expression arrays that characterize inflorescence cells and primordial cells of sepals, petals, stamens, and carpels. The network used is binary, and the logical rules that govern its dynamics are grounded in experimental evidence. We introduced different levels of uncertainty in the updating rules of the network. Interestingly, for a level of noise of around 0.5-10%, the system exhibited a sequence of transitions among attractors that mimics the sequence of gene activation configurations observed in real flowers. We also implemented the gene regulatory network as a continuous system using the Glass model of differential equations, that can be considered as a first approximation of kinetic-reaction equations, but which are not necessarily equivalent to the Boolean model. Interestingly, the Glass dynamics recover a temporal sequence of attractors, that is qualitatively similar, although not identical, to that obtained using the Boolean model. Thus, time ordering in the emergence of cell-fate patterns is not an artifact of synchronous updating in the Boolean model. Therefore, our model provides a novel explanation for the emergence and robustness of the ubiquitous temporal pattern of floral organ specification. It also constitutes a new approach to understanding morphogenesis, providing predictions on the population dynamics of cells with different

  7. Abnormal Head Position

    MedlinePlus

    ... cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal head posture could cause permanent ... occipitocervical synostosis and unilateral hearing loss. Are there any ... postures? Yes. Abnormal head postures can usually be improved depending ...

  8. Urine - abnormal color

    MedlinePlus

    ... straw-yellow. Abnormally colored urine may be cloudy, dark, or blood-colored. Causes Abnormal urine color may ... red blood cells, or mucus in the urine. Dark brown but clear urine is a sign of ...

  9. Floral thermogenesis: An adaptive strategy of pollination biology in Magnoliaceae.

    PubMed

    Wang, Ruohan; Zhang, Zhixiang

    2015-01-01

    Floral thermogenesis plays a crucial role in pollination biology, especially in plant-pollinator interactions. We have recently explored how thermogenesis is related to pollinator activity and odour release in Magnolia sprengeri. By analyzing flower temperatures, emission of volatiles, and insect visitation, we found that floral blends released during pistillate and staminate stages were similar and coincided with sap beetle visitation. Thus, odour mimicry of staminate-stage flowers may occur during the pistillate stage and may be an adaptive strategy of Magnolia species to attract pollinators during both stages, ensuring successful pollination. In addition to the biological significance of floral thermogenesis in Magnolia species, we explored the underlying regulatory mechanisms via profiling miRNA expression in M. denudata flowers during thermogenic and non-thermogenic stages. We identified 17 miRNAs that may play regulatory roles in floral thermogenesis. Functional annotation of their target genes indicated that these miRNAs regulate floral thermogenesis by influencing cellular respiration and light reactions. These findings increase our understanding of plant-pollinator interactions and the regulatory mechanisms in thermogenic plants. PMID:26844867

  10. Floral nectar guide patterns discourage nectar robbing by bumble bees.

    PubMed

    Leonard, Anne S; Brent, Joshua; Papaj, Daniel R; Dornhaus, Anna

    2013-01-01

    Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant's reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create. This behavior is called "nectar robbing" because bees may acquire the nectar without transporting pollen. We asked whether the presence of a symmetric floral nectar guide pattern on artificial flowers affected bumble bees' (Bombus impatiens) propensity to rob or access nectar "legitimately." We discovered that nectar guides made legitimate visits more efficient for bees than robbing, and increased the relative frequency of legitimate visits, compared to flowers lacking nectar guides. This study is the first to show that beyond speeding nectar discovery, a nectar guide pattern can influence bees' flower handling in a way that could benefit the plant. PMID:23418475

  11. Floral thermogenesis: An adaptive strategy of pollination biology in Magnoliaceae

    PubMed Central

    Wang, Ruohan; Zhang, Zhixiang

    2015-01-01

    Floral thermogenesis plays a crucial role in pollination biology, especially in plant–pollinator interactions. We have recently explored how thermogenesis is related to pollinator activity and odour release in Magnolia sprengeri. By analyzing flower temperatures, emission of volatiles, and insect visitation, we found that floral blends released during pistillate and staminate stages were similar and coincided with sap beetle visitation. Thus, odour mimicry of staminate-stage flowers may occur during the pistillate stage and may be an adaptive strategy of Magnolia species to attract pollinators during both stages, ensuring successful pollination. In addition to the biological significance of floral thermogenesis in Magnolia species, we explored the underlying regulatory mechanisms via profiling miRNA expression in M. denudata flowers during thermogenic and non-thermogenic stages. We identified 17 miRNAs that may play regulatory roles in floral thermogenesis. Functional annotation of their target genes indicated that these miRNAs regulate floral thermogenesis by influencing cellular respiration and light reactions. These findings increase our understanding of plant–pollinator interactions and the regulatory mechanisms in thermogenic plants. PMID:26844867

  12. Floral Nectar Guide Patterns Discourage Nectar Robbing by Bumble Bees

    PubMed Central

    Leonard, Anne S.; Brent, Joshua; Papaj, Daniel R.; Dornhaus, Anna

    2013-01-01

    Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant’s reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create. This behavior is called “nectar robbing” because bees may acquire the nectar without transporting pollen. We asked whether the presence of a symmetric floral nectar guide pattern on artificial flowers affected bumble bees’ (Bombus impatiens) propensity to rob or access nectar “legitimately.” We discovered that nectar guides made legitimate visits more efficient for bees than robbing, and increased the relative frequency of legitimate visits, compared to flowers lacking nectar guides. This study is the first to show that beyond speeding nectar discovery, a nectar guide pattern can influence bees’ flower handling in a way that could benefit the plant. PMID:23418475

  13. Genetics of mutations affecting the development of a barley floral bract.

    PubMed Central

    Pozzi, C; Faccioli, P; Terzi, V; Stanca, A M; Cerioli, S; Castiglioni, P; Fink, R; Capone, R; Müller, K J; Bossinger, G; Rohde, W; Salamini, F

    2000-01-01

    Two groups of mutants that affect the morphology of the lemma, a floral bract of barley, are described. The first comprises phenotypes associated with mutant alleles of calcaroides loci. On the lemma of these mutants, a well-organized neomorphic structure is formed, termed the sac. We provide a morphological description of wild-type (WT) and mutant lemmas, based on scanning electron microscopy (SEM), showing that both consist of similar tissues, but that the mutant is characterized by reversed growth polarity. The sac is a unique structure among grasses, and it is remarkable that recessive mutations at five different genetic loci lead to the same organ. The second group of mutants carry recessive alleles of two leafy lemma genes, both of which are necessary to cause the transformation of the lemma into a structure having all characteristics of a vegetative leaf, as shown by SEM analysis. The presence of sheath, blade, and ligule in the mutant lemma suggests that wild-type lemma development is interrupted at a leaf-like stage. The genes cal a, b, C, d, 23, lel1, and lel2 have now been mapped at precise positions on linkage groups 2, 7, 7, 3, 7, 5, and 7, respectively. The mutants considered in this article are unaffected in other floral organs. A model for lemma development is suggested. PMID:10757774

  14. Ethylene-Regulated Floral Volatile Synthesis in Petunia Corollas1[w

    PubMed Central

    Underwood, Beverly A.; Tieman, Denise M.; Shibuya, Kenichi; Dexter, Richard J.; Loucas, Holly M.; Simkin, Andrew J.; Sims, Charles A.; Schmelz, Eric A.; Klee, Harry J.; Clark, David G.

    2005-01-01

    In many flowering plants, such as petunia (Petunia × hybrida), ethylene produced in floral organs after pollination elicits a series of physiological and biochemical events, ultimately leading to senescence of petals and successful fertilization. Here, we demonstrate, using transgenic ethylene insensitive (44568) and Mitchell Diploid petunias, that multiple components of emission of volatile organic compounds (VOCs) are regulated by ethylene. Expression of benzoic acid/salicylic acid carboxyl methyltransferase (PhBSMT1 and 2) mRNA is temporally and spatially down-regulated in floral organs in a manner consistent with current models for postpollination ethylene synthesis in petunia corollas. Emission of methylbenzoate and other VOCs after pollination and exogenous ethylene treatment parallels a reduction in PhBSMT1 and 2 mRNA levels. Under cyclic light conditions (day/night), PhBSMT mRNA levels are rhythmic and precede emission of methylbenzoate by approximately 6 h. When shifted into constant dark or light conditions, PhBSMT mRNA levels and subsequent methylbenzoate emission correspondingly decrease or increase to minimum or maximum levels observed during normal conditions, thus suggesting that light may be a more critical influence on cyclic emission of methylbenzoate than a circadian clock. Transgenic PhBSMT RNAi flowers with reduced PhBSMT mRNA levels show a 75% to 99% decrease in methylbenzoate emission, with minimal changes in other petunia VOCs. These results implicate PhBSMT1 and 2 as genes responsible for synthesis of methylbenzoate in petunia. PMID:15849311

  15. Down-regulation of TM29, a tomato SEPALLATA homolog, causes parthenocarpic fruit development and floral reversion.

    PubMed

    Ampomah-Dwamena, Charles; Morris, Bret A; Sutherland, Paul; Veit, Bruce; Yao, Jia-Long

    2002-10-01

    We have characterized the tomato (Lycopersicon esculentum Mill.) MADS box gene TM29 that shared a high amino acid sequence homology to the Arabidopsis SEP1, 2, and 3 (SEPALLATA1, 2, and 3) genes. TM29 showed similar expression profiles to SEP1, with accumulation of mRNA in the primordia of all four whorls of floral organs. In addition, TM29 mRNA was detected in inflorescence and vegetative meristems. To understand TM29 function, we produced transgenic tomato plants in which TM29 expression was down-regulated by either cosuppression or antisense techniques. These transgenic plants produced aberrant flowers with morphogenetic alterations in the organs of the inner three whorls. Petals and stamens were green rather than yellow, suggesting a partial conversion to a sepalloid identity. Stamens and ovaries were infertile, with the later developing into parthenocarpic fruit. Ectopic shoots with partially developed leaves and secondary flowers emerged from the fruit. These shoots resembled the primary transgenic flowers and continued to produce parthenocarpic fruit and additional ectopic shoots. Based on the temporal and spatial expression pattern and transgenic phenotypes, we propose that TM29 functions in floral organ development, fruit development, and maintenance of floral meristem identity in tomato. PMID:12376628

  16. Down-Regulation of TM29, a Tomato SEPALLATA Homolog, Causes Parthenocarpic Fruit Development and Floral Reversion1

    PubMed Central

    Ampomah-Dwamena, Charles; Morris, Bret A.; Sutherland, Paul; Veit, Bruce; Yao, Jia-Long

    2002-01-01

    We have characterized the tomato (Lycopersicon esculentum Mill.) MADS box gene TM29 that shared a high amino acid sequence homology to the Arabidopsis SEP1, 2, and 3 (SEPALLATA1, 2, and 3) genes. TM29 showed similar expression profiles to SEP1, with accumulation of mRNA in the primordia of all four whorls of floral organs. In addition, TM29 mRNA was detected in inflorescence and vegetative meristems. To understand TM29 function, we produced transgenic tomato plants in which TM29 expression was down-regulated by either cosuppression or antisense techniques. These transgenic plants produced aberrant flowers with morphogenetic alterations in the organs of the inner three whorls. Petals and stamens were green rather than yellow, suggesting a partial conversion to a sepalloid identity. Stamens and ovaries were infertile, with the later developing into parthenocarpic fruit. Ectopic shoots with partially developed leaves and secondary flowers emerged from the fruit. These shoots resembled the primary transgenic flowers and continued to produce parthenocarpic fruit and additional ectopic shoots. Based on the temporal and spatial expression pattern and transgenic phenotypes, we propose that TM29 functions in floral organ development, fruit development, and maintenance of floral meristem identity in tomato. PMID:12376628

  17. Hormonal changes during flower development in floral tissues of Lilium.

    PubMed

    Arrom, L; Munné-Bosch, S

    2012-08-01

    Much effort has been focussed on better understanding the key signals that modulate floral senescence. Although ethylene is one of the most important regulators of floral senescence in several species, Lilium flowers show low sensitivity to ethylene; thus their senescence may be regulated by other hormones. In this study we have examined how (1) endogenous levels of hormones in various floral tissues (outer and inner tepals, androecium and gynoecium) vary throughout flower development, (2) endogenous levels of hormones in such tissues change in cut versus intact flowers at anthesis, and (3) spray applications of abscisic acid and pyrabactin alter flower longevity. Results show that floral tissues behave differently in their hormonal changes during flower development. Cytokinin and auxin levels mostly increased in tepals prior to anthesis and decreased later during senescence. In contrast, levels of abscisic acid increased during senescence, but only in outer tepals and the gynoecium, and during the latest stages. In addition, cut flowers at anthesis differed from intact flowers in the levels of abscisic acid and auxins in outer tepals, salicylic acid in inner tepals, cytokinins, gibberellins and jasmonic acid in the androecium, and abscisic acid and salicylic acid in the gynoecium, thus showing a clear differential response between floral tissues. Furthermore, spray applications of abscisic acid and pyrabactin in combination accelerated the latest stages of tepal senescence, yet only when flower senescence was delayed with Promalin. It is concluded that (1) floral tissues differentially respond in their endogenous variations of hormones during flower development, (2) cut flowers have drastic changes in the hormonal balance not only of outer and inner tepals but also of androecium and gynoecium, and (3) abscisic acid may accelerate the progression of tepal senescence in Lilium. PMID:22367063

  18. Floral colour change as a potential signal to pollinators.

    PubMed

    Ruxton, Graeme D; Schaefer, H Martin

    2016-08-01

    Colour change in flowers (with age and/or after pollination) is taxonomically widespread, has evolved repeatedly, and has a range of putative selective benefits linked to modifying pollinator behaviour; however, this phenomenon seems paradoxically uncommon. We explore this paradox by reviewing the empirical evidence and argue that the evolution and maintenance of floral colour change as a signal to modify pollinator behaviour require special ecological circumstances that will often not be met across a plant population for a sustained number of generations, which potentially explains the scarcity of this phenomenon. We discuss alternative explanations for floral colour change and potentially fruitful lines of future research. PMID:27428780

  19. Abnormal Uterine Bleeding (Beyond the Basics)

    MedlinePlus

    ... Approach to abnormal uterine bleeding in nonpregnant reproductive-age women Differential diagnosis of genital tract bleeding in women Postmenopausal uterine bleeding The following organizations also provide reliable health information. ● National Library of Medicine ( www.nlm.nih.gov/ ...

  20. Flower power: its association with bee power and floral functional morphology in papilionate legumes

    PubMed Central

    Córdoba, Silvina A.; Cocucci, Andrea A.

    2011-01-01

    Background and Aims A test was made of the hypothesis that papilionate legume flowers filter pollinators according to their ability to exert strength to open flowers to access rewards. In addition, interactions with pollen vectors were expected to explain the structural complexity of the architecture of these flowers since operative flower strength may be determined by a combination of morphological traits which form part of an intrafloral functional module. Methods Six papilionate species were studied: Collaea argentina, Desmodium uncinatum, Galactia latisiliqua, Lathyrus odoratus, Spartium junceum and Tipuana tipu. Measurements were made of the strength needed to open keels and the strength that pollinators were capable of exerting. Morphological traits of all petals were also measured to determine which of them could be either mutually correlated or correlated with operative strength and moment of strength and participated in a functional module. Key Results It was observed that pollinators were capable in all cases of exerting forces higher and often several times higher than that needed to access floral rewards, and no association could be detected between floral operative strength and strength exerted by the corresponding pollinators. On the other hand, strong and significant correlations were found among morphometric traits and, of these, with operative strength and moment. This was particularly evident among traits of the keel and the wings, presumably involved in the functioning of the floral moveable mechanism. Conclusions Though visitors are often many times stronger than the operative strength of the flowers they pollinate, exceptionally weak bees such as Apis mellifera cannot open the strongest flowers. On the other hand, strong correlations among certain petal morphometric traits (particularly between the keel and wings) give support to the idea that an intrafloral module is associated with the functioning of the mechanism of these legume flowers. In

  1. Discrete spatial and temporal cis-acting elements regulate transcription of the Arabidopsis floral homeotic gene APETALA3.

    PubMed

    Hill, T A; Day, C D; Zondlo, S C; Thackeray, A G; Irish, V F

    1998-05-01

    The APETALA3 floral homeotic gene is required for petal and stamen development in Arabidopsis. APETALA3 transcripts are first detected in a meristematic region that will give rise to the petal and stamen primordia, and expression is maintained in this region during subsequent development of these organs. To dissect how the APETALA3 gene is expressed in this spatially and temporally restricted domain, various APETALA3 promoter fragments were fused to the uidA reporter gene encoding beta-glucuronidase and assayed for the resulting patterns of expression in transgenic Arabidopsis plants. Based on these promoter analyses, we defined cis-acting elements required for distinct phases of APETALA3 expression, as well as for petal-specific and stamen-specific expression. By crossing the petal-specific construct into different mutant backgrounds, we have shown that several floral genes, including APETALA3, PISTILLATA, UNUSUAL FLORAL ORGANS, and APETALA1, encode trans-acting factors required for second-whorl-specific APETALA3 expression. We have also shown that the products of the APETALA1, APETALA3, PISTILLATA and AGAMOUS genes bind to several conserved sequence motifs within the APETALA3 promoter. We present a model whereby spatially and temporally restricted APETALA3 transcription is controlled via interactions between proteins binding to different domains of the APETALA3 promoter. PMID:9521909

  2. The AP2-like gene NsAP2 from water lily is involved in floral organogenesis and plant height.

    PubMed

    Luo, Huolin; Chen, Sumei; Jiang, Jiafu; Teng, Nianjun; Chen, Yu; Chen, Fadi

    2012-07-01

    APETALA2 (AP2) genes are ancient and widely distributed among the seed plants, and play an important role during the plant life cycle, acting as key regulators of many developmental processes. In this study, an AP2 homologue, NsAP2, was characterized from water lily (Nymphaea sp. cv. 'Yellow Prince') and is believed to be rather primitive in the evolution of the angiosperms. In situ RNA hybridization showed that NsAP2 transcript was present in all regions of the floral primordium, but had the highest level in the emerging floral organ primordium. After the differentiation of floral organs, NsAP2 was strongly expressed in sepals and petals, while low levels were found in stamens and carpels. The NsAP2 protein was suggested to be localized in the cell nucleus by onion transient expression experiment. Overexpression of NsAP2 in Arabidopsis led to more petal numbers, and Arabidopsis plants expressing NsAP2 exhibited higher plant height, which may be a result of down-regulated expression of GA2ox2 and GA2ox7. Our results indicated that the NsAP2 protein may function in flower organogenesis in water lily, and it is a promising gene for plant height improvement. PMID:22591856

  3. Retail Flower Shop Salesperson and Floral Designer. Instructor's Manual.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This document is the instructor's manual for a course in retail flower shop sales and floral design for use in vocational education courses in high schools in South Carolina. The manual consists primarily of instructor's guides to the 22 learning modules contained in the student manual, which provide the subject matter needed by workers in these…

  4. Floral and ecological isolation between Aquilegia formosa and Aquilegia pubescens

    SciTech Connect

    Hodges, S.A.; Arnold, M.L.

    1994-03-29

    Habitat preference and pollination syndrome have been suggested as major factors in reproductive isolation among plant species. The columbine genus Aquilegia contains species that have been used as classic examples of reproductive isolation due to ecological and floral factors. In this analysis Aquilegia formosa, Aquilegia pubescens, and natural hybrid populations between these two species were assayed for genetic and morphological variation. Clinal variation was evident for three {open_quotes}random amplified polymorphic DNA{close_quotes} loci and five morphological characters along a transect extending from a lower altitude A. formosa population, through an intermediate hybrid population, to a higher altitude A. pubescens population. Similar clinal variation was also discovered for a transect that included A. formosa-like, hybrid, and A. pubescens-like populations at a single elevation. The change in the frequency of both sets of markers was closely associated with change in habitat. The molecular markers indicate the presence of bidirectional introgression between these two species. In contrast, there was apparently selection against introgression of four of the five alternate floral characters. Selection against the incorporation of floral characters from one species into the other species was suggested by the introgression of the DNA markers with little or no introgression of the four floral characters. These findings suggest the importance of adaptations associated with both pollination syndromes and habitat preference on species integrity.

  5. How scent and nectar influence floral antagonists and mutualists

    PubMed Central

    Kessler, Danny; Kallenbach, Mario; Diezel, Celia; Rothe, Eva; Murdock, Mark; Baldwin, Ian T

    2015-01-01

    Many plants attract and reward pollinators with floral scents and nectar, respectively, but these traits can also incur fitness costs as they also attract herbivores. This dilemma, common to most flowering plants, could be solved by not producing nectar and/or scent, thereby cheating pollinators. Both nectar and scent are highly variable in native populations of coyote tobacco, Nicotiana attenuata, with some producing no nectar at all, uncorrelated with the tobacco's main floral attractant, benzylacetone. By silencing benzylacetone biosynthesis and nectar production in all combinations by RNAi, we experimentally uncouple these floral rewards/attractrants and measure their costs/benefits in the plant's native habitat and experimental tents. Both scent and nectar increase outcrossing rates for three, separately tested, pollinators and both traits increase oviposition by a hawkmoth herbivore, with nectar being more influential than scent. These results underscore that it makes little sense to study floral traits as if they only mediated pollination services. DOI: http://dx.doi.org/10.7554/eLife.07641.001 PMID:26132861

  6. Transcriptional control of floral anthocyanin pigmentation in monkeyflowers (Mimulus)

    PubMed Central

    Yuan, Yao-Wu; Sagawa, Janelle M.; Frost, Laura; Vela, James P.; Bradshaw, Harvey D.

    2014-01-01

    Summary A molecular description of the control of floral pigmentation in a multi-species group displaying various flower color patterns is of great interest for understanding the molecular bases of phenotypic diversification and pollinator-mediated speciation. Through transcriptome profiling, mutant analyses, and transgenic experiments, we aim to establish a ‘baseline’ floral anthocyanin regulation model in Mimulus lewisii and to examine the different ways of tinkering with this model in generating the diversity of floral anthocyanin patterns in other Mimulus species. We find one WD40 and one bHLH gene controlling anthocyanin pigmentation in the entire corolla of M. lewisii, and two R2R3-MYB genes, PELAN and NEGAN, controlling anthocyanin production in the petal lobe and nectar guide, respectively. The autoregulation of NEGAN might be a critical property to generate anthocyanin spots. Independent losses of PELAN expression (via different mechanisms) explain two natural yellow-flowered populations of M. cardinalis (typically red-flowered). The NEGAN ortholog is the only anthocyanin-activating MYB expressed in the M. guttatus flowers. The mutant lines and transgenic tools available for M. lewisii will enable gene-by-gene replacement experiments to dissect the genetic and developmental bases of more complex floral color patterns, and to test hypotheses on phenotypic evolution in general. PMID:25103615

  7. Floral Structure of Kirkia (Kirkiaceae) and its Position in Sapindales

    PubMed Central

    Bachelier, Julien B.; Endress, Peter K.

    2008-01-01

    Background and Aims The monogeneric Kirkiaceae (Sapindales) were formerly placed as Kirkioideae in Simaroubaceae. However, recent molecular phylogenetic studies indicate that they are not in Simaroubaceae and they appear to be sister to the clade of Anacardiaceae plus Burseraceae. Such affinity was never considered or discussed since the first description of Kirkia. The present study is the first detailed analysis of the floral structure of a representative of Kirkiaceae and the first comparison with other sapindalean families, especially Anacardiaceae and Burseraceae. Methods Floral structure of Kirkia wilmsii was studied using transversal and longitudinal microtome section series, scanning electron microscopy and light microscopy. Key Results The flowers of Kirkia wilmsii are morphologically bisexual but functionally unisexual. They are polysymmetric, isomerous (tetramerous) and haplostemonous. The ovary is syncarpous and entirely synascidiate. The floral apex forms a hemispherical protrusion on top of the ovary. The styles are free but postgenitally united and apically form a stigmatic head with a compitum. Each carpel is uniovulate (biovulate in a few other species) and ovules are crassinucellar, bitegmic and slightly campylotropous. The micropyle is formed by both integuments and is unusually long. The unusual two radially disposed locules in each carpel in the former genus Pleiokirkia can be explained developmentally by the two offset and tightly contiguous lateral placentae. Conclusions Paralleling the molecular results, a suite of floral features supports the position of Kirkiaceae close to the Anacardiaceae–Burseraceae clade, and not in Simaroubaceae. PMID:18687798

  8. Patterns and development of floral asymmetry in Senna (Leguminosae, Cassiinae).

    PubMed

    Marazzi, Brigitte; Endress, Peter K

    2008-01-01

    The buzz-pollinated genus Senna (Leguminosae) is outstanding for including species with monosymmetric flowers and species with diverse asymmetric, enantiomorphic (enantiostylous) flowers. To recognize patterns of homology, we dissected the floral symmetry character complex and explored corolla morphology in 60 Senna species and studied floral development of four enantiomorphic species. The asymmetry morph of a flower is correlated with the direction of spiral calyx aestivation. We recognized five patterns of floral asymmetry, resulting from different combinations of six structural elements: deflection of the carpel, deflection of the median abaxial stamen, deflection or modification in size of one lateral abaxial stamen, and modification in shape and size of one or both lower petals. Prominent corolla asymmetry begins in the earl-stage bud (unequal development of lower petals). Androecium asymmetry begins either in the midstage bud (unequal development of thecae in median abaxial stamen; twisting of androecium) or at anthesis (stamen deflection). Gynoecium asymmetry begins in early bud (primordium off the median plane, ventral slit laterally oriented) or midstage to late bud (carpel deflection). In enantiostylous flowers, pronouncedly concave and robust petals of both monosymmetric and asymmetric corollas likely function to ricochet and direct pollen flow during buzz pollination. Occurrence of particular combinations of structural elements of floral symmetry in the subclades is shown. PMID:21632312

  9. Diallel analysis of floral longevity in Impatiens walleriana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impatiens walleriana is currently among the most valuable and widely cultivated floriculture crops in the world. Highly floriferous cultivars are a primary goal for breeders of I. walleriana. Although breeders have selected for floriferousness, little consideration has been given to floral longevity...

  10. Retail Flower Shop Salesperson and Floral Designer. Student's Manual.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This document consists of the student manual for a course in retail flower shop sales and floral design for use in vocational education courses in high schools in South Carolina. The guide consists of 22 learning modules that incorporate the subject matter needed by workers in these jobs. Each learning module consists of an introduction,…

  11. Trapping noctuid moths with synthetic floral volatile lures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Male and female noctuid moths were collected from plastic bucket traps that were baited with different synthetic floral chemicals and placed in peanut fields. Traps baited with phenylacetaldehyde, benzyl acetate, and a blend of phenylacetaldehyde, benzyl acetate, and benzaldehyde collected more soyb...

  12. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... The appearance of normal teeth varies, especially the molars. ... conditions. Specific diseases can affect tooth shape, tooth ...

  13. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... from many different conditions. Specific diseases can affect tooth shape, tooth color, time of appearance, or absence ...

  14. The Impact of Biochemistry vs. Population Membership on Floral Scent Profiles in Colour Polymorphic Hesperis matronalis

    PubMed Central

    Majetic, Cassie J.; Raguso, Robert A.; Ashman, Tia-Lynn

    2008-01-01

    Background and Aims Studies of floral scent evolution often attribute variation in floral scent to differences in pollinator behaviour, ignoring the potential for shared biochemistry between floral scent and floral colour to dictate patterns of phenotypic variation in scent production. To determine the relative effects of shared biochemistry and/or localized population-level phenomena on floral scent phenotype, floral scent composition and emission rate were examined in five wild populations of colour polymorphic Hesperis matronalis (Brassicaceae). Methods Floral scent was collected by in situ dynamic headspace extraction on purple and white colour morphs in each of five wild populations. Gas chromatography–mass spectroscopy of extracts allowed determination of floral scent composition and emission rate for all individuals, which were examined by non-metric multidimensional scaling and analysis of variance (ANOVA), respectively, to determine the contributions of floral colour and population membership to scent profile variation. Key Results Despite the fact that colour morph means were very similar in some populations and quite different in other populations, colour morphs within populations did not differ from each other in terms of scent composition or emission rate. Populations differed significantly from one another in terms of both floral scent composition and emission rate. Conclusions Shared biochemistry alone cannot explain the variation in floral scent phenotype found for H. matronalis. Such a result may suggest that the biochemical association between floral scent and floral colour is complex or dependent on genetic background. Floral scent does vary significantly with population membership; several factors, including environmental conditions, founder effects and genetics, may account for this differentiation and should be considered in future studies. PMID:18819948

  15. Floral and vegetative cues in oil-secreting and non-oil-secreting Lysimachia species

    PubMed Central

    Schäffler, I.; Balao, F.; Dötterl, S.

    2012-01-01

    Background and Aims Unrelated plants pollinated by the same group or guild of animals typically evolve similar floral cues due to pollinator-mediated selection. Related plant species, however, may possess similar cues either as a result of pollinator-mediated selection or as a result of sharing a common ancestor that possessed the same cues or traits. In this study, visual and olfactory floral cues in Lysimachia species exhibiting different pollination strategies were analysed and compared, and the importance of pollinators and phylogeny on the evolution of these floral cues was determined. For comparison, cues of vegetative material were examined where pollinator selection would not be expected. Methods Floral and vegetative scents and colours in floral oil- and non-floral oil-secreting Lysimachia species were studied by chemical and spectrophotometric analyses, respectively, compared between oil- and non-oil-secreting species, and analysed by phylogenetically controlled methods. Key Results Vegetative and floral scent was species specific, and variability in floral but not vegetative scent was lower in oil compared with non-oil species. Overall, oil species did not differ in their floral or vegetative scent from non-oil species. However, a correlation was found between oil secretion and six floral scent constituents specific to oil species, whereas the presence of four other floral compounds can be explained by phylogeny. Four of the five analysed oil species had bee-green flowers and the pattern of occurrence of this colour correlated with oil secretion. Non-oil species had different floral colours. The colour of leaves was similar among all species studied. Conclusions Evidence was found for correlated evolution between secretion of floral oils and floral but not vegetative visual and olfactory cues. The cues correlating with oil secretion were probably selected by Macropis bees, the specialized pollinators of oil-secreting Lysimachia species, and may have

  16. Influences of floral composition and environment on plant biomarkers across a Cretaceous landscape (Big Cedar Ridge)

    NASA Astrophysics Data System (ADS)

    Bush, R. T.; Diefendorf, A. F.; Wing, S. L.; McInerney, F. A.

    2013-12-01

    The Late Cretaceous fossil site at Big Cedar Ridge (BCR; late Campanian, 72.7 Ma), located in the Bighorn Basin, Wyoming, USA, contains a flora preserved in situ in a volcanic ash tuff over an organic-rich paleosol. The BCR flora is irregularly but extensively exposed along a ~4 km north-south transect and records a lowland flora that grew on a coastal delta on the western shore of the Cretaceous Interior Seaway (Meeteetse Formation). The transect spans a diverse landscape and a range of environmental gradients from very carbon-rich, swampy soils in the southern portion to less carbon-rich in the north; the landscape is also intersected by multiple inactive channel cuts that were filling with sediment and organic matter at the time of ash deposition. Recently Wing and others (2012, Ecological Monographs) described the composition of the local plant community at high resolution across the entire landscape, including identification and quantification of cover and richness for >122 taxonomic morphotypes, for each of 100 sites along the transect. Big Cedar Ridge captures an important time in the ecological development of plant communities: the site preserves ferns, gymnosperms, and angiosperms in 'fern thicket' floral assemblages, which are rare today, as well as disturbed habitats with abundant herbaceous 'dicot' angiosperms. During the Late Cretaceous angiosperms were globally increasing in abundance, displacing other plant groups as vegetational dominants. This setting allows for a novel analysis of plant biomarkers in the context of floral diversity, abundance, and landscape heterogeneity. We quantified leaf waxes (n-alkyl lipids), plant-derived terpenoids, bacterial hopanes, carbon isotope values (including bulk and compound-specific), and percent total organic carbon of the underlying paleosol for 36 sites along the transect in order to assess the influence of floral composition and soil environment on biomarker distributions and preservation. We compare lipid

  17. Characterizing Floral Symmetry in the Core Goodeniaceae with Geometric Morphometrics.

    PubMed

    Gardner, Andrew G; Fitz Gerald, Jonathan N; Menz, John; Shepherd, Kelly A; Howarth, Dianella G; Jabaily, Rachel S

    2016-01-01

    Core Goodeniaceae is a clade of ~330 species primarily distributed in Australia. Considerable variation in flower morphology exists within this group and we aim to use geometric morphometrics to characterize this variation across the two major subclades: Scaevola sensu lato (s.l.) and Goodenia s.l., the latter of which was hypothesized to exhibit greater variability in floral symmetry form. We test the hypothesis that floral morphological variation can be adequately characterized by our morphometric approach, and that discrete groups of floral symmetry morphologies exist, which broadly correlate with subjectively determined groups. From 335 images of 44 species in the Core Goodeniaceae, two principal components were computed that describe >98% of variation in all datasets. Increasing values of PC1 ventralize the dorsal petals (increasing the angle between them), whereas increasing values of PC2 primarily ventralize the lateral petals (decreasing the angle between them). Manipulation of these two morphological "axes" alone was sufficient to recreate any of the general floral symmetry patterns in the Core Goodeniaceae. Goodenia s.l. exhibits greater variance than Scaevola s.l. in PC1 and PC2, and has a significantly lower mean value for PC1. Clustering clearly separates fan-flowers (with dorsal petals at least 120° separated) from the others, whereas the distinction between pseudo-radial and bilabiate clusters is less clear and may form a continuum rather than two distinct groups. Transitioning from the average fan-flower to the average non-fan-flower is described almost exclusively by PC1, whereas PC2 partially describes the transition between bilabiate and pseudo-radial morphologies. Our geometric morphometric method accurately models Core Goodeniaceae floral symmetry diversity. PMID:27148960

  18. Characterizing Floral Symmetry in the Core Goodeniaceae with Geometric Morphometrics

    PubMed Central

    Gardner, Andrew G.; Fitz Gerald, Jonathan N.; Menz, John; Shepherd, Kelly A.; Howarth, Dianella G.; Jabaily, Rachel S.

    2016-01-01

    Core Goodeniaceae is a clade of ~330 species primarily distributed in Australia. Considerable variation in flower morphology exists within this group and we aim to use geometric morphometrics to characterize this variation across the two major subclades: Scaevola sensu lato (s.l.) and Goodenia s.l., the latter of which was hypothesized to exhibit greater variability in floral symmetry form. We test the hypothesis that floral morphological variation can be adequately characterized by our morphometric approach, and that discrete groups of floral symmetry morphologies exist, which broadly correlate with subjectively determined groups. From 335 images of 44 species in the Core Goodeniaceae, two principal components were computed that describe >98% of variation in all datasets. Increasing values of PC1 ventralize the dorsal petals (increasing the angle between them), whereas increasing values of PC2 primarily ventralize the lateral petals (decreasing the angle between them). Manipulation of these two morphological “axes” alone was sufficient to recreate any of the general floral symmetry patterns in the Core Goodeniaceae. Goodenia s.l. exhibits greater variance than Scaevola s.l. in PC1 and PC2, and has a significantly lower mean value for PC1. Clustering clearly separates fan-flowers (with dorsal petals at least 120° separated) from the others, whereas the distinction between pseudo-radial and bilabiate clusters is less clear and may form a continuum rather than two distinct groups. Transitioning from the average fan-flower to the average non-fan-flower is described almost exclusively by PC1, whereas PC2 partially describes the transition between bilabiate and pseudo-radial morphologies. Our geometric morphometric method accurately models Core Goodeniaceae floral symmetry diversity. PMID:27148960

  19. DOH1, a Class 1 knox Gene, Is Required for Maintenance of the Basic Plant Architecture and Floral Transition in Orchid

    PubMed Central

    Yu, Hao; Yang, Shu Hua; Goh, Chong Jin

    2000-01-01

    We report here the isolation and identification of an orchid homeobox gene, DOH1, from Dendrobium Madame Thong-In. Analyses of its sequence and genomic organization suggest that DOH1 may be the only class 1 knox gene in the genome. DOH1 mRNA accumulates in meristem-rich tissues, and its expression is greatly downregulated during floral transition. In situ hybridization analysis demonstrates that DOH1 is also expressed in the incipient leaf primordia and is later detected in the same region of the inflorescence apex, as in DOMADS1. Overexpression of DOH1 in orchid plants completely suppresses shoot organization and development. Transgenic orchid plants expressing antisense mRNA for DOH1 show multiple shoot apical meristem (SAM) formations and early flowering. In addition, both the sense and antisense transformants exhibit defects in leaf development. These findings suggest that DOH1 plays a key role in maintaining the basic plant architecture of orchid through control of the formation and development of the SAM and shoot structure. Investigations of DOMADS1 expression in the SAM during floral transition reveal that the precocious flowering phenotype exhibited by DOH1 antisense transformants is coupled with the early onset of DOMADS1 expression. This fact, together with the reciprocal expression of DOH1 and DOMADS1 during floral transition, indicates that downregulation of DOH1 in the SAM is required for floral transition in orchid and that DOH1 is a possible upstream regulator of DOMADS1. PMID:11090215

  20. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  1. Floral development and molecular phylogeny support the generic status of Tasmannia (Winteraceae).

