Biochemical Basis of S-RNase-Based Self-Incompatibility

提案号：ios - 0843195提案题目：基于s - rase的自交不亲和性的生化基础大多数开花植物产生两性花，同时包含雄性和雌性生殖器官，如果没有机制阻止它们这样做，它们会有很强的自交受精倾向。由于近亲繁殖对任何生物都是有害的，开花植物已经进化出各种生殖策略，包括自交不亲和（SI），以防止近亲繁殖和促进异交。SI允许雌蕊拒绝自交花粉，接受非自交花粉受精。本项目以膨胀矮牵牛为研究对象，研究了其中一种SI机制，此前已经鉴定出雌蕊表达的S-RNase和花粉表达的PiSLF（膨胀矮牵牛S-locus F-box）。在雌蕊花粉管生长过程中，花粉管中的PiSLF仅允许自身S-RNase抑制花粉管生长。几个解释PiSLF和S-RNase如何相互作用以引起自身花粉管特异性排斥的假设将被测试。该项目将使用体内方法，通过剖析PiSLF与S-RNase相互作用的三个结构域的功能，研究含有PiSLF复合物的潜在组分的生化功能，以及检查S-RNase糖基化在SI中的作用，来验证这些假设。SI为研究自我/非自我认知提供了一个模型，因此该项目的完成将对生物科学产生更广泛的影响。利用PiSLF和S-RNase可以恢复作物的SI，促进杂交制种，具有巨大的农艺效益。该项目将聘请三名研究生和三名本科生，为他们未来的研究事业做好准备。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，向与会者，特别是K-12的与会者介绍植物生殖生物学和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.