Evolutionary Developmental Biology (Evo-Devo)
Diggle, Pamela , Di Stilio, Veronica , Gschwend, Andrea , Golenberg, Edward , Moore, Richard , Russell, John , Sinclair, Jordan .
Multiple developmental processes underlie flower sex differentiation in angiosperms.
The production of unisexual flowers has evolved numerous times in dioecious and monoecious taxa. Based on repeated evolutionary origins, a great variety of developmental and genetic mechanisms underlying unisexual flower development is predicted. We comprehensively review the modes of development of unisexual flowers, and ask: When during development, and by what process, does loss of reproductive organ function occur? Is organ abortion more common at certain stages and are some developmental mechanisms of abortion more prevalent than others? Does organ abortion vary according to sexual system or among male and female flowers within the same species? We recognized four stages of organ abortion in 292 angiosperm taxa. Among these taxa, loss of sexual organ function occurs with equal frequency at each of the four developmental stages in both male and female flowers, and in monoecious and dioecious taxa. Arrest of development does not tend to occur preferentially at any particular stage, suggesting that there are no key stages of androecialor gynoecial development that are affected repeatedly upon the evolutionary origin of unisexual flowers. Even among closely related taxa, there is no evidence that loss of organ function tends to occur at the same stage. Surprisingly, we found that stage of organ abortion in male and female flowers is temporally correlated within species. Review of developmental processes that terminate organ development found that no process predominates and several may contribute to sterility of the same organ. Changes in the timing of otherwise "normal" developmental processes (cell death, senescence, termination of cell division) often contribute to organ abortion. Clearly, diverse modifications of development underlie the termination of organ development is unisexual flowers.
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1 - Wayne State University, Department of Biological Sciences, Detroit, MI, USA
2 - University Of Washington, Kincaid Hall 24, PO BOX 351800, SEATTLE, WA, 98115-1800, USA
3 - University of Illinois, Department of Plant Biology, Champaign, IL, USA
4 - Wayne State University, Department of Biological Sciences, Detroit, MI, USA
5 - Miami University, Botany, 316 Pearson Hall, Oxford, OH, 45056, USA
6 - University of Oxford, Department of Plant Sciences, Oxford, UK
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 11:15 AM