    PubMed

    Doust, Andrew N; Drinnan, Andrew N

    2004-03-01

    The taxonomic status of and evolutionary relationship between Tasmannia and Drimys (Winteraceae) have been subjects of controversy for many years. In this paper, a molecular phylogenetic analysis of the family with sequences of previously unpublished Tasmannia and Drimys species confirms earlier conclusions that Tasmannia and Drimys do not form a monophyletic group, despite the fact that they appear to share distinctive inflorescence and floral morphological attributes. Examination of alternative hypotheses of relationships with likelihood-ratio tests and parametric bootstrapping supports the separation of Tasmannia and Drimys. A detailed analysis of floral development in Tasmannia lanceolata and T. xerophila indicates that timing and position of sepal initiation differs between them, but that the position of subsequent organ initiation predictably follows from sepal position. This is in contrast to Drimys winteri, where a prolonged delay between sepal and petal initiation leads to the production of many phyllotactic patterns. The prolonged period of calyx tube growth leading to the formation of a calyptra in Tasmannia and Drimys probably evolved in parallel in the two lineages. PMID:21653389

  2. An Arabidopsis F-box protein acts as a transcriptional co-factor to regulate floral development.

    PubMed

    Chae, Eunyoung; Tan, Queenie K-G; Hill, Theresa A; Irish, Vivian F

    2008-04-01

    Plants flower in response to both environmental and endogenous signals. The Arabidopsis LEAFY (LFY) transcription factor is crucial in integrating these signals, and acts in part by activating the expression of multiple floral homeotic genes. LFY-dependent activation of the homeotic APETALA3 (AP3) gene requires the activity of UNUSUAL FLORAL ORGANS (UFO), an F-box component of an SCF ubiquitin ligase, yet how this regulation is effected has remained unclear. Here, we show that UFO physically interacts with LFY both in vitro and in vivo, and this interaction is necessary to recruit UFO to the AP3 promoter. Furthermore, a transcriptional repressor domain fused to UFO reduces endogenous LFY activity in plants, supporting the idea that UFO acts as part of a transcriptional complex at the AP3 promoter. Moreover, chemical or genetic disruption of proteasome activity compromises LFY-dependent AP3 activation, indicating that protein degradation is required to promote LFY activity. These results define an unexpected role for an F-box protein in functioning as a DNA-associated transcriptional co-factor in regulating floral homeotic gene expression. These results suggest a novel mechanism for promoting flower development via protein degradation and concomitant activation of the LFY transcription factor. This mechanism may be widely conserved, as homologs of UFO and LFY have been identified in a wide array of plant species. PMID:18287201

  3. The ERECTA, CLAVATA and class III HD-ZIP Pathways Display Synergistic Interactions in Regulating Floral Meristem Activities

    PubMed Central

    Landau, Udi; Asis, Lior; Eshed Williams, Leor

    2015-01-01

    In angiosperms, the production of flowers marks the beginning of the reproductive phase. At the emergence of flower primordia on the flanks of the inflorescence meristem, the WUSCHEL (WUS) gene, which encodes a homeodomain transcription factor starts to be expressed and establishes de novo stem cell population, founder of the floral meristem (FM). Similarly to the shoot apical meristem a precise spatial and temporal expression pattern of WUS is required and maintained through strict regulation by multiple regulatory inputs to maintain stem cell homeostasis. However, following the formation of a genetically determined fixed number of floral organs, this homeostasis is shifted towards organogenesis and the FM is terminated. In here we performed a genetic study to test how a reduction in ERECTA, CLAVATA and class III HD-ZIP pathways affects floral meristem activity and flower development. We revealed strong synergistic phenotypes of extra flower number, supernumerary whorls, total loss of determinacy and extreme enlargement of the meristem as compared to any double mutant combination indicating that the three pathways, CLV3, ER and HD-ZIPIII distinctively regulate meristem activity and that they act in parallel. Our findings yield several new insights into stem cell-driven development. We demonstrate the crucial requirement for coupling floral meristem termination with carpel formation to ensure successful reproduction in plants. We also show how regulation of meristem size and alternation in spatial structure of the meristem serve as a mechanism to determine flower organogenesis. We propose that the loss of FM determinacy due to the reduction in CLV3, ER and HD-ZIPIII activity is genetically separable from the AGAMOUS core mechanism of meristem termination. PMID:25946150

  4. Turned on by heat: differential expression of FT and LFY-like genes in Narcissus tazetta during floral transition.

    PubMed

    Noy-Porat, Tal; Cohen, Doron; Mathew, Deepu; Eshel, Amram; Kamenetsky, Rina; Flaishman, Moshe A

    2013-08-01

    In Narcissus tazetta, a monocotyledonous bulbous geophyte, floral initiation and differentiation occur within the bulb during the quiescent period in summer, when ambient temperatures are relatively high and the bulb is located underground with no foliage or roots. In many plant species, FLOWERING LOCUS T (FT) and its homologues are considered powerful promoters of flowering. The Narcissus FT gene homologue (NtFT) was isolated, and organ-specific expression patterns of NtFT during the annual cycle and reproductive development under different temperature regimes were analysed using quantitative reverse transcription-PCR (qRT-PCR) and RNA in situ hybridization. During floral induction, NtFT was not expressed in bulb scales, roots, or foliage leaves, but it was detected inside the bulb in the apical meristem and leaf primordia. The expression of another key flowering gene, NLF, the LEAFY homologue in N. tazetta, was also observed only in meristem and leaf primordia within the bulbs; however, its expression did not coincide with that of NtFT during meristem transition to reproductive stage. Under high temperatures (25-30 °C) in the dark, NtFT expression occurred simultaneously with floral induction timing, indicating that floral induction is affected by high temperatures but not by photoperiod or vernalization. Monitoring the apical meristem of Narcissus in February-August of two growing seasons under ambient and controlled storage conditions showed that transition to flowering is temperature dependent and varies between years. Lack of NtFT and NLF expression in foliage leaves suggests that flower initiation control in Narcissus differs from that in common model plants. PMID:23833196

  5. The effect of polyploidy and hybridization on the evolution of floral colour in Nicotiana (Solanaceae)

    PubMed Central

    McCarthy, Elizabeth W.; Arnold, Sarah E. J.; Chittka, Lars; Le Comber, Steven C.; Verity, Robert; Dodsworth, Steven; Knapp, Sandra; Kelly, Laura J.; Chase, Mark W.; Baldwin, Ian T.; Kovařík, Aleš; Mhiri, Corinne; Taylor, Lin; Leitch, Andrew R.

    2015-01-01

    Background and Aims Speciation in angiosperms can be accompanied by changes in floral colour that may influence pollinator preference and reproductive isolation. This study investigates whether changes in floral colour can accompany polyploid and homoploid hybridization, important processes in angiosperm evolution. Methods Spectral reflectance of corolla tissue was examined for 60 Nicotiana (Solanaceae) accessions (41 taxa) based on spectral shape (corresponding to pigmentation) as well as bee and hummingbird colour perception in order to assess patterns of floral colour evolution. Polyploid and homoploid hybrid spectra were compared with those of their progenitors to evaluate whether hybridization has resulted in floral colour shifts. Key Results Floral colour categories in Nicotiana seem to have arisen multiple times independently during the evolution of the genus. Most younger polyploids displayed an unexpected floral colour, considering those of their progenitors, in the colour perception of at least one pollinator type, whereas older polyploids tended to resemble one or both of their progenitors. Conclusions Floral colour evolution in Nicotiana is weakly constrained by phylogeny, and colour shifts do occur in association with both polyploid and homoploid hybrid divergence. Transgressive floral colour in N. tabacum has arisen by inheritance of anthocyanin pigmentation from its paternal progenitor while having a plastid phenotype like its maternal progenitor. Potentially, floral colour evolution has been driven by, or resulted in, pollinator shifts. However, those polyploids that are not sympatric (on a regional scale) with their progenitor lineages are typically not divergent in floral colour from them, perhaps because of a lack of competition for pollinators. PMID:25979919

  6. Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens.

    PubMed

    McArt, Scott H; Koch, Hauke; Irwin, Rebecca E; Adler, Lynn S

    2014-05-01

    Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology. PMID:24528408

  7. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

    PubMed Central

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral

  8. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides.

    PubMed

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral guides affect

  9. Transcript and metabolite signature of maize source leaves suggests a link between transitory starch to sucrose balance and the autonomous floral transition

    PubMed Central

    2012-01-01

    Little is known about the nature of floral inductive cues in day-neutral plants that are insensitive to photoperiod variations and, therefore, rely on endogenous signals to initiate reproductive growth. The INDETERMINATE1 (ID1) transcription factor is a key regulator of the transition to flowering in day-neutral maize. The ID1 gene is expressed exclusively in developing leaves, where it controls the production or transmission of leaf-derived florigenic signals. Florigen-producing source leaves were compared with mature leaves of late-flowering id1 plants, and metabolite and gene expression differences associated with the floral transition in maize were observed. While id1 mutants have a similar capacity for photosynthesis to wild-type siblings, id1 source leaves show quantitative differences in carbohydrate allocation prior to the floral transition stage, with a marked increase in sucrose and other soluble sugars, accompanied by a decrease in tricarboxylic acid (TCA) cycle organic acids. Importantly, source leaves of autonomous-flowering maize are typified by a higher transitory starch to sucrose ratio and a transcript profile enriched for sucrose synthesis and starch metabolism-related gene function. Finally, similar changes in transitory starch and sucrose are not observed in teosinte, the tropical progenitor of maize that requires short-day photoperiods to induce flowering. Together, these data define a transcript and metabolite signature associated with the autonomous floral transition in temperate maize leaves. PMID:22791826

  10. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  11. Abnormal Uterine Bleeding

    MedlinePlus

    ... Abnormal uterine bleeding is any bleeding from the uterus (through your vagina) other than your normal monthly ... or fibroids (small and large growths) in the uterus can also cause bleeding. Rarely, a thyroid problem, ...

  12. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... as cancer of the uterus, cervix, or vagina • Polycystic ovary syndrome How is abnormal bleeding diagnosed? Your health care ... before the fetus can survive outside the uterus. Polycystic Ovary Syndrome: A condition characterized by two of the following ...

  13. Multicomponent floral signals elicit selective foraging in bumblebees

    NASA Astrophysics Data System (ADS)

    Gegear, Robert J.

    2005-06-01

    Flower constancy, or the tendency of individual pollinators to visit sequentially a single flower type even when other equally rewarding types are available, has important implications for animal-pollinated plants. Yet, the proximal reason for the behaviour still remains poorly understood. Here I show that bumblebees visiting equally rewarding flowers that differ in size and odour are more flower constant and less efficient (visited fewer flowers per minute) than bees visiting flowers that differ in size only and odour only. These results are consistent with the view that flower constancy in pollinators is related to their inability to perceive, process or recall multicomponent floral signals. I discuss these findings in the context of pollinator behavioural mechanisms and the evolution of floral diversity.

  14. 21. On the left is the Butte Floral Co. It ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. On the left is the Butte Floral Co. It was built sometime before 1884, and housed the offices of the Daily Intermountain and the Butte Miner. The building was remodeled in 1906, and a green-glazed brick facade with three ogee-arched was added. There is a wide wooden cornice, with a band of egg-and-dart molding. The parapet is castellated. Adjacent to the Floral Co. is the Mantle and Bielenberg Building, constructed in 1891. Interesting features include the large arched entrance and romanesque-arched windows on the third floor. The original cornice has been removed. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

  15. Patterning and evolution of floral structures - marking time.

    PubMed

    McKim, Sarah; Hay, Angela

    2010-08-01

    The diversity of flowering structures dazzles the eye, dominates the landscape, and invites evolutionary questions regarding the development of such variety. Comparative work in a number of genetically tractable plant species has addressed how diverse floral architectures develop, and started to reveal the balance between conservation and divergence of the patterning mechanisms responsible for when and where flowers form on a plant. We highlight findings from Petunia where conserved LFY/UFO function is under species-specific regulation, and a novel mechanism involving WOX homeodomain proteins for modulating cyme development in diverse nightshades. We also draw attention to recent findings in Arabidopsis of miRNA and chromatin-based timing mechanisms controlling floral development, and illustrate how genetic studies in Arabidopsis relatives can reveal how evolutionary changes in such mechanisms generate diversity in form. PMID:20452201

  16. Natural selection on floral morphology can be influenced by climate

    PubMed Central

    Campbell, Diane R.; Powers, John M.

    2015-01-01

    Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced. PMID:25972465

  17. Origin of floral isolation between ornithophilous and sphingophilous plant species.

    PubMed Central

    Grant, V

    1993-01-01

    Three plant groups in temperate western North America contain closely related ornithophilous and sphingophilous species: the Aquilegia formosa/Aquilegia caerulea group (Ranunculaceae), the Ipomopsis aggregata group (Polemoniaceae), and the Diplacus longiflorus group (Scrophulariaceae). The ornithophilous and sphingophilous species are products of allopatric speciation on the diploid level. Geographical races which are adapted to one class of pollinators in one area where these pollinators are abundant and effective and to another class of pollinators in another geographically isolated area (pollination races) represent a probable intermediate stage in the process of allopatric speciation. Mechanical and ethological isolation (collectively, floral isolation) is a byproduct of the divergence in pollination systems. Selection for reproductive isolation per se has not played any detectable role in the origin of the floral isolation in the three plant groups. PMID:11607421

  18. Natural selection on floral morphology can be influenced by climate.

    PubMed

    Campbell, Diane R; Powers, John M

    2015-06-01

    Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced. PMID:25972465

  19. Phosphatidic acid is a major phospholipid class in reproductive organs of Arabidopsis thaliana

    PubMed Central

    Yunus, Ian Sofian; Cazenave-Gassiot, Amaury; Liu, Yu-chi; Lin, Ying-Chen; Wenk, Markus R; Nakamura, Yuki

    2015-01-01

    Phospholipids are the crucial components of biological membranes and signal transduction. Among different tissues, flower phospholipids are one of the least characterized features of plant lipidome. Here, we report that floral reproductive organs of Arabidopsis thaliana contain high levels of phosphatidic acid (PA), a known lipid second messenger. By using floral homeotic mutants enriched with specific floral organs, lipidomics study showed increased levels of PA species in ap3-3 mutant with enriched pistils. Accompanied gene expression study for 7 diacylglycerol kinases and 11 PA phosphatases revealed distinct floral organ specificity, suggesting an active phosphorylation/dephosphorylation between PA and diacylglycerol in flowers. Our results suggest that PA is a major phospholipid class in floral reproductive organs of A. thaliana. PMID:26179579

  20. Abnormal organic-matter maturation in the Yinggehai Basin, South China Sea: Implications for hydrocarbon expulsion and fluid migration from overpressured systems

    USGS Publications Warehouse

    Hao, F.; Li, S.; Dong, W.; Hu, Z.; Huang, B.

    1998-01-01

    Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. A number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. Because the reservoir intervals are shallow and very young, they must have filled with gas rapidly. The thick (up to 17 km) Tertiary and Quaternary sedimentary succession is dominated by shales, and is not disrupted by major faulting in the study area, a factor which seems to have had an important effect on both hydrocarbon generation and fluid migration. Organic-matter maturation in the deepest, most overpressured compartment has been significantly retarded as a result of the combined effects of excess pressure, the presence of large volumes of water, and the retention of generated hydrocarbons. This retardation is indicated by both kerogen-related parameters (vitrinite reflectance and Rock-Eval T(max)); and also by parameters based on the analysis of soluble organic matter (such as the C15+ hydrocarbon content, and the concentration of isoprenoid hydrocarbons relative to adjacent normal alkanes). In contrast to this, organic-matter maturation in shallow, normally-pressured strata in the diapiric area has been enhanced by hydrothermal fluid flow, which is clearly not topography-driven in origin. As a result, the hydrocarbon generation 'window' in the basin is considerably wider than could be expected from traditional geochemical modelling. These two unusual and contrasting anomalies in organic-matter maturation, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of the intense overpressuring, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids (both water and hydrocarbons) retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal

  1. Chromosomal Abnormalities and Schizophrenia

    PubMed Central

    BASSETT, ANNE S.; CHOW, EVA W.C.; WEKSBERG, ROSANNA

    2011-01-01

    Schizophrenia is a common and serious psychiatric illness with strong evidence for genetic causation, but no specific loci yet identified. Chromosomal abnormalities associated with schizophrenia may help to understand the genetic complexity of the illness. This paper reviews the evidence for associations between chromosomal abnormalities and schizophrenia and related disorders. The results indicate that 22q11.2 microdeletions detected by fluorescence in-situ hybridization (FISH) are significantly associated with schizophrenia. Sex chromosome abnormalities seem to be increased in schizophrenia but insufficient data are available to indicate whether schizophrenia or related disorders are increased in patients with sex chromosome aneuploidies. Other reports of chromosomal abnormalities associated with schizophrenia have the potential to be important adjuncts to linkage studies in gene localization. Advances in molecular cytogenetic techniques (i.e., FISH) have produced significant increases in rates of identified abnormalities in schizophrenia, particularly in patients with very early age at onset, learning difficulties or mental retardation, or dysmorphic features. The results emphasize the importance of considering behavioral phenotypes, including adult onset psychiatric illnesses, in genetic syndromes and the need for clinicians to actively consider identifying chromosomal abnormalities and genetic syndromes in selected psychiatric patients. PMID:10813803

  2. Features of Rice DNA Methylation Pathways in Floral Symmetry.

    PubMed

    Garcês, Helena Maria Pereira; Spencer, Victoria M R; Kim, Minsung

    2016-07-01

    All members of Asteraceae, the largest flowering family, have a unique compressed inflorescence known as a capitulum, which resembles a solitary flower. The capitulum often consists of bilateral (zygomorphic) ray florets and radial (actinomorphic) disc florets. In Antirrhinum majus, floral zygomorphy is established by the interplay between dorsal petal identity genes, CYCLOIDEA (CYC) and RADIALIS (RAD), and a ventral gene DIVARICATA (DIV). To investigate the role of CYC, RAD, and DIV in the development of ray and disc florets within a capitulum, we isolated homologs of these genes from an Asteraceae species, Senecio vulgaris (common groundsel). After initial uniform expression of RAY3 (CYC), SvRAD, and SvDIV1B in ray florets only, RAY3 and SvRAD were exclusively expressed in the ventral petals of the ray florets. Our functional analysis further showed that RAY3 promotes and SvDIV1B represses petal growth, confirming their roles in floral zygomorphy. Our results highlight that while floral symmetry genes such as RAY3 and SvDIV1B appear to have a conserved role in petal growth in both Senecio and Antirrhinum, the regulatory relationships and expression domains are divergent, allowing ventral petal elongation in Senecio versus dorsal petal elongation in Antirrhinum In S vulgaris, diversification of CYC genes has led to novel interactions; SvDIV1B inhibits RAY3 and SvRAD, and may activate RAY2 This highlights how recruitment of floral symmetry regulators into dynamic networks was crucial for creating a complex and elaborate structure such as the capitulum. PMID:27208229

  3. Morphology of Floral Papillae in Maxillaria Ruiz & Pav. (Orchidaceae)

    PubMed Central

    DAVIES, K. L.; TURNER, M. P.

    2004-01-01

    • Background and Aims The labellar papillae and trichomes of Maxillaria Ruiz & Pav. show great diversity. Although papillae also occur upon other parts of the flower (e.g. column and anther cap), these have not yet been studied. Labellar trichomes of Maxillaria are useful in taxonomy, but hitherto the taxonomic value of floral papillae has not been assessed. The aim of this paper is to describe the range of floral papillae found in Maxillaria and to determine whether papillae are useful as taxonomic characters. • Methods Light microscopy, histochemistry, low‐vacuum scanning and transmission electron microscopy. • Key Results A total of 75 taxa were studied. Conical papillae with rounded or pointed tips were the most common. The column and anther cap usually bear conical, obpyriform or villiform papillae, whereas those around the stigmatic surface and at the base of the anther are often larger and swollen. Labellar papillae show greater diversity, and may be conical, obpyriform, villiform, fusiform or clavate. Papillae may also occur on multiseriate trichomes that perhaps function as pseudostamens. Labellar papillae contain protein but most lack lipid. The occurrence of starch, however, is more variable. Many papillae contain pigment or act as osmophores, thereby attracting insects. Rewards such as nectar or a protein‐rich, wax‐like, lipoidal substance may be secreted by papillae onto the labellar surface. Some papillae may have a protective role in preventing desiccation. Species of diverse vegetative morphology may have identical floral papillae, whereas others of similar vegetative morphology may not. • Conclusions Generally, floral papillae in Maxillaria have little taxonomic value. Nevertheless, the absence of papillae from members of the M. cucullata alliance, the occurrence of clavate papillae with distended apices in the M. rufescens alliance and the presence of papillose trichomes in some species may yet prove to be useful. PMID:14630691

  4. Association Between Floral Traits and Rewards in Erysimum mediohispanicum (Brassicaceae)

    PubMed Central

    Gómez, José M.; Bosch, Jordi; Perfectti, Francisco; Fernández, J. D.; Abdelaziz, Mohamed; Camacho, J. P. M.

    2008-01-01

    Background and Aims Floral rewards may be associated with certain morphological floral traits and thus act as underlying factors promoting selection on these traits. This study investigates whether some traits that are under pollinator-mediated selection (flower number, stalk height, corolla diameter, corolla tube length and corolla tube width) in the Mediterranean herb E. mediohispanicum (Brassicaceae) are associated with rewards (pollen and nectar). Methods During 2005 the phenotypic traits and the visitation rate of the main pollinator functional groups were quantified in 720 plants belonging to eight populations in south-east Spain, and during 2006 the same phenotypic traits and the reward production were quantified in 400 additional plants from the same populations. Key Results A significant correlation was found between nectar production rate and corolla tube length, and between pollen production and corolla diameter. Visitation rates of large bees and butterflies were significantly higher in plants exhibiting larger flowers with longer corolla tubes. Conclusions The association between reward production and floral traits may be a factor underlying the pattern of visitation rate displayed by some pollinators. PMID:18424472

  5. The evolution of floral biology in basal angiosperms.

    PubMed

    Endress, Peter K

    2010-02-12

    In basal angiosperms (including ANITA grade, magnoliids, Choranthaceae, Ceratophyllaceae) almost all bisexual flowers are dichogamous (with male and female functions more or less separated in time), and nearly 100 per cent of those are protogynous (with female function before male function). Movements of floral parts and differential early abscission of stamens in the male phase are variously associated with protogyny. Evolution of synchronous dichogamy based on the day/night rhythm and anthesis lasting 2 days is common. In a few clades in Magnoliales and Laurales heterodichogamy has also evolved. Beetles, flies and thrips are the major pollinators, with various degrees of specialization up to large beetles and special flies in some large-flowered Nymphaeaceae, Magnoliaceae, Annonaceae and Aristolochiaceae. Unusual structural specializations are involved in floral biological adaptations (calyptras, inner staminodes, synandria and food bodies, and secretory structures on tepals, stamens and staminodes). Numerous specializations that are common in monocots and eudicots are absent in basal angiosperms. Several families are poorly known in their floral biology. PMID:20047868

  6. Duplication of floral regulatory genes in the Lamiales.

    PubMed

    Aagaard, Jan E; Olmstead, Richard G; Willis, John H; Phillips, Patrick C

    2005-08-01

    Duplication of some floral regulatory genes has occurred repeatedly in angiosperms, whereas others are thought to be single-copy in most lineages. We selected three genes that interact in a pathway regulating floral development conserved among higher tricolpates (LFY/FLO, UFO/FIM, and AP3/DEF) and screened for copy number among families of Lamiales that are closely related to the model species Antirrhinum majus. We show that two of three genes have duplicated at least twice in the Lamiales. Phylogenetic analyses of paralogs suggest that an ancient whole genome duplication shared among many families of Lamiales occurred after the ancestor of these families diverged from the lineage leading to Veronicaceae (including the single-copy species A. majus). Duplication is consistent with previous patterns among angiosperm lineages for AP3/DEF, but this is the first report of functional duplicate copies of LFY/FLO outside of tetraploid species. We propose Lamiales taxa will be good models for understanding mechanisms of duplicate gene preservation and how floral regulatory genes may contribute to morphological diversity. PMID:21646149

  7. Scale-dependent shifts in the species composition of flower visitors with changing floral density.

    PubMed

    Essenberg, Carla J

    2013-01-01

    Responses of flower-visiting animals to floral density can alter interactions between plants, influencing a variety of biological processes, including plant population dynamics and the evolution of flowering phenology. Many studies have found effects of floral or plant density on pollinator visitation rates at patch scales, but little is known about responses of flower visitors to floral densities at larger scales. Here, I present data from an observational field study in which I measured the effects of floral density on visitation to the annual composite Holocarpha virgata at both patch (4 m(2)) and site (12.6 ha) spatial scales. The species composition of flower visitors changed with floral density, and did so in different ways at the two scales. At the site scale, average floral density within patches of H. virgata or within patches of all summer-flowering species combined had a significant positive effect on per-flowerhead visitation by the long-horned bee Melissodes lupina and no significant effects on visitation by any other taxa. At the patch scale, per-flowerhead visitation by honeybees significantly increased whereas visitation by M. lupina often decreased with increasing floral density. For both species, responses to patch-scale floral density were strongest when site-scale floral density was high. The scale-dependence of flower visitor responses to floral density and the interactions between site- and patch-scale effects of floral density observed in this study underscore the importance of improving our understanding of pollinators' responses to floral density at population scales. PMID:22752187

  8. Floral polymorphism and the fitness implications of attracting pollinating and florivorous insects

    PubMed Central

    de Jager, Marinus L.; Ellis, Allan G.

    2014-01-01

    Background and Aims Floral polymorphism is frequently attributed to pollinator-mediated selection. Multiple studies, however, have revealed the importance of non-pollinating visitors in floral evolution. Using the polymorphic annual daisy Ursinia calenduliflora, this study investigated the importance of different insect visitors, and their effects on fitness, in the maintenance of floral polymorphism. Methods The spatial structure of a discrete floral polymorphism was characterized based on the presence/absence of anthocyanin floret spots in U. calenduliflora. A 3-year observational study was then conducted in polymorphic populations to investigate differences in visitation rates of dominant visitors to floral morphs. Experiments were performed to explore the floral preference of male and female Megapalpus capensis (the dominant insect visitor) and their effectiveness as pollinators. Next, floral damage by antagonistic florivores and the reproductive success of the two floral morphs were surveyed in multiple populations and years. Key Results Floral polymorphism in U. calenduliflora was structured spatially, as were insect visitation patterns. Megapalpus capensis males were the dominant visitors and exhibited strong preference for the spotted morph in natural and experimental observations. While this may indicate potential fitness benefits for the spotted morph, female fitness did not differ between floral morphs. However, as M. capensis males are very efficient at exporting U. calenduliflora pollen, their preference may likely increase the reproductive fitness of the spotted morph through male fitness components. The spotted morph, however, also suffered significantly greater costs due to ovule predation by florivores than the spotless morph. Conclusions The results suggest that pollinators and florivores may potentially exert antagonistic selection that could contribute to the maintenance of floral polymorphism across the range of U. calenduliflora. The relative

  9. Heritability of floral volatiles and pleiotropic responses to artificial selection in Brassica rapa.

    PubMed

    Zu, Pengjuan; Blanckenhorn, Wolf U; Schiestl, Florian P

    2016-02-01

    The evolution of the vast diversity of floral volatiles is little understood, although they serve fundamental functions, such as pollinator attraction and herbivore deterrence. Floral volatiles are often species specific, yet highly variable and sensitive to environmental factors. To date, nothing is known about the heritability of floral volatiles, and whether individual compounds can evolve independently or solely in concert with the whole volatile bouquet. We conducted bi-directional artificial selection on four target floral volatiles to estimate heritability and correlated pleiotropic responses in the wild turnip (Brassica rapa). The realized heritability of the four target volatiles ranged from 20% to 45%. The average narrow-sense heritability of all 13 analyzed floral volatiles was 18% based on parent-offspring regressions. There were pleiotropic effects of the selected floral volatile compounds on other constituents of the floral scent bouquet, on flowering time and on some morphological traits. We found that the whole floral scent bouquet changed, even when there was selection only on single compounds, with the overall phenotypic covariance being unaffected. Our study demonstrates that floral scent can evolve rapidly under phenotypic selection, but with additional correlated responses in traits that are not direct targets of selection. PMID:26391626

  10. EAG responses of Apis cerana to floral compounds of a biodiesel plant, Jatropha curcas (Euphorbiaceae).

    PubMed

    Luo, Changwei; Huang, Zachary Y; Li, Kun; Chen, Xiaoming; Chen, You; Sun, Yongyu

    2013-08-01

    The Eastern honey bee, [Apis cerana (F.)], is an important and common pollinator for an important biodiesel tree, [Jatropha curcas (L.)]. To understand sensitivity of A. cerana to different floral compounds, we quantified volatile floral compounds of J. curcas, then determined electroantennogram (EAG) responses of A. cerana to 11 compounds each at five doses (0.4, 4, 40, 400, and 4,000 microg) of six most active floral compounds. Our results demonstrated that floral compounds of J. curcas differ in variety and quantity while linalool is always a major constituent in floral blends from three different plantations. Antennae of A. cerana responded to all 11 floral compounds, implying a broad sensitivity of A. cerana to different floral compounds of J. curcas. Antennae of A. cerana were most sensitive to six compounds, including all aldehydes (decanal, hexanal, nonanal, and octanal), linalool, and an alcohol (3-hexenol), suggesting that A. cerana possesses chemoreceptors to aldehydes, linalool, and alcohol on the antenna. Furthermore, low doses elicited a zero EAG response and high doses a positive one under all of six most active compounds. Thus, EAG responses of A. cerana were both chemical specific and dose-dependent. Our results here suggest that A. cerana is senstive to various floral compounds, and linalool in the floral blends of J. curcas plays a key role to attract A. cerana. PMID:24020278

  11. Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors.

    PubMed

    Koski, Matthew H; Ashman, Tia-Lynn

    2016-07-01

    Selection driven by biotic interactions can generate variation in floral traits. Abiotic selection, however, also contributes to floral diversity, especially with respect to patterns of pigmentation. Combining comparative studies of floral pigmentation and geography can reveal the bioclimatic factors that may drive macroevolutionary patterns of floral color. We create a molecular phylogeny and measure ultraviolet (UV) floral pattern for 177 species in the Potentilleae tribe (Rosaceae). Species are similar in flower shape and visible color but vary in UV floral pattern. We use comparative approaches to determine whether UV pigmentation variation is associated with geography and/or bioclimatic features (UV-B, precipitation, temperature). Floral UV pattern was present in half of the species, while others were uniformly UV-absorbing. Phylogenetic signal was detected for presence/absence of pattern, but among patterned species, quantitative variation in UV-absorbing area was evolutionarily labile. Uniformly UV-absorbing species tended to experience higher UV-B irradiance. Patterned species occurring at higher altitudes had larger UV-absorbing petal areas, corresponding with low temperature and high UV exposure. This analysis expands our understanding of the covariation of UV-B irradiance and UV floral pigmentation from within species to that among species, and supports the view that abiotic selection is associated with floral diversification among species. PMID:26987355

  12. Floral variation and environmental heterogeneity in a tristylous clonal aquatic of the Pantanal wetlands of Brazil

    PubMed Central

    Leme da Cunha, Nicolay; Fischer, Erich; Lorenz-Lemke, Aline P.; Barrett, Spencer C. H.

    2014-01-01

    Background and Aims The balance between stochastic forces and frequency-dependent mating largely governs style morph frequencies in heterostylous populations. In clonal species, deviations from equal morph ratios often result from founder events and unfavourable conditions for sexual reproduction. The aim of this study was to investigate whether different flooding regimes, because of their influence on sexual vs. clonal reproduction, are associated with regional variation in morph frequencies and floral trait differentiation in populations of the clonal, tristylous, aquatic Eichhornia azurea (Pontederiaceae) in the Pantanal wetlands of Brazil. Methods Style morph frequencies were sampled from 73 populations distributed across four flooding regimes differing in depth and duration. Measurements of flower size, sex-organ dimension, pollen size and pollen production were made in selected populations, and pollinator assemblages and their functional traits were recorded. Key Results Most populations of E. azurea were tristylous (78 %), but the majority exhibited uneven morph ratios. The frequency of the mid-styled morph was significantly lower than that of the long- and short-styled morphs. Morph evenness was positively associated with population size but not with flooding regime. There were significant phenotypic differences among flooding regimes for all floral traits, including populations with reduced flower size, sex-organ length and smaller pollen. Pollinator assemblages varied with flood duration. Conclusions The similar morph structure and evenness of populations, regardless of flooding regime, suggest that sexual reproduction and clonal dispersal are sufficiently common to prevent the signature of founder events from dominating in a region. However, the pervasive occurrence of biased morph ratios in most populations suggests that many are in a non-equilibrium state. The reduced frequency of the mid-styled morph in trimorphic and dimorphic populations may be

  13. Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F-box protein, regulates meristem fate.

    PubMed

    Ikeda, Kyoko; Ito, Momoyo; Nagasawa, Nobuhiro; Kyozuka, Junko; Nagato, Yasuo

    2007-09-01

    Inflorescence architecture is one of the most important agronomical traits. Characterization of rice aberrant panicle organization 1 (apo1) mutants revealed that APO1 positively controls spikelet number by suppressing the precocious conversion of inflorescence meristems to spikelet meristems. In addition, APO1 is associated with the regulation of the plastchron, floral organ identity, and floral determinacy. Phenotypic analyses of apo1 and floral homeotic double mutants demonstrate that APO1 positively regulates class-C floral homeotic genes, but not class-B genes. Molecular studies revealed that APO1 encodes an F-box protein, an ortholog of Arabidopsis UNUSUAL FLORAL ORGAN (UFO), which is a positive regulator of class-B genes. Overexpression of APO1 caused an increase in inflorescence branches and spikelets. As the mutant inflorescences and flowers differed considerably between apo1 and ufo, the functions of APO1 and UFO appear to have diverged during evolution. PMID:17666027

  14. The Arabidopsis floral homeotic gene PISTILLATA is regulated by discrete cis-elements responsive to induction and maintenance signals.

