The Experts below are selected from a list of 7113 Experts worldwide ranked by ideXlab platform
Shigeyuki Kawano - One of the best experts on this subject based on the ideXlab platform.
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an asexual flower of silene latifolia and microbotryum lychnidis dioicae promotes sex organ development
PLOS ONE, 2019Co-Authors: Hiroki Kawamoto, Yusuke Kazama, Ayako Koizumi, Tomoko Abe, Kaori Yamanaka, Kotaro Ishii, Shigeyuki KawanoAbstract:Silene latifolia is a dioecious flowering plant with sex chromosomes in the family Caryophyllaceae. Development of a gynoecium and Stamens are suppressed in the male and female flowers of S. latifolia, respectively. Microbotryum lychnidis-dioicae promotes Stamen development when it infects the female flower. If suppression of the Stamen and gynoecium development is regulated by the same mechanism, suppression of gynoecium and Stamen development is released simultaneously with the infection by M. lychnidis-dioicae. To assess this hypothesis, an asexual mutant without a gynoecium or Stamen was infected with M. lychnidis-dioicae. A filament of the Stamen in the infected asexual mutant was elongated at stages 11 and 12 of flower bud development as well as in the male, but the gynoecium did not form. Instead of the gynoecium, a filamentous structure was suppressed as in the male flower. Developmental suppression of the Stamen was released by M. lychnidis-dioicae, but that of gynoecium development was not released. M. lychnidis-dioicae would have a function similar to Stamen-promoting factor (SPF), since the elongation of the Stamen that is not observed in the healthy asexual mutant was observed after stage 8 of flower bud development. An infection experiment also revealed that a deletion on the Y chromosome of the asexual mutant eliminated genes for maturation of tapetal cells because the tapetal cells did not mature in the asexual mutant infected with M. lychnidis-dioicae.
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an asexual flower of silene latifolia and microbotryum lychnidis dioicae promoting its sexual organ development
bioRxiv, 2019Co-Authors: Hiroki Kawamoto, Yusuke Kazama, Ayako Koizumi, Tomoko Abe, Kaori Yamanaka, Kotaro Ishii, Shigeyuki KawanoAbstract:Abstract Silene latifolia is a dioecious flowering plant with sex chromosomes in the family Caryophyllaceae. Development of a gynoecium and Stamens are suppressed in the male and female flowers of S. latifolia, respectively. Microbtryum lychnidis-dioicae promotes Stamen development when it infects the female flower. If suppression of the Stamen and gynoecium development is regulated by the same mechanism, suppression of gynoecium and Stamen development is released simultaneously with the infection by M. lychnidis-dioicae. To assess this hypothesis, an asexual mutant, without gynoecium or Stamen, was infected with M. lychnidis-dioicae. A filament of the Stamen in the infected asexual mutant was elongated at stages 11 and 12 of the flower bud development as well as the male, but the gynoecium did not form. Instead of the gynoecium, a filamentous structure was suppressed as in the male flower. Developmental suppression of the Stamen was released by M. lychnidis-dioicae, but that of gynoecium development was not released. It is thought, therefore, that the suppression of gynoecium development was not released by the infection of M. lychnidis-dioicae. M. lychnidis-dioicae would have a function similar to SPF since the elongation of the Stamen that is not observed in the healthy asexual mutant was observed after stage 8 of flower bud development. Such an infection experiment also that the Y chromosome of the asexual mutant has genes related to the differentiation of archesporial cells, but none related to maturation of the tapetal cells.
Hiroki Kawamoto - One of the best experts on this subject based on the ideXlab platform.
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an asexual flower of silene latifolia and microbotryum lychnidis dioicae promotes sex organ development
PLOS ONE, 2019Co-Authors: Hiroki Kawamoto, Yusuke Kazama, Ayako Koizumi, Tomoko Abe, Kaori Yamanaka, Kotaro Ishii, Shigeyuki KawanoAbstract:Silene latifolia is a dioecious flowering plant with sex chromosomes in the family Caryophyllaceae. Development of a gynoecium and Stamens are suppressed in the male and female flowers of S. latifolia, respectively. Microbotryum lychnidis-dioicae promotes Stamen development when it infects the female flower. If suppression of the Stamen and gynoecium development is regulated by the same mechanism, suppression of gynoecium and Stamen development is released simultaneously with the infection by M. lychnidis-dioicae. To assess this hypothesis, an asexual mutant without a gynoecium or Stamen was infected with M. lychnidis-dioicae. A filament of the Stamen in the infected asexual mutant was elongated at stages 11 and 12 of flower bud development as well as in the male, but the gynoecium did not form. Instead of the gynoecium, a filamentous structure was suppressed as in the male flower. Developmental suppression of the Stamen was released by M. lychnidis-dioicae, but that of gynoecium development was not released. M. lychnidis-dioicae would have a function similar to Stamen-promoting factor (SPF), since the elongation of the Stamen that is not observed in the healthy asexual mutant was observed after stage 8 of flower bud development. An infection experiment also revealed that a deletion on the Y chromosome of the asexual mutant eliminated genes for maturation of tapetal cells because the tapetal cells did not mature in the asexual mutant infected with M. lychnidis-dioicae.
