Biochemical Basis of S-RNase-Based Self-Incompatibility

大多数开花植物产生完整的花，花药和雌蕊位于很近的位置。这种排列有利于自花授粉，从而导致近亲繁殖，从而降低后代的适合度。许多开花植物采用自交不亲和（SI）来规避近亲繁殖的倾向。这一遗传特性使雌蕊可以拒绝自花花粉而接受非自花花粉受精。该研究以矮人马花（Petunia inflata）为研究对象，旨在了解雌蕊如何区分自性花粉和非自性花粉，以及这种识别如何导致对自性花粉的特异性排斥。他的研究小组先前发现S-RNase基因负责雌蕊识别和拒绝自花花粉的能力。PI的研究小组和日本的高山清司（Seiji Takayama）博士的研究小组发现，花粉在其SI功能中使用了多个s位点F-box （SLF）基因。在这个项目中，PI将使用分子方法来测试协作非自我识别模型，该模型解释了多个SLF蛋白如何与单个S-RNase相互作用，从而使非自体花粉管（而非自体花粉管）逃脱其毒性作用。获得的结果将有助于更好地理解这些蛋白质之间的相互作用，这些相互作用是这种重要的近交预防机制的基础。本研究对自我/非自我识别过程（生物学中的一个基本过程）以及蛋白质降解（许多生物过程中的一个关键调节机制）的研究具有更广泛的意义。SLF和S-RNase基因可以用来促进杂交种子的生产，如果完成，这将具有巨大的农艺效益。该项目将招募4名研究生和5至6名本科生参与该项目，为他们未来的研究生涯做好准备，并将继续参加宾夕法尼亚州立大学的年度生物学博览会，向公众，特别是K-12年级的公众宣传植物生殖生物学和科学科学。

Most flowering plants produce complete flowers, with anthers and pistil located in close proximity. This arrangement is conducive to self-pollination, which leads to inbreeding and consequent reduced fitness in progeny. Many flowering plants have adopted self-incompatibility (SI) to circumvent the tendency for inbreeding. This genetic trait allows the pistil to reject self-pollen but accept non-self pollen for fertilization. The PI is using Petunia inflata as a model to study SI, with the ultimate goal of understanding how the pistil can distinguish self and non-self pollen, and how this recognition leads to specific rejection of self-pollen. His group previously identified the S-RNase gene as responsible for the pistil's ability to recognize and reject self-pollen. The PI's group, along with Dr. Seiji Takayama's group in Japan, found that pollen employs multiple S-locus F-box (SLF) genes in its SI function. In this project, the PI will use molecular approaches to test the collaborative non-self-recognition model that explains how multiple SLF proteins interact with a single S-RNase to allow non-self pollen tubes, but not self pollen tubes, to escape its toxic effect. The results obtained will lead to a better understanding of the interactions between these proteins that underlie this important inbreeding-preventing mechanism. This proposed research has wider implications for the self/non-self recognition process, a fundamental process in biology, as well as for studying protein degradation, a key regulatory mechanism in many biological processes. The SLF and S-RNase genes could be used to facilitate hybrid-seed production, and if accomplished, this will have tremendous agronomic benefits. The PI will engage four graduate and five to six undergraduate students in this project to prepare them for future careers in research, and will continue to participate in an annual biology fair at Penn State to educate the public, particularly K-12, about plant reproductive biology and SI.