    PubMed

    Honma, T; Goto, K

    2000-05-01

    PISTILLATA is a B-class floral organ identity gene required for the normal development of petals and stamens in Arabidopsis. PISTILLATA expression is induced in the stage 3 flowers (early expression) and is maintained until anthesis (late expression). To explore in more detail the developmentally regulated gene expression of PISTILLATA, we have analyzed the PISTILLATA promoter using uidA (beta)-glucuronidase gene) fusion constructs (PI::GUS) in transgenic Arabidopsis. Promoter deletion analyses suggest that early PISTILLATA expression is mediated by the distal region and that late expression is mediated by the proximal region. Based on the PI::GUS expression patterns in the loss- and gain-of-function alleles of meristem or organ identity genes, we have shown that LEAFY and UNUSUAL FLORAL ORGANS induce PISTILLATA expression in a flower-independent manner via a distal promoter, and that PISTILLATA and APETALA3 maintain PISTILLATA expression (autoregulation) in the later stages of flower development via a proximal promoter. In addition, we have demonstrated that de novo protein synthesis is required for the PISTILLATA autoregulatory circuit. PMID:10769227

  15. Thermogenesis, Flowering and the Association with Variation in Floral Odour Attractants in Magnolia sprengeri (Magnoliaceae)

    PubMed Central

    Wang, Ruohan; Xu, Sai; Liu, Xiangyu; Zhang, Yiyuan; Wang, Jianzhong; Zhang, Zhixiang

    2014-01-01

    Magnolia sprengeri Pamp. is an ornamentally and ecologically important tree that blooms at cold temperatures in early spring. In this study, thermogenesis and variation in the chemical compounds of floral odours and insect visitation in relation to flowering cycles were studied to increase our understanding of the role of floral thermogenesis in the pollination biology of M. sprengeri. There were five distinct floral stages across the floral cycle of this species: pre-pistillate, pistillate, pre-staminate, staminate and post-staminate. Floral thermogenesis during anthesis and consisted of two distinct peaks: one at the pistillate stage and the other at the staminate stage. Insects of five families visited M. sprengeri during the floral cycle, and sap beetles (Epuraea sp., Nitidulidae) were determined to be the most effective pollinators, whereas bees (Apis cerana, Apidae) were considered to be occasional pollinators. A strong fragrance was released during thermogenesis, consisting of 18 chemical compounds. Although the relative proportions of these compounds varied at different floral stages across anthesis, linalool, 1-iodo-2-methylundecane and 2,2,6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol were dominant. Importantly, we found that the floral blends released during the pistillate and staminate stages were very similar, and coincided with flower visitation by sap beetles and the two thermogenic episodes. Based on these results, we propose that odour acts as a signal for a reward (pollen) and that an odour mimicry of staminate-stage flowers occurs during the pistillate stage. PMID:24922537

  16. Variation in floral longevity in the genus Leptosiphon: mating system consequences.

    PubMed

    Weber, J J; Goodwillie, C

    2013-01-01

    Pollination or fertilisation trigger floral senescence in a wide range of flowering plants, and yet little attention has been given to the implications of this phenomenon to mating system evolution. We examined the effects of pollination on floral senescence in the genus Leptosiphon. Species in the genus exhibit a wide range of breeding systems. In all cases, compatible pollination induced senescence; emasculated flowers lived longer than hand-outcrossed flowers. In the self-compatible species, Leptosiphon acicularis and L. bicolor, and in one highly selfing population of L. jepsonii, unmanipulated flowers had reduced longevity compared to emasculated flowers, suggesting that autonomous self-pollination limits floral longevity in these species. Limited floral longevity in these highly selfing taxa may reduce opportunities for male outcross success, representing a possible source of selection on the mating system. In turn, the mating system might influence how selection acts on floral longevity; obligately outcrossing taxa are expected to benefit from longer floral longevities to maximise opportunities for pollination, while selfing taxa might benefit from earlier floral senescence to reduce resource expenditure. Overall, the longevity of unpollinated flowers increased with the level of outcrossing in the genus Leptosiphon. Our results taken together with those of a previous study and similar results in other species suggest that floral longevity may represent a largely unexamined role in mating system evolution. PMID:22607097

  17. Enantiostyly in Chamaecrista ramosa (Fabaceae-Caesalpinioideae): floral morphology, pollen transfer dynamics and breeding system.

    PubMed

    Almeida, N M de; Castro, C C de; Leite, A V de Lima; Novo, R R; Machado, I C

    2013-03-01

    Enantiostyly is a form of reciprocal herkogamy, in which floral morphs present reciprocal differences in the position of sexual elements, and occurs in monomorphic and dimorphic forms. This polymorphism maximises cross-pollination and reduces self-pollination, being very common within the subtribe Cassiinae (Fabaceae). Nevertheless, few studies have investigated the functionality of enantiostyly, particularly in this plant group. The present study aimed to investigate enantiostyly and its functionality in Chamaecrista ramosa, a monomorphic enantiostylous shrub, in an area of coastal vegetation in northeast Brazil. Pollen deposition and capture on the body of floral visitors, the relationship of these data with floral biology and breeding system, and morph ratio were evaluated. Pollen deposition and capture occurred in specific sites of the floral visitor body, showing the functionality of enantiostyly. The floral architecture, associated with the floral visitor behaviour, resulted in indirect pollen deposition on the floral visitor body. This occurred through a loop made by the pollen upon the inner petal surface, similar that generally reported for other Cassiinae. Chamaecrista ramosa is self-compatible, although no fruit set was observed through spontaneous self-pollination. The occurrence and number of floral morphs was similar within clumps. Enantiostyly seems to be advantageous for this species, as it results in efficient pollen capture and deposition, reduces the chances of autogamy and maximises intermorph pollen flow. PMID:23127184

  18. Two GATA transcription factors are downstream effectors of floral homeotic gene action in Arabidopsis.

    PubMed

    Mara, Chloe D; Irish, Vivian F

    2008-06-01

    Floral organogenesis is dependent on the combinatorial action of MADS-box transcription factors, which in turn control the expression of suites of genes required for growth, patterning, and differentiation. In Arabidopsis (Arabidopsis thaliana), the specification of petal and stamen identity depends on the action of two MADS-box gene products, APETALA3 (AP3) and PISTILLATA (PI). In a screen for genes whose expression was altered in response to the induction of AP3 activity, we identified GNC (GATA, nitrate-inducible, carbon-metabolism-involved) as being negatively regulated by AP3 and PI. The GNC gene encodes a member of the Arabidopsis GATA transcription factor family and has been implicated in the regulation of chlorophyll biosynthesis as well as carbon and nitrogen metabolism. In addition, we found that the GNC paralog, GNL (GNC-like), is also negatively regulated by AP3 and PI. Using chromatin immunoprecipitation, we showed that promoter sequences of both GNC and GNL are bound by PI protein, suggesting a direct regulatory interaction. Analyses of single and double gnc and gnl mutants indicated that the two genes share redundant roles in promoting chlorophyll biosynthesis, suggesting that in repressing GNC and GNL, AP3/PI have roles in negatively regulating this biosynthetic pathway in flowers. In addition, coexpression analyses of genes regulated by AP3, PI, GNC, and GNL indicate a complex regulatory interplay between these transcription factors in regulating a variety of light and nutrient responsive genes. Together, these results provide new insights into the transcriptional cascades controlling the specification of floral organ identities. PMID:18417639

  19. Floral Transcriptomes in Woodland Strawberry Uncover Developing Receptacle and Anther Gene Networks.

    PubMed

    Hollender, Courtney A; Kang, Chunying; Darwish, Omar; Geretz, Aviva; Matthews, Benjamin F; Slovin, Janet; Alkharouf, Nadim; Liu, Zhongchi

    2014-05-14

    Flowers are reproductive organs and precursors to fruits and seeds. While the basic tenets of the ABCE model of flower development are conserved in angiosperms, different flowering plants exhibit different and sometimes unique characteristics. A distinct feature of strawberry (Fragaria spp.) flowers is the development of several hundreds of individual apocarpous (unfused) carpels. These individual carpels are arranged in a spiral pattern on the subtending stem tip, the receptacle. Therefore, the receptacle is an integral part of the strawberry flower and is of significant agronomic importance, being the precursor to strawberry fruit. Taking advantage of next-generation sequencing and laser capture microdissection, we generated different tissue- and stage-transcriptomic profiling of woodland strawberry (Fragaria vesca) flower development. Using pairwise comparisons and weighted gene coexpression network analysis, we identified modules of coexpressed genes and hub genes of tissue-specific networks. Of particular importance is the discovery of a developing receptacle-specific module exhibiting similar molecular features to those of young floral meristems. The strawberry homologs of a number of meristem regulators, including LOST MERISTEM and WUSCHEL, are identified as hub genes operating in the developing receptacle network. Furthermore, almost 25% of the F-box genes in the genome are transiently induced in developing anthers at the meiosis stage, indicating active protein degradation. Together, this work provides important insights into the molecular networks underlying strawberry's unique reproductive developmental processes. This extensive floral transcriptome data set is publicly available and can be readily queried at the project Web site, serving as an important genomic resource for the plant biology research community. PMID:24828307

  20. Uncovering the Arabidopsis thaliana nectary transcriptome: investigation of differential gene expression in floral nectariferous tissues

    PubMed Central

    Kram, Brian W; Xu, Wayne W; Carter, Clay J

    2009-01-01

    Background Many flowering plants attract pollinators by offering a reward of floral nectar. Remarkably, the molecular events involved in the development of nectaries, the organs that produce nectar, as well as the synthesis and secretion of nectar itself, are poorly understood. Indeed, to date, no genes have been shown to directly affect the de novo production or quality of floral nectar. To address this gap in knowledge, the ATH1 Affymetrix® GeneChip array was used to systematically investigate the Arabidopsis nectary transcriptome to identify genes and pathways potentially involved in nectar production. Results In this study, we identified a large number of genes differentially expressed between secretory lateral nectaries and non-secretory median nectary tissues, as well as between mature lateral nectaries (post-anthesis) and immature lateral nectaries (pre-anthesis). Expression within nectaries was also compared to thirteen non-nectary reference tissues, from which 270 genes were identified as being significantly upregulated in nectaries. The expression patterns of 14 nectary-enriched genes were also confirmed via RT PCR. Upon looking into functional groups of upregulated genes, pathways involved in gene regulation, carbohydrate metabolism, and lipid metabolism were particularly enriched in nectaries versus reference tissues. Conclusion A large number of genes preferentially expressed in nectaries, as well as between nectary types and developmental stages, were identified. Several hypotheses relating to mechanisms of nectar production and regulation thereof are proposed, and provide a starting point for reverse genetics approaches to determine molecular mechanisms underlying nectar synthesis and secretion. PMID:19604393

  1. Floral elaiophores in Lockhartia Hook. (Orchidaceae: Oncidiinae): their distribution, diversity and anatomy

    PubMed Central

    Blanco, Mario A.; Davies, Kevin L.; Stpiczyńska, Malgorzata; Carlsward, Barbara S.; Ionta, Gretchen M.; Gerlach, Günter

    2013-01-01

    Background and Aims A significant proportion of orchid species assigned to subtribe Oncidiinae produce floral oil as a food reward that attracts specialized bee pollinators. This oil is produced either by glabrous glands (epithelial elaiophores) or by tufts of secretory hairs (trichomal elaiophores). Although the structure of epithelial elaiophores in the Oncidiinae has been well documented, trichomal elaiophores are less common and have not received as much attention. Only trichomal elaiophores occur in the genus Lockhartia, and their distribution and structure are surveyed here for the first time. Methods Flowers of 16 species of Lockhartia were studied. The location of floral elaiophores was determined histochemically and their anatomical organization and mode of oil secretion was investigated by means of light microscopy, scanning electron microscopy and transmission electron microscopy. Key Results and Conclusions – All species of Lockhartia investigated have trichomal elaiophores on the adaxial surface of the labellum. Histochemical tests revealed the presence of lipoidal substances within the labellar trichomes. However, the degree of oil production and the distribution of trichomes differed between the three major groups of species found within the genus. All trichomes were unicellular and, in some species, of two distinct sizes, the larger being either capitate or apically branched. The trichomal cuticle was lamellate, and often appeared distended due to the subcuticular accumulation of oil. The labellar trichomes of the three species examined using transmission electron microscopy contained dense, intensely staining cytoplasm with apically located vacuoles. Oil-laden secretory vesicles fused with the plasmalemma and discharged their contents. Oil eventually accumulated between the cell wall and cuticle of the trichome and contained electron-transparent profiles or droplets. This condition is considered unique to Lockhartia among those species of

  2. Pollinarium Morphology and Floral Rewards inBrazilian Maxillariinae (Orchidaceae)

    PubMed Central

    SINGER, RODRIGO B.; KOEHLER, SAMANTHA

    2004-01-01

    • Background and Aims There is strong support for the monophyly of the orchid subtribe Maxillariinae s.l., yet generic boundaries within it are unsatisfactory and need re‐evaluation. In an effort to assemble sets of morphological characters to distinguish major clades within this subtribe, the pollinarium morphology and floral rewards of representative Brazilian species of this subtribe were studied. • Methods The study was based on fresh material from 60 species and seven genera obtained from cultivated specimens. Variation of pollinarium structure and floral rewards was assessed using a stereomicroscope and by SEM analysis. • Key Results Four morphological types of pollinaria are described. Type 1 appears to be the most widespread and is characterized by a well‐developed tegula. Type 2 lacks a stipe and the pollinia are attached directly to the viscidium. Type 3 also lacks a stipe, and the viscidium is rigid and dark. In Type 4, the stipe consists of the whole median rostelar portion and, so far, is known only from Maxillaria uncata. Nectar, trichomes, wax‐like and resin‐like secretions are described as flower rewards for different groups of species within the genus Maxillaria. Data on the biomechanics and pollination biology are also discussed and illustrated. In Maxillariinae flowers with arcuate viscidia, the pollinaria are deposited on the scuttellum of their Hymenopteran pollinators. In contrast, some flowers with rounded to rectangular, pad‐like viscidia fix their pollinaria on the face of their pollinators. • Conclusions Pollinarium morphology and floral features related to pollination in Brazilian Maxillariinae are more diverse than previously suggested. It is hoped that the data presented herein, together with other data sources such as vegetative traits and molecular tools, will be helpful in redefining and diagnosing clades within the subtribe Maxillariinae. PMID:14644913

  3. Induced abnormality in Mir- and Earth grown Super Dwarf wheat

    NASA Technical Reports Server (NTRS)

    Bubenheim, D. L.; Stieber, J.; Campbell, W. F.; Salisbury, F. B.; Levinski, M.; Sytchev, V.; Podolsky, I.; Chernova, L.; Pdolsky, I.

    2003-01-01

    Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with Earth-grown wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super-Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen gains, however, contained only one nuclei, while normal viable pollen is tri-nucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was the presence of a high level of atmospheric ethylene (1,200 ppb). Ground studies conducted by exposing 'Super-Dwarf' wheat to ethylene just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

  4. Induced abnormality in Mir- and earth grown super dwarf wheat

    NASA Astrophysics Data System (ADS)

    Bubenheim, D. L.; Stieber, J.; Campbell, W. F.; Salisbury, F. B.; Levinski, M.; Sytchev, V.; Pdolsky, I.; Chernova, L.

    Super-dwarf wheat grown on the Mir space station using the Svet ``Greenhouse'' exhibited morphological, metabolic and reproductive abnormalities compared with Earth-grown wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of `Super-Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen gains, however, contained only one nuclei, while normal viable pollen is tri-nucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was the presence of a high level of atmospheric ethylene (1,200 ppb). Ground studies conducted by exposing `Super-Dwarf' wheat to ethylene just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples.

  5. Pestalotioid fungi from Restionaceae in the Cape Floral Kingdom

    PubMed Central

    Lee, Seonju; Crous, Pedro W.; Wingfield, Michael J.

    2006-01-01

    Eight pestalotioid fungi were isolated from the Restionaceae growing in the Cape Floral Kingdom of South Africa. Sarcostroma restionis, Truncatella megaspora, T. restionacearum and T. spadicea are newly described. New records include Pestalotiopsis matildae, Sarcostroma lomatiae, Truncatella betulae and T. hartigii. To resolve generic affiliations, phylogenetic analyses were performed on ITS (ITS1, 5.8S, ITS2) and part of 28S rDNA. DNA data support the original generic concept of Truncatella, which encompasses Pestalotiopsis species having 3-septate conidia. The genus Sarcostroma is retained as separate from Seimatosporium. PMID:18490978

  6. Floral CO2 reveals flower profitability to moths.

    PubMed

    Thom, Corinna; Guerenstein, Pablo G; Mechaber, Wendy L; Hildebrand, John G

    2004-06-01

    The hawkmoth Manduca sexta (Lepidoptera: Sphingidae), an experimentally favorable Lepidopteran that is highly sensitive to carbon dioxide (CO2), feeds on the nectar of a range of flowering plants, such as Datura wrightii (Solanaceae). Newly opened Datura flowers give off dramatically elevated levels of CO2 and offer ample nectar. Thus, floral CO2 emission could indicate food-source profitability. This study documents that foraging Manduca moths prefer surrogate flowers that emit high levels of CO2, characteristic of newly opened Datura flowers. We show for the first time that CO2 may play an important role in the foraging behavior of nectar-feeding insects. PMID:15303329

  7. Induced Abnormality In Mir- and Earth-Grown Super Dwarf Wheat

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.; Stieber, Joseph; Campbell, William F.; Salisbury, Frank B.; Levinski, Margarita; Sytchev, Vladimir; Podolsky, Igor; Chernova, Lola; Ivanova, Irene; Kliss, Mark (Technical Monitor)

    1998-01-01

    Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with normal wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen grains however, contain only one nucleus, while normal viable pollen is trinucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was identified - a high level of atmospheric ethylene (1200 ppb). Ground studies conducted exposing "Super-dwarf" wheat to ethylene at just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples.

  8. Sex Determination in the Monoecious Species Cucumber Is Confined to Specific Floral Whorls

    PubMed Central

    Kater, Martin M.; Franken, John; Carney, Kim J.; Colombo, Lucia; Angenent, Gerco C.

    2001-01-01

    In unisexual flowers, sex is determined by the selective repression of growth or the abortion of either male or female reproductive organs. The mechanism by which this process is controlled in plants is still poorly understood. Because it is known that the identity of reproductive organs in plants is controlled by homeotic genes belonging to the MADS box gene family, we analyzed floral homeotic mutants from cucumber, a species that bears both male and female flowers on the same individual. To study the characteristics of sex determination in more detail, we produced mutants similar to class A and C homeotic mutants from well-characterized hermaphrodite species such as Arabidopsis by ectopically expressing and suppressing the cucumber gene CUCUMBER MADS1 (CUM1). The cucumber mutant green petals (gp) corresponds to the previously characterized B mutants from several species and appeared to be caused by a deletion of 15 amino acid residues in the coding region of the class B MADS box gene CUM26. These homeotic mutants reveal two important concepts that govern sex determination in cucumber. First, the arrest of either male or female organ development is dependent on their positions in the flower and is not associated with their sexual identity. Second, the data presented here strongly suggest that the class C homeotic function is required for the position-dependent arrest of reproductive organs. PMID:11251091

  9. The Myb-domain protein ULTRAPETALA1 INTERACTING FACTOR 1 controls floral meristem activities in Arabidopsis.

    PubMed

    Moreau, Fanny; Thévenon, Emmanuel; Blanvillain, Robert; Lopez-Vidriero, Irene; Franco-Zorrilla, Jose Manuel; Dumas, Renaud; Parcy, François; Morel, Patrice; Trehin, Christophe; Carles, Cristel C

    2016-04-01

    Higher plants continuously and iteratively produce new above-ground organs in the form of leaves, stems and flowers. These organs arise from shoot apical meristems whose homeostasis depends on coordination between self-renewal of stem cells and their differentiation into organ founder cells. This coordination is stringently controlled by the central transcription factor WUSCHEL (WUS), which is both necessary and sufficient for stem cell specification in Arabidopsis thaliana ULTRAPETALA1 (ULT1) was previously identified as a plant-specific, negative regulator of WUS expression. However, molecular mechanisms underlying this regulation remain unknown. ULT1 protein contains a SAND putative DNA-binding domain and a B-box, previously proposed as a protein interaction domain in eukaryotes. Here, we characterise a novel partner of ULT1, named ULT1 INTERACTING FACTOR 1 (UIF1), which contains a Myb domain and an EAR motif. UIF1 and ULT1 function in the same pathway for regulation of organ number in the flower. Moreover, UIF1 displays DNA-binding activity and specifically binds to WUS regulatory elements. We thus provide genetic and molecular evidence that UIF1 and ULT1 work together in floral meristem homeostasis, probably by direct repression of WUS expression. PMID:26903506

  10. Ecology and evolution of floral volatile-mediated information transfer in plants.

    PubMed

    Schiestl, Florian P

    2015-04-01

    Floral volatiles are complex, multi-functional signals that are often used by pollinators in combination with other signals, such as color. Floral visitors use floral scent to estimate the amount of reward present in flowers, to facilitate the identification of a specific host flower or as signals that chemically resemble those important for pollinator insects in other ecological contexts. There is good evidence that floral scent evolves under selection imposed by both mutualists and antagonists. Antagonists may often limit the amount of scent emitted by flowers, thus contributing to spatial population variation, and select for phenotypic plasticity after enemy attack. Floral scent is also an important component of pollinator-mediated reproductive isolation, as it often co-varies with color and morphology in sister species with different pollination systems. PMID:25605223

  11. Floral Reversion in Arabidopsis suecica Is Correlated with the Onset of Flowering and Meristem Transitioning

    PubMed Central

    Gordon, Spencer; Kirkpatrick, H. E.; Madlung, Andreas

    2015-01-01

    Angiosperm flowers are usually determinate structures that may produce seeds. In some species, flowers can revert from committed flower development back to an earlier developmental phase in a process called floral reversion. The allopolyploid Arabidopsis suecica displays photoperiod-dependent floral reversion in a subset of its flowers, yet little is known about the environmental conditions enhancing this phenotype, or the morphological processes leading to reversion. We have used light and electron microscopy to further describe this phenomenon. Additionally, we have further studied the phenology of flowering and floral reversion in A. suecica. In this study we confirm and expand upon our previous findings that floral reversion in the allopolyploid A. suecica is photoperiod-dependent, and show that its frequency is correlated with the timing for the onset of flowering. Our results also suggest that floral reversion in A. suecica displays natural variation in its penetrance between geographic populations of A. suecica. PMID:26011630

  12. Pollen Morphology and Boron Concentration in Floral Tissues as Factors Triggering Natural and GA-Induced Parthenocarpic Fruit Development in Grapevine

    PubMed Central

    Pérez-Díaz, Ricardo; Yáñez, Mónica; Tapia, Jaime; Moreno, Yerko

    2015-01-01

    Parthenocarpic fruit development (PFD) reduces fruit yield and quality in grapevine. Parthenocarpic seedless berries arise from fruit set without effective fertilization due to defective pollen germination. PFD has been associated to micronutrient deficiency but the relation of this phenomenon with pollen polymorphism has not been reported before. In this work, six grapevine cultivars with different tendency for PFD and grown under micronutrient-sufficient conditions were analyzed to determine pollen structure and germination capability as well as PFD rates. Wide variation in non-germinative abnormal pollen was detected either among cultivars as well as for the same cultivar in different growing seasons. A straight correlation with PFD rates was found (R2 = 0.9896), suggesting that natural parthenocarpy is related to defective pollen development. Such relation was not observed when PFD was analyzed in grapevine plants exposed to exogenous gibberellin (GA) or abscissic acid (ABA) applications at pre-anthesis. Increase (GA treatment) or reduction (ABA treatment) in PFD rates without significative changes in abnormal pollen was determined. Although these plants were maintained at sufficient boron (B) condition, a down-regulation of the floral genes VvBOR3 and VvBOR4 together with a reduction of floral B content in GA-treated plants was established. These results suggest that impairment in B mobility to reproductive tissues and restriction of pollen tube growth could be involved in the GA-induced parthenocarpy. PMID:26440413

  13. Pollen Morphology and Boron Concentration in Floral Tissues as Factors Triggering Natural and GA-Induced Parthenocarpic Fruit Development in Grapevine.

    PubMed

    Alva, Orlando; Roa-Roco, Rosa Nair; Pérez-Díaz, Ricardo; Yáñez, Mónica; Tapia, Jaime; Moreno, Yerko; Ruiz-Lara, Simón; González, Enrique

    2015-01-01

    Parthenocarpic fruit development (PFD) reduces fruit yield and quality in grapevine. Parthenocarpic seedless berries arise from fruit set without effective fertilization due to defective pollen germination. PFD has been associated to micronutrient deficiency but the relation of this phenomenon with pollen polymorphism has not been reported before. In this work, six grapevine cultivars with different tendency for PFD and grown under micronutrient-sufficient conditions were analyzed to determine pollen structure and germination capability as well as PFD rates. Wide variation in non-germinative abnormal pollen was detected either among cultivars as well as for the same cultivar in different growing seasons. A straight correlation with PFD rates was found (R2 = 0.9896), suggesting that natural parthenocarpy is related to defective pollen development. Such relation was not observed when PFD was analyzed in grapevine plants exposed to exogenous gibberellin (GA) or abscissic acid (ABA) applications at pre-anthesis. Increase (GA treatment) or reduction (ABA treatment) in PFD rates without significative changes in abnormal pollen was determined. Although these plants were maintained at sufficient boron (B) condition, a down-regulation of the floral genes VvBOR3 and VvBOR4 together with a reduction of floral B content in GA-treated plants was established. These results suggest that impairment in B mobility to reproductive tissues and restriction of pollen tube growth could be involved in the GA-induced parthenocarpy. PMID:26440413

  14. Newly discovered quick, non-invasive screening method of bone marrow malignancies including various leukemias, Hodgkin's lymphoma, non-Hodgkin's lymphoma, & multiple myeloma by abnormality of small rectangular area within bone marrow organ representation areas of the face.

    PubMed

    Omura, Yoshiaki; O'Young, Brian; Jones, Marilyn; Nihrane, Abdalla; Duvvi, Harsha; Paluch, Kamila; Shimotsuura, Yasuhiro; Ohki, Motomu

    2012-01-01

    Diagnoses of bone marrow associated malignancies such as Acute & Chronic Lymphocytic Leukemia, Acute & Chronic Myelogenous (Myeloid) Leukemia, Hodgkin's Lymphoma & Non-Hodgkin's Lymphoma, and Multiple Myeloma are often missed without a blood test. However, in 2008, Omura Y reported several newly discovered organ representation areas that exist between the lower end of the eyebrows and upper end of the upper eyelid. This space was divided into 5 organ representation areas. The first space (more than 1/4 of entire space) near the side of the face (temple) is the bone marrow representation area (BMRA). Therefore, we examined the bone marrow representation areas non-invasively using the Bi-Digital O-Ring Test (BDORT). When the small rectangular shaped part of the BMRA is strong negative (-) with more than -2, often there is a malignancy associated with bone marrow. In this area, we found 1) Integrin alpha5beta1 & Oncogen C-fos Ab2 increased very significantly between 125-300 ng BDORT units; 2) very high Chrysotile Asbestos (0.11-0.14 mg); 3) markedly reduced Acetylcholine of less than 1 ng; 4) significantly reduced telomere of less than 1 yg (= 10(-24) g); and 5) Increased 8-OH-dG (often more than 5 ng). Once the abnormal small rectangular area is localized by BDORT, by detecting the specific microscope slide which produces EMF (electromagnetic field) resonance, one can diagnose these malignancies non-invasively in about 10 minutes. When a subject has any one of the above 7 types of bone marrow associated malignancies, the 5 aforementioned abnormal parameters can be detected. When Acetylcholine is markedly reduced to 0.25 ng or less, 8-OH-dG is 10 ng or higher, and Sirtuin 1 (one of the 7 mammalian longevity genes products) in both the Hippocampus and the body is 0.025 pg or less, most of the patients have a very poor prognosis. However, we found that increasing normal cell telomere & longevity gene product Sirtuin 1 can often improve both pathology & prognosis. All

  15. Floral visitation by the Argentine ant reduces bee visitation and plant seed set.

    PubMed

    Hanna, Cause; Naughton, Ida; Boser, Christina; Alarcón, Ruben; Hung, Keng-Lou James; Holway, David

    2015-01-01

    Ants often visit flowers, but have only seldom been documented to provide effective pollination services. Floral visitation by ants can also compromise plant reproduction in situations where ants interfere with more effective pollinators. Introduced ants may be especially likely to reduce plant reproductive success through floral visitation, but existing experimental studies have found little support for this hypothesis. Here, we combine experimental and observational approaches to examine the importance of floral visitation by the nonnative Argentine ant (Linepithema humile) on plant species native to Santa Cruz Island, California, USA. First, we determine how L. humile affects floral visitor diversity, bee visitation rates, and levels of pollen limitation for the common, focal plant species island morning glory (Calystegia macrostegia ssp. macrostegia). Second, we assess the broader ecological consequences of floral visitation by L. humile by comparing floral visitation networks between invaded and uninvaded sites. The Argentine ant and native ants both visited island morning glory flowers, but L. humile was much more likely to behave aggressively towards other floral visitors and to be the sole floral occupant. The presence of L. humile in morning glory flowers reduced floral visitor diversity, decreased rates of bee visitation, and increased levels of pollen limitation. Network comparisons between invaded and uninvaded. sites revealed differences in both network structure and species-level attributes. In. invaded sites, floral visitors were observed on fewer plant species, ants had a higher per-plant interaction strength relative to that of other visitors, and interaction strengths between bees and plants were weaker. These results illustrate that introduced ants can negatively affect plant reproduction and potentially disrupt pollination services at an ecosystem scale. PMID:26236907

  16. Morphological abnormalities in elasmobranchs.

    PubMed

    Moore, A B M

    2015-08-01

    A total of 10 abnormal free-swimming (i.e., post-birth) elasmobranchs are reported from The (Persian-Arabian) Gulf, encompassing five species and including deformed heads, snouts, caudal fins and claspers. The complete absence of pelvic fins in a milk shark Rhizoprionodon acutus may be the first record in any elasmobranch. Possible causes, including the extreme environmental conditions and the high level of anthropogenic pollution particular to The Gulf, are briefly discussed. PMID:25903257

  17. SQUINT promotes stem cell homeostasis and floral meristem termination in Arabidopsis through APETALA2 and CLAVATA signalling.

    PubMed

    Prunet, Nathanaël; Morel, Patrice; Champelovier, Priscilla; Thierry, Anne-Marie; Negrutiu, Ioan; Jack, Thomas; Trehin, Christophe

    2015-11-01

    Plant meristems harbour stem cells, which allow for the continuous production of new organs. Here, an analysis of the role of SQUINT (SQN) in stem cell dynamics in Arabidopsis is reported. A close examination of sqn mutants reveals defects that are very similar to that of weak clavata (clv) mutants, both in the flower meristem (increased number of floral organs, occasional delay in stem cell termination) and in the shoot apical meristem (meristem and central zone enlargement, occasional fasciation). sqn has a very mild effect in a clv mutant background, suggesting that SQN and the CLV genes act in the same genetic pathway. Accordingly, a loss-of-function allele of SQN strongly rescues the meristem abortion phenotype of plants that overexpress CLV3. Altogether, these data suggest that SQN is necessary for proper CLV signalling. SQN was shown to be required for normal accumulation of various miRNAs, including miR172. One of the targets of miR172, APETALA2 (AP2), antagonizes CLV signalling. The ap2-2 mutation strongly suppresses the meristem phenotypes of sqn, indicating that the effect of SQN on stem cell dynamics is largely, but not fully, mediated by the miR172/AP2 tandem. This study refines understanding of the intricate genetic networks that control both stem cell homeostasis and floral stem cell termination, two processes that are critical for the proper development and fertility of the plant. PMID:26269626

  18. Chromosome abnormalities in glioma

    SciTech Connect

    Li, Y.S.; Ramsay, D.A.; Fan, Y.S.

    1994-09-01

    Cytogenetic studies were performed in 25 patients with gliomas. An interesting finding was a seemingly identical abnormality, an extra band on the tip of the short arm of chromosome 1, add(1)(p36), in two cases. The abnormality was present in all cells from a patient with a glioblastoma and in 27% of the tumor cells from a patient with a recurrent irradiated anaplastic astrocytoma; in the latter case, 7 unrelated abnormal clones were identified except 4 of those clones shared a common change, -Y. Three similar cases have been described previously. In a patient with pleomorphic astrocytoma, the band 1q42 in both homologues of chromosome 1 was involved in two different rearrangements. A review of the literature revealed that deletion of the long arm of chromosome 1 including 1q42 often occurs in glioma. This may indicate a possible tumor suppressor gene in this region. Cytogenetic follow-up studies were carried out in two patients and emergence of unrelated clones were noted in both. A total of 124 clonal breakpoints were identified in the 25 patients. The breakpoints which occurred three times or more were: 1p36, 1p22, 1q21, 1q25, 3q21, 7q32, 8q22, 9q22, 16q22, and 22q13.

  19. [Congenital foot abnormalities].

    PubMed

    Delpont, M; Lafosse, T; Bachy, M; Mary, P; Alves, A; Vialle, R

    2015-03-01

    The foot may be the site of birth defects. These abnormalities are sometimes suspected prenatally. Final diagnosis depends on clinical examination at birth. These deformations can be simple malpositions: metatarsus adductus, talipes calcaneovalgus and pes supinatus. The prognosis is excellent spontaneously or with a simple orthopedic treatment. Surgery remains outstanding. The use of a pediatric orthopedist will be considered if malposition does not relax after several weeks. Malformations (clubfoot, vertical talus and skew foot) require specialized care early. Clubfoot is characterized by an equine and varus hindfoot, an adducted and supine forefoot, not reducible. Vertical talus combines equine hindfoot and dorsiflexion of the forefoot, which is performed in the midfoot instead of the ankle. Skew foot is suspected when a metatarsus adductus is resistant to conservative treatment. Early treatment is primarily orthopedic at birth. Surgical treatment begins to be considered after walking age. Keep in mind that an abnormality of the foot may be associated with other conditions: malposition with congenital hip, malformations with syndromes, neurological and genetic abnormalities. PMID:25524290

  20. Nectar robbery by a hermit hummingbird: association to floral phenotype and its influence on flowers and network structure.

    PubMed

    Maruyama, Pietro Kiyoshi; Vizentin-Bugoni, Jeferson; Dalsgaard, Bo; Sazima, Ivan; Sazima, Marlies

    2015-07-01

    Interactions between flowers and their visitors span the spectrum from mutualism to antagonism. The literature is rich in studies focusing on mutualism, but nectar robbery has mostly been investigated using phytocentric approaches focused on only a few plant species. To fill this gap, we studied the interactions between a nectar-robbing hermit hummingbird, Phaethornis ruber, and the array of flowers it visits. First, based on a literature review of the interactions involving P. ruber, we characterized the association of floral larceny to floral phenotype. We then experimentally examined the effects of nectar robbing on nectar standing crop and number of visits of the pollinators to the flowers of Canna paniculata. Finally, we asked whether the incorporation of illegitimate interactions into the analysis affects plant-hummingbird network structure. We identified 97 plant species visited by P. ruber and found that P. ruber engaged in floral larceny in almost 30% of these species. Nectar robbery was especially common in flowers with longer corolla. In terms of the effect on C. paniculata, the depletion of nectar due to robbery by P. ruber was associated with decreased visitation rates of legitimate pollinators. At the community level, the inclusion of the illegitimate visits of P. ruber resulted in modifications of how modules within the network were organized, notably giving rise to a new module consisting of P. ruber and mostly robbed flowers. However, although illegitimate visits constituted approximately 9% of all interactions in the network, changes in nestedness, modularity, and network-level specialization were minor. Our results indicate that although a flower robber may have a strong effect on the pollination of a particular plant species, the inclusion of its illegitimate interactions has limited capacity to change overall network structure. PMID:25740333

  1. Floral ontogeny and gene protein localization rules out euanthial interpretation of reproductive units in Lepironia (Cyperaceae, Mapanioideae, Chrysitricheae)

    PubMed Central

    Prychid, C. J.; Bruhl, J. J.