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an asexual flower of silene latifolia and microbotryum lychnidis dioicae promoting its sexual organ development
bioRxiv, 2019Co-Authors: Hiroki Kawamoto, Yusuke Kazama, Ayako Koizumi, Tomoko Abe, Kaori Yamanaka, Kotaro Ishii, Shigeyuki KawanoAbstract:Abstract Silene latifolia is a dioecious flowering plant with sex chromosomes in the family Caryophyllaceae. Development of a gynoecium and Stamens are suppressed in the male and female flowers of S. latifolia, respectively. Microbtryum lychnidis-dioicae promotes Stamen development when it infects the female flower. If suppression of the Stamen and gynoecium development is regulated by the same mechanism, suppression of gynoecium and Stamen development is released simultaneously with the infection by M. lychnidis-dioicae. To assess this hypothesis, an asexual mutant, without gynoecium or Stamen, was infected with M. lychnidis-dioicae. A filament of the Stamen in the infected asexual mutant was elongated at stages 11 and 12 of the flower bud development as well as the male, but the gynoecium did not form. Instead of the gynoecium, a filamentous structure was suppressed as in the male flower. Developmental suppression of the Stamen was released by M. lychnidis-dioicae, but that of gynoecium development was not released. It is thought, therefore, that the suppression of gynoecium development was not released by the infection of M. lychnidis-dioicae. M. lychnidis-dioicae would have a function similar to SPF since the elongation of the Stamen that is not observed in the healthy asexual mutant was observed after stage 8 of flower bud development. Such an infection experiment also that the Y chromosome of the asexual mutant has genes related to the differentiation of archesporial cells, but none related to maturation of the tapetal cells.
Jinrong Peng - One of the best experts on this subject based on the ideXlab platform.
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gibberellin and jasmonate crosstalk during Stamen development
Journal of Integrative Plant Biology, 2009Co-Authors: Jinrong PengAbstract:Gibberellin (GA) and jasmonate (JA) are two types of phytohormones that play important roles during Stamen development. For example, Arabidopsis plants deficient in either of GA or JA develop short Stamens. An apparent question to ask is whether GA action and JA action during Stamen filament development are independent of each other or are in a hierarchy. Recent studies showed that GA modulates the expression of genes essential for JA biosynthesis to promote JA production and high levels of JA will induce the expression of three MYB genes MYB21, MYB24 and MYB57. These three MYB genes are crucial factors for the normal development of Stamen filament in Arabidopsis.
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gibberellin regulates arabidopsis floral development via suppression of della protein function
Development, 2004Co-Authors: Hui Cheng, Nicholas P Harberd, Donald E Richards, Xiangdong Fu, Jinrong PengAbstract:The phytohormone gibberellin (GA) regulates the development and fertility of Arabidopsis flowers. The mature flowers of GA-deficient mutant plants typically exhibit reduced elongation growth of petals and Stamens. In addition, GA-deficiency blocks anther development, resulting in male sterility. Previous analyses have shown that GA promotes the elongation of plant organs by opposing the function of the DELLA proteins, a family of nuclear growth repressors. However, it was not clear that the DELLA proteins are involved in the GA-regulation of Stamen and anther development. We show that GA regulates cell elongation rather than cell division during Arabidopsis Stamen filament elongation. In addition, GA regulates the cellular developmental pathway of anthers leading from microspore to mature pollen grain. Genetic analysis shows that the Arabidopsis DELLA proteins RGA and RGL2 jointly repress petal, Stamen and anther development in GA-deficient plants, and that this function is enhanced by RGL1 activity. GA thus promotes Arabidopsis petal, Stamen and anther development by opposing the function of the DELLA proteins RGA, RGL1 and RGL2.
Anita Dirksmulder - One of the best experts on this subject based on the ideXlab platform.
