Biochemical Basis of S-RNase-Based Self-Incompatibility

拟议号：IOS-0843195拟议题：S核糖核酸酶自交不亲和性的生化基础大多数开花植物都会产生两性花，如果没有机制阻止它们自交，它们会有很强的自交倾向。由于近亲交配对任何生物都是有害的，开花植物进化出了各种繁殖策略，包括自交不亲和(SI)，以防止近亲交配和促进异交。SI允许雌蕊拒绝自体花粉，接受非自体花粉受精。本课题以矮牵牛为材料研究了一种SI机制，并在此基础上鉴定了雌蕊表达的S核糖核酸酶和花粉表达的PISLF(P.flata S基因座F-box)。在雌蕊中花粉管的生长过程中，花粉管中的PiSLF只允许自身的S核糖核酸酶抑制花粉管的生长。几个解释PISLF和S核糖核酸酶如何相互作用以引起对自身花粉管的特定排斥的假说将被测试。该项目将使用体内方法来验证这些假说，方法是解剖PiSLF的三个结构域与S-核糖核酸酶相互作用的功能，研究含有PiSLF的复合体的一个潜在成分的生化功能，并研究S-核糖化酶在SI中的作用。SI为研究自我/非我识别提供了一个模型，因此该项目的完成将对生物科学产生更广泛的影响。PISLF和S核糖核酸酶可用于恢复作物品种的SI，以利于杂交制种，具有巨大的农艺效益。该项目将吸引三名研究生和三名本科生，为他们未来的研究生涯做好准备。该项目的研究人员将继续参加宾夕法尼亚州立大学的年度生物学博览会，以教育与会者，特别是K-12学生，了解植物生殖生物学和SI。

PI: Teh-hui Kao Proposal Number: IOS-0843195Title of Proposal: Biochemical Basis of S-RNase-Based Self-IncompatibilityMost flowering plants produce bisexual flowers containing both male and female reproductive organs, and they would have a strong tendency to self-fertilize, if no mechanisms prevent them from doing so. Since inbreeding is deleterious to any organism, flowering plants have evolved a variety of reproductive strategies, including self-incompatibility (SI), to prevent inbreeding and promote out-crossing. SI allows pistils to reject self-pollen and accept non-self pollen for fertilization. This project uses Petunia inflata to study one type of SI mechanism, and has previously identified the S-RNase expressed by the pistil and PiSLF (P. inflata S-locus F-box) that is expressed by the pollen. During growth of a pollen tube in a pistil, the PiSLF in the pollen tube only allows self S-RNase to inhibit pollen tube growth. Several hypotheses that explain how PiSLF and S-RNase interact to elicit specific rejection of self pollen tubes will be tested. The project will use in vivo approaches to test these hypotheses by dissecting the functions of three domains of PiSLF in interactions with S-RNase, studying the biochemical function of a potential component of the PiSLF-containing complex, and examining the role of glycosylation of S-RNase in SI. SI provides a model for studying self/non-self recognition, so completion of this project will have wider implications for biological sciences. PiSLF and S-RNase could be used for restoring SI to crop species to facilitate hybrid seed production, which will have tremendous agronomic benefits. The project will engage three graduate and three undergraduate students to prepare them for future careers in research. The researchers in this project will continue to participate in an annual biology fair at Penn State to educate the attendees, particularly K-12, about plant reproductive biology and SI.