    2013-01-01

    Background and Aims In the sedge subfamily Mapanioideae there are considerable discrepancies between the standard trimerous monocot floral architecture expected and the complex floral and inflorescence morphologies seen. Decades of debate about whether the basic reproductive units are single flowers or pseudanthia have not resolved the question. This paper evaluates current knowledge about Mapaniid reproductive structures and presents an ontogenetic study of the Mapaniid genus Lepironia with the first floral protein expression maps for the family, localizing the products of the APETALA1/FRUITFULL-like (AP1/FUL) MADS-box genes with the aim of shedding light on this conundrum. Methods A range of reproductive developmental stages, from spikelet primordia through to infructescence material, were processed for anatomical and immunohistochemical analyses. Key Results The basic reproductive unit is subtended by a bract and possesses two prophyll-like structures, the first organs to be initiated on the primordium, which grow rapidly, enclosing two whorls of initiating leaf-like structures with intervening stamens and a central gynoecium, formed from an annular primordium. The subtending bract and prophyll-like structures possess very different morphologies from that of the internal leaf-like structures and do not show AP1/FUL-like protein localization, which is otherwise strongly localized in the internal leaf-like structures, stamens and gynoecia. Conclusions Results support the synanthial hypothesis as the evolutionary origin of the reproductive unit. Thus, the basic reproductive unit in Lepironia is an extremely condensed pseudanthium, of staminate flowers surrounding a central terminal pistillate female flower. Early in development the reproductive unit becomes enclosed by a split-prophyll, with the whole structure subtended by a bract. PMID:23723258

  2. Floral to green: mating switches moth olfactory coding and preference

    PubMed Central

    Saveer, Ahmed M.; Kromann, Sophie H.; Birgersson, Göran; Bengtsson, Marie; Lindblom, Tobias; Balkenius, Anna; Hansson, Bill S.; Witzgall, Peter; Becher, Paul G.; Ignell, Rickard

    2012-01-01

    Mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. Here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. Unmated females of the cotton leafworm (Spodoptera littoralis) are strongly attracted to lilac flowers (Syringa vulgaris). After mating, attraction to floral odour is abolished and the females fly instead to green-leaf odour of the larval host plant cotton, Gossypium hirsutum. This behavioural switch is owing to a marked change in the olfactory representation of floral and green odours in the primary olfactory centre, the antennal lobe (AL). Calcium imaging, using authentic and synthetic odours, shows that the ensemble of AL glomeruli dedicated to either lilac or cotton odour is selectively up- and downregulated in response to mating. A clear-cut behavioural modulation as a function of mating is a useful substrate for studies of the neural mechanisms underlying behavioural decisions. Modulation of odour-driven behaviour through concerted regulation of odour maps contributes to our understanding of state-dependent choice and host shifts in insect herbivores. PMID:22319127

  3. Responses of social and solitary bees to pulsed floral resources.

    PubMed

    Crone, Elizabeth E

    2013-10-01

    Pulsed food resources lead to mismatches between distribution of consumers and resources in space and time. Many studies have investigated how pollinators and floral resources covary in space, but few have looked at their covariance among years. I studied responses of two bee taxa, Bombus (a social genus) and Anthophora (a solitary genus), to variation in flowering by Astragalus scaphoides, a perennial herb that flowers in alternate years. First, I quantified the rate at which individual plants were visited by bees. Anthophora showed evidence of a demographic response to resource pulses--that is, more individuals were seen in the year after a high-flowering year--whereas Bombus did not. Second, I quantified pollinator behavior by following individual bees and recording the proportion of visits to A. scaphoides within single foraging bouts. The proportion of visits to A. scaphoides by both taxa increased with A. scaphoides's flowering density. Higher specialization in high-flowering years likely makes both taxa better pollinators in high-flowering years. If these taxa differ in effectiveness as pollinators, then these responses translate into variation in pollination services in space and time, specifically, more activity by Bombus in high-flowering years and more by Anthophora in years following high-flowering years. They also emphasize that pollinator activity depends in part on past-as well as current-floral resources. PMID:24021399

  4. A novel role for proline in plant floral nectars

    NASA Astrophysics Data System (ADS)

    Carter, Clay; Shafir, Sharoni; Yehonatan, Lia; Palmer, Reid G.; Thornburg, Robert

    2006-02-01

    Plants offer metabolically rich floral nectar to attract visiting pollinators. The composition of nectar includes not only sugars, but also amino acids. We have examined the amino acid content of the nectar of ornamental tobacco and found that it is extremely rich (2 mM) in proline. Because insect pollinators preferentially utilize proline during the initial phases of insect flight and can reportedly taste proline, we determined whether honeybees showed a preference for synthetic nectars rich in proline. We therefore established an insect preference test and found that honeybees indeed prefer nectars rich in the amino acid proline. To determine whether this was a general phenomenon, we also examined the nectars of two insect-pollinated wild perennial species of soybean. These species also showed high levels of proline in their nectars demonstrating that plants often produce proline-rich floral nectar. Because insects such as honeybees prefer proline-rich nectars, we hypothesize that some plants offer proline-rich nectars as a mechanism to attract visiting pollinators.

  5. Floral traits and pollination ecology of European Arum hybrids.

    PubMed

    Chartier, Marion; Liagre, Suzanne; Weiss-Schneeweiss, Hanna; Kolano, Bozena; Bessière, Jean-Marie; Schönenberger, Jürg; Gibernau, Marc

    2016-02-01

    Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colonisation of new ecological niches and to speciation. Here, we describe inflorescence morphology, ploidy levels, pollinator attractive scents, and pollinator guilds of natural hybrids of Arum italicum and A. maculatum (Araceae) from a site with sympatric parental populations in southern France to determine how these traits affect the hybrid pollination ecology. Hybrids were characterised by inflorescences with a size and a number of flowers more similar to A. italicum than to A. maculatum. In most cases, hybrid stamens were purple, as in A. maculatum, and spadix appendices yellow, as in A. italicum. Hybrid floral scent was closer to that of A. italicum, but shared some compounds with A. maculatum and comprised unique compounds. Also, the pollinator guild of the hybrids was similar to that of A. italicum. Nevertheless, the hybrids attracted a high proportion of individuals of the main pollinator of A. maculatum. We discuss the effects of hybridisation in sympatric parental zones in which hybrids exhibit low levels of reproductive success, the establishment of reproductive barriers between parental species, the role of the composition of floral attractive scents in the differential attraction of pollinators and in the competition between hybrids and their parental species, and the potential of hybridisation to give rise to new independent lineages. PMID:26552380

  6. Metabolome profiling of floral scent production in Petunia axillaris.

    PubMed

    Oyama-Okubo, Naomi; Sakai, Tomoyuki; Ando, Toshio; Nakayama, Masayoshi; Soga, Tomoyoshi

    2013-06-01

    Emission of floral scent benzenoid/phenylpropanoid compounds in Petunia axillaris increases significantly at night, a change that is primarily determined by the endogenous concentration of these compounds in the corolla. Among wild type P. axillaris plants, there are lines that emit different amounts of scent. To understand how the nocturnal rhythm of floral scent concentrations is controlled, the concentration profiles of metabolites in the scent biosynthetic pathway in two lines of P. axillaris, a strongly scented line and a weakly scented line, are reported. In the strongly scented line, the concentration of a series of compounds from glucose-6-phosphate (G6P) to the scent compounds changed synchronously. In the weakly scented lines, the concentrations of some metabolites including 6-phosphogluconate (6PG) and downstream metabolites of shikimic acid were remarkably lower, suggesting a reduction in metabolism of G6P to 6PG and the metabolism of shikimic acid in the weakly scented line. Nocturnal increases in the concentrations of sucrose, fructose, and glucose were not found in strongly scented line. Nocturnal increases in concentrations of S-adenosylhomocysteine (SAH) and methionine and reductions in the concentrations of S-adenosylmethionine (SAM), a methylation donor to benzenoid-skeletons, were observed only in strongly scented line. It is concluded that the biosynthetic regulation of each step from G6P to the volatile scent benzenoids is performed by, at least in part, concentrations of substrates, and the regulation also affects concentrations of SAM cycle compounds. PMID:23562394

  7. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  8. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  9. Hemorheological abnormalities in human arterial hypertension

    NASA Astrophysics Data System (ADS)

    Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

    2014-05-01

    Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

  10. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  11. Exercises to Improve Gait Abnormalities

    MedlinePlus

    ... Home About iChip Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

  12. Convergent evolution of floral signals underlies the success of Neotropical orchids

    PubMed Central

    Papadopulos, Alexander S. T.; Powell, Martyn P.; Pupulin, Franco; Warner, Jorge; Hawkins, Julie A.; Salamin, Nicolas; Chittka, Lars; Williams, Norris H.; Whitten, W. Mark; Loader, Deniz; Valente, Luis M.; Chase, Mark W.; Savolainen, Vincent

    2013-01-01

    The great majority of plant species in the tropics require animals to achieve pollination, but the exact role of floral signals in attraction of animal pollinators is often debated. Many plants provide a floral reward to attract a guild of pollinators, and it has been proposed that floral signals of non-rewarding species may converge on those of rewarding species to exploit the relationship of the latter with their pollinators. In the orchid family (Orchidaceae), pollination is almost universally animal-mediated, but a third of species provide no floral reward, which suggests that deceptive pollination mechanisms are prevalent. Here, we examine floral colour and shape convergence in Neotropical plant communities, focusing on certain food-deceptive Oncidiinae orchids (e.g. Trichocentrum ascendens and Oncidium nebulosum) and rewarding species of Malpighiaceae. We show that the species from these two distantly related families are often more similar in floral colour and shape than expected by chance and propose that a system of multifarious floral mimicry—a form of Batesian mimicry that involves multiple models and is more complex than a simple one model–one mimic system—operates in these orchids. The same mimetic pollination system has evolved at least 14 times within the species-rich Oncidiinae throughout the Neotropics. These results help explain the extraordinary diversification of Neotropical orchids and highlight the complexity of plant–animal interactions. PMID:23804617

  13. Convergent evolution of floral signals underlies the success of Neotropical orchids.

    PubMed

    Papadopulos, Alexander S T; Powell, Martyn P; Pupulin, Franco; Warner, Jorge; Hawkins, Julie A; Salamin, Nicolas; Chittka, Lars; Williams, Norris H; Whitten, W Mark; Loader, Deniz; Valente, Luis M; Chase, Mark W; Savolainen, Vincent

    2013-08-22

    The great majority of plant species in the tropics require animals to achieve pollination, but the exact role of floral signals in attraction of animal pollinators is often debated. Many plants provide a floral reward to attract a guild of pollinators, and it has been proposed that floral signals of non-rewarding species may converge on those of rewarding species to exploit the relationship of the latter with their pollinators. In the orchid family (Orchidaceae), pollination is almost universally animal-mediated, but a third of species provide no floral reward, which suggests that deceptive pollination mechanisms are prevalent. Here, we examine floral colour and shape convergence in Neotropical plant communities, focusing on certain food-deceptive Oncidiinae orchids (e.g. Trichocentrum ascendens and Oncidium nebulosum) and rewarding species of Malpighiaceae. We show that the species from these two distantly related families are often more similar in floral colour and shape than expected by chance and propose that a system of multifarious floral mimicry--a form of Batesian mimicry that involves multiple models and is more complex than a simple one model-one mimic system--operates in these orchids. The same mimetic pollination system has evolved at least 14 times within the species-rich Oncidiinae throughout the Neotropics. These results help explain the extraordinary diversification of Neotropical orchids and highlight the complexity of plant-animal interactions. PMID:23804617

  14. Microbial diversity in the floral nectar of seven Epipactis (Orchidaceae) species

    PubMed Central

    Jacquemyn, Hans; Lenaerts, Marijke; Tyteca, Daniel; Lievens, Bart

    2013-01-01

    Abstract Floral nectar of animal-pollinated plants is commonly infested with microorganisms, yet little is known about the microorganisms inhabiting the floral nectar of orchids. In this study, we investigated microbial communities occurring in the floral nectar of seven Epipactis (Orchidaceae) species. Culturable bacteria and yeasts were isolated and identified by partially sequencing the small subunit (SSU) ribosomal RNA (rRNA) gene and the D1/D2 domains of the large subunit (LSU) rRNA gene, respectively. Using three different culture media, we found that bacteria were common inhabitants of the floral nectar of Epipactis. The most widely distributed bacterial operational taxonomic units (OTUs) in nectar of Epipactis were representatives of the family of Enterobacteriaceae, with an unspecified Enterobacteriaceae bacterium as the most common. In contrast to previous studies investigating microbial communities in floral nectar, very few yeast species (mainly of the genus Cryptococcus) were observed, and most of them occurred in very low densities. Total OTU richness (i.e., the number of bacterial and yeast OTUs per orchid species) varied between 4 and 20. Cluster analysis revealed that microbial communities of allogamous species differed from those of autogamous and facultatively autogamous species. This study extends previous efforts to identify microbial communities in floral nectar and indicates that the floral nectar of the orchids investigated mainly contained bacterial communities with moderate phylogenetic diversity. PMID:23836678

  15. Herbivory by a Phloem-Feeding Insect Inhibits Floral Volatile Production

    PubMed Central

    Pareja, Martin; Qvarfordt, Erika; Webster, Ben; Mayon, Patrick; Pickett, John; Birkett, Michael; Glinwood, Robert

    2012-01-01

    There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry. PMID:22384116

  16. Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths.

    PubMed

    von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A

    2012-06-12

    Most research on plant-pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue--transient humidity gradients--using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12-24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator. PMID:22645365

  17. Matching floral and pollinator traits through guild convergence and pollinator ecotype formation

    PubMed Central

    Newman, Ethan; Manning, John; Anderson, Bruce

    2014-01-01

    Background and Aims Pollinator landscapes, as determined by pollinator morphology/behaviour, can vary inter- or intraspecifically, imposing divergent selective pressures and leading to geographically divergent floral ecotypes. Assemblages of plants pollinated by the same pollinator (pollinator guilds) should exhibit convergence of floral traits because they are exposed to similar selective pressures. Both convergence and the formation of pollination ecotypes should lead to matching of traits among plants and their pollinators. Methods We examined 17 floral guild members pollinated in all or part of their range by Prosoeca longipennis, a long-proboscid fly with geographic variation in tongue length. Attractive floral traits such as colour, and nectar properties were recorded in populations across the range of each species. The length of floral reproductive parts, a mechanical fit trait, was recorded in each population to assess possible correlation with the mouthparts of the local pollinator. A multiple regression analysis was used to determine whether pollinators or abiotic factors provided the best explanation for variation in floral traits, and pollinator shifts were recorded in extralimital guild member populations. Key Results Nine of the 17 species were visited by alternative pollinator species in other parts of their ranges, and these displayed differences in mechanical fit and attractive traits, suggesting putative pollination ecotypes. Plants pollinated by P. longipennis were similar in colour throughout the pollinator range. Tube length of floral guild members co-varied with the proboscis length of P. longipennis. Conclusions Pollinator shifts have resulted in geographically divergent pollinator ecotypes across the ranges of several guild members. However, within sites, unrelated plants pollinated by P. longipennis are similar in the length of their floral parts, most probably as a result of convergent evolution in response to pollinator morphology. Both

  18. Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths

    PubMed Central

    von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A.

    2012-01-01

    Most research on plant–pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue—transient humidity gradients—using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12–24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator. PMID:22645365

  19. Floral thermogenesis of three species of Hydnora (Hydnoraceae) in Africa

    PubMed Central

    Seymour, Roger S.; Maass, Erika; Bolin, Jay F.

    2009-01-01

    Background and Aims Floral thermogenesis occurs in at least 12 families of ancient seed plants. Some species show very high rates of respiration through the alternative pathway, and some are thermoregulatory, with increasing respiration at decreasing ambient temperature. This study assesses the intensity and regulation of respiration in three species of African Hydnora that represent the Hydnoraceae, an unusual family of holoparasitic plants from arid environments. Methods Long-term respirometry (CO2 production) and thermometry were carried out on intact flowers of H. africana, H. abyssinica and H. esculenta in the field, and short-term measurements were made on floral parts during the protogynous flowering sequence. Key Results For H. africana, there was no temperature elevation in either the osmophores or the gynoecial chamber in any phase, and mass-specific respiration rates of the flower parts were low (maximum 8·3 nmol CO2 g−1 s−1 in osmophore tissue). Respiration tracked ambient and floral temperatures, eliminating the possibility of the inverse relationship expected in thermoregulatory flowers. Hydnora abyssinica flowers had higher respiration (maximum 27·5 nmol g−1 s−1 in the osmophores) and a slight elevation of osmophore temperature (maximum 2·8 °C) in the female stage. Respiration by gynoecial tissue was similar to that of osmophores in both species, but there was no measurable elevation of gynoecial chamber temperature. Gynoecial chamber temperature of H. esculenta could reach 3·8 °C above ambient, but there are no respiration data available. Antheral tissue respiration was maximal in the male phase (4·8 nmol g−1 s−1 in H. africana and 10·3 nmol g−1 s−1 in H. abyssinica), but it did not raise the antheral ring temperature, which showed that thermogenesis is not a by-product of pollen maturation or release. Conclusions The exceptionally low thermogenesis in Hydnora appears to be associated with scent production and possibly

  20. Retinal abnormalities in β-thalassemia major.

    PubMed

    Bhoiwala, Devang L; Dunaief, Joshua L

    2016-01-01

    Patients with beta (β)-thalassemia (β-TM: β-thalassemia major, β-TI: β-thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelial degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-thalassemia major are transfusion dependent and require iron chelation therapy to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by iron chelation therapy. Some who were never treated with iron chelation therapy exhibited retinopathy, and others receiving iron chelation therapy had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-thalassemia major viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. PMID:26325202

  1. Schizophrenia and abnormal brain network hubs

    PubMed Central

    Rubinov, Mikail; Bullmore, Ed.

    2013-01-01

    Schizophrenia is a heterogeneous psychiatric disorder of unknown cause or characteristic pathology. Clinical neuroscientists increasingly postulate that schizophrenia is a disorder of brain network organization. In this article we discuss the conceptual framework of this dysconnection hypothesis, describe the predominant methodological paradigm for testing this hypothesis, and review recent evidence for disruption of central/hub brain regions, as a promising example of this hypothesis. We summarize studies of brain hubs in large-scale structural and functional brain networks and find strong evidence for network abnormalities of prefrontal hubs, and moderate evidence for network abnormalities of limbic, temporal, and parietal hubs. Future studies are needed to differentiate network dysfunction from previously observed gray- and white-matter abnormalities of these hubs, and to link endogenous network dysfunction phenotypes with perceptual, behavioral, and cognitive clinical phenotypes of schizophrenia. PMID:24174905

  2. Spirometric abnormalities among welders

    SciTech Connect

    Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. )

    1991-10-01

    A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

  3. Floral markers of cornflower (Centaurea cyanus) honey and its peroxide antibacterial activity for an alternative treatment of digital dermatitis.

    PubMed

    Oelschlaegel, Stefanie; Pieper, Laura; Staufenbiel, Rudolf; Gruner, Margit; Zeippert, Linda; Pieper, Bernd; Koelling-Speer, Isabelle; Speer, Karl

    2012-11-28

    Cornflower (Centaurea cyanus) honey can be characterized by a greenish yellow color and an intense flavor with a bitter aftertaste. Because cornflower honey contains only a limited amount of pollen for the verification of its floral origin, one objective was the characterization of its polyphenol and norisoprenoid contents to assign floral markers. Here, lumichrome (18.8-43.5 mg/kg), 7-carboxylumichrome, (Z/E)-3-oxo-retro-α-ionol, and 3-oxo-α-ionol appeared to be quite suitable for distinguishing cornflower honey from other unifloral honeys. Additionally, due to its comparably high hydrogen peroxide content (0.5-0.9 mM/h) and the associated antibacterial activity, cornflower honey was used as an alternative treatment of digital dermatitis on an organic dairy farm. Cows affected by this hoof disease often show severe lameness and a subsequent decline in milk yield and loss of body condition. The cows' hooves treated with cornflower honey showed significantly faster healing than the control group without any treatment. PMID:23140532

  4. Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.

    PubMed

    Kusters, Elske; Della Pina, Serena; Castel, Rob; Souer, Erik; Koes, Ronald

    2015-08-15

    Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homologous FMI genes from Arabidopsis, petunia, tomato and Antirrhinum. Analysis of promoter-reporter constructs in petunia and Arabidopsis, as well as complementation experiments, showed that the divergent expression of leafy (LFY) and the petunia homolog aberrant leaf and flower (ALF) results from alterations in the upstream regulatory network rather than cis-regulatory changes. The divergent expression of unusual floral organs (UFO) from Arabidopsis, and the petunia homolog double top (DOT), however, is caused by the loss or gain of cis-regulatory promoter elements, which respond to trans-acting factors that are expressed in similar patterns in both species. Introduction of pUFO:UFO causes no obvious defects in Arabidopsis, but in petunia it causes the precocious and ectopic formation of flowers. This provides an example of how a change in a cis-regulatory region can account for a change in the plant body plan. PMID:26220938

  5. Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

    PubMed

    Zhao, Yafei; Zhang, Teng; Broholm, Suvi K; Tähtiharju, Sari; Mouhu, Katriina; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

    2016-09-01

    The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. PMID:27382139

  6. Molecular basis of floral petaloidy: insights from androecia of Canna indica

    PubMed Central

    Fu, Qian; Liu, Huanfang; Almeida, Ana M. R.; Kuang, Yanfeng; Zou, Pu; Liao, Jingping

    2014-01-01

    Floral organs that take on the characteristics of petals can occur in all whorls of the monocot order Zingiberales. In Canna indica, the most ornamental or ‘petaloid’ parts of the flowers are of androecial origin and are considered staminodes. However, the precise nature of these petaloid organs is yet to be determined. In order to gain a better understanding of the genetic basis of androecial identity, a molecular investigation of B- and C-class genes was carried out. Two MADS-box genes GLOBOSA (GLO) and AGAMOUS (AG) were isolated from young inflorescences of C. indica by 3′ rapid amplification of cDNA ends polymerase chain reaction (3′-RACE PCR). Sequence characterization and phylogenetic analyses show that CiGLO and CiAG belong to the B- and C-class MADS-box gene family, respectively. CiAG is expressed in petaloid staminodes, the labellum, the fertile stamen and carpels. CiGLO is expressed in petals, petaloid staminodes, the labellum, the fertile stamen and carpels. Expression patterns in mature tissues of CiGLO and CiAG suggest that petaloid staminodes and the labellum are of androecial identity, in agreement with their position within the flower and with described Arabidopsis thaliana expression patterns. Although B- and C-class genes are important components of androecial determination, their expression patterns are not sufficient to explain the distinct morphology observed in staminodes and the fertile stamen in C. indica. PMID:24876297

  7. Floral advertisement and the competition for pollination services.

    PubMed

    Fishman, Michael A; Hadany, Lilach

    2015-06-01

    Flowering plants are a major component of terrestrial ecosystems, and most of them depend on animal pollinators for reproduction. Thus, the mutualism between flowering plants and their pollinators is a keystone ecological relationship in both natural and agricultural ecosystems. Though plant-pollinator interactions have received considerable amount of attention, there are still many unanswered questions. In this paper, we use methods of evolutionary game theory to investigate the co-evolution of floral advertisement and pollinator preferences Our results indicate that competition for pollination services among plant species can in some cases lead to specialization of the pollinator population to a single plant species (oligolecty). However, collecting pollen from multiple plants - at least at the population level - is evolutionarily stable under a wider parameter range. Finally, we show that, in the presence of pollinators, plants that optimize their investment in attracting vs. rewarding visiting pollinators outcompete plants that do not. PMID:25869274

  8. Biosynthesis of floral scent 2-phenylethanol in rose flowers.

    PubMed

    Hirata, Hiroshi; Ohnishi, Toshiyuki; Watanabe, Naoharu

    2016-10-01

    Plants emit chemically diverse volatile compounds for attracting pollinators or putting up a chemical defense against herbivores. 2-Phenylethanol (2PE) is one of the abundantly emitted scent compounds in rose flowers. Feeding experiments with l-[(2)H8]phenylalanine into rose flowers and subsequent analysis using gas chromatography-mass spectrometry analysis revealed the hypothetical biosynthetic intermediates to [(2)H8]-2PE, and the biochemical and genetic analyses elucidated the principal pathway to [(2)H8]-2PE. We recently found season-specific 2PE pathway producing [(2)H7]-2PE from l-[(2)H8]phenylalanine. This is a unique example where the dominant pathway to a specific compound changes with the seasons. This review focuses on the biosynthesis of floral volatiles and their regulation to adapt to the changes in the environment. PMID:27297332

  9. Antioxidative, antibrowning and antibacterial activities of sixteen floral honeys.

    PubMed

    Chang, Xin; Wang, Jiehua; Yang, Shaohui; Chen, Shan; Song, Yingjin

    2011-09-01

    Commonly consumed honeys from sixteen different single floral sources were analyzed for their in vitro antioxidant capacities by several methods including DPPH, ABTS, FRAP, SASR and MDA assays. The total polyphenol contents varied among the tested honeys and were highly correlated to their antioxidant capacity values. The antioxidant capacity of Chinese milk vetch flower honeys was significantly higher than those of other flower honeys. All honeys tested were active in inhibiting the browning of apple homogenate and linden honey displayed the highest inhibition rate as 85%. When the antimicrobial activity of the investigated honeys was screened using Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), clover honey exhibited the strongest antibacterial activity as 2.2 mg mL(-1) kanamycin equivalent inhibition. PMID:21860856

  10. Global Transcriptome Profiling of Developing Leaf and Shoot Apices Reveals Distinct Genetic and Environmental Control of Floral Transition and Inflorescence Development in Barley[OPEN

    PubMed Central

    2015-01-01

    Timing of the floral transition and inflorescence development strongly affect yield in barley (Hordeum vulgare). Therefore, we examined the effects of daylength and the photoperiod response gene PHOTOPERIOD1 (Ppd-H1) on barley development and analyzed gene expression changes in the developing leaves and main shoot apices (MSAs) of barley by RNA sequencing. The daylength sensitivity of MSA development had two phases, floret primordia initiated under long and short days, whereas successful inflorescence development occurred only under long days. The transcripts associated with floral transition were largely regulated independently of photoperiod and allelic variation at Ppd-H1. The photoperiod- and Ppd-H1-dependent differences in inflorescence development and flower fertility were associated with the induction of barley FLOWERING LOCUS T orthologs: FT1 in leaves and FT2 in MSAs. FT1 expression was coregulated with transcripts involved in nutrient transport, carbohydrate metabolism, and cell cycle regulation, suggesting that FT1 might alter source-sink relationships. Successful inflorescence development correlated with upregulation of FT2 and transcripts related to floral organ development, phytohormones, and cell cycle regulation. Identification of photoperiod and stage-specific transcripts gives insights into the regulation of reproductive development in barley and provides a resource for investigation of the complexities of development and yield in temperate grasses. PMID:26307377

  11. Floral Induction in Arabidopsis by FLOWERING LOCUS T Requires Direct Repression of BLADE-ON-PETIOLE Genes by the Homeodomain Protein PENNYWISE1[OPEN

    PubMed Central

    Andrés, Fernando; Romera-Branchat, Maida; Martínez-Gallegos, Rafael; Patel, Vipul; Schneeberger, Korbinian; Jang, Seonghoe; Altmüller, Janine; Nürnberg, Peter; Coupland, George

    2015-01-01

    Flowers form on the flanks of the shoot apical meristem (SAM) in response to environmental and endogenous cues. In Arabidopsis (Arabidopsis thaliana), the photoperiodic pathway acts through FLOWERING LOCUS T (FT) to promote floral induction in response to day length. A complex between FT and the basic leucine-zipper transcription factor FD is proposed to form in the SAM, leading to activation of APETALA1 and LEAFY and thereby promoting floral meristem identity. We identified mutations that suppress FT function and recovered a new allele of the homeodomain transcription factor PENNYWISE (PNY). Genetic and molecular analyses showed that ectopic expression of BLADE-ON-PETIOLE1 (BOP1) and BOP2, which encode transcriptional coactivators, in the SAM during vegetative development, confers the late flowering of pny mutants. In wild-type plants, BOP1 and BOP2 are expressed in lateral organs close to boundaries of the SAM, whereas in pny mutants, their expression occurs in the SAM. This ectopic expression lowers FD mRNA levels, reducing responsiveness to FT and impairing activation of APETALA1 and LEAFY. We show that PNY binds to the promoters of BOP1 and BOP2, repressing their transcription. These results demonstrate a direct role for PNY in defining the spatial expression patterns of boundary genes and the significance of this process for floral induction by FT. PMID:26417007

  12. Floral Induction in Arabidopsis by FLOWERING LOCUS T Requires Direct Repression of BLADE-ON-PETIOLE Genes by the Homeodomain Protein PENNYWISE.

    PubMed

    Andrés, Fernando; Romera-Branchat, Maida; Martínez-Gallegos, Rafael; Patel, Vipul; Schneeberger, Korbinian; Jang, Seonghoe; Altmüller, Janine; Nürnberg, Peter; Coupland, George

    2015-11-01

    Flowers form on the flanks of the shoot apical meristem (SAM) in response to environmental and endogenous cues. In Arabidopsis (Arabidopsis thaliana), the photoperiodic pathway acts through FLOWERING LOCUS T (FT) to promote floral induction in response to day length. A complex between FT and the basic leucine-zipper transcription factor FD is proposed to form in the SAM, leading to activation of APETALA1 and LEAFY and thereby promoting floral meristem identity. We identified mutations that suppress FT function and recovered a new allele of the homeodomain transcription factor PENNYWISE (PNY). Genetic and molecular analyses showed that ectopic expression of BLADE-ON-PETIOLE1 (BOP1) and BOP2, which encode transcriptional coactivators, in the SAM during vegetative development, confers the late flowering of pny mutants. In wild-type plants, BOP1 and BOP2 are expressed in lateral organs close to boundaries of the SAM, whereas in pny mutants, their expression occurs in the SAM. This ectopic expression lowers FD mRNA levels, reducing responsiveness to FT and impairing activation of APETALA1 and LEAFY. We show that PNY binds to the promoters of BOP1 and BOP2, repressing their transcription. These results demonstrate a direct role for PNY in defining the spatial expression patterns of boundary genes and the significance of this process for floral induction by FT. PMID:26417007

  13. Loss of YABBY2-Like Gene Expression May Underlie the Evolution of the Laminar Style in Canna and Contribute to Floral Morphological Diversity in the Zingiberales

    PubMed Central

    Morioka, Kelsie; Yockteng, Roxana; Almeida, Ana M. R.; Specht, Chelsea D.

    2015-01-01

    The Zingiberales is an order of tropical monocots that exhibits diverse floral morphologies. The evolution of petaloid, laminar stamens, staminodes, and styles contributes to this diversity. The laminar style is a derived trait in the family Cannaceae and plays an important role in pollination as its surface is used for secondary pollen presentation. Previous work in the Zingiberales has implicated YABBY2-like genes, which function in promoting laminar outgrowth, in the evolution of stamen morphology. Here, we investigate the evolution and expression of Zingiberales YABBY2-like genes in order to understand the evolution of the laminar style in Canna. Phylogenetic analyses show that multiple duplication events have occurred in this gene lineage prior to the diversification of the Zingiberales. Reverse transcription-PCR in Canna, Costus, and Musa reveals differential expression across floral organs, taxa, and gene copies, and a role for YABBY2-like genes in the evolution of the laminar style is proposed. Selection tests indicate that almost all sites in conserved domains are under purifying selection, consistent with their functional relevance, and a motif unique to monocot YABBY2-like genes is identified. These results contribute to our understanding of the molecular mechanisms underlying the evolution of floral morphologies. PMID:26734021

  14. Loss of YABBY2-Like Gene Expression May Underlie the Evolution of the Laminar Style in Canna and Contribute to Floral Morphological Diversity in the Zingiberales.

    PubMed

    Morioka, Kelsie; Yockteng, Roxana; Almeida, Ana M R; Specht, Chelsea D

    2015-01-01

    The Zingiberales is an order of tropical monocots that exhibits diverse floral morphologies. The evolution of petaloid, laminar stamens, staminodes, and styles contributes to this diversity. The laminar style is a derived trait in the family Cannaceae and plays an important role in pollination as its surface is used for secondary pollen presentation. Previous work in the Zingiberales has implicated YABBY2-like genes, which function in promoting laminar outgrowth, in the evolution of stamen morphology. Here, we investigate the evolution and expression of Zingiberales YABBY2-like genes in order to understand the evolution of the laminar style in Canna. Phylogenetic analyses show that multiple duplication events have occurred in this gene lineage prior to the diversification of the Zingiberales. Reverse transcription-PCR in Canna, Costus, and Musa reveals differential expression across floral organs, taxa, and gene copies, and a role for YABBY2-like genes in the evolution of the laminar style is proposed. Selection tests indicate that almost all sites in conserved domains are under purifying selection, consistent with their functional relevance, and a motif unique to monocot YABBY2-like genes is identified. These results contribute to our understanding of the molecular mechanisms underlying the evolution of floral morphologies. PMID:26734021

  15. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem. PMID:22377853

  16. Evolution and diversity of floral scent chemistry in the euglossine bee-pollinated orchid genus Gongora

    PubMed Central

    Hetherington-Rauth, Molly C.; Ramírez, Santiago R.

    2016-01-01

    •Background and Aims Animal-pollinated angiosperms have evolved a variety of signalling mechanisms to attract pollinators. Floral scent is a key component of pollinator attraction, and its chemistry modulates both pollinator behaviour and the formation of plant–pollinator networks. The neotropical orchid genus Gongora exhibits specialized pollinator associations with male orchid bees (Euglossini). Male bees visit orchid flowers to collect volatile chemical compounds that they store in hind-leg pouches to use subsequently during courtship display. Hence, Gongora floral scent compounds simultaneously serve as signalling molecules and pollinator rewards. Furthermore, because floral scent acts as the predominant reproductive isolating barrier among lineages, it has been hypothesized that chemical traits are highly species specific. A comparative analysis of intra- and inter-specific variation of floral scent chemistry was conducted to investigate the evolutionary patterns across the genus. •Methods Gas chromatography–mass spectrometry (GC-MS) was used to analyse the floral scent of 78 individuals belonging to 28 different species of Gongora from two of the three major lineages sampled across the neotropical region. Multidimensional scaling and indicator value analyses were implemented to investigate the patterns of chemical diversity within and among taxonomic groups at various geographic scales. Additionally, pollinator observations were conducted on a sympatric community of Gongora orchids exhibiting distinct floral scent phenotypes. •Key Results A total of 83 floral volatiles, mainly terpenes and aromatic compounds, were detected. Many of the identified compounds are common across diverse angiosperm families (e.g. cineole, eugenol, β-ocimene, β-pinene and terpinen-4-ol), while others are relatively rare outside euglossine bee-pollinated orchid lineages. Additionally, 29 volatiles were identified that are known to attract and elicit collection behaviour

  17. Floral polymorphism in Chamaecrista flexuosa (Fabaceae-Caesalpinioideae): a possible case of atypical enantiostyly?

    PubMed Central

    Almeida, Natan Messias; Castro, Cibele Cardoso; Leite, Ana Virgínia; Novo, Reinaldo Rodrigo; Machado, Isabel Cristina

    2013-01-01

    Background and Aims Reciprocal herkogamy, including enantiostyly and heterostyly, involves reciprocity in the relative positions of the sexual elements within the flower. Such systems result in morphologically and, since pollen is deposited on and captured from different parts of the pollinator, functionally distinct floral forms. Deviations from the basic pattern may modify the functionality of these mechanisms. For heterostylous species, such deviations are generally related to environmental disturbances, pollination services and/or reduced numbers of one floral morph. Deviations for enantiostylous species have not yet been reported. This study aims to investigate enantiostyly in Chamaecrista flexuosa, in particular the presence of deviations from the standard form, in an area of coastal vegetation in north-east Brazil. Methods Observations and investigations of floral biology, the reproductive system, pollinator behaviour, floral morphology and morphometry were performed. Key Results In C. flexuosa flowers, anthers of different size but similar function are grouped. The flowers were self-compatible and set fruits after every treatment, except in the spontaneous self-pollination experiment, thereby indicating their dependence on pollen vectors. The flowers were pollinated by bees, especially Xylocopa cearensis and X. grisencens. Pollen is deposited and captured from the ventral portion of the pollinator's body. Variations in the spatial arrangement of floral elements allowed for the identification of floral morphs based on both morphological and functional criteria. Using morphological criteria, morphologically right (MR) and morphologically left (ML) floral morphs were identified. Three floral morphs were identified using functional criteria: functionally right (FR), functionally central (FC) and functionally left (FL). Combinations of morphologically and functionally defined morphs did not occur in equal proportions. There was a reduced frequency of the MR

  18. Quantitative genetics of floral traits in a gynodioecious wild strawberry Fragaria virginiana: implications for the independent evolution of female and hermaphrodite floral phenotypes.