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exploring the evolutionary origin of floral organs of erycina pusilla an emerging orchid model system
BMC Evolutionary Biology, 2017Co-Authors: Roland Butôt, Louie Krol, Sadhana Doebar, Anita Dirksmulder, Peter Van Schaik, Jan Willem Wijnands, Roel Van Den Berg, Kelly Van Kooperen, Hugo J De BoerAbstract:Thousands of flowering plant species attract pollinators without offering rewards, but the evolution of this deceit is poorly understood. Rewardless flowers of the orchid Erycina pusilla have an enlarged median sepal and incised median petal (‘lip’) to attract oil-collecting bees. These bees also forage on similar looking but rewarding Malpighiaceae flowers that have five unequally sized petals and gland-carrying sepals. The lip of E. pusilla has a ‘callus’ that, together with winged ‘stelidia’, mimics these glands. Different hypotheses exist about the evolutionary origin of the median sepal, callus and stelidia of orchid flowers. The evolutionary origin of these organs was investigated using a combination of morphological, molecular and phylogenetic techniques to a developmental series of floral buds of E. pusilla. The vascular bundle of the median sepal indicates it is a first whorl organ but its convex epidermal cells reflect convergence of petaloid features. Expression of AGL6 EpMADS4 and APETALA3 EpMADS14 is low in the median sepal, possibly correlating with its petaloid appearance. A vascular bundle indicating second whorl derivation leads to the lip. AGL6 EpMADS5 and APETALA3 EpMADS13 are most highly expressed in lip and callus, consistent with current models for lip identity. Six vascular bundles, indicating a Stamen-derived origin, lead to the callus, stelidia and Stamen. AGAMOUS is not expressed in the callus, consistent with its sterilization. Out of three copies of AGAMOUS and four copies of SEPALLATA, EpMADS22 and EpMADS6 are most highly expressed in the Stamen. Another copy of AGAMOUS, EpMADS20, and the single copy of SEEDSTICK, EpMADS23, are most highly expressed in the stelidia, suggesting EpMADS22 may be required for fertile Stamens. The median sepal, callus and stelidia of E. pusilla appear to be derived from a sepal, a Stamen that gained petal identity, and Stamens, respectively. Duplications, diversifying selection and changes in spatial expression of different MADS-box genes shaped these organs, enabling the rewardless flowers of E. pusilla to mimic an unrelated rewarding flower for pollinator attraction. These genetic changes are not incorporated in current models and urge for a rethinking of the evolution of deceptive flowers.
Jürg Schönenberger - One of the best experts on this subject based on the ideXlab platform.
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Stamen dimorphism in bird pollinated flowers investigating alternative hypotheses on the evolution of heteranthery
Evolution, 2021Co-Authors: Agnes S Dellinger, Silvia Artuso, Diana Fernandezfernandez, Jürg SchönenbergerAbstract:Heteranthery, the presence of distinct Stamen types within a flower, is commonly explained as functional adaptation to alleviate the "pollen dilemma," defined as the dual and conflicting function of pollen as pollinator food resource and male reproductive agent. A single primary hypothesis, "division of labor," has been central in studies on heteranthery. This hypothesis postulates that one Stamen type functions in rewarding pollen-collecting pollinators and the other in reproduction, thereby minimizing pollen loss. Only recently, alternative functions (i.e., staggered pollen release), were proposed, but comparative and experimental investigations are lagging behind. Here, we used 63 species of the tribe Merianieae (Melastomataceae) to demonstrate that, against theory, heteranthery occurs in flowers offering rewards other than pollen, such as staminal food bodies or nectar. Although shifts in reward type released species from the "pollen dilemma," heteranthery has evolved repeatedly de novo in food-body-rewarding, passerine-pollinated flowers. We used field investigations to show that foraging passerines discriminated between Stamen types and removed large Stamens more quickly than small Stamens. Passerines removed small Stamens on separate visits towards the end of flower anthesis. We propose that the staggered increase in nutritive content of small Stamens functions to increase chances for outcross-pollen transfer.
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early floral development and androecium organization in fouquieriaceae ericales
Plant Systematics and Evolution, 2005Co-Authors: Jürg Schönenberger, A GrenhagenAbstract:Early floral development with focus on the androecium was studied with the help of scanning electron microscopy and serial microtome sectioning in Fouquieria columnaris and F. splendens. Perianth organs appear in a spiral pattern on the floral apex. The spiral may be a clockwise or anti-clockwise. The androecium is best interpreted as two-whorled with all the Stamens arranged in a single series. In F. splendens, two or more of the five epipetalous Stamen positions are doubled, i.e. they are occupied by Stamen pairs. Unusual features in the floral development of Fouquieriaceae include (1) a strong spiral component even in whorled organ categories and (2) a pronouncedly asymmetric floral apex during an early phase of floral development. From a phylogenetic point of view, it seems plausible that the common ancestor of Fouquieriaceae and its sister family Polemoniaceae was characterized by two alternating, pentamerous Stamen-whorls.
