U.S.-Italy Cooperative Research: Competition Between Microspores Within Tetrads

该奖项将支持马萨诸塞大学的David Mulcahy教授与意大利锡耶纳大学的Mauro Cresti教授的一项研究合作。研究人员打算研究花粉粒之间类似微生物的竞争。初步数据表明，虽然小孢子（未来的花粉粒）仍然是四分体，但它们正在相互竞争资源。这种内部竞争的主要证据是，在四分体中删除一到三个成员的特征是可存活成员的大小增加。存活的成员在多大程度上能够吸收终止成员的资源，存活的成员在多大程度上相互竞争，以及超微结构变化在多大程度上表达这种竞争是本研究将讨论的一些主题。在被子植物（和裸子植物）中，花粉代表了一个巨大种群和基因型的微生物系统。虽然花粉只占被子植物生命周期的一小部分，但它表达并因此暴露于选择中，约占所有孢子表达基因的60%。这一系统在被子植物中特别有效，可能是被子植物在世界植物区系中具有适应优势的重要原因。通过将美国研究人员的遗传方法与意大利研究人员对花粉微观结构的关注相结合，本研究不仅将研究小孢子竞争的一个新方面，还可能揭示一些信息，这些信息可能有助于利用花粉选择来开发具有重要农艺学和生态学意义的植物抗性。

This award will support Professor David Mulcahy of the University of Massachusetts in a research collaboration with Professor Mauro Cresti of the University of Siena, Italy. The investigators intend to study microbial-like competition among pollen grains. Preliminary data indicate that while microspores (pollen grains-to-be) are still united in tetrads, they are competing with each other for resources. The major evidence for such intratetrad competition is that the deletion of one to three members within the tetrad is characterized by increases in the size of the viable members. The extent to which surviving members are able to absorb the resources of aborted members, the degree to which viable members compete among themselves, and the extent to which ultrastructural changes may express this competition are some of the topics that will be addressed by this research. In the angiosperms (and gymnosperms) pollen represents a microbial-like system of extremely large population and genotypes. Although pollen comprises a small portion of the angiosperm life cycle, it expresses, and thus exposes to selection, approximately 60% of all spirophytically expressed genes. This system is particularly effective in the angiosperms and may represent a significant contributor to the adaptive superiority of that group in the world flora. By combining the genetic approach of the U.S. researcher with the focus on pollen microstructure of the Italian investigator, this study will not only examine a newly appreciated aspect of microspore competition, it may also reveal information which could be useful in using pollen selection to develop plants resistant to agronomically and ecologically important stresses.