    PubMed

    Ashman, T L

    1999-12-01

    The independent evolution of floral phenotype is an important part of the process of gender specialization during the evolution of dioecy from hermaphroditism. However, we have little information on the genetic variation of floral traits in species with separate genders. Gynodioecious species (co-occurrence of females and hermaphrodites) have a breeding system intermediate between hermaphroditism and complete separation of the sexes (dioecy) and thus can provide insight into the genetic architecture underlying floral phenotype with respect to both primary (stamens and carpels) and secondary (petals) sexual traits. I used a nested breeding design to examine the potential for response to selection on floral traits and to examine whether this response would be similar in the two sex morphs of gynodioecious Fragaria virginiana. There was significant genetic variation underlying all floral traits, although narrow-sense heritabilities (ranging from -0.25 to 0.44) were, in most cases, much lower than broad-sense ones (ranging from 0.28 to 1. 53). Moreover, the sex morphs differed significantly in their heritabilities for shared traits, such as stamen length, and showed a tendency towards differing significantly in others, like carpel number and petal length. In addition, correlations between the sex morphs for these traits (ranging from 0.41 to 0.58) were significantly greater than 0, but less than 1. These results indicate that greater sexual dimorphism could evolve in this population of F. virginiana, even if selection on these traits is not divergent. However, strong developmental integration of floral traits (e.g. stamen length and petal length) and high levels of nonadditive genetic variance may represent barriers to the evolution of complete sexual dimorphism. PMID:10651918

  19. Size Does Matter: Staging of Silene latifolia Floral Buds for Transcriptome Studies

    PubMed Central

    Toh, Su San; Perlin, Michael H.

    2015-01-01

    Dioecious plants in the Caryophyllaceae family are susceptible to infection by members of the anthericolous smut fungi. In our studies of the Silene latifolia/Microbotryum lychnidis-dioicae pathosystem, we were interested in characterizing the plant-pathogen interaction at the molecular level before and during teliosporogenesis. This takes place during floral bud development, and we hoped to capture the interaction by Illumina Next-Gen RNA-Sequencing. Using previous literature that documented the stages of the floral buds for S. latifolia, we examined the floral buds from plants grown and infected under growth chamber conditions, using the disserting microscope to determine the stage of floral buds based on the morphology. We compiled the information and determined the size of floral buds that correspond to the desired stages of development for tissue collection, for the purpose of RNA-sequencing. This offers a practical approach for researchers who require a large number of floral buds/tissue categorized by stages of development, ascertaining whether infected/uninfected buds are at comparable stages of development and whether this also holds true for male vs. female buds. We also document our experience in infecting the plants and some of the unusual morphologies we observed after infection. PMID:26378529

  20. Direct regulation of the floral homeotic APETALA1 gene by APETALA3 and PISTILLATA in Arabidopsis.

    PubMed

    Sundström, Jens F; Nakayama, Naomi; Glimelius, Kristina; Irish, Vivian F

    2006-05-01

    The floral homeotic gene APETALA1 (AP1) specifies floral meristem identity and sepal and petal identity in Arabidopsis. Consistent with its multiple roles during floral development, AP1 is initially expressed throughout the floral meristem, and later its expression becomes restricted to sepal and petal primordia. Using chromatin immunoprecipitation, we show that the floral homeotic PISTILLATA (PI) protein, required for petal and stamen development, has the ability to bind directly to the promoter region of AP1. In support of the hypothesis that PI, and its interacting partner APETALA3 (AP3), regulates the transcription of AP1, we show that AP1 transcript levels are elevated in strong ap3-3 mutant plants. Kinetic studies, using transgenic Arabidopsis plants in which both AP3 and PI are under post-translational control, show that AP1 transcript levels are down regulated within 2 h of AP3/PI activation. This implies that the reduction in AP1 transcripts is an early event in the cascade following AP3/PI induction and provides independent support for the hypothesis that AP1 is a direct target of the AP3/PI heterodimer. Together these results suggest a model whereby AP3/PI directly acts, in combination with other factors, to restrict the expression of AP1 during early stages of floral development. PMID:16640596

  1. Intraspecific divergence and convergence of floral tube length in specialized pollination interactions

    PubMed Central

    Anderson, B.; Ros, P.; Wiese, T. J.; Ellis, A. G.

    2014-01-01

    Floral tubes are often thought to be a consequence of adaptive specialization towards pollinator morphology. We explore floral tube length evolution within Tritoniopsis revoluta (Iridaceae), a species with considerable geographical tube length variation. We ask whether tube lengths of T. revoluta populations are associated with pollinator proboscis lengths, whether floral divergence occurs in the presence of different pollinators and whether floral convergence occurs between distantly related populations pollinated by the same pollinator. Finally, we ask whether tube length evolution is directional. Shifts between morphologically different pollinators were always associated with shifts in floral morphology, even when populations were very closely related. Distantly related populations had similar tube lengths when they were pollinated by the same pollinator. Shifts in tube length tended to be from short to long, although reversals were not infrequent. After correcting for the population-level phylogeny, there was a strong positive, linear relationship between floral tube length and pollinator proboscis length, suggesting that plants are functionally specialized on different pollinators at different sites. However, because tube length evolution in this system can be a bidirectional process, specialization to the local pollinator fauna is unlikely to result in evolutionary or ecological dead-ends such as canalization or range limitation. PMID:25274360

  2. Plant-pollinator interactions and floral convergence in two species of Heliconia from the Caribbean Islands.

    PubMed

    Martén-Rodríguez, Silvana; Kress, W John; Temeles, Ethan J; Meléndez-Ackerman, Elvia

    2011-12-01

    Variation in interspecific interactions across geographic space is a potential driver of diversification and local adaptation. This study quantitatively examined variation in floral phenotypes and pollinator service of Heliconia bihai and H. caribaea across three Antillean islands. The prediction was that floral characters would correspond to the major pollinators of these species on each island. Analysis of floral phenotypes revealed convergence among species and populations of Heliconia from the Greater Antilles. All populations of H. caribaea were similar, characterized by long nectar chambers and short corolla tubes. In contrast, H. bihai populations were strongly divergent: on Dominica, H. bihai had flowers with short nectar chambers and long corollas, whereas on Hispaniola, H. bihai flowers resembled those of H. caribaea with longer nectar chambers and shorter corolla tubes. Morphological variation in floral traits corresponded with geographic differences or similarities in the major pollinators on each island. The Hispaniolan mango, Anthracothorax dominicus, is the principal pollinator of both H. bihai and H. caribaea on Hispaniola; thus, the similarity of floral phenotypes between Heliconia species suggests parallel selective regimes imposed by the principal pollinator. Likewise, divergence between H. bihai populations from Dominica and Hispaniola corresponded with differences in the pollinators visiting this species on the two islands. The study highlights the putative importance of pollinator-mediated selection as driving floral convergence and the evolution of locally-adapted plant variants across a geographic mosaic of pollinator species. PMID:21792557

  3. A morphological and quantitative characterization of early floral development in apple (Malus x domestica Borkh.).

    PubMed

    Foster, Toshi; Johnston, Robyn; Seleznyova, Alla

    2003-08-01

    Apple is an important crop and a focus of research worldwide. However, some aspects of floral commitment and morphogenesis remain unclear. A detailed characterization of bourse shoot apex development was undertaken to provide a framework for future genetic, molecular and physiological studies. Eight morphologically distinct stages of shoot apex development, prior to winter dormancy, were defined. Based on measurements of meristem diameter, two stages of vegetative development were recognized. Vegetative meristems were flat, and either narrow (stage 0) or broad (stage 1). Pronounced doming of the apex marked stage 2. During stage 3, the domed meristem initiated four to six lateral floral meristems and subtending bracts before converting to a terminal floral meristem (stage 4). The terminal floral meristem proceeded directly with bractlet and sepal initiation, while lateral floral meristems initiated bractlets (stage 5). Sepal initiation began on the basal lateral flower (stage 6) and continued in an acropetal direction until all floral meristems had completed sepal initiation (stage 7). In this study, only stage 0 and stage 7 apices were observed in dormant buds, indicating that stages 1-6 are transient. The results suggest that broadening of the apex (stage 1) is the first morphological sign of commitment to flowering. PMID:12805080

  4. Major Transient Floral Change During the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Wing, S. L.; Harrington, G. J.; Bloch, J. I.; Boyer, D. M.; Smith, F.

    2004-12-01

    New continental sections representing the Paleocene-Eocene Thermal Maximum (PETM) have been discovered in the southern Bighorn Basin, Wyoming. Three localities preserving leaves and fruits are the first megafossil record of plants from this geologically short (about 150ky) period of intense warming. The localities produce fossil pollen and spores as well. The plant remains are in sections that preserve vertebrate fossils characteristic of the Wa-0 faunal zone that elsewhere is restricted to the period of negative carbon isotopic values that occurred during the PETM. The megaflora and palynoflora from the three localities contain a small number of long-ranging taxa that are common in many late Paleocene and early Eocene localities from the Bighorn Basin (e.g., Macginitiea, Caryapollenites, Ulmipollenites, Alnipollenites), however they also produce up to 10 taxa that have not been seen before in either the Paleocene or Eocene of this area. In the palynoflora, several of these previously unrecorded taxa (e.g, Labropollis, cf. Bombax, and a distinctive large tricolpate grain) are common in the Gulf Coastal Plain Paleogene. Although the number of dicot leaf species so far is too small to produce a robust physiognomic estimate of temperature or precipitation, it is notable that one locality near the base of the PETM is dominated by small-leaved legumes, and another near the top by an undetermined dicot leaf with an extremely long drip-tip. Preliminary analysis of the floral data strongly suggests that some types of plants extended their ranges up to 1500 km northward during the PETM, where they became sympatric with native mid-latitude taxa. These range extensions are restricted to the PETM. Furthermore, PETM floral change was essentially synchronous with the better-known mammalian turnover event. The unusual physiognomy of PETM fossil leaves raises the possibility of major changes in seasonality or amount of precipitation. We plan to measure stable carbon isotope ratios

  5. Ictal Cardiac Ryhthym Abnormalities

    PubMed Central

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic–clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  6. Abnormal uterine bleeding.

    PubMed

    Whitaker, Lucy; Critchley, Hilary O D

    2016-07-01

    Abnormal uterine bleeding (AUB) is a common and debilitating condition with high direct and indirect costs. AUB frequently co-exists with fibroids, but the relationship between the two remains incompletely understood and in many women the identification of fibroids may be incidental to a menstrual bleeding complaint. A structured approach for establishing the cause using the Fédération International de Gynécologie et d'Obstétrique (FIGO) PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system will facilitate accurate diagnosis and inform treatment options. Office hysteroscopy and increasing sophisticated imaging will assist provision of robust evidence for the underlying cause. Increased availability of medical options has expanded the choice for women and many will no longer need to recourse to potentially complicated surgery. Treatment must remain individualised and encompass the impact of pressure symptoms, desire for retention of fertility and contraceptive needs, as well as address the management of AUB in order to achieve improved quality of life. PMID:26803558

  7. Identification and quantification of antioxidant components of honeys from various floral sources.

    PubMed

    Gheldof, Nele; Wang, Xiao-Hong; Engeseth, Nicki J

    2002-10-01

    Little is known about the individual components of honey that are responsible for its antioxidant activity. The present study was carried out to characterize the phenolics and other antioxidants present in honeys from seven floral sources. Chromatograms of the phenolic nonpolar fraction of the honeys indicated that most honeys have similar but quantitatively different phenolic profiles. Many of the flavonoids and phenolic acids identified have been previously described as potent antioxidants. A linear correlation between phenolic content and ORAC activity was demonstrated (R(2) = 0.963, p < 0.0001). Honeys were separated by solid-phase extraction into four fractions for sugar removal and separation based on solubility to identify the relative contribution of each fraction to the antioxidant activity of honey. Antioxidant analysis of the different honey fractions suggested that the water-soluble fraction contained most of the antioxidant components. Specific water-soluble antioxidant components were quantified, including protein; gluconic acid; ascorbic acid; hydroxymethylfuraldehyde; and the combined activities of the enzymes glucose oxidase, catalase and peroxidase. Of these components, a significant correlation could be established only between protein content and ORAC activity (R(2) = 0.674, p = 0.024). In general, the antioxidant capacity of honey appeared to be a result of the combined activity of a wide range of compounds including phenolics, peptides, organic acids, enzymes, Maillard reaction products, and possibly other minor components. The phenolic compounds contributed significantly to the antioxidant capacity of honey but were not solely responsible for it. PMID:12358452

  8. Analysis of Phosphorylation of the Receptor-Like Protein Kinase HAESA during Arabidopsis Floral Abscission

    PubMed Central

    Taylor, Isaiah; Wang, Ying; Seitz, Kati; Baer, John; Bennewitz, Stefan; Mooney, Brian P.; Walker, John C.

    2016-01-01

    Receptor-like protein kinases (RLKs) are the largest family of plant transmembrane signaling proteins. Here we present functional analysis of HAESA, an RLK that regulates floral organ abscission in Arabidopsis. Through in vitro and in vivo analysis of HAE phosphorylation, we provide evidence that a conserved phosphorylation site on a region of the HAE protein kinase domain known as the activation segment positively regulates HAE activity. Additional analysis has identified another putative activation segment phosphorylation site common to multiple RLKs that potentially modulates HAE activity. Comparative analysis suggests that phosphorylation of this second activation segment residue is an RLK specific adaptation that may regulate protein kinase activity and substrate specificity. A growing number of RLKs have been shown to exhibit biologically relevant dual specificity toward serine/threonine and tyrosine residues, but the mechanisms underlying dual specificity of RLKs are not well understood. We show that a phospho-mimetic mutant of both HAE activation segment residues exhibits enhanced tyrosine auto-phosphorylation in vitro, indicating phosphorylation of this residue may contribute to dual specificity of HAE. These results add to an emerging framework for understanding the mechanisms and evolution of regulation of RLK activity and substrate specificity. PMID:26784444

  9. Soil and fertilizer amendments and edge effects on the floral succession of pulverized fuel ash

    SciTech Connect

    Shaw, P.

    2009-01-15

    Plots of fresh pulverized fuel ash (PFA, an industrial waste) were inoculated with soils from existing PFA sites and fertilizers in a factorial design, then left unmanaged for 12 years during which time the floral development and soil chemistry were monitored annually. For the first 3 years, the site supported a sparse mix of chenopods (including the scarce Chenopodium glaucum) and halophytes. As salinity declined, ruderals, legumes, and grasses plus the fire-site moss Funaria hygrometrica colonized, followed by Festuca arundinacea grassland (NVC community MG12) and Hippophae rhamnoides scrub. Dactylorhiza incarnata (orchidacea) appeared after 7 years, but only in plots that had received soil from existing orchid colonies. Four years later, a larger second generation of Dactylorhiza appeared, but only in the central zone of the site where vegetation was thinnest. By year 12, the site was dominated by coarse grasses and scrub, with early successional species persisting only in the sparsely vegetated center, where nitrate levels were lowest. This edge effect is interpreted as centripetal encroachment, a process of potentially wider concern for the conservation of low-fertility habitat patches. Overall, seed bank inoculation seems to have introduced few but desirable species (D. incarnata, Pyrola rotundifolia, some halophytes, and annuals), whereas initial application of organic fertilizer had long-lasting ({ge} 10 years) effects on cover and soil composition.

  10. Acidic α-galactosidase is the most abundant nectarin in floral nectar of common tobacco (Nicotiana tabacum)

    PubMed Central

    Zha, Hong-Guang; Flowers, V. Lynn; Yang, Min; Chen, Ling-Yang; Sun, Hang

    2012-01-01

    Background and Aims To date, most floral nectarins (nectar proteins) are reported to function in nectar defence, particularly for insect-pollinated outcrossing species. We compared nectarin composition and abundance in selfing common tobacco (Nicotiana tobaccum) with outcrossing ornamental tobacco plants to elucidate the functional difference of nectarins in different reproductive systems. Methods Common tobacco (CT) nectarins were separated by SDS-PAGE and the N terminus of the most abundant nectarin was sequenced via Edman degradation. The full-length nectarin gene was amplified and cloned from genomic DNA and mRNA with hiTail-PCR and RACE (rapid amplification of cDNA ends), and expression patterns were then investigated in different tissues using semi-quantitative reverse transcriptase PCR. Additionally, high-performance liquid chromatography and enzymatic analyses of nectar sugar composition, and other biochemical traits and functions of the novel nectarin were studied. Key Results The most abundant nectarin in CT nectar is an acidic α-galactosidase, here designated NTα-Gal. This compound has a molecular mass of 40 013 Da and a theoretical pI of 5·33. NTα-Gal has a conserved α-Gal characteristic signature, encodes a mature protein of 364 amino acids and is expressed in different organs. Compared with 27 other melliferous plant species from different families, CT floral nectar demonstrated the highest α-Gal activity, which is inhibited by d-galactose. Raffinose family oligosaccharides were not detected in CT nectar, indicating that NTα-Gal does not function in post-secretory hydrolysis. Moreover, tobacco plant fruits did not develop intact skin with galactose inhibition of NTα-Gal activity in nectar, suggesting that NTα-Gal induces cell-wall surface restructuring during the initial stages of fruit development. Conclusions α-Gal was the most abundant nectarin in selfing CT plants, but was not detected in the nectar of strictly outcrossing sister tobacco

  11. Biochemical abnormalities in Pearson syndrome.

    PubMed

    Crippa, Beatrice Letizia; Leon, Eyby; Calhoun, Amy; Lowichik, Amy; Pasquali, Marzia; Longo, Nicola

    2015-03-01

    Pearson marrow-pancreas syndrome is a multisystem mitochondrial disorder characterized by bone marrow failure and pancreatic insufficiency. Children who survive the severe bone marrow dysfunction in childhood develop Kearns-Sayre syndrome later in life. Here we report on four new cases with this condition and define their biochemical abnormalities. Three out of four patients presented with failure to thrive, with most of them having normal development and head size. All patients had evidence of bone marrow involvement that spontaneously improved in three out of four patients. Unique findings in our patients were acute pancreatitis (one out of four), renal Fanconi syndrome (present in all patients, but symptomatic only in one), and an unusual organic aciduria with 3-hydroxyisobutyric aciduria in one patient. Biochemical analysis indicated low levels of plasma citrulline and arginine, despite low-normal ammonia levels. Regression analysis indicated a significant correlation between each intermediate of the urea cycle and the next, except between ornithine and citrulline. This suggested that the reaction catalyzed by ornithine transcarbamylase (that converts ornithine to citrulline) might not be very efficient in patients with Pearson syndrome. In view of low-normal ammonia levels, we hypothesize that ammonia and carbamylphosphate could be diverted from the urea cycle to the synthesis of nucleotides in patients with Pearson syndrome and possibly other mitochondrial disorders. PMID:25691415

  12. First-Trimester Detection of Surface Abnormalities

    PubMed Central

    Rousian, Melek; Koning, Anton H. J.; Bonsel, Gouke J.; Eggink, Alex J.; Cornette, Jérôme M. J.; Schoonderwaldt, Ernst M.; Husen-Ebbinge, Margreet; Teunissen, Katinka K.; van der Spek, Peter J.; Steegers, Eric A. P.; Exalto, Niek

    2014-01-01

    The aim was to determine the diagnostic performance of 3-dimensional virtual reality ultrasound (3D_VR_US) and conventional 2- and 3-dimensional ultrasound (2D/3D_US) for first-trimester detection of structural abnormalities. Forty-eight first trimester cases (gold standard available, 22 normal, 26 abnormal) were evaluated offline using both techniques by 5 experienced, blinded sonographers. In each case, we analyzed whether each organ category was correctly indicated as normal or abnormal and whether the specific diagnosis was correctly made. Sensitivity in terms of normal or abnormal was comparable for both techniques (P = .24). The general sensitivity for specific diagnoses was 62.6% using 3D_VR_US and 52.2% using 2D/3D_US (P = .075). The 3D_VR_US more often correctly diagnosed skeleton/limb malformations (36.7% vs 10%; P = .013). Mean evaluation time in 3D_VR_US was 4:24 minutes and in 2D/3D_US 2:53 minutes (P < .001). General diagnostic performance of 3D_VR_US and 2D/3D_US apparently is comparable. Malformations of skeleton and limbs are more often detected using 3D_VR_US. Evaluation time is longer in 3D_VR_US. PMID:24440996

  13. Visual detection of diminutive floral guides in the bumblebee Bombus terrestris and in the honeybee Apis mellifera.

    PubMed

    Lunau, Klaus; Unseld, Katrin; Wolter, Franziska

    2009-12-01

    Many flowers display colour patterns comprising a large peripheral colour area that serves to attract flower visitors from some distance, and a small central, contrastingly coloured area made up by stamens or floral guides. In this study, we scaled down the size of floral guides to detect the minimal size bumblebees (Bombus terrestris) and honeybees (Apis mellifera) require for guidance. We analyzed the approach and the precise contact of the antennal tips with the floral guide of artificial flowers which precedes landing and inspection. Both bumblebees and honeybees were able to make antennal contact with circular floral guides which were 2 mm in diameter; bumblebees performed better than honeybees and antennated also at floral guides smaller than 2 mm. In discrimination experiments with bumblebees, a minimum floral guide size of 2 mm was required for discrimination between artificial flowers with and without floral guides. With increasing experience bumblebees targeted close to the site of reward instead of making antennal contact with the floral guide, whereas honeybees did not alter their initial behaviour with growing experience. Bumblebees and honeybees spontaneously target diminutive floral guides to achieve physical contact with flowers by means of their antennae which helps them to inspect flowers. PMID:19813017

  14. Organizations.

    ERIC Educational Resources Information Center

    Aviation/Space, 1980

    1980-01-01

    This is a list of aerospace organizations and other groups that provides educators with assistance and information in specific areas. Both government and nongovernment organizations are included. (Author/SA)

  15. Electrocardiograph abnormalities revealed during laparoscopy

    PubMed Central

    Nijjer, Sukhjinder; Dubrey, Simon William

    2010-01-01

    This brief case presents a well patient in whom an electrocardiograph abnormality consistent with an accessory pathway was found during a routine procedure. We present the electrocardiographs, explain the underlying condition, and consider why the abnormality was revealed in this manner. PMID:22419949

  16. Abnormal pressure in hydrocarbon environments

    USGS Publications Warehouse

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  17. Haem degradation in abnormal haemoglobins.

    PubMed Central

    Brown, S B; Docherty, J C

    1978-01-01

    The coupled oxidation of certain abnormal haemoglobins leads to different bile-pigment isomer distributions from that of normal haemoglobin. The isomer pattern may be correlated with the structure of the abnormal haemoglobin in the neighbourhood of the haem pocket. This is support for haem degradation by an intramolecular reaction. PMID:708385

  18. Floral and insect-induced volatile formation in Arabidopsis lyrata ssp. petraea, a perennial, outcrossing relative of A. thaliana.

    PubMed

    Abel, Christian; Clauss, Maria; Schaub, Andrea; Gershenzon, Jonathan; Tholl, Dorothea

    2009-06-01

    Volatile organic compounds have been reported to serve some important roles in plant communication with other organisms, but little is known about the biological functions of most of these substances. To gain insight into this problem, we have compared differences in floral and vegetative volatiles between two closely related plant species with different life histories. The self-pollinating annual, Arabidopsis thaliana, and its relative, the outcrossing perennial, Arabidopsis lyrata, have markedly divergent life cycles and breeding systems. We show that these differences are in part reflected in the formation of distinct volatile mixtures in flowers and foliage. Volatiles emitted from flowers of a German A. lyrata ssp. petraea population are dominated by benzenoid compounds in contrast to the previously described sesquiterpene-dominated emissions of A. thaliana flowers. Flowers of A. lyrata ssp. petraea release benzenoid volatiles in a diurnal rhythm with highest emission rates at midday coinciding with observed visitations of pollinating insects. Insect feeding on leaves of A. lyrata ssp. petraea causes a variable release of the volatiles methyl salicylate, C11- and C16-homoterpenes, nerolidol, plus the sesquiterpene (E)-beta-caryophyllene, which in A. thaliana is emitted exclusively from flowers. An insect-induced gene (AlCarS) with high sequence similarity to the florally expressed (E)-beta-caryophyllene synthase (AtTPS21) from A. thaliana was identified from individuals of a German A. lyrata ssp. petraea population. Recombinant AlCarS converts the sesquiterpene precursor, farnesyl diphosphate, into (E)-beta-caryophyllene with alpha-humulene and alpha-copaene as minor products indicating its close functional relationship to the A. thaliana AtTPS21. Differential regulation of these genes in flowers and foliage is consistent with the different functions of volatiles in the two Arabidopsis species. PMID:19322583

  19. Geographic variation of floral traits in Nicotiana glauca : Relationships with biotic and abiotic factors

    NASA Astrophysics Data System (ADS)

    Nattero, Julieta; Sérsic, Alicia N.; Cocucci, Andrea A.

    2011-09-01

    Geographic pattern of phenotypic variation can appear in a clinal or a mosaic fashion and can evidence adaptive or non-adaptive variation. To shed light on the mechanisms underlying this variation, we studied the relationships between geographic variation of floral traits and both biotic and abiotic factors of the hummingbird-pollinated plant, Nicotiana glauca, across its natural range. We obtained floral measures of 38 populations from an area about 1600 km long and 1050 km wide and an altitude range from 7 to over 3400 m. We used a MANOVA to detect between-population differentiations in flower traits and a DFA to determine the traits that best discriminate between populations. To test for associations between floral traits and climatic variables we used correlation analysis. We explored any possible distance-based pattern of variation (either geographic or altitudinal) in floral traits or bill length of pollinators using Mantel tests. Finally, we used a multiple regression to analyze simultaneously the effects and relative importance of abiotic predictor variables and bill length on corolla length. We found a high variation in flower traits among populations. Morphometric traits were the ones that best discriminated across populations. There was a clinal pattern of floral phenotypic variation explained by climatic factors. Differences in floral phenotypic distances were structured by altitudinal distances but not by geographic distances. Bill length of the hummingbird pollinators was structured both by altitudinal and geographic distances. Differences in bill length of hummingbird pollinators explained differences in corolla length across populations. Our findings support the assumption of flower evolution at a broad geographic scale. Floral traits seem to be structured not only by altitude but also by climatic factors.

  20. Floral scent in natural hybrids of Ipomopsis (Polemoniaceae) and their parental species

    PubMed Central

    Bischoff, Mascha; Jürgens, Andreas; Campbell, Diane R.

    2014-01-01

    Background and Aims Floral traits, such as floral volatiles, can contribute to pre-zygotic reproductive isolation by promoting species-specific pollinator foraging. When hybrid zones form, floral traits could also influence post-zygotic isolation. This study examined floral volatiles in parental species and natural hybrids in order to explore potential scent mediation of pre-zygotic and post-zygotic isolation. Methods Floral bouquets were analysed for the sister species Ipomopsis aggregata and I. tenuituba and their natural hybrids at two contact sites differing in both hybridization rate and temporal foraging pattern of hawkmoth pollinators. Floral volatiles were quantified in diurnal and nocturnal scent samples using gas chromatography–mass spectrometry. Key Results The bouquets of parental species and hybrids showed qualitative overlap. All flowers emitted similar sets of monoterpenoid, sesquiterpenoid, aliphatic and benzenoid compounds, but separated into groups defined by multivariate analysis of quantitative emissions. The parental species differed most strikingly in the nitrogenous compound indole, which was found almost exclusively in nocturnal bouquets of I. tenuituba. Natural hybrid bouquets were highly variable, and showed emission rates of several compounds that appeared transgressive. However, indole emission rates were intermediate in the hybrids compared with rates in the parents. Volatile bouquets at the contact site with lower hybridization did not show greater species specificity in overall scent emission, but I. tenuituba presented a stronger indole signal during peak hawkmoth activity at that site. Conclusions The two species of Ipomopsis differed in patterns of floral bouquets, with indole emitted in nocturnal I. tenuituba, but not in I. aggregata. Natural hybrid bouquets were not consistently intermediate between the parents, although hybrids were intermediate in indole emission. The indole signal could potentially serve as a hawkmoth

  1. Is Floral Longevity Influenced by Reproductive Costs and Pollination Success in Cohniella ascendens (Orchidaceae)?

    PubMed Central

    Abdala-Roberts, Luis; Parra-Tabla, Víctor; Navarro, Jorge

    2007-01-01

    Background and Aims Although studies have shown that pollen addition and/or removal decreases floral longevity, less attention has been paid to the relationship between reproductive costs and floral longevity. In addition, the influence of reproductive costs on floral longevity responses to pollen addition and/or removal has not yet been evaluated. Here, the orchid Cohniella ascendens is used to answer the following questions. (a) Does experimental removal of flower buds in C. ascendens increase flower longevity? (b) Does pollen addition and/or removal decrease floral longevity, and does this response depend on plant reproductive resource status? Methods To study the effect of reproductive costs on floral longevity 21 plants were selected from which we removed 50 % of the developing flower buds on a marked inflorescence. Another 21 plants were not manipulated (controls). One month later, one of four flowers on each marked inflorescence received one of the following pollen manipulation treatments: control, pollinia removal, pollination without pollinia removal or pollination with pollinia removal. The response variable measured was the number of days each flower remained open (i.e. longevity). Key Results The results showed significant flower bud removal and pollen manipulation effects on floral longevity; the interaction between these two factors was not significant. Flowers on inflorescences with previously removed flower buds remained open significantly longer than flowers on control inflorescences. On the other hand, pollinated flowers closed much faster than control and removed-pollinia flowers, the latter not closing significantly faster than control flowers, although this result was marginal. Conclusions The results emphasize the strong relationship between floral longevity and pollination in orchids, as well as the influence of reproductive costs on the former. PMID:17881335

  2. Divergence on floral traits and vertebrate pollinators of two endemic Encholirium bromeliads.

    PubMed

    Christianini, A V; Forzza, R C; Buzato, S

    2013-03-01

    Shifts in pollen vectors favour diversification of floral traits, and differences in pollination strategies between congeneric sympatric species can contribute to reproductive isolation. Divergence in flowering phenology and selfing could also reduce interspecific crossing between self-compatible species. We investigated floral traits and visitation rates of pollinators of two sympatric Encholirium species on rocky outcrops to evaluate whether prior knowledge of floral characters could indicate actual pollinators. Data on flowering phenology, visitation rates and breeding system were used to evaluate reproductive isolation. Flowering phenology overlapped between species, but there were differences in floral characters, nectar volume and concentration. Several hummingbird species visited flowers of both Encholirium spp., but the endemic bat Lonchophylla bokermanni and an unidentified sphingid only visited E. vogelii. Pollination treatments demonstrated that E. heloisae and E. vogelii were partially self-compatible, with weak pollen limitation to seed set. Herbivores feeding on inflorescences decreased reproductive output of both species, but for E. vogelii the damage was higher. Our results indicate that actual pollinators can be known beforehand through floral traits, in agreement with pollination syndromes stating that a set of floral traits can be associated with the attraction of specific groups of pollinators. Divergence on floral traits and pollinator assemblage indicate that shifts in pollination strategies contribute to reproductive isolation between these Encholirium species, not divergence on flowering phenology or selfing. We suggest that hummingbird pollination might be the ancestral condition in Encholirium and that evolution of bat pollination made a substantial contribution to the diversification of this clade. PMID:22882351

  3. Secondary metabolites in floral nectar reduce parasite infections in bumblebees.

    PubMed

    Richardson, Leif L; Adler, Lynn S; Leonard, Anne S; Andicoechea, Jonathan; Regan, Karly H; Anthony, Winston E; Manson, Jessamyn S; Irwin, Rebecca E

    2015-03-22

    The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. PMID:25694627

  4. Pollinators' mating rendezvous and the evolution of floral advertisement.

    PubMed

    Fishman, Michael A; Hadany, Lilach

    2013-01-01

    Successful cross-fertilization in plant species that rely on animal pollinators depends not just on the number of pollinator visits, but also on these visits' duration. Furthermore, in non-deceptive pollination, a visit's duration depends on the magnitude of the reward provided to the pollinator. Accordingly, plants that rely on biotic pollination have to partition their investment in cross-fertilization assurance between attracting pollinator visits - advertisement, and rewarding visitors to assure that the visit is of productive duration. Here we analyze these processes by a combination of optimality methods and game theoretical modeling. Our results indicate that the optimality in such allocation of resources depends on the types of reward offered to the pollinators. More precisely, we show that plants that offer both food reward and mating rendezvous to pollinators will evolve to allocate a higher proportion of their cross-fertilization assurance budget to advertisement than plants that offer only food reward. That is, our results indicate that pollinators' mating habits may play a role in floral evolution. PMID:23023108

  5. Do Honeybees Shape the Bacterial Community Composition in Floral Nectar?

    PubMed Central

    Aizenberg-Gershtein, Yana; Izhaki, Ido; Halpern, Malka

    2013-01-01

    Floral nectar is considered the most important reward animal-pollinated plants offer to attract pollinators. Here we explore whether honeybees, which act as pollinators, affect the composition of bacterial communities in the nectar. Nectar and honeybees were sampled from two plant species: Amygdalus communis and Citrus paradisi. To prevent the contact of nectar with pollinators, C. paradisi flowers were covered with net bags before blooming (covered flowers). Comparative analysis of bacterial communities in the nectar and on the honeybees was performed by the 454-pyrosequencing technique. No significant differences were found among bacterial communities in honeybees captured on the two different plant species. This resemblance may be due to the presence of dominant bacterial OTUs, closely related to the Arsenophonus genus. The bacterial communities of the nectar from the covered and uncovered C. paradisi flowers differed significantly; the bacterial communities on the honeybees differed significantly from those in the covered flowers’ nectar, but not from those in the uncovered flowers’ nectar. We conclude that the honeybees may introduce bacteria into the nectar and/or may be contaminated by bacteria introduced into the nectar by other sources such as other pollinators and nectar thieves. PMID:23844027

  6. Floral odor learning within the hive affects honeybees' foraging decisions

    NASA Astrophysics Data System (ADS)

    Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

    2007-03-01

    Honeybees learn odor cues quickly and efficiently when visiting rewarding flowers. Memorization of these cues facilitates the localization and recognition of food sources during foraging flights. Bees can also use information gained inside the hive during social interactions with successful foragers. An important information cue that can be learned during these interactions is food odor. However, little is known about how floral odors learned in the hive affect later decisions of foragers in the field. We studied the effect of food scent on foraging preferences when this learning is acquired directly inside the hive. By using in-hive feeders that were removed 24 h before the test, we showed that foragers use the odor information acquired during a 3-day stimulation period with a scented solution during a food-choice situation outside the nest. This bias in food preference is maintained even 24 h after the replacement of all the hive combs. Thus, without being previously collected outside by foragers, food odors learned within the hive can be used during short-range foraging flights. Moreover, correct landings at a dual-choice device after replacing the storing combs suggests that long-term memories formed within the colony can be retrieved while bees search for food in the field.

