Biochemical Basis of S-RNase-Based Self-Incompatibility

大多数开花植物产生完整的花，花药和雌蕊位于靠近。 这种安排有利于自花授粉，这导致近亲繁殖，从而降低后代的适应性。 许多开花植物采用自交不亲和性（SI）来避免近亲繁殖的趋势。 这种遗传特性允许雌蕊拒绝自花花粉，但接受非自花花粉进行受精。 PI正在使用矮牵牛作为研究SI的模型，最终目标是了解雌蕊如何区分自我和非自我花粉，以及这种识别如何导致对自我花粉的特异性排斥。 他的研究小组先前确定了S-RNase基因负责雌蕊识别和拒绝自花花粉的能力。 PI的团队与日本Seiji Takayama博士的团队一起发现，花粉在其SI功能中使用多个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，以允许非自我花粉管而不是自我花粉管逃脱其毒性作用。 所获得的结果将导致更好地了解这些蛋白质之间的相互作用，这些蛋白质是这一重要的防止近亲繁殖机制的基础。 这项研究对自我/非自我识别过程（生物学中的一个基本过程）以及研究蛋白质降解（许多生物过程中的一个关键调节机制）具有更广泛的意义。 SLF和S-RNase基因可用于促进杂交种子生产，如果实现，这将具有巨大的农艺效益。 PI将在这个项目中吸引四名研究生和五到六名本科生，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，以教育公众，特别是K-12，关于植物生殖生物学和SI。

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.