  7. Secondary metabolites in floral nectar reduce parasite infections in bumblebees

    PubMed Central

    Richardson, Leif L.; Adler, Lynn S.; Leonard, Anne S.; Andicoechea, Jonathan; Regan, Karly H.; Anthony, Winston E.; Manson, Jessamyn S.; Irwin, Rebecca E.

    2015-01-01

    The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. PMID:25694627

  8. Pollination of Adenocalymma bracteatum (Bignoniaceae): floral biology and visitors.

    PubMed

    Almeida-Soares, Stela; Polatto, Leandro P; Dutra, João C S; Torezan-Silingardi, Helena M

    2010-01-01

    Adenocalymma bracteatum is a shrub of dense foliage and yellow flowers, easily found on grasslands areas in Central Brazil. The aim of this study was to determine the reproductive biology and the flower visitors of A. bracteatum in a pasture area nearby Ivinhema city, MS (Brazil). The flowering peak occurs in winter. The flower reflects ultraviolet light. Anthesis begins at 6:30h, and pollen and nectar are the resources to visitors. We captured 1,038 floral visitors. The bees Apis mellifera (L.), Trigona sp., Trigona spinipes (Fabricius), (Hymenoptera: Apoidea) and the ant Cephalotes sp. (Hymenoptera: Formicidae) were the main visitors. The reproductive tests indicate that A. bracteatum is self compatible, justifying its expansion in altered environments; however, the largest reproductive success was dependant on cross-pollination and self-pollination, evidencing the pollinators importance. Adenocalymma bracteatum presents melittophilous syndrome and bumblebees were the main pollinators in the area. The correlations observed between the climatic variables and the main pollinator species were low or medium. PMID:21271062

  9. Floral ecology and insect visitation in riparian Tamarix sp. (saltcedar)

    USGS Publications Warehouse

    Andersen, D.C.; Nelson, S.M.

    2013-01-01

    Climate change projections for semiarid and arid North America include reductions in stream discharge that could adversely affect riparian plant species dependent on stream-derived ground water. In order to better understand this potential impact, we used a space-for-time substitution to test the hypotheses that increasing depth-to-groundwater (DGW) is inversely related to Tamarix sp. (saltcedar) flower abundance (F) and nectar production per flower (N). We also assessed whether DGW affected the richness or abundance of insects visiting flowers. We examined Tamarix floral attributes and insect visitation patterns during 2010 and 2011 at three locations along a deep DWG gradient (3.2–4.1 m) on a floodplain terrace adjacent to Las Vegas Wash, an effluent-dominated Mojave Desert stream. Flower abundance and insect visitation patterns differed between years, but no effect from DGW on either F or N was detected. An eruption of a novel non-native herbivore, the splendid tamarisk weevil (Coniatus splendidulus), likely reduced flower production in 2011.

  10. Chemical and morphological filters in a specialized floral mimicry system.

    PubMed

    Martos, Florent; Cariou, Marie-Louise; Pailler, Thierry; Fournel, Jacques; Bytebier, Benny; Johnson, Steven D

    2015-07-01

    Many plant species attract insect pollinators through chemical mimicry of their oviposition sites, often detaining them in a trap chamber that ensures pollen transfer. These plant mimics are considered to be unspecialized at the pollinator species level, yet field observations of a mycoheterotrophic rainforest orchid (Gastrodia similis), which emits an odour reminiscent of rotting fruit, indicate that it is pollinated by a single drosophilid fly species (Scaptodrosophila bangi). We investigated the roles of floral volatiles and the dimensions of the trap chamber in enforcing this specialization, using gas chromatography-mass spectrometry analyses, bioassays and scanning electron microscopy. We showed that G. similis flowers predominantly emit three fatty-acid esters (ethyl acetate, ethyl isobutyrate and methyl isobutyrate) that were shown in experiments to attract only Scaptodrosophila flies. We additionally showed that the trap chamber, which flies enter into via a touch-sensitive 'trapdoor', closely matches the body size of the pollinator species S. bangi and plays a key role in pollen transfer. Our study demonstrates that specialization in oviposition site mimicry is due primarily to volatile chemistry and is reflected in the dimensions of the trapping apparatus. It also indicates that mycoheterotrophic plants can be specialized both on mycorrhizal fungi and insect pollinators. PMID:25704464

  11. Comparative proteomic analysis of floral color variegation in peach.

    PubMed

    Zhou, Yong; Wu, Xinxin; Zhang, Zhen; Gao, Zhihong

    2015-09-01

    Variegation in flower is a special trait in ornamental peach (Prunus persica L.). To investigate the mechanism of color variegation, we used a combination of two dimensional gel electrophoresis and mass spectrometry to explore the proteomic profiles between variegated flower (VF) and red flower (RF) buds of the peach cultivar 'Sahong Tao'. More than 500 highly reproducible protein spots (P < 0.05) were detected and 72 protein spots showed a greater than two-fold difference in their values. We identified 70 proteins that may play roles in petal coloration. The mRNA levels of the corresponding genes were detected using quantitative RT-PCR. The results show that most of the proteins are involved in energy and metabolism, which provide energy and substrates. We found that LDOX, WD40, ACC, and PPO II are related to the pigment biosynthetic pathway. The activity of PPO enzyme was further validated and showed the higher with significant differences in RF compared with the VF ones. Moreover, the four UCH proteins are involved in protein fate and may be important in post-translational modifications in peach flowers. Our study is the first comparative proteomic analysis of floral variegation and will contribute to further investigations into the molecular mechanism of flower petal coloration in ornamental peach. PMID:26192118

  12. The euAP1 Protein MPF3 Represses MPF2 to Specify Floral Calyx Identity and Displays Crucial Roles in Chinese Lantern Development in Physalis[C][W

    PubMed Central

    Zhao, Jing; Tian, Ying; Zhang, Ji-Si; Zhao, Man; Gong, Pichang; Riss, Simone; Saedler, Rainer; He, Chaoying

    2013-01-01

    The Chinese lantern phenotype or inflated calyx syndrome (ICS) is a postfloral morphological novelty in Physalis. Its origin is associated with the heterotopic expression of the MADS box gene 2 from Physalis floridana (MPF2) in floral organs, yet the process underlying its identity remains elusive. Here, we show that MPF3, which is expressed specifically in floral tissues, encodes a core eudicot APETALA1-like (euAP1) MADS-domain protein. MPF3 was primarily localized to the nucleus, and it interacted with MPF2 and some floral MADS-domain proteins to selectively bind the CC-A-rich-GG (CArG) boxes in the MPF2 promoter. Downregulating MPF3 resulted in a dramatic elevation in MPF2 in the calyces and androecium, leading to enlarged and leaf-like floral calyces; however, the postfloral lantern was smaller and deformed. Starch accumulation in pollen was blocked. MPF3 MPF2 double knockdowns showed normal floral calyces and more mature pollen than those found in plants in which either MPF3 or MPF2 was downregulated. Therefore, MPF3 specifies calyx identity and regulates ICS formation and male fertility through interactions with MPF2/MPF2. Furthermore, both genes were found to activate Physalis floridana invertase gene 4 homolog, which encodes an invertase cleaving Suc, a putative key gene in sugar partitioning. The novel role of the MPF3-MPF2 regulatory circuit in male fertility is integral to the origin of ICS. Our results shed light on the evolution and development of ICS in Physalis and on the functional evolution of euAP1s in angiosperms. PMID:23792370

  13. Trees as huge flowers and flowers as oversized floral guides: the role of floral color change and retention of old flowers in Tibouchina pulchra

    PubMed Central

    Brito, Vinícius L. G.; Weynans, Kevin; Sazima, Marlies; Lunau, Klaus

    2015-01-01

    Floral color changes and retention of old flowers are frequently combined phenomena restricted to the floral guide or single flowers in few-flowered inflorescences. They are thought to increase the attractiveness over long distances and to direct nearby pollinators toward the rewarding flowers. In Tibouchina pulchra, a massively flowering tree, the whole flower changes its color during anthesis. On the first day, the flowers are white and on the next 3 days, they change to pink. This creates a new large-scale color pattern in which the white pre-changed flowers contrast against the pink post-changed ones over the entire tree. We describe the spectral characteristics of floral colors of T. pulchra and test bumblebees’ response to this color pattern when viewed at different angles (simulating long and short distances). The results indicated the role of different color components in bumblebee attraction and the possible scenario in which this flower color pattern has evolved. We tested bumblebees’ preference for simulated trees with 75% pink and 25% white flowers resembling the color patterns of T. pulchra, and trees with green leaves and pink flowers (control) in long-distance approach. We also compared an artificial setting with three pink flowers and one white flower (T. pulchra model) against four pink flowers with white floral guides (control) in short-distance approach. Bumblebees spontaneously preferred the simulated T. pulchra patterns in both approaches despite similar reward. Moreover, in short distances, pollinator visits to peripheral, non-rewarding flowers occurred only half as frequently in the simulated T. pulchra when compared to the control. Thefore, this exceptional floral color change and the retention of old flowers in T. pulchra favors the attraction of pollinators over long distances in a deception process while it honestly directs them toward the rewarding flowers at short distances possibly exploring their innate color preferences. PMID

  14. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  15. The role of short-tongued insects in floral variation across the range of a style-dimorphic plant

    PubMed Central

    Santos-Gally, Rocío; Pérez-Barrales, Rocío; Simón, Violeta I.; Arroyo, Juan

    2013-01-01

    Background and Aims Heterostyly and related style polymorphisms are suitable model systems to evaluate the importance of functional pollinators in the maintenance of population variability. In Narcissus papyraceus different functional pollinators, incompatibility system and flower morphology have been proposed to influence the maintenance of polymorphism through their effect on disassortative mating. Here a test is done to find out if the visitation rate of long- versus short-tongued pollinators correlates with the morph ratio and if the latter is related to other flower traits of the species across its main geographic range. Methods Floral traits from 34 populations in the south-west of the Iberian Peninsula and in north-west Africa were measured, perianth variation was described and a comparison was made of allometric relationships between sex organs and floral tube. Correlations between pollinator guilds, stigma–anther separation of reciprocal morphs (our proxy for disassortative mating) and morph-ratio variation were analysed. Finally, the incompatibility system of the species in the northern and southern borders of its distribution are described. Key Results Flowers from southern populations were significantly larger than flowers from centre and northern populations. The abundance of short-styled plants decreased gradually with increasing distance from the core region (the Strait of Gibraltar), with these disappearing only in the northern range. Although there was a significant difference in stigma–anther separation among populations, morph ratio was not associated with reciprocity or floral tube length. Long-style morph frequency increased with short-tongued pollinator visitation rate. Populations from both edges of the distribution range were self-incompatible and within- and between-morph compatible. Conclusions The style morph ratio changed gradually, whereas perianth trait variation showed abrupt changes with two morphotypes across the range. The

  16. Haematological abnormalities in mitochondrial disorders

    PubMed Central

    Finsterer, Josef; Frank, Marlies

    2015-01-01

    INTRODUCTION This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. METHODS The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as ‘definite’, ‘probable’ or ‘possible’ according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. RESULTS A total of 46 patients (‘definite’ = 5; ‘probable’ = 9; ‘possible’ = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. CONCLUSION MID should be considered if a patient’s abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem. PMID:26243978

  17. Floral asymmetry and predation risk modify pollinator behavior, but only predation risk decreases plant fitness.

    PubMed

    Antiqueira, Pablo Augusto Poleto; Romero, Gustavo Quevedo

    2016-06-01

    Although predators and floral herbivores can potentially decrease plant fitness by changing pollinator behaviors, studies comparing the strength of these factors as well as their additive and interactive effects on pollinator visitation and plant fitness have not been conducted. In this study, we manipulated the floral symmetry and predator presence (artificial crab spiders) on the flowers of the shrub Rubus rosifolius (Rosaceae) in a 2 × 2 factorial randomized block design. We found that asymmetry and predators decreased pollinator visitation (mainly hymenopterans), and overall these factors did not interact (additive effects). The effect of predation risk on pollinator avoidance behavior was 62 % higher than that of floral asymmetry. Furthermore, path analyses revealed that only predation risk cascaded down to plant fitness, and it significantly decreased fruit biomass by 33 % and seed number by 28 %. We also demonstrated that R. rosifolius fitness is indirectly affected by visiting and avoidance behaviors of pollinators. The strong avoidance behavioral response triggered by predation risk may be related to predator pressure upon flowers. Although floral asymmetry caused by herbivory can alter the quality of resources, it should not exert the same evolutionary pressure as that of predator-prey interactions. Our study highlights the importance of considering simultaneous forces, such as predation risk and floral asymmetry, as well as pollinator behavior when evaluating ecological processes involving mutualistic plant-pollinator systems. PMID:26861474

  18. The Role of Abiotic Environmental Conditions and Herbivory in Shaping Bacterial Community Composition in Floral Nectar

    PubMed Central

    Samuni-Blank, Michal; Izhaki, Ido; Laviad, Sivan; Bar-Massada, Avi; Gerchman, Yoram; Halpern, Malka

    2014-01-01

    Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that “everything is everywhere, but the environment selects”. Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs. PMID:24922317

  19. Floral neighborhood influences pollinator assemblages and effective pollination in a native plant.

    PubMed

    Bruckman, Daniela; Campbell, Diane R

    2014-10-01

    Pollinators represent an important intermediary by which different plant species can influence each other's reproductive fitness. Floral neighbors can modify the quantity of pollinator visits to a focal species but may also influence the composition of visitor assemblages that plants receive leading to potential changes in the average effectiveness of floral visits. We explored how the heterospecific floral neighborhood (abundance of native and non-native heterospecific plants within 2 m × 2 m) affects pollinator visitation and composition of pollinator assemblages for a native plant, Phacelia parryi. The relative effectiveness of different insect visitors was also assessed to interpret the potential effects on plant fitness of shifts in pollinator assemblage composition. Although the common non-native Brassica nigra did not have a significant effect on overall pollinator visitation rate to P. parryi, the proportion of flower visits that were made by native pollinators increased with increasing abundance of heterospecific plant species in the floral neighborhood other than B. nigra. Furthermore, native pollinators deposited twice as many P. parryi pollen grains per visit as did the nonnative Apis mellifera, and visits by native bees also resulted in more seeds than visits by A. mellifera. These results indicate that the floral neighborhood can influence the composition of pollinator assemblages that visit a native plant and that changes in local flower communities have the potential to affect plant reproductive success through shifts in these assemblages towards less effective pollinators. PMID:25047026

  20. Explaining variation in the effect of floral density on pollinator visitation.

    PubMed

    Essenberg, Carla J

    2012-08-01

    Pollinator responses to floral density have important implications for plant biology. In particular, a decline in pollinator visitation at low density can cause an Allee effect (a positive relation of fitness to density) in the plant population, which heightens that population's vulnerability to extinction. Empiricists have reported a variety of relations between flower or plant density and pollinator visitation rates. Here I develop and test a model that provides explanations for this diversity. The model assumes that pollinators distribute themselves between a focal patch of flowers and the surrounding environment so as to maximize foraging success. The resulting relation of per-flower visitation rate to focal-patch floral density is nonlinear, with positive effects at low floral densities and weaker or negative effects at higher densities. The relation is influenced by floral density in the surrounding environment and traits of both the plants and their pollinators. In a field experiment, floral density of Holocarpha virgata ssp. virgata had a nonlinear effect on per-flower visitation that was largely consistent with the model's predictions. By producing testable hypotheses based on biologically reasonable assumptions, this model serves as a starting point for explaining an important facet of plant-pollinator mutualisms. PMID:22766928

  1. Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

    PubMed

    Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

    2016-01-01

    Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness. PMID:27072926

  2. Dynamics of DNA methylation and Histone H4 acetylation during floral bud differentiation in azalea

    PubMed Central

    2010-01-01

    Background The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression. Results The results of this work indicate that epigenetic mechanisms such as DNA methylation and histone H4 acetylation have opposite and particular dynamics during the transition from vegetative to reproductive development in the apical shoots of azalea. Global levels of DNA methylation and histone H4 acetylation as well as immunodetection of 5-mdC and acetylated H4, in addition to a morphological study have permitted the delimitation of four basic phases in the development of the azalea bud and allowed the identification of a stage of epigenetic reprogramming which showed a sharp decrease of whole DNA methylation similar to that is defined in other developmental processes in plants and in mammals. Conclusion The epigenetic control and reorganization of chromatin seem to be decisive for coordinating floral development in azalea. DNA methylation and H4 deacetylation act simultaneously and co-ordinately, restructuring the chromatin and regulating the gene expression during soot apical meristem development and floral differentiation. PMID:20067625

  3. Local adaptation: Mechanical fit between floral ecotypes of Nerine humilis (Amaryllidaceae) and pollinator communities.

    PubMed

    Newman, Ethan; Manning, John; Anderson, Bruce

    2015-09-01

    Geographic variation in floral morphology is often assumed to reflect geographic variation in pollinator communities and associated divergence in selective pressures. We studied populations of Nerine humilis (Amaryllidaceae) to assess whether geographic variation in floral form is the result of local adaptation to different pollinator communities. We first tested for associations between floral traits and visitor communities, and found that populations with similar floral morphologies were visited by similar insect communities. Mean style length in each population was also closely associated with the mean body length of the local visitor community. A reciprocal translocation experiment demonstrated that native phenotypes set more seed than translocated phenotypes. Single visitation experiments showed that native flowers received more pollen, and set more seed per visit, than introduced phenotypes in both populations. This suggests that the effectiveness of pollinator visits is determined by the degree of mechanical fit between flowers and visitors. We provide strong evidence that the observed among-population variation in floral traits is an adaptive response to geographic variation in the pollinator community. PMID:26194119

  4. Separating selection by diurnal and nocturnal pollinators on floral display and spur length in Gymnadenia conopsea.

    PubMed

    Sletvold, Nina; Trunschke, Judith; Wimmergren, Carolina; Agren, Jon

    2012-08-01

    Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal and nocturnal pollinators on floral display and spur length in the rewarding orchid Gymnadenia conopsea, we manipulated the environment by conducting supplemental hand-pollinations and selective pollinator exclusions in two populations in central Norway. In both populations, the exclusion of diurnal pollinators significantly reduced seed production compared to open pollination, whereas the exclusion of nocturnal pollinators did not. There was significant selection on traits expected to influence pollinator attraction and pollination efficiency in both the diurnal and nocturnal pollination treatment. The relative strength of selection among plants exposed to diurnal and nocturnal visitors varied among traits and populations, but the direction of selection was consistent. The results suggest that diurnal pollinators are more important than nocturnal pollinators for seed production in the study populations, but that both categories contribute to selection on floral morphology. The study illustrates how experimental manipulations can link specific categories of pollinators to observed selection on floral traits, and thus improve our understanding of how species interactions shape patterns of selection. PMID:22928416

  5. Leaf herbivory increases floral fragrance in male but not female Cucurbita pepo subsp. texana (Cucurbitaceae) flowers.

    PubMed

    Theis, Nina; Kesler, Karen; Adler, Lynn S

    2009-05-01

    Mutualisms are key interactions that affect population dynamics and structure communities, but the extent to which mutualists can attract potential partners may depend on community context. Many studies have shown that leaf herbivory reduces pollinator visitation and have focused on reduced floral visual display and rewards as potential mechanisms. However, olfactory display plays a critical role in mediating interactions between plants, herbivores, and pollinators. We simulated leaf damage in Cucurbita pepo subsp. texana and measured fragrance emission and other floral characters of both male and female flowers. Contrary to our expectations, damage increased fragrance production, but only in male flowers. Female flowers, which were bigger and produced more fragrance than males, were unaffected by leaf damage. The greatest increase in floral fragrance compounds was in the terpenoids, which we hypothesize could be byproducts of defensively induced cucurbitacins, or they may function defensively themselves. In summary, this study is the first to demonstrate changes in floral fragrance due to leaf damage. Such changes in floral fragrance following herbivory may be a critical and overlooked mechanism mediating interactions between plants, herbivores, and pollinators. PMID:21628242

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

    PubMed Central

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

    2014-01-01

    Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants. PMID:24682234

  7. Competition with wind-pollinated plant species alters floral traits of insect-pollinated plant species

    PubMed Central

    Flacher, Floriane; Raynaud, Xavier; Hansart, Amandine; Motard, Eric; Dajoz, Isabelle

    2015-01-01

    Plant traits related to attractiveness to pollinators (e.g. flowers and nectar) can be sensitive to abiotic or biotic conditions. Soil nutrient availability, as well as interactions among insect-pollinated plants species, can induce changes in flower and nectar production. However, further investigations are needed to determine the impact of interactions between insect-pollinated species and abiotically pollinated species on such floral traits, especially floral rewards. We carried out a pot experiment in which three insect-pollinated plant species were grown in binary mixtures with four wind-pollinated plant species, differing in their competitive ability. Along the flowering period, we measured floral traits of the insect-pollinated species involved in attractiveness to pollinators (i.e. floral display size, flower size, daily and total 1) flower production, 2) nectar volume, 3) amount of sucrose allocated to nectar). Final plant biomass was measured to quantify competitive interactions. For two out of three insect-pollinated species, we found that the presence of a wind-pollinated species can negatively impact floral traits involved in attractiveness to pollinators. This effect was stronger with wind-pollinated species that induced stronger competitive interactions. These results stress the importance of studying the whole plant community (and not just the insect-pollinated plant community) when working on plant-pollinator interactions. PMID:26335409

  8. Flowers help bees cope with uncertainty: signal detection and the function of floral complexity

    PubMed Central

    Leonard, Anne S.; Dornhaus, Anna; Papaj, Daniel R.

    2011-01-01

    Plants often attract pollinators with floral displays composed of visual, olfactory, tactile and gustatory stimuli. Since pollinators' responses to each of these stimuli are usually studied independently, the question of why plants produce multi-component floral displays remains relatively unexplored. Here we used signal detection theory to test the hypothesis that complex displays reduce a pollinator's uncertainty about the floral signal. Specifically, we asked whether one component of the floral display, scent, improved a bee's certainty about the value of another component, color hue. We first trained two groups of bumble bees (Bombus impatiens Cresson) to discriminate between rewarding and unrewarding artificial flowers of slightly different hues in the presence vs absence of scent. In a test phase, we presented these bees with a gradient of floral hues and assessed their ability to identify the hue rewarded during training. We interpreted the extent to which bees' preferences were biased away from the unrewarding hue (‘peak shift’) as an indicator of uncertainty in color discrimination. Our data show that the presence of an olfactory signal reduces uncertainty regarding color: not only was color learning facilitated on scented flowers but also bees showed a lower amount of peak shift in the presence of scent. We explore potential mechanisms by which scent might reduce uncertainty about color, and discuss the broader significance of our results for our understanding of signal evolution. PMID:21147975

  9. Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae)

    PubMed Central

    Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

    2016-01-01

    Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness. PMID:27072926

  10. How floral odours are learned inside the bumblebee ( Bombus terrestris) nest

    NASA Astrophysics Data System (ADS)

    Molet, Mathieu; Chittka, Lars; Raine, Nigel E.

    2009-02-01

    Recruitment in social insects often involves not only inducing nestmates to leave the nest, but also communicating crucial information about finding profitable food sources. Although bumblebees transmit chemosensory information (floral scent), the transmission mechanism is unknown as mouth-to-mouth fluid transfer (as in honeybees) does not occur. Because recruiting bumblebees release a pheromone in the nest that triggers foraging in previously inactive workers, we tested whether this pheromone helps workers learn currently rewarding floral odours, as found in food social learning in rats. We exposed colonies to artificial recruitment pheromone, paired with anise scent. The pheromone did not facilitate learning of floral scent. However, we found that releasing floral scent in the air of the colony was sufficient to trigger learning and that learning performance was improved when the chemosensory cue was provided in the nectar in honeypots; probably because it guarantees a tighter link between scent and reward, and possibly because gustatory cues are involved in addition to olfaction. Scent learning was maximal when anise-scented nectar was brought into the nest by demonstrator foragers, suggesting that previously unidentified cues provided by successful foragers play an important role in nestmates learning new floral odours.

  11. Coagulation abnormalities in sepsis.

    PubMed

    Tsao, Cheng-Ming; Ho, Shung-Tai; Wu, Chin-Chen

    2015-03-01

    Although the pathophysiology of sepsis has been elucidated with the passage of time, sepsis may be regarded as an uncontrolled inflammatory and procoagulant response to infection. The hemostatic changes in sepsis range from subclinical activation of blood coagulation to acute disseminated intravascular coagulation (DIC). DIC is characterized by widespread microvascular thrombosis, which contributes to multiple organ dysfunction/failure, and subsequent consumption of platelets and coagulation factors, eventually causing bleeding manifestations. The diagnosis of DIC can be made using routinely available laboratory tests, scoring algorithms, and thromboelastography. In this cascade of events, the inhibition of coagulation activation and platelet function is conjectured as a useful tool for attenuating inflammatory response and improving outcomes in sepsis. A number of clinical trials of anticoagulants were performed, but none of them have been recognized as a standard therapy because recombinant activated protein C was withdrawn from the market owing to its insufficient efficacy in a randomized controlled trial. However, these subgroup analyses of activated protein C, antithrombin, and thrombomodulin trials show that overt coagulation activation is strongly associated with the best therapeutic effect of the inhibitor. In addition, antiplatelet drugs, including acetylsalicylic acid, P2Y12 inhibitors, and glycoprotein IIb/IIIa antagonists, may reduce organ failure and mortality in the experimental model of sepsis without a concomitant increased bleeding risk, which should be supported by solid clinical data. For a state-of-the-art treatment of sepsis, the efficacy of anticoagulant and antiplatelet agents needs to be proved in further large-scale prospective, interventional, randomized validation trials. PMID:25544351

  12. Organics.

    ERIC Educational Resources Information Center

    Chian, Edward S. K.; DeWalle, Foppe B.

    1978-01-01

    Presents water analysis literature for 1978. This review is concerned with organics, and it covers: (1) detergents and surfactants; (2) aliphatic and aromatic hydrocarbons; (3) pesticides and chlorinated hydrocarbons; and (4) naturally occurring organics. A list of 208 references is also presented. (HM)

  13. Organizers.

    ERIC Educational Resources Information Center

    Callison, Daniel

    2000-01-01

    Focuses on "organizers," tools or techniques that provide identification and classification along with possible relationships or connections among ideas, concepts, and issues. Discusses David Ausubel's research and ideas concerning advance organizers; the implications of Ausubel's theory to curriculum and teaching; "webbing," a specific…

  14. Neuroimaging of schizophrenia: structural abnormalities and pathophysiological implications

    PubMed Central

    Buckley, Peter F

    2005-01-01

    Schizophrenia, once considered a psychological malady devoid of any organic brain substrate, has been the focus of intense neuroimaging research. Findings reveal mild but generalized tissue loss as well as more selective focal loss. It is unclear whether these abnormalities reflect neurodevelopmental or neurodegenerative processes, or some combination of each; current evidence favors a preponderance of neurodevelopmental abnormalities. The pattern of brain abnormalities is also influenced by environmental and genetic risk factors, as well as by the course (and possibly even treatment) of this illness. These findings are described in this article. PMID:18568069

  15. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    NASA Astrophysics Data System (ADS)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  16. Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Qualitative changes in floral pollen protein have been shown to be an important aspect of pollinator health. Flowering late in the season, goldenrod (Solidago spp.), provides an essential autumnal source of floral pollen for wild bee and honeybee populations prior to winter, with tall or Canada gol...

  17. Analysis of the Postsecondary Training Certificate Program in Floral Design and Marketing at Florida Community College at Jacksonville.

    ERIC Educational Resources Information Center

    Gordon, Howard R. D.; Cooper, Sharon P.

    In 1990, a study was conducted at Florida Community College at Jacksonville (FCCJ) to determine enrollment, withdrawal, and placement patterns in the college's floral design and marketing certificate program and to identify changes needed to strengthen the program. The program focused on the theory and practice of floral design and marketing,…

  18. Speciation via floral heterochrony and presumed mycorrhizal host switching of endemic butterfly orchids on the Azorean archipelago.

    PubMed

    Bateman, Richard M; Rudall, Paula J; Bidartondo, Martin I; Cozzolino, Salvatore; Tranchida-Lombardo, Valentina; Carine, Mark A; Moura, Mónica

    2014-06-01

    • Premise of the study: Most orchid species native to the Macaronesian islands reflect immigration from western Europe or North Africa followed by anagenesis. The only putative exception is the butterfly orchids (Platanthera) of the Azores, where three species apparently reflect at least one cladogenetic speciation event. This multidisciplinary study explores the origin, speciation, phenotypic, and genotypic cohesion of these Azorean species and their mainland relatives.• Methods: Plants of Platanthera from 30 localities spanning all nine Azorean islands were compared with those of four continental European relatives for 38 morphometric characters; substantial subsets were also analyzed for plastid microsatellites, and for nrITS of both the orchids and their mycorrhizae.• Key results: Although the three Azorean and four mainland species are all readily distinguished morphometrically using several floral characters, and hybridization appears rare, divergence in ITS and especially plastid sequences is small. Despite occupying similar laurisilva habitats, the Azorean species differ radically in the identities and diversity of their mycorrhizal partners; specialism apparently increases rarity.• Conclusions: Although morphological evidence suggests two invasions of the islands from NW Africa and/or SW Europe, ITS data imply only one. As the molecular data are unable to distinguish among the potential mainland ancestors, two scenarios of relationship are explored that imply different ancestors. Both scenarios require both anagenetic and cladogenetic speciation events, involving homoplastic shifts in overall flower size and (often substantial) changes in the relative dimensions of individual floral organs. Limited genotypic divergence among the three species compared with greater phenotypic divergence suggests comparatively recent speciation. Mycorrhizae may be the most critical factor dictating the respective ecological tolerances, and thus the relative

  19. Bees use honest floral signals as indicators of reward when visiting flowers.

    PubMed

    Knauer, A C; Schiestl, F P

    2015-02-01

    Pollinators visit flowers for rewards and should therefore have a preference for floral signals that indicate reward status, so called 'honest signals'. We investigated honest signalling in Brassica rapa L. and its relevance for the attraction of a generalised pollinator, the bumble bee Bombus terrestris (L.). We found a positive association between reward amount (nectar sugar and pollen) and the floral scent compound phenylacetaldehyde. Bumble bees developed a preference for phenylacetaldehyde over other scent compounds after foraging on B. rapa. When foraging on artificial flowers scented with synthetic volatiles, bumble bees developed a preference for those specific compounds that honestly indicated reward status. These results show that the honesty of floral signals can play a key role in their attractiveness to pollinators. In plants, a genetic constraint, resource limitation in reward and signal production, and sanctions against cheaters may contribute to the evolution and maintenance of honest signalling. PMID:25491788

  20. Fragrance of Canada thistle (Cirsium arvense) attracts both floral herbivores and pollinators.

    PubMed

    Theis, Nina

    2006-05-01

    The evolution of floral scent as a plant reproductive signal is assumed to be driven by pollinator behavior, with little attention paid to other potential selective forces such as herbivores. I tested 10 out of the 13 compounds emitted by dioecious Cirsium arvense, Canada thistle, including 2-phenylethanol, methyl salicylate, p-anisaldehyde, benzaldehyde, benzyl alcohol, phenylacetaldehyde, linalool, furanoid linalool oxides (E and Z), and dimethyl salicylate. Single compounds (and one isomer) set out in scent-baited water-bowl traps trapped over 10 species of pollinators and 16 species of floral herbivores. The two dominant components of the fragrance blend of C. arvense, benzaldehyde and phenylacetaldehyde, trapped both pollinators and florivores. Other compounds attracted either pollinators or florivores. Florivores of C. arvense appear to use floral scent compounds as kairomones; by advertising to pollinators, C. arvense also attracts its own enemies. PMID:16739013

  1. A quantitative review of pollination syndromes: do floral traits predict effective pollinators?

    PubMed

    Rosas-Guerrero, Víctor; Aguilar, Ramiro; Martén-Rodríguez, Silvana; Ashworth, Lorena; Lopezaraiza-Mikel, Martha; Bastida, Jesús M; Quesada, Mauricio

    2014-03-01

    The idea of pollination syndromes has been largely discussed but no formal quantitative evaluation has yet been conducted across angiosperms. We present the first systematic review of pollination syndromes that quantitatively tests whether the most effective pollinators for a species can be inferred from suites of floral traits for 417 plant species. Our results support the syndrome concept, indicating that convergent floral evolution is driven by adaptation to the most effective pollinator group. The predictability of pollination syndromes is greater in pollinator-dependent species and in plants from tropical regions. Many plant species also have secondary pollinators that generally correspond to the ancestral pollinators documented in evolutionary studies. We discuss the utility and limitations of pollination syndromes and the role of secondary pollinators to understand floral ecology and evolution. PMID:24393294

  2. Structured floral arrangement programme for improving visuospatial working memory in schizophrenia

    PubMed Central

    Mochizuki-Kawai, Hiroko; Yamakawa, Yuriko; Mochizuki, Satoshi; Anzai, Shoko; Arai, Masanobu

    2010-01-01

    Several cognitive therapies have been developed for patients with schizophrenia. However, little is known about the outcomes of these therapies in terms of non-verbal/visuospatial working memory, even though this may affect patients’ social outcomes. In the present pilot study, we investigated the effect of a structured floral arrangement (SFA) programme, where participants were required to create symmetrical floral arrangements. In this programme, the arrangement pattern and the order of placing each of the natural materials was predetermined. Participants have to identify where to place each material, and memorise the position temporarily to complete the floral arrangement. The schizophrenic patients who participated in this programme showed significant improvement in their scores for a block-tapping task backward version; whereas, non-treated control patients did not show such an improvement. The present results suggest that the SFA programme may positively stimulate visuospatial working memory in patients. PMID:20467963

  3. Transgressive phenotypes and generalist pollination in the floral evolution of Nicotiana polyploids.

    PubMed

    McCarthy, Elizabeth W; Chase, Mark W; Knapp, Sandra; Litt, Amy; Leitch, Andrew R; Le Comber, Steven C

    2016-01-01

    Polyploidy is an important driving force in angiosperm evolution, and much research has focused on genetic, epigenetic and transcriptomic responses to allopolyploidy. Nicotiana is an excellent system in which to study allopolyploidy because half of the species are allotetraploids of different ages, allowing us to examine the trajectory of floral evolution over time. Here, we study the effects of allopolyploidy on floral morphology in Nicotiana, using corolla tube measurements and geometric morphometrics to quantify petal shape. We show that polyploid morphological divergence from the intermediate phenotype expected (based on progenitor morphology) increases with time for floral limb shape and tube length, and that most polyploids are distinct or transgressive in at least one trait. In addition, we show that polyploids tend to evolve shorter and wider corolla tubes, suggesting that allopolyploidy could provide an escape from specialist pollination via reversion to more generalist pollination strategies. PMID:27501400

  4. More lessons from linalool: insights gained from a ubiquitous floral volatile.

    PubMed

    Raguso, Robert A

    2016-08-01

    Linalool (3,7-dimethyl-1,6-octadien-3-ol) is a common floral volatile with two distinct enantiomers and related metabolites involved in the full spectrum of plant-pollinator interactions. Recent studies reveal a complex interplay between pollinator attraction and plant defense mediated by linalool and its derivatives, from the smallest (Arabidopsis, Mitella) to the largest (Datura) flowers studied. Accordingly, fig wasps, fungus gnats and moths of all sizes show remarkable electrophysiological, neural and behavioral sensitivity to different enantiomers and quantitative ratios of linalool in floral bouquets. The diverse functions of linalool, ranging from toxin to long distance pollinator attractant are discussed in the broader context of floral volatile ecology and evolution. PMID:27286000

  5. Normal and Abnormal Development in the Arabidopsis Vegetative Shoot Apex.

    PubMed Central

    Medford, JI; Behringer, FJ; Callos, JD; Feldmann, KA

    1992-01-01

    Vegetative development in the Arabidopsis shoot apex follows both sequential and repetitive steps. Early in development, the young vegetative meristem is flat and has a rectangular shape with bilateral symmetry. The first pair of leaf primordia is radially symmetrical and is initiated on opposite sides of the meristem. As development proceeds, the meristem changes first to a bilaterally symmetrical trapezoid and then to a radially symmetrical dome. Vegetative development from the domed meristem continues as leaves are initiated in a repetitive manner. Abnormal development of the vegetative shoot apex is described for a number of mutants. The mutants we describe fall into at least three classes: (1) lesions in the shoot apex that do not show an apparent alteration in the shoot apical meristem, (2) lesions in the apical meristem that also (directly or indirectly) alter leaf primordia, and (3) lesions in the apical meristem that alter meristem size and leaf number but not leaf morphology. These mutations provide tools both to genetically analyze vegetative development of the shoot apex and to learn how vegetative development influences floral development. PMID:12297656

  6. The effects of flower, floral display, and reward sizes on bumblebee foraging behavior when pollen is the reward and plants are dichogamous

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-pollinated plants have developed showy flowers and floral displays that attract pollinators. Pollinators, in turn, show preferences for specific floral traits and their foraging behavior is influenced by floral traits. In this study, we examined the preference of bumble bees for flower size, ...

  7. Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity.

    PubMed

    Stefanaki, Anastasia; Kantsa, Aphrodite; Tscheulin, Thomas; Charitonidou, Martha; Petanidou, Theodora

    2015-01-01

    The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant's proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant-pollinator specializations to identify plant species particularly at

  8. Floral volatile alleles can contribute to pollinator-mediated reproductive isolation in monkeyflowers (Mimulus)

    PubMed Central

    Byers, Kelsey J.R.P.; Vela, James P.; Peng, Foen; Riffell, Jeffrey A.; Bradshaw, H.D.

    2014-01-01

    Summary Pollinator-mediated reproductive isolation is a major factor in driving the diversification of flowering plants. Studies of floral traits involved in reproductive isolation have focused nearly exclusively on visual signals, such as flower color. The role of less obvious signals, such as floral scent, has been studied only recently. In particular, the genetics of floral volatiles involved in mediating differential pollinator visitation remains unknown. The bumblebee-pollinated Mimulus lewisii and hummingbird-pollinated M. cardinalis are a model system for studying reproductive isolation via pollinator preference. We have shown that these two species differ in three floral terpenoid volatiles - D-limonene, β-myrcene, and E-β-ocimene - that are attractive to bumblebee pollinators. By genetic mapping and in vitro enzyme activity analysis we demonstrate that these interspecific differences are consistent with allelic variation at two loci – LIMONENE-MYRCENE SYNTHASE (LMS) and OCIMENE SYNTHASE (OS). M. lewisii LMS (MlLMS) and OS (MlOS) are expressed most strongly in floral tissue in the last stages of floral development. M. cardinalis LMS (McLMS) is weakly expressed and has a nonsense mutation in exon 3. M. cardinalis OS (McOS) is expressed similarly to MlOS, but the encoded McOS enzyme produces no E-β-ocimene. Recapitulating the M. cardinalis phenotype by reducing the expression of MlLMS by RNAi in transgenic M. lewisii produces no behavioral difference in pollinating bumblebees; however, reducing MlOS expression produces a 6% decrease in visitation. Allelic variation at the OCIMENE SYNTHASE locus likely contributes to differential pollinator visitation, and thus promotes reproductive isolation between M. lewisii and M. cardinalis. OCIMENE SYNTHASE joins a growing list of “speciation genes” (“barrier genes”) in flowering plants. PMID:25319242

  9. Floral symmetry genes and the origin and maintenance of zygomorphy in a plant-pollinator mutualism.

    PubMed

    Zhang, Wenheng; Kramer, Elena M; Davis, Charles C

    2010-04-01

    The evolution of floral zygomorphy is an important innovation in flowering plants and is thought to arise principally from specialization on various insect pollinators. Floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to be caused by selection by its oil-bee pollinators. We sought to characterize the genetic basis of floral zygomorphy in Malpighiaceae by investigating CYCLOIDEA2-like (CYC2-like) genes, which are required for establishing symmetry in diverse core eudicots. We identified two copies of CYC2-like genes in Malpighiaceae, which resulted from a gene duplication in the common ancestor of the family. A likely role for these loci in the development of floral zygomorphy in Malpighiaceae is demonstrated by the conserved pattern of dorsal gene expression in two distantly related neotropical species, Byrsonima crassifolia and Janusia guaranitica. Further evidence for this function is observed in a Malpighiaceae species that has moved to the paleotropics and experienced coincident shifts in pollinators, floral symmetry, and CYC2-like gene expression. The dorsal expression pat-tern observed in Malpighiaceae contrasts dramatically with their actinomorphic-flowered relatives, Centroplacaceae (Bhesa paniculata) and Elatinaceae (Bergia texana). In particular, B. texana exhibits a previously undescribed pattern of uniform CYC2 expression, suggesting that CYC2 expression among the actinomorphic ancestors of zygomorphic lineages may be much more complex than previously thought. We consider three evolutionary models that may have given rise to this patterning, including the hypothesis that floral zygomorphy in Malpighiaceae arose earlier than standard morphology-based character reconstructions suggest. PMID:20363959

  10. Floral volatile alleles can contribute to pollinator-mediated reproductive isolation in monkeyflowers (Mimulus).

    PubMed

    Byers, Kelsey J R P; Vela, James P; Peng, Foen; Riffell, Jeffrey A; Bradshaw, Harvey D

    2014-12-01

    Pollinator-mediated reproductive isolation is a major factor in driving the diversification of flowering plants. Studies of floral traits involved in reproductive isolation have focused nearly exclusively on visual signals, such as flower color. The role of less obvious signals, such as floral scent, has been studied only recently. In particular, the genetics of floral volatiles involved in mediating differential pollinator visitation remains unknown. The bumblebee-pollinated Mimulus lewisii and hummingbird-pollinated Mimulus cardinalis are a model system for studying reproductive isolation via pollinator preference. We have shown that these two species differ in three floral terpenoid volatiles - d-limonene, β-myrcene, and E-β-ocimene - that are attractive to bumblebee pollinators. By genetic mapping and in vitro analysis of enzyme activity we demonstrate that these interspecific differences are consistent with allelic variation at two loci, LIMONENE-MYRCENE SYNTHASE (LMS) and OCIMENE SYNTHASE (OS). Mimulus lewisii LMS (MlLMS) and OS (MlOS) are expressed most strongly in floral tissue in the last stages of floral development. Mimulus cardinalis LMS (McLMS) is weakly expressed and has a nonsense mutation in exon 3. Mimulus cardinalis OS (McOS) is expressed similarly to MlOS, but the encoded McOS enzyme produces no E-β-ocimene. Recapitulating the M. cardinalis phenotype by reducing the expression of MlLMS by RNA interference in transgenic M. lewisii produces no behavioral difference in pollinating bumblebees; however, reducing MlOS expression produces a 6% decrease in visitation. Allelic variation at the OCIMENE SYNTHASE locus is likely to contribute to differential pollinator visitation, and thus promote reproductive isolation between M. lewisii and M. cardinalis. OCIMENE SYNTHASE joins a growing list of 'speciation genes' ('barrier genes') in flowering plants. PMID:25319242

  11. Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators.

    PubMed

    Queiroz, Joel A; Quirino, Zelma G M; Machado, Isabel C

    2015-01-01

    Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat-hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h(-1)) than in I. aff. marcellia (0.57 visits h(-1)), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h(-1) and I. aff. marcellia: 0.64 visits h(-1)). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat-hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

  12. Floral symmetry genes and the origin and maintenance of zygomorphy in a plant-pollinator mutualism

    PubMed Central

    Zhang, Wenheng; Kramer, Elena M.; Davis, Charles C.

    2010-01-01

    The evolution of floral zygomorphy is an important innovation in flowering plants and is thought to arise principally from specialization on various insect pollinators. Floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to be caused by selection by its oil-bee pollinators. We sought to characterize the genetic basis of floral zygomorphy in Malpighiaceae by investigating CYCLOIDEA2-like (CYC2-like) genes, which are required for establishing symmetry in diverse core eudicots. We identified two copies of CYC2-like genes in Malpighiaceae, which resulted from a gene duplication in the common ancestor of the family. A likely role for these loci in the development of floral zygomorphy in Malpighiaceae is demonstrated by the conserved pattern of dorsal gene expression in two distantly related neotropical species, Byrsonima crassifolia and Janusia guaranitica. Further evidence for this function is observed in a Malpighiaceae species that has moved to the paleotropics and experienced coincident shifts in pollinators, floral symmetry, and CYC2-like gene expression. The dorsal expression pat-tern observed in Malpighiaceae contrasts dramatically with their actinomorphic-flowered relatives, Centroplacaceae (Bhesa paniculata) and Elatinaceae (Bergia texana). In particular, B. texana exhibits a previously undescribed pattern of uniform CYC2 expression, suggesting that CYC2 expression among the actinomorphic ancestors of zygomorphic lineages may be much more complex than previously thought. We consider three evolutionary models that may have given rise to this patterning, including the hypothesis that floral zygomorphy in Malpighiaceae arose earlier than standard morphology-based character reconstructions suggest. PMID:20363959

  13. Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

    PubMed Central

    Queiroz, Joel A.; Quirino, Zelma G. M.; Machado, Isabel C.

    2015-01-01

    Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat–hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h−1) than in I. aff. marcellia (0.57 visits h−1), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h−1 and I. aff. marcellia: 0.64 visits h−1). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat–hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

  14. Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity

    PubMed Central

    Stefanaki, Anastasia; Kantsa, Aphrodite; Tscheulin, Thomas; Charitonidou, Martha; Petanidou, Theodora

    2015-01-01

    The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant—pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant’s proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant—pollinator specializations to identify plant species particularly

  15. Ultrastructure and post-floral secretion of the pericarpial nectaries of Erythrina speciosa (Fabaceae)

    PubMed Central

    Paiva, Elder Antônio Sousa

    2009-01-01

    Background and Aims The occurrence of nectaries in fruits is restricted to a minority of plant families and consistent reports of their occurrence are not found associated with Fabaceae, mainly showing cellular details. The present study aims to describe the anatomical organization and ultrastructure of the pericarpial nectaries (PNs) in Erythrina speciosa, a bird-pollinated species, discussing functional aspects of these unusual structures. Methods Samples of floral buds, ovaries of flowers at anthesis and fruits at several developmental stages were fixed and processed by the usual methods for studies using light, and scanning and transmission electron microscopy. Nectar samples collected by filter paper wicks were subjected to chemical analysis using thin-layer chromatography. Key Results The PNs are distributed in isolation on the exocarp. Each PN is represented by a single hyaline trichome that consists of a basal cell at epidermal level, stalk cell(s) and a small secretory multicellular head. The apical stalk cell shows inner periclinal and anticlinal walls impregnated by lipids and lignin and has dense cytoplasm with a prevalence of mitochondria and endoplasmic reticulum. The secretory cells show voluminous nuclei and dense cytoplasm, which predominantly has dictyosomes, rough endoplasmic reticulum, plastids, mitochondria and free ribosomes. At the secretory stage the periplasmic space is prominent and contains secretion residues. Tests for sugar indicate the presence of non-reducing sugars in the secretory cells. Nectar samples from PNs contained sucrose, glucose and fructose. Conclusions The secretory stage of these PNs extends until fruit maturation and evidence suggests that the energetic source of nectar production is based on pericarp photosynthesis. Patrolling ants were seen foraging on fruits during all stages of fruit development, which suggests that the PNs mediate a symbiotic relationship between ants and plant, similar to the common role of many

  16. Comparative floral spur anatomy and nectar secretion in four representatives of Ranunculaceae.

    PubMed

    Antoń, Sebastian; Kamińska, Magdalena

    2015-11-01

    Nectaries are common in Ranunculaceae. These secretory structures, however, have not been studied in detail despite their importance in plant-animal interactions, and data relating to the structure of nectary spurs, which are so characteristic of several genera of this family, remain scarce. In order to redress this imbalance, we sought, in the present paper, to analyze the anatomical and ultrastructural organization of the nectary spurs of four representatives of Ranunculaceae, i.e., Aconitum lycoctonum L., Aquilegia vulgaris L., Consolida regalis Gray, and Delphinium elatum L. Nectary spurs were examined using light, fluorescence, scanning electron, and transmission electron microscopy. The floral nectaries of A. lycoctonum and A. vulgaris are situated at the apices of the spurs, whereas in C. regalis and D. elatum, the nectary is located along the floor surface of the spurs. Nectar in C. regalis and D. elatum is exuded through micro-channels in the cuticle, whereas in A. lycoctonum and A. vulgaris, it is released by means of cell wall disruption, indicating that the method of nectar secretion here is holocrine. Structurally, the nectary of all four investigated species is quite similar, and its cells are typical of nectar-producing cells described in the literature. It is proposed that in A. lycoctonum and A. vulgaris, disruption of the cell wall and the release of the entire cell contents into the spur cavity contribute to the composition of the nectar that the latter contains, enriching it with cytoplasmic components. We conclude that the manner of nectar exudation may vary considerably between closely related plant species, regardless of their geographical origin and phylogeny. PMID:25772682

  17. Self-pollination rate and floral-display size in Asclepias syriaca (Common Milkweed) with regard to floral-visitor taxa

    PubMed Central

    2014-01-01

    Background Animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. Many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. In this study, we utilized the highly self-incompatible pollinium-pollination system of Asclepias syriaca (Common Milkweed) to quantify how insect visitors influenced male reproductive success measured as pollen removal, female reproductive success measured as pollen deposition, and self-pollination rate. We also determined how floral-display size impacts both visitor behavior and self-pollination rate. Results Four insect taxonomic orders visited A. syriaca: Coleoptera, Diptera, Hymenoptera, and Lepidoptera. We focused on three groups of visitor taxa within two orders (Hymenoptera and Lepidoptera) with sample sizes large enough for quantitative analysis: Apis mellifera (Western Honey Bee), Bombus spp. (bumble bees) and lepidopterans (butterflies and moths). Qualitatively, lepidopterans had the highest pollinator importance values, but the large variability in the lepidopteran data precluded meaningful interpretation of much of their behavior. The introduced A. mellifera was the most effective and most important diurnal pollinator with regard to both pollen removal and pollen deposition. However, when considering the self-incompatibility of A. syriaca, A. mellifera was not the most important pollinator because of its high self-pollination rate as compared to Bombus spp. Additionally, the rate of self-pollination increased more rapidly with the number of flowers per inflorescence in A. mellifera than in the native Bombus spp. Conclusions Apis mellifera’s high rate of self-pollination may have significant negative effects on both male

  18. Molecular abnormalities in Ewing's sarcoma.

    PubMed

    Burchill, Susan Ann

    2008-10-01

    Ewing's sarcoma is one of the few solid tumors for which the underlying molecular genetic abnormality has been described: rearrangement of the EWS gene on chromosome 22q12 with an ETS gene family member. These translocations define the Ewing's sarcoma family of tumors (ESFT) and provide a valuable tool for their accurate and unequivocal diagnosis. They also represent ideal targets for the development of tumor-specific therapeutics. Although secondary abnormalities occur in over 80% of primary ESFT the clinical utility of these is currently unclear. However, abnormalities in genes that regulate the G(1)/S checkpoint are frequently described and may be important in predicting outcome and response. Increased understanding of the molecular events that arise in ESFT and their role in the development and maintenance of the malignant phenotype will inform the improved stratification of patients for therapy and identify targets and pathways for the design of more effective cancer therapeutics. PMID:18925858

  19. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  20. [Emotion Disorders and Abnormal Perspiration].

    PubMed

    Umeda, Satoshi

    2016-08-01

    This article reviewed the relationship between emotional disorders and abnormal perspiration. First, I focused on local brain areas related to emotional processing, and summarized the functions of the emotional network involving those local areas. Functional disorders followed by the damage in the amygdala, orbitofrontal cortex, and insular cortex were reviewed, including related abnormal perspiration. I then addressed the mechanisms of how autonomic disorders influence emotional processing. Finally, possible future directions for integrated understanding of the connection between neural activities and bodily reactions were discussed. PMID:27503817

  1. Ultrasonographic assessment of abnormal pregnancy.

    PubMed

    England, G C

    1998-07-01

    Ultrasonographic imaging is widely used in small animal practice for the diagnosis of pregnancy and the determination of fetal number. Ultrasonography can also be used to monitor abnormal pregnancies, for example, conceptuses that are poorly developed for their gestational age (and therefore are likely to fail), and pregnancies in which there is embryonic resorption or fetal abortion. An ultrasound examination may reveal fetal abnormalities and therefore alter the management of the pregnant bitch or queen prior to parturition. There are, however, a number of ultrasonographic features of normal pregnancies that may mimic disease, and these must be recognized. PMID:9698618

  2. Selection by pollinators on floral traits in generalized Trollius ranunculoides (Ranunculaceae) along altitudinal gradients.

    PubMed

    Zhao, Zhi-Gang; Wang, Yi-Ke

    2015-01-01

    Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators. PMID:25692295

  3. Pollinators of the Rocky Mountain Columbine: Temporal Variation, Functional Groups and Association with Floral Traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollinators together with other biotic and some abiotic factors can select for floral traits. However, variation in pollinator abundance over time and space can weaken such selection. In this study, we examined the variation in pollinator abundance over time and space in populations of the rocky mou...

  4. Drought stress, plant water status, and floral trait expression in fireweed, Epilobium angustifolium (Onagraceae).

    PubMed

    Carroll, A B; Pallardy, S G; Galen, C

    2001-03-01

    In a controlled environment, we artificially induced drought during flowering of Epilobium angustifolium, an animal-pollinated plant. Leaf water potential (ψ(l)) and floral traits were monitored over a 12-d period of soil moisture depletion. Soil moisture depletion induced drought stress over time, as revealed by significant treatment × day interactions for predawn and midday ψ(l). Nectar volume and flower size showed significant negative responses to drought stress, but nectar sugar concentration did not vary between treatments. Floral traits were more buffered from drought than leaf water potentials. We used path analysis to examine direct and indirect effects of ψ(l) on floral traits for plants in well-watered (control) vs. drought treatments. According to the best-fit path models, midday ψ(l) has significant positive effects on flower size and nectar volume in both environments. However, for controls midday ψ(l) also had a significant negative effect on nectar sugar concentration. Results indicate that traits influencing floral attractiveness to pollinators in E. angustifolium vary with plant water status, such that pollinator-mediated selection could indirectly target physiological or biochemical controls on ψ(l). Moreover, under mesic conditions selection for greater nectar sugar reward may be constrained by the antagonistic effects of plant water status on nectar volume and sugar concentration. PMID:11250821

  5. Secondary compounds in floral rewards of toxic rangeland plants: Impacts on pollinators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study of plant secondary chemistry has been essential in understanding plant consumption by herbivores. There is growing evidence that secondary compounds also occur in floral rewards, including nectar and pollen. Many pollinators are generalist nectar and pollen foragers and thus are exposed to...

  6. Attraction of pest moths (Lepidoptera: Noctuidae, Crambidae) to floral lures on the island of Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traps baited with floral chemicals on the island of Hawaii captured several pest moth species. Chrysodeixis eriosoma (Doubleday)(green garden looper), Autographa biloba (Doubleday)(bi-lobed looper), and Mythimna unipuncta (Haworth)(true armyworm), all Noctuidae, as well as Hymenia recurvalis (L.)(be...

  7. 40 CFR 180.1127 - Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl alcohol, 4-methoxy cinnamaldehyde, 3-phenyl propanol, 4-methoxy phenethyl alcohol, indole, and 1,2,4-trimethoxybenzene; exemptions from the requirement of a tolerance. 180.1127 Section...

  8. Bearded-Ear Encodes a MADS-box Transcription Factor Critical for Maize Floral Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We cloned bde by positional cloning and found that it encodes zag3, a MADS-box transcription factor in the conserved AGL6 clade. Mutants in the maize homolog of AGAMOUS, zag1, have a subset of bde floral defects. bde; zag1 double mutants have a severe ear phenotype, not observed in either single m...

  9. Hydrology of the Floral City Pool of Tsala Apopka Lake, west-central Florida

    USGS Publications Warehouse

    Bradner, L.A.

    1988-01-01

    Tsala Apopka Lake, in west-central Florida, has an area of about 19,000 acres and is divided into three water-management pools, with the Floral City Pool, the most upgradient. The Floral City Pool, which has a surface area of approximately 4,750 acres, contains an extensive combination of lakes, wetlands, and connecting canals. The Pool receives inflow from the Withlacoochee River through two canals. Outflow is through one manmade canal and one natural slough. Canal flow is partially controlled by manmade structures. A cumulative deficit of 19.4 inches of rainfall from August 1984 through May 1985 reduced surface-water inflow to the Floral City Pool to about 0.5 cu ft/sec by May 1985. During May 1985, pool levels declined approximately 0.04 ft/day. By the end of May, there was no observable outflow. From June 1985 through September 1985, 39.8 inches of rainfall caused above-average inflow to the Floral City Pool and a pool-level increase of 6.2 ft. The inflow of 340 CFS nearly equaled the outflow of 338 CFS by the end of September. (USGS)

  10. Additive effects of pollinators and herbivores result in both conflicting and reinforcing selection on floral traits.

    PubMed

    Sletvold, Nina; Moritz, Kim K; Agren, Jon

    2015-01-01

    Mutualists and antagonists are known to respond to similar floral cues, and may thus cause opposing selection on floral traits. However, we lack a quantitative understanding of their independent and interactive effects. In a population of the orchid Gymnadenia conopsea, we manipulated the intensity of pollination and herbivory in a factorial design to examine whether both interactions influence selection on flowering phenology, floral display, and morphology. Supplemental hand-pollination increased female fitness by 31% and one-quarter of all plants were damaged by herbivores. Both interactions contributed to selection. Pollinators mediated selection for later flowering and herbivores for earlier flowering, while both selected for longer spurs. The strength of selection was similar for both agents, and their effects were additive. As a consequence, there was no. net selection on phenology, whereas selection on spur length was strong. The experimental results demonstrate that both pollinators and herbivores can markedly influence the strength of selection on flowering phenology and floral morphology, and cause both conflicting and reinforcing selection. They also indicate that the direction of selection on phenology will vary with the relative intensity of the mutualistic and antagonistic interaction, potentially resulting in both temporal and among-population variation in optimal flowering time. PMID:26236906

  11. Floral scent of Canada thistle and its potential as a generic insect attractant.

    PubMed

    El-Sayed, A M; Byers, J A; Manning, L M; Jürgens, A; Mitchell, V J; Suckling, D M

    2008-06-01

    The flowers of Canada thistle, Cirsium arvense (L.), attract a wide range of insects, including pollinators and herbivorous species. This attraction is primarily mediated by floral odor, which offers potential for developing generic insect attractants based on odor. In this study, we have analyzed the chemical composition of the volatiles produced by Canada thistle flowers. Nineteen floral compounds were identified in the headspace, including phenylacetaldehyde (55%), methyl salicylate (14%), dimethyl salicylate (8%), pyranoid linalool oxide (4.5%), and benzaldehyde (3.5%). Other minor compounds include benzyl alcohol, methylbenzoate, linalool, phenylethyl alcohol, furanoid linalool oxide, p-anisaldehyde, 2,6-dimethyl-1,3,5,7-octatetraene, benzylacetate, benzyl tiglate, (E,E)-alpha-farnesene, benzyl benzoate, isopropyl myristate, and 2-phenylethyl ester benzoic acid. The relative attractiveness of various doses of the main floral volatile compound phenylacetaldehyde (i.e., 10, 100, 200, and 400 mg) was tested for insect attraction. Both the total catch and the biodiversity of insect species trapped increased as the loading of phenylacetaldehyde increased. Volatiles were chosen from the odors from the flowers of Canada thistle and formulated and tested in the field. An 11-component blend was the most attractive of several floral blends tested. These findings indicate that chemical components of flower odors of Canada thistle can serve as a generic insect attractant for monitoring of invasive pest species. PMID:18613571

  12. Explaining the effects of floral density on flower visitor species composition.

    PubMed

    Essenberg, Carla J

    2013-03-01

    Floral density often influences the species composition of flower visitors. This variation in visitor species composition could have significant effects on pollination success and plant fitness but is poorly understood, especially in the many pollination guilds dominated by nonterritorial species. This article presents a foraging model that explores how flower visitors with diverse traits should distribute themselves across resource patches differing in floral density. The model predicts that species with low flower search speeds and low flower handling costs compared to those of competitors will usually dominate dense flower patches. In addition, among flower visitors that have lower energy expenditure rates while handling flowers than while traveling, species maximizing energetic efficiency are typically associated with dense flower patches, whereas those maximizing net rate of energy intake are associated with sparse patches. The model is able to predict some key aspects of a previously observed effect of floral density on species composition of flower visitors to the yellowflower tarweed (Holocarpha virgata). By providing insights into how flower visitors' traits shape the effects of floral density on the species composition of flower visitors, this study makes an important step towards understanding how pollinator diversity influences relationships between plant density and plant fitness. PMID:23448884

  13. Attraction of Plecia nearctica (dipter:bibionidae) to floral lures containing phenylacetaldehyde

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We observed that the floral odorant, phenylacetaldehyde (PAA), was attractive to both sexes of adult lovebugs (Plecia nearctica, Diptera: Bibionidae) in central and southern Florida. The addition of ß-myrcene and methyl salicylate to PAA did not improve the numbers of P. nearctica caught in delta tr...

  14. Supporting crop pollinators with floral resources: network-based phenological matching

    PubMed Central

    Russo, Laura; DeBarros, Nelson; Yang, Suann; Shea, Katriona; Mortensen, David

    2013-01-01

    The production of diverse and affordable agricultural crop species depends on pollination services provided by bees. Indeed, the proportion of pollinator-dependent crops is increasing globally. Agriculture relies heavily on the domesticated honeybee; the services provided by this single species are under threat and becoming increasingly costly. Importantly, the free pollination services provided by diverse wild bee communities have been shown to be sufficient for high agricultural yields in some systems. However, stable, functional wild bee communities require floral resources, such as pollen and nectar, throughout their active season, not just when crop species are in flower. To target floral provisioning efforts to conserve and support native and managed bee species, we apply network theoretical methods incorporating plant and pollinator phenologies. Using a two-year dataset comprising interactions between bees (superfamily Apoidea, Anthophila) and 25 native perennial plant species in floral provisioning habitat, we identify plant and bee species that provide a key and central role to the stability of the structure of this community. We also examine three specific case studies: how provisioning habitat can provide temporally continuous support for honeybees (Apis mellifera) and bumblebees (Bombus impatiens), and how resource supplementation strategies might be designed for a single genus of important orchard pollinators (Osmia). This framework could be used to provide native bee communities with additional, well-targeted floral resources to ensure that they not only survive, but also thrive. PMID:24101999

  15. Flowering synchrony and floral display size affect pollination success in a deceit-pollinated tropical orchid

    NASA Astrophysics Data System (ADS)

    Parra-Tabla, Victor; Vargas, Carlos F.

    2007-07-01

    ue to frequency-dependent negative selection, a strong relationship between reproductive phenology traits and pollination success is expected in deceit-pollinated species. This paper assesses the effects of floral display size on both female (fruit production) and male (pollen removal) pollination success in a population of the deceit-pollinated tropical orchid Myrmecophila christinae during two consecutive years (1998-1999). Low pollen removal (˜9% of total flowers) and fruit production values (˜3% of total flowers) were recorded during both years. As expected, binary logistic regressions showed a significant negative effect of floral synchrony, and a positive effect of floral display size on both male and female success, although these effects varied across years. Pollination rates in the field and in hand pollinations suggest a doubling in pollinator abundance between years. Results suggest that floral display size and flowering synchrony are of adaptive value for M. christinae. However, between-year fluctuations might indicate that reproductive phenology traits in deceit-pollinated species undergo fluctuating selection regimes among years and are probably linked to short-term changes in environmental (abiotic and biotic) conditions.

  16. Soybean and Tobacco Floral nectary Glands: their Structural and Functional Similarities and Differences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect attraction and pollination of flowers are controlled by characters such as: color (visual cue); shape (accommodation); opening and pollen dehiscence (timing); volatiles production (smell); and nectar secretion from nectary glands (reward). The floral nectary and its secretion products are tw...

  17. Aphid Sex Pheromone Compounds Interfere with Attraction of Common Green Lacewings to Floral Bait.

    PubMed

    Koczor, Sándor; Szentkirályi, Ferenc; Pickett, John A; Birkett, Michael A; Tóth, Miklós

    2015-06-01

    Common green lacewings (Chrysoperla carnea complex) form a group of generalist predators important for biological control. Several reports show attraction of these insects to plant volatiles, and a highly attractive ternary compound floral bait has been developed. With aphids being a preferred prey of larvae, one might expect these lacewings to be attracted to aphid semiochemicals, for instance, to aphid sex pheromones, as found for several other green lacewing species. However, in a previous study, we found that traps containing aphid sex pheromone compounds (1R,4aS,7S,7aR)-nepetalactol (NEPOH), (4aS,7S,7aR)-nepetalactone (NEPONE), and a ternary floral bait attracted fewer individuals than those containing the ternary floral bait alone. In the present study, possible causes for this effect of NEPOH and NEPONE on trap capture were studied. We established that C. carnea complex catches in traps with a ternary floral lure were not influenced by the presence of Chrysopa formosa individuals in traps (attracted by NEPOH and NEPONE) or by synthetic skatole (a characteristic component of Chrysopa defense secretion). A direct negative effect of NEPOH and NEPONE on attraction of C. carnea complex was found, suggesting active avoidance of these aphid sex pheromone components. This finding is surprising as the larvae of these lacewings prey preferentially on aphids. Possible mechanisms underlying this phenomenon are discussed. PMID:25956798

  18. Comparing different floral resources on the longevity of a parasitic wasp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nectar and pollen are natural means of enhancing the longevity and reproductive success of beneficial insects. Pest suppression strategies that use vegetation management may eliminate floral resources, and thus an important food source for beneficial insects. Successful integration of biological c...

  19. Floral Trait Associations in Hawkmoth-Specialized and Mixed Pollination Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variation in floral traits including odor, color and morphology, demonstrate the selective pressures imposed by specific pollinator taxa, such as insects and birds. In southern Arizona, Manduca sexta (Sphingidae) hawkmoths are associated with Datura wrightii (Solanaceae) at both the larval (herbivo...

  20. Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton (Gossypium hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glu...

  1. Nectar Sugar Production across Floral Phases in the Gynodioecious Protandrous Plant Geranium sylvaticum

    PubMed Central

    Varga, Sandra; Nuortila, Carolin; Kytöviita, Minna-Maarit

    2013-01-01

    Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar production in nectar standing crop and secretion rate were investigated in Geranium sylvaticum, a gynodioecious plant species with protandry (i.e. with hermaphrodite flowers releasing their pollen before the stigma is receptive). We found that flowers from hermaphrodites produced more nectar than female flowers in terms of total nectar sugar content. In addition, differences in nectar production among floral phases were found in hermaphrodite flowers but not in female flowers. In hermaphrodite flowers, maximum sugar content coincided with pollen presentation and declined slightly towards the female phase, indicating nectar reabsorption, whereas in female flowers sugar content did not differ between the floral phases. These differences in floral reward are discussed in relation to visitation patterns by pollinators and seed production in this species. PMID:23614053

  2. Attractiveness of floral compounds to male and female moths in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluation of combinations of flower odor compounds in the field revealed several chemicals that were attractive or co-attractive with phenylacetaldehyde (PAA) to pest noctuid and pyralid moths. A number of moth species responded positively to PAA. The floral odorants cis-jasmone, linalool, benzyl a...

  3. Attractiveness of binary blends of floral odorant compounds to moths in Florida, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluation of combinations of flower odor compounds in the field revealed several chemicals that were attractive or co-attractive with phenylacetaldehyde (PAA) to pest noctuid and pyralid moths. A number of moth species responded positively to PAA. The floral odorants cis-jasmone, linalool, benzyl...

  4. A PRELIMINARY STUDY OF FLORAL NECTARY STRUCTURE AND DEVELOPMENT IN GLYCINE MAX L. MERR. (LEGUMINOSAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The floral nectary of the cultivated, annual Glycine max develops from ground tissue in the young flower into a circular mound at the base of the gynoecium. The position of the nectary places it above the flower pedicel and a large mass of cells that are innervated by vascular tissue. Many non-vasc...

  5. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops.

    PubMed

    Rodrigues, L C; Rodrigues, M

    2015-01-01

    Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality. PMID:25945619

  6. Teaching Flower Structure & Floral Formulae--A Mix of the Real & Virtual Worlds

    ERIC Educational Resources Information Center

    Burrows, Geoff

    2010-01-01

    The study of flower structure is essential in plant identification and in understanding sexual reproduction in plants, pollination syndromes, plant breeding, and fruit structure. Thus, study of flower structure and construction of floral formulae are standard parts of first-year university botany and biology courses. These activities involve…

  7. Floral scent of Canada thistle, and its potential as a generic insect attractant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flowers of Canada thistles, Cirsium arvense (L.)attract a wide range of insects including pollinators and herbivorous species. This attraction is primarily mediated by floral odor, which offers potential for developing generic insect attractants based on odor. In this study we have analyzed the ...

  8. Interspecific mouthpart length variation and floral visitation in the parasitic wasp genus Agathirsia (Braconidae: Agathidinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrate energy sources are known to be important for many adult parasitic wasps. Floral visitation is commonly observed and the occurrence of specialized mouth part morphology associated with deep nectar extraction exists in many groups. In parasitic wasps, it is not well established what, if...

  9. Chromosomal abnormalities associated with cyclopia and synophthalmia.

    PubMed Central

    Howard, R O

    1977-01-01

    At the present time, essentially all known facts concerning cyclopia are consistent with some chromosomal disease, including clinical features of the pregnancy (fetal wastage, prematurity, intrauterine growth retardation, maternal age factor, complications of pregnancy), the generalized developmental abnormalities, specific ocular dysgenesis, by the high incidence of chromosomal abnormality already demonstrated, and the possibility of error in those cases of cyclopia with normal chromosomes. Even if chromosomal aberrations represent only one group of several different etiologic factors leading to cyclopia, at the present time chromosomal errors would seem to be the most common cause of cyclopia now recognized. Further studies will establish or disprove a chromosomal error in those instances which are now considered to be the result of an environmental factor alone or those with apparent familial patterns of inheritance. This apparent diverse origin of cyclopia can be clarified if future cyclopic specimens are carefully investigated. The evaluation should include a careful gross and microscopic examination of all organs, including the eye, and chromosome banding studies of all organs, including the eye, and chromosome banding studies of at least two cyclopic tissues. Then the presence or absence of multiple causative factors can be better evaluated. Images FIGURE 2 A FIGURE 2 B FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 1 D FIGURE 1 E FIGURE 1 F FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B FIGURE 4 C FIGURE 4 D FIGURE 5 FIGURE 6 FIGURE 7 A FIGURE 7 B PMID:418547

  10. Floral divergence, pollinator partitioning and the spatiotemporal pattern of plant-pollinator interactions in three sympatric Adenophora species.

    PubMed

    Liu, Chang-Qiu; Huang, Shuang-Quan

    2013-12-01

    Floral divergence among congeners may relate to differential utilization of pollinators and contribute to reducing overlap in pollination niches. To investigate whether and how floral differences are associated with differential utilization of pollinators in three sympatric Adenophora species, we analyzed floral traits and evaluated the contribution of different visitors to pollination. We compared visitation rates of different pollinator categories in different years and sites. A suite of floral traits differed among the three Adenophora species, suggesting adaptation to diurnal versus nocturnal pollination and an intermediate condition. However, many visitor species were shared among the three plant species, suggesting that floral traits did not rigorously filter visitors. Effective pollinators were large bees and moths. The importance of large bees as pollinators decreased whereas that of moths increased along the gradient from typically bee-pollinated to moth-pollinated flowers. The intermediate species (A. khasiana) differed substantially from the other two species in pollinator species but not in pollinator categories. The principal pollinator category of each species was constant across years and sites except in the intermediate species where it differed between two sites. Overall, the three sympatric species of Adenophora partition pollinators by floral divergence and the principal pollinators coincide with the predictions based on floral syndromes. PMID:23824141

  11. A pollinator shift explains floral divergence in an orchid species complex in South Africa

    PubMed Central

    Peter, Craig I.; Johnson, Steven D.

    2014-01-01

    Background and Aims Floral diversification driven by shifts between pollinators has been one of the key explanations for the radiation of angiosperms. According to the Grant–Stebbins model of pollinator-driven speciation, these shifts result in morphologically distinct ‘ecotypes’ which may eventually become recognizable as species. The current circumscription of the food-deceptive southern African orchid Eulophia parviflora encompasses a highly variable monophyletic species complex. In this study, two forms were identified within this complex that differ in distribution, floral morphology, scent chemistry and phenology, and a test was made of whether these differences represent adaptations for different pollinators. Methods and Results Multivariate analysis of floral and vegetative traits revealed that there are at least two discrete morphological forms in the species complex. Field observations revealed that each form is pollinated by a different insect species, and thus represent distinct ecotypes. The early-flowering coastal form which has long spurs and floral scent dominated by sesquiterpene compounds is pollinated exclusively by the long-tongued bee Amegilla fallax (Apidae, Anthophorinae), while the late-flowering inland form with short spurs and floral scent dominated by benzenoid compounds is pollinated exclusively by the beetle Cyrtothyrea marginalis (Cetoniinae; Scarabaeidae). Choice experiments in a Y-maze olfactometer showed that beetles are preferentially attracted to the scent of the short-spurred form. A spur-shortening experiment showed that long spurs are required for effective pollination of the bee-pollinated form. Although it was initially thought likely that divergence occurred across a geographical pollinator gradient, plants of the long-spurred form were effectively pollinated when transplanted to an inland locality outside the natural coastal range of this form. Thus, the underlying geographical basis for the evolution of ecotypes in

  12. Comparative anatomy of floral elaiophores in Vitekorchis Romowicz & Szlach., Cyrtochilum Kunth and a florally dimorphic species of Oncidium Sw. (Orchidaceae: Oncidiinae)

    PubMed Central

    Davies, Kevin L.; Stpiczyńska, Małgorzata; Rawski, Michał

    2014-01-01

    Background and Aims Recently, molecular approaches have been used to investigate the phylogeny of subtribe Oncidiinae, resulting in the re-alignment of several of its genera. Here, a description is given of the structure of the floral elaiophores (oil glands) of four species formerly assigned to Oncidium Sw. Those of Vitekorchis excavata (Lindl.) Romowicz & Szlach., Cyrtochilum meirax (Rchb.f.) Dalström and a species of Oncidium displaying floral dimorphism, namely O. heteranthum Poepp. & Endl. var. album, are compared with that of Gomesa longipes (Lindl.) M.W. Chase & N.H. Williams, whose epithelial elaiophores are typical of many Oncidiinae, in order to extend our understanding of elaiophore diversity within this subtribe. Methods Floral elaiophore structure was examined and compared at anthesis for all four species using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. Key Results In all species investigated, with the exception of C. meirax, the floral elaiophore occurs on the labellar callus and is of the intermediate type, possessing both glabrous and trichomatous regions. By contrast, although all four species produce lipid secretions, C. meirax lacks an obvious elaiophore. In each case, the secretory tissue is represented by a single-layered epidermis of cuboidal cells (trichomatous and/or atrichomatous). Palisade cells are absent. The secretion may be wax- or oil-like and is usually produced by smooth endoplasmic reticulum (SER). However, in C. meirax, where rough endoplasmic reticulum (RER) predominates, oil accumulates as plastoglobuli within elaioplasts. These plastoglobuli are then discharged into the cytoplasm, forming oil bodies. In some species, oil usually accumulates within vesicles at the plasmalemma or in the periplasmic space before traversing the cell wall and accumulating beneath the cuticle, sometimes with distension of the latter. Gomesa longipes is unusual in its production of a

  13. Pollination syndromes in a Caatinga plant community in northeastern Brazil: seasonal availability of floral resources in different plant growth habits.

    PubMed

    Quirino, Z G M; Machado, I C

    2014-02-01

    To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Brazil (7° 28' 45″ S and 36° 54' 18″ W), during two years. Flowering was monitored monthly in all the species, over two years (from January 2003 to December 2004). Pollination syndromes were characterised based on floral traits such as size, colour, morphology, symmetry, floral resources, as well as on direct visual observation of floral visitors on focal plants and published information. We observed differences among the plant growth habits with respect to floral traits, types of resources offered, and floral syndromes. The flowering periods of the species varied among floral syndrome groups. The majority of the melittophilous species flowered during the rainy season in the two study years, while the species of the other pollination syndroms flowered at the end of the dry season. An asynchrony of flowering was noted among the chiropterophilous species, while the phalenophilous group concentrated during the rainy season. The overall availability of floral resources was different during the rainy and the dry seasons, and also it varied among plants with different growth habits. The availability of oil-flowers coincided with the period of low nectar availability. We observed a relationship between the temporal distribution of the pollination syndromes and the availability of floral resources among each growth habits in this tropical ecosystem. Resource allocation in seasonal environments, such as the Caatinga, can function as a strategy for maintaining pollinators, facilitating therefore the reproductive success of plant species. The availability of floral resources during

  14. The application of low frequency longitudinal guided wave mode for the inspection of multi-hole steel floral pipes

    NASA Astrophysics Data System (ADS)

    Liu, Z. H.; Xie, X. D.; Wu, B.; Li, Y. H.; He, C. F.

    2012-03-01

    Shed-pipe grouting technology, an effective advanced supporting method, is often used in the excavation of soft strata. Steel floral pipes are one of the key load-carrying components of shed-pipe grouting supporting structures. Guided waves are a very attractive methodology to inspect multi-hole steel floral pipes as they offer long range inspection capability, mode and frequency tuning, and cost effectiveness. In this contribution, preliminary experiments are described for the inspection of steel floral pipes using a low frequency longitudinal guided wave mode, L(0,2). The relation between the number of grouting holes and the peak-to-peak amplitude of the first end-reflected signal was obtained. The effect of the grouting holes in steel floral pipes on the propagation velocity of the L(0,2) mode at 30 kHz was analyzed. Experimental results indicate that the typical grouting holes in steel floral pipe have no significant effect on the propagation of this mode. As a result, low frequency longitudinal guided wave modes have potential for the non-destructive long range inspection of multi-hole steel floral pipes. Furthermore, the propagation velocity of the investigated L(0,2) mode at 30 kHz decreases linearly with the increase of the number of grouting holes in a steel floral pipe. It is also noticeable that the effect of the grouting holes cumulates along with the increase in the number of grouting holes and subsequent increase in reflection times of longitudinal guided waves in the steel floral pipe. The application potential of the low frequency longitudinal guided wave technique for the inspection of embedded steel floral pipes is discussed.

  15. Loss-of-Function and Gain-of-Function Mutations in FAB1A/B Impair Endomembrane Homeostasis, Conferring Pleiotropic Developmental Abnormalities in Arabidopsis1[C][W][OA

    PubMed Central

    Hirano, Tomoko; Matsuzawa, Tomohiko; Takegawa, Kaoru; Sato, Masa H.

    2011-01-01

    In eukaryotic cells, PtdIns 3,5-kinase, Fab1/PIKfyve produces PtdIns (3,5) P2 from PtdIns 3-P, and functions in vacuole/lysosome homeostasis. Herein, we show that expression of Arabidopsis (Arabidopsis thaliana) FAB1A/B in fission yeast (Schizosaccharomyces pombe) fab1 knockout cells fully complements the vacuole morphology phenotype. Subcellular localizations of FAB1A and FAB1B fused with green fluorescent protein revealed that FAB1A/B-green fluorescent proteins localize to the endosomes in root epidermal cells of Arabidopsis. Furthermore, reduction in the expression levels of FAB1A/B by RNA interference impairs vacuolar acidification and endocytosis. These results indicate that Arabidopsis FAB1A/B functions as PtdIns 3,5-kinase in plants and in fission yeast. Conditional knockdown mutant shows various phenotypes including root growth inhibition, hyposensitivity to exogenous auxin, and disturbance of root gravitropism. These phenotypes are observed also in the overproducing mutants of FAB1A and FAB1B. The overproducing mutants reveal additional morphological phenotypes including dwarfism, male-gametophyte sterility, and abnormal floral organs. Taken together, this evidence indicates that imbalanced expression of FAB1A/B impairs endomembrane homeostasis including endocytosis, vacuole formation, and vacuolar acidification, which causes pleiotropic developmental phenotypes mostly related to the auxin signaling in Arabidopsis. PMID:21173023

  16. Extracellular Matrix Abnormalities in Schizophrenia

    PubMed Central

    Berretta, Sabina

    2011-01-01

    Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission. PMID:21856318

  17. Evolution of pollination niches and floral divergence in the generalist plant Erysimum mediohispanicum

    PubMed Central

    Gómez, J. M.; Muñoz-Pajares, A. J.; Abdelaziz, M.; Lorite, J.; Perfectti, F.

    2014-01-01

    Background and Aims How generalist plants diverge in response to pollinator selection without becoming specialized is still unknown. This study explores this question, focusing on the evolution of the pollination system in the pollination generalist Erysimum mediohispanicum (Brassicaceae). Methods Pollinator assemblages were surveyed from 2001 to 2010 in 48 geo-referenced populations covering the entire geographic distribution of E. mediohispanicum. Bipartite modularity, a complex network tool, was used to find the pollination niche of each population. Evolution of the pollination niches and the correlated evolution of floral traits and pollination niches were explored using within-species comparative analyses. Key Results Despite being generalists, the E. mediohispanicum populations studied can be classified into five pollination niches. The boundaries between niches were not sharp, the niches differing among them in the relative frequencies of the floral visitor functional groups. The absence of spatial autocorrelation and phylogenetic signal indicates that the niches were distributed in a phylogeographic mosaic. The ancestral E. mediohispanicum populations presumably belonged to the niche defined by a high number of beetle and ant visits. A correlated evolution was found between pollination niches and some floral traits, suggesting the existence of generalist pollination ecotypes. Conclusions It is conjectured that the geographic variation in pollination niches has contributed to the observed floral divergence in E. mediohispanicum. The process mediating this floral divergence presumably has been adaptive wandering, but the adaptation to the local pollinator faunas has been not universal. The outcome is a landscape where a few populations locally adapted to their pollination environment (generalist pollination ecotypes) coexist with many populations where this local adaptation has failed and where the plant phenotype is not primarily shaped by pollinators. PMID

  18. Floral traits mediate the vulnerability of aloes to pollen theft and inefficient pollination by bees

    PubMed Central

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

    2012-01-01

    Background and Aims Pollen-collecting bees are among the most important pollinators globally, but are also the most common pollen thieves and can significantly reduce plant reproduction. The pollination efficiency of pollen collectors depends on the frequency of their visits to female(-phase) flowers, contact with stigmas and deposition of pollen of sufficient quantity and quality to fertilize ovules. Here we investigate the relative importance of these components, and the hypothesis that floral and inflorescence characteristics mediate the pollination role of pollen collection by bees. Methods For ten Aloe species that differ extensively in floral and inflorescence traits, we experimentally excluded potential bird pollinators to quantify the contributions of insect visitors to pollen removal, pollen deposition and seed production. We measured corolla width and depth to determine nectar accessibility, and the phenology of anther dehiscence and stigma receptivity to quantify herkogamy and dichogamy. Further, we compiled all published bird-exclusion studies of aloes, and compared insect pollination success with floral morphology. Key Results Species varied from exclusively insect pollinated, to exclusively bird pollinated but subject to extensive pollen theft by insects. Nectar inaccessibility and strong dichogamy inhibited pollination by pollen-collecting bees by discouraging visits to female-phase (i.e. pollenless) flowers. For species with large inflorescences of pollen-rich flowers, pollen collectors successfully deposited pollen, but of such low quality (probably self-pollen) that they made almost no contribution to seed set. Indeed, considering all published bird-exclusion studies (17 species in total), insect pollination efficiency varied significantly with floral shape. Conclusions Species-specific floral and inflorescence characteristics, especially nectar accessibility and dichogamy, control the efficiency of pollen-collecting bees as pollinators of aloes

  19. Historical nectar assessment reveals the fall and rise of floral resources in Britain.

    PubMed

    Baude, Mathilde; Kunin, William E; Boatman, Nigel D; Conyers, Simon; Davies, Nancy; Gillespie, Mark A K; Morton, R Daniel; Smart, Simon M; Memmott, Jane

    2016-02-01

    There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation. PMID:26842058

  20. Pollinator Competition as a Driver of Floral Divergence: An Experimental Test.

    PubMed

    Temeles, Ethan J; Newman, Julia T; Newman, Jennifer H; Cho, Se Yeon; Mazzotta, Alexandra R; Kress, W John

    2016-01-01

    Optimal foraging models of floral divergence predict that competition between two different types of pollinators will result in partitioning, increased assortative mating, and divergence of two floral phenotypes. We tested these predictions in a tropical plant-pollinator system using sexes of purple-throated carib hummingbirds (Anthracothorax jugularis) as the pollinators, red and yellow inflorescence morphs of Heliconia caribaea as the plants, and fluorescent dyes as pollen analogs in an enclosed outdoor garden. When foraging alone, males exhibited a significant preference for the yellow morph of H. caribaea, whereas females exhibited no preference. In competition, males maintained their preference for the yellow morph and through aggression caused females to over-visit the red morph, resulting in resource partitioning. Competition significantly increased within-morph dye transfer (assortative mating) relative to non-competitive environments. Competition and partitioning of color morphs by sexes of purple-throated caribs also resulted in selection for floral divergence as measured by dye deposition on stigmas. Red and yellow morphs did not differ significantly in dye deposition in the competition trials, but differences in dye deposition and preferences for morphs when sexes of purple-throated caribs foraged alone implied fixation of one or the other color morph in the absence of competition. Competition also resulted in selection for divergence in corolla length, with the red morph experiencing directional selection for longer corollas and the yellow morph experiencing stabilizing selection on corolla length. Our results thus support predictions of foraging models of floral divergence and indicate that pollinator competition is a viable mechanism for divergence in floral traits of plants. PMID:26814810

  1. Realized tolerance to nectar robbing: compensation to floral enemies in Ipomopsis aggregata

    PubMed Central

    Irwin, Rebecca E.

    2009-01-01

    Background and Aims Although the ecological and evolutionary consequences of foliar herbivory are well understood, how plants cope with floral damage is less well explored. Here the concept of tolerance, typically studied within the context of plant defence to foliar herbivores and pathogens, is extended to floral damage. Variation in tolerance to floral damage is examined, together with some of the mechanisms involved. Methods The study was conducted on Ipomopsis aggregata, which experiences floral damage and nectar removal by nectar-robbing bees. High levels of robbing can reduce seeds sired and produced by up to 50 %, an indirect effect mediated through pollinator avoidance of robbed plants. Using an experimental common garden with groups of I. aggregata, realized tolerance to robbing was measured. Realized tolerance included both genetic and environmental components of tolerance. It was hypothesized that both resource acquisition and storage traits, and traits involved in pollination would mitigate the negative effects of robbers. Key Results Groups of I. aggregata varied in their ability to tolerate nectar robbing. Realized tolerance was observed only through a component of male plant reproduction (pollen donation) and not through components of female plant reproduction. Some groups fully compensated for robbing while others under- or overcompensated. Evidence was found only for a pollination-related trait, flower production, associated with realized tolerance. Plants that produced more flowers and that had a higher inducibility of flower production following robbing were more able to compensate through male function. Conclusions Variation in realized tolerance to nectar robbing was found in I. aggregata, but only through an estimate of male reproduction, and traits associated with pollination may confer realized tolerance to robbing. By linking concepts and techniques from studies of plant–pollinator and plant–herbivore interactions, this work provides

  2. Historical nectar assessment reveals the fall and rise of floral resources in Britain

    NASA Astrophysics Data System (ADS)

    Baude, Mathilde; Kunin, William E.; Boatman, Nigel D.; Conyers, Simon; Davies, Nancy; Gillespie, Mark A. K.; Morton, R. Daniel; Smart, Simon M.; Memmott, Jane

    2016-02-01

    There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation.

  3. Pollinator Competition as a Driver of Floral Divergence: An Experimental Test

    PubMed Central

    Temeles, Ethan J.; Newman, Julia T.; Newman, Jennifer H.; Cho, Se Yeon; Mazzotta, Alexandra R.; Kress, W. John

    2016-01-01

    Optimal foraging models of floral divergence predict that competition between two different types of pollinators will result in partitioning, increased assortative mating, and divergence of two floral phenotypes. We tested these predictions in a tropical plant-pollinator system using sexes of purple-throated carib hummingbirds (Anthracothorax jugularis) as the pollinators, red and yellow inflorescence morphs of Heliconia caribaea as the plants, and fluorescent dyes as pollen analogs in an enclosed outdoor garden. When foraging alone, males exhibited a significant preference for the yellow morph of H. caribaea, whereas females exhibited no preference. In competition, males maintained their preference for the yellow morph and through aggression caused females to over-visit the red morph, resulting in resource partitioning. Competition significantly increased within-morph dye transfer (assortative mating) relative to non-competitive environments. Competition and partitioning of color morphs by sexes of purple-throated caribs also resulted in selection for floral divergence as measured by dye deposition on stigmas. Red and yellow morphs did not differ significantly in dye deposition in the competition trials, but differences in dye deposition and preferences for morphs when sexes of purple-throated caribs foraged alone implied fixation of one or the other color morph in the absence of competition. Competition also resulted in selection for divergence in corolla length, with the red morph experiencing directional selection for longer corollas and the yellow morph experiencing stabilizing selection on corolla length. Our results thus support predictions of foraging models of floral divergence and indicate that pollinator competition is a viable mechanism for divergence in floral traits of plants. PMID:26814810

  4. A comparative survey of floral characters in Capanemia Barb. Rodr. (Orchidaceae: Oncidiinae)

    PubMed Central

    Buzatto, Cristiano Roberto; Davies, Kevin L.; Singer, Rodrigo B.; Pires dos Santos, Rinaldo; van den Berg, Cássio

    2012-01-01

    Background and Aims Capanemia Barb. Rodr. comprises seven species that mostly inhabit the Brazilian Atlantic Rain Forest domain. The genus currently consists of two sections: Capanemia Cogn. and Planifolia Pabst, distinguished on the basis of leaf shape. We compare the floral morphology and anatomy of all species to determine whether separation into sections is supported by floral characters. Methods Both fresh flowers and herbarium specimens were investigated, and column and pollinarium features, together with the presence or absence of floral rewards, recorded. Anatomical features were examined using both light microscopy and scanning electron microscopy. Key Results and Conclusions With the sole exception of Capanemia therezae, all species shared a distinctive set of floral characters. Flowers were mostly white or yellowish-white and fragrant, and column wings were positioned parallel to the labellum, concealing the stigmatic cavity. Pollinaria had proportionally long tegular stipes and clavate to reniform pollinia, whereas the labellum possessed a conspicuous indument of trichomes, but was devoid of nectar or any other secretion that might function as a food-reward. Capanemia therezae, however, was exceptional in having greenish, unscented flowers with short, rounded and divergent column wings and an exposed stigmatic cavity. Its pollinaria had proportionally short tegular stipes and round pollinia, whereas the labellum lacked trichomes. Droplets of nectar were evident on the adaxial surface of the labellum, adjacent to the callus. Floral features did not support the currently accepted sectional division of Capanemia. If ongoing phylogenetic studies demonstrate that both sections are indeed monophyletic, then these taxa should be distinguished solely on the basis of foliar features. PMID:21937482

  5. Floral Traits and Pollination Systems in the Caatinga, a Brazilian Tropical Dry Forest

    PubMed Central

    Machado, Isabel Cristina; Lopes, Ariadna Valentina

    2004-01-01

    • Background and aims Pollination is a critical stage in plant reproduction and thus in the maintenance and evolution of species and communities. The Caatinga is the fourth largest ecosystem in Brazil, but despite its great extent and its importance few studies providing ecological information are available, with a notable lack of work focusing on pollination biology. Here, general data are presented regarding the frequency of pollination systems within Caatinga communities, with the aim of characterizing patterns related to floral attributes in order to make possible comparisons with data for plant communities in other tropical areas, and to test ideas about the utility of syndromes. This paper also intends to provide a reference point for further studies on pollination ecology in this threatened ecosystem. • Methods The floral traits and the pollination systems of 147 species were analysed in three areas of Caatinga vegetation in northeastern Brazil, and compared with world-wide studies focusing on the same subject. For each species, floral attributes were recorded as form, size, colour, rewards and pollination units. The species were grouped into 12 guilds according to the main pollinator vector. Analyses of the frequencies of the floral traits and pollination systems were undertaken. • Key Results Nectar and pollen were the most common floral resources and insect pollination was the most frequent, occurring in 69·9 % of the studied species. Of the entomophilous species, 61·7 % were considered to be melittophilous (43·1 % of the total). Vertebrate pollination occurred in 28·1 % of the species (ornithophily in 15·0 % and chiropterophily in 13·1 %), and anemophily was recorded in only 2·0 %. • Conclusions The results indicated that the pollination systems in Caatinga, despite climatic restrictions, are diversified, with a low percentage of generalist flowers, and similar to other tropical dry and wet forest communities, including those with high

  6. Isolation and Functional Analyses of a Putative Floral Homeotic C-Function Gene in a Basal Eudicot London Plane Tree (Platanus acerifolia)

    PubMed Central

    Liu, Guofeng; Bao, Manzhu

    2013-01-01

    The identification of mutants in model plant species has led to the isolation of the floral homeotic function genes that play crucial roles in flower organ specification. However, floral homeotic C-function genes are rarely studied in basal eudicots. Here, we report the isolation and characterization of the AGAMOUS (AG) orthologous gene (PaAG) from a basal eudicot London plane tree (Platanus acerifolia Willd). Phylogenetic analysis showed that PaAG belongs to the C- clade AG group of genes. PaAG was found to be expressed predominantly in the later developmental stages of male and female inflorescences. Ectopic expression of PaAG-1 in tobacco (Nicotiana tabacum) resulted in morphological alterations of the outer two flower whorls, as well as some defects in vegetative growth. Scanning electron micrographs (SEMs) confirmed homeotic sepal-to-carpel transformation in the transgenic plants. Protein interaction assays in yeast cells indicated that PaAG could interact directly with PaAP3 (a B-class MADS-box protein in P. acerifolia), and also PaSEP1 and PaSEP3 (E-class MADS-box proteins in P. acerifolia). This study performed the functional analysis of AG orthologous genes outside core eudicots and monocots. Our findings demonstrate a conserved functional role of AG homolog in London plane tree, which also represent a contribution towards understanding the molecular mechanisms of flower development in this monoecious tree species. PMID:23691041

  7. Isolation and functional analyses of a putative floral homeotic C-function gene in a basal eudicot London plane tree (Platanus acerifolia).

    PubMed

    Zhang, Jiaqi; Li, Zhineng; Guo, Cong; Liu, Guofeng; Bao, Manzhu

    2013-01-01

    The identification of mutants in model plant species has led to the isolation of the floral homeotic function genes that play crucial roles in flower organ specification. However, floral homeotic C-function genes are rarely studied in basal eudicots. Here, we report the isolation and characterization of the AGAMOUS (AG) orthologous gene (PaAG) from a basal eudicot London plane tree (Platanus acerifolia Willd). Phylogenetic analysis showed that PaAG belongs to the C- clade AG group of genes. PaAG was found to be expressed predominantly in the later developmental stages of male and female inflorescences. Ectopic expression of PaAG-1 in tobacco (Nicotiana tabacum) resulted in morphological alterations of the outer two flower whorls, as well as some defects in vegetative growth. Scanning electron micrographs (SEMs) confirmed homeotic sepal-to-carpel transformation in the transgenic plants. Protein interaction assays in yeast cells indicated that PaAG could interact directly with PaAP3 (a B-class MADS-box protein in P. acerifolia), and also PaSEP1 and PaSEP3 (E-class MADS-box proteins in P. acerifolia). This study performed the functional analysis of AG orthologous genes outside core eudicots and monocots. Our findings demonstrate a conserved functional role of AG homolog in London plane tree, which also represent a contribution towards understanding the molecular mechanisms of flower development in this monoecious tree species. PMID:23691041

  8. Floral homeotic genes were recruited from homologous MADS-box genes preexisting in the common ancestor of ferns and seed plants

    PubMed Central

    Münster, Thomas; Pahnke, Jens; Di Rosa, Alexandra; Kim, Jan T.; Martin, William; Saedler, Heinz; Theissen, Günter

    1997-01-01

    Flowers sensu lato are short, specialized axes bearing closely aggregated sporophylls. They are typical for seed plants (spermatophytes) and are prominent in flowering plants sensu stricto (angiosperms), where they often comprise an attractive perianth. There is evidence that spermatophytes evolved from gymnosperm-like plants with a fern-like mode of reproduction called progymnosperms. It seems plausible, therefore, that the stamens/carpels and pollen sacs/nucelli of spermatophytes are homologous to fern sporophylls and sporangia, respectively. However, the exact mode and molecular basis of early seed and flower evolution is not yet known. Comparing flower developmental control genes to their homologs from lower plants that do not flower may help to clarify the issue. We have isolated and characterized MADS-box genes expressed in gametophytes and sporophytes of the fern Ceratopteris. The data indicate that at least two different MADS-box genes homologous to floral homeotic genes existed in the last common ancestor of contemporary vascular plants, some descendants of which underwent multiple duplications and diversifications and were recruited into novel developmental networks during the evolution of floral organs. PMID:9122209

  9. The MADS-Domain Factors AGAMOUS-LIKE15 and AGAMOUS-LIKE18, along with SHORT VEGETATIVE PHASE and AGAMOUS-LIKE24, Are Necessary to Block Floral Gene Expression during the Vegetative Phase.

    PubMed

    Fernandez, Donna E; Wang, Chieh-Ting; Zheng, Yumei; Adamczyk, Benjamin J; Singhal, Rajneesh; Hall, Pamela K; Perry, Sharyn E

    2014-06-19

    Multiple factors, including the MADS-domain proteins AGAMOUS-LIKE15 (AGL15) and AGL18, contribute to the regulation of the transition from vegetative to reproductive growth. AGL15 and AGL18 were previously shown to act redundantly as floral repressors and upstream of FLOWERING LOCUS T (FT) in Arabidopsis (Arabidopsis thaliana). A series of genetic and molecular experiments, primarily focused on AGL15, was performed to more clearly define their role. agl15 agl18 mutations fail to suppress ft mutations but show additive interactions with short vegetative phase (svp) mutations in ft and suppressor of constans1 (soc1) backgrounds. Chromatin immunoprecipitation analyses with AGL15-specific antibodies indicate that AGL15 binds directly to the FT locus at sites that partially overlap those bound by SVP and FLOWERING LOCUS C. In addition, expression of AGL15 in the phloem effectively restores wild-type flowering times in agl15 agl18 mutants. When agl15 agl18 mutations are combined with agl24 svp mutations, the plants show upward curling of rosette and cauline leaves, in addition to early flowering. The change in leaf morphology is associated with elevated levels of FT and ectopic expression of SEPALLATA3 (SEP3), leading to ectopic expression of floral genes. Leaf curling is suppressed by sep3 and ft mutations and enhanced by soc1 mutations. Thus, AGL15 and AGL18, along with SVP and AGL24, are necessary to block initiation of floral programs in vegetative organs. PMID:24948837

  10. Abnormal Bleeding During Menopause Hormone Therapy: Insights for Clinical Management

    PubMed Central

    de Medeiros, Sebastião Freitas; Yamamoto, Márcia Marly Winck; Barbosa, Jacklyne Silva

    2013-01-01

    Objective Our objective was to review the involved mechanisms and propose actions for controlling/treating abnormal uterine bleeding during climacteric hormone therapy. Methods A systemic search of the databases SciELO, MEDLINE, and Pubmed was performed for identifying relevant publications on normal endometrial bleeding, abnormal uterine bleeding, and hormone therapy bleeding. Results Before starting hormone therapy, it is essential to exclude any abnormal organic condition, identify women at higher risk for bleeding, and adapt the regimen to suit eachwoman’s characteristics. Abnormal bleeding with progesterone/progestogen only, combined sequential, or combined continuous regimens may be corrected by changing the progestogen, adjusting the progestogen or estrogen/progestogen doses, or even switching the initial regimen to other formulation. Conclusion To diminish the occurrence of abnormal bleeding during hormone therapy (HT), it is important to tailor the regimen to the needs of individual women and identify those with higher risk of bleeding. The use of new agents as adjuvant therapies for decreasing abnormal bleeding in women on HT awaits future studies. PMID:24665210

  11. GLIAL ABNORMALITIES IN MOOD DISORDERS

    PubMed Central

    Öngür, Dost; Bechtholt, Anita J.; Carlezon, William A.; Cohen, Bruce M.

    2015-01-01

    Multiple lines of evidence indicate that mood disorders are associated with abnormalities in the brain's cellular composition, especially in glial cells. Considered inert support cells in the past, glial cells are now known to be important for brain function. Treatments for mood disorders enhance glial cell proliferation, and experimental stimulation of cell growth has antidepressant effects in animal models of mood disorders. These findings suggest that the proliferation and survival of glial cells may be important in the pathogenesis of mood disorders and may be possible targets for the development of new treatments. In this chapter, we will review the evidence for glial abnormalities in mood disorders. We will discuss glial cell biology and evidence from postmortem studies of mood disorders. This is not carry out a comprehensive review; rather we selectively discuss existing evidence in building an argument for the role of glial cells in mood disorders. PMID:25377605

  12. Geographical differentiation in floral traits across the distribution range of the Patagonian oil-secreting Calceolaria polyrhiza: do pollinators matter?

    PubMed Central

    Cosacov, Andrea; Cocucci, Andrea A.; Sérsic, Alicia N.

    2014-01-01

    Background and Aims The underlying evolutionary processes of pollinator-driven floral diversification are still poorly understood. According to the Grant–Stebbins model speciation begins with adaptive local differentiation in the response to spatial heterogeneity in pollinators. Although this crucial process links the micro- and macroevolution of floral adaptation, it has received little attention. In this study geographical phenotypic variation was investigated in Patagonian Calceolaria polyrhiza and its pollinators, two oil-collecting bee species that differ in body size and geographical distribution. Methods Patterns of phenotypic variation were examined together with their relationships with pollinators and abiotic factors. Six floral and seven vegetative traits were measured in 45 populations distributed across the entire species range. Climatic and edaphic parameters were determined for 25 selected sites, 2–16 bees per site of the most frequent pollinator species were captured, and a critical flower–bee mechanical fitting trait involved in effective pollination was measured. Geographical patterns of phenotypic and environmental variation were examined using uni- and multivariate analyses. Decoupled geographical variation between corolla area and floral traits related to the mechanical fit of pollinators was explored using a Mantel test. Key Results The body length of pollinators and the floral traits related to mechanical fit were strongly correlated with each other. Geographical variation of the mechanical-fit-related traits was decoupled from variation in corolla size; the latter had a geographical pattern consistent with that of the vegetative traits and was mainly affected by climatic gradients. Conclusions The results are consistent with pollinators playing a key role in shaping floral phenotype at a geographical scale and promoting the differentiation of two floral ecotypes. The relationship between the critical floral-fit-related trait and bee

  13. Extreme variation in floral characters and its consequences for pollinator attraction among populations of an Andean cactus

    PubMed Central

    Schlumpberger, Boris O.; Cocucci, Andrea A.; Moré, Marcela; Sérsic, Alicia N.; Raguso, Robert A.

    2009-01-01

    Background and aims A South American cactus species, Echinopsis ancistrophora (Cactaceae), with dramatic among-population variation in floral traits is presented. Methods Eleven populations of E. ancistrophora were studied in their habitats in northern Argentina, and comparisons were made of relevant floral traits such as depth, stigma position, nectar volume and sugar concentration, and anthesis time. Diurnal and nocturnal pollinator assemblages were evaluated for populations with different floral trait combinations. Key Results Remarkable geographical variations in floral traits were recorded among the 11 populations throughout the distribution range of E. ancistrophora, with flower lengths ranging from 4·5 to 24·1 cm. Other floral traits associated with pollinator attraction also varied in a population-specific manner, in concert with floral depth. Populations with the shortest flowers showed morning anthesis and those with the longest flowers opened at dusk, whereas those with flowers of intermediate length opened at unusual times (2300–0600 h). Nectar production varied non-linearly with floral length; it was absent to low (population means up to 15 µL) in short- to intermediate-length flowers, but was high (population means up to 170 µL) in the longest tubed flowers. Evidence from light-trapping of moths, pollen carriage on their bodies and moth scale deposition on stigmas suggests that sphingid pollination is prevalent only in the four populations with the longest flowers, in which floral morphological traits and nectar volumes match the classic expectations for the hawkmoth pollination syndrome. All other populations, with flowers 4·5–15 cm long, were pollinated exclusively by solitary bees. Conclusions The results suggest incipient differentiation at the population level and local adaptation to either bee or hawkmoth (potentially plus bee) pollination. PMID:19342397

  14. Diversification in Monkeyflowers: An Investigation of the Effects of Elevation and Floral Color in the Genus Mimulus

    PubMed Central

    Vamosi, Jana C.

    2014-01-01

    The vast diversity of floral colours in many flowering plant families, paired with the observation of preferences among pollinators, suggests that floral colour may be involved in the process of speciation in flowering plants. While transitions in floral colour have been examined in numerous genera, we have very little information on the consequences of floral colour transitions to the evolutionary success of a clade. Overlaid upon these patterns is the possibility that certain floral colours are more prevalent in certain environments, with the causes of differential diversification being more directly determined by geographical distribution. Here we examine transition rates to anthocyanin + carotenoid rich (red/orange/fuschia) flowers and examine whether red/orange flowers are associated with differences in speciation and/or extinction rates in Mimulus. Because it has been suggested that reddish flowers are more prevalent at high elevation, we also examine the macroevolutionary evidence for this association and determine if there is evidence for differential diversification at high elevations. We find that, while red/orange clades have equivalent speciation rates, the trait state of reddish flowers reverts more rapidly to the nonreddish trait state. Moreover, there is evidence for high speciation rates at high elevation and no evidence for transition rates in floral colour to differ depending on elevation. PMID:24511412

  15. Effect of floral cluster pruning on anthocyanin levels and anthocyanain-related gene expression in 'Houman' grape.

    PubMed

    Zhang, Lei; Xu, Yan-Shuai; Jia, Yue; Wang, Ji-Yuan; Yuan, Yue; Yu, Yang; Tao, Jian-Min

    2016-01-01

    Lateral floral clusters were removed from the main axis of the floral clusters of 'Houman' grape plants, leaving only 3-5-cm-long region of flowers at the end of the central axis. The floral clusters were pruned at 7 days prior to flowering. The effect of the pruning on fruit quality was assessed by determining the composition and levels of anthocyanins in the fruit and anthocyanin-related gene expression. Results indicated that floral cluster pruning significantly improved the quality of the fruit by increasing berry size, fruit weight and the total content of soluble solids. Floral cluster pruning also decreased the level of titratable acidity. Sixteen different anthocyanins were detected in fruit of the pruned clusters, while only 15 were detected in fruit from unpruned clusters. The level of anthocyanins was also significantly higher in fruit of the pruned clusters than in the unpruned clusters. Anthocyanin-related gene expression was also significantly upregulated to a higher level in fruit from pruned floral clusters as compared with unpruned clusters. The upregulation was closely associated with increases in anthocyanin biosynthesis. PMID:27555920