Examining the correlated molecular mechanisms of self and heterospecific pollen-pistil recognition

检查自体和异体花粉雌蕊识别的相关分子机制

• 批准号: 1906113
• 负责人: Robin Hopkins
• 金额: $ 70万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1906113&HistoricalAwards=false
• 关键词: Examining; correlated; molecular; mechanisms; self

Flowering plants display their charismatic flowers open and ready for pollinators or wind to bring pollen for reproduction. Determining how plants successfully reproduce requires understanding the molecular mechanisms underlying how female reproductive organs (pistils) recognize and accept high quality pollen while rejecting low quality pollen. The recognition between pistils and pollen is significant for two important mate choices in plants - distinguishing between self-pollen and non-self-pollen as well as between pollen from the same species and pollen from different species. This research investigates the molecular mechanisms underlying self-pollen reject and foreign-species pollen rejection in Phlox drummondii, a native Texas wildflower. In this species there is extensive natural variation in the ability of pistils to recognize and reject self and foreign pollen and the variation in these two recognition systems is highly correlated across individuals. This research involves a detailed genetic investigation of molecular mechanisms causing pollen-pistil recognition and the causes of the correlation between incompatibilities. Specifically, this research combines quantitative genetic dissection of variation in incompatibilities, with genome-wide gene expression analyses, and an artificial selection experiment to discover new mechanisms of pollen-pistil interactions in a species that has evolved self and foreign incompatibly independently of those found in model plant systems. This research will be complemented by outreach activities associated with the local natural history museum. The scientists will create educational activities for elementary and high school students, provide teacher professional development workshops about floral diversity, and organize public lectures on plant science. This project investigates the long-standing hypothesis that self and heterospecific pollen-pistil incompatibility systems are mechanistically linked by dissecting the molecular basis of variation in incompatibility within a non-model wildflower species. Specifically, this research will determine if self and heterospecific recognition share genetic mechanisms, if the breakdown of self and heterospecific incompatibility involves multiple genes including genes outside the self-identity locus, and if the correlation between self and heterospecific incompatibility could constrain the evolution of pollen-pistil recognition. To accomplish these goals, this research will determine the molecular mechanisms underlying incompatibly through whole-genome gene expression analyses, characterize the genetic architecture of the breakdown of self and heterospecific pollen recognition through genetic mapping experiments, and quantify the genetic constraint imposed by the correlation between incompatibilities using an artificial selection experiment. This integrative research will test specific hypotheses about the genetic basis of incompatibly in plants while discovering new mechanisms of pollen-pistil recognition.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

开花植物展示其魅力的花朵开放，准备授粉或风带来的花粉繁殖。确定植物如何成功繁殖需要了解雌性生殖器官（雌蕊）如何识别和接受高质量花粉，同时拒绝低质量花粉的分子机制。雌蕊和花粉的识别对于植物的两个重要的配偶选择-区分自花花粉和非自花花粉以及来自同一物种的花粉和来自不同物种的花粉-具有重要意义。本研究探讨了德克萨斯州原生野生花福禄考（Phlox drummondii）的自体花粉排斥和外来种花粉排斥的分子机制。在这个物种中，雌蕊识别和拒绝自我和外来花粉的能力存在广泛的自然变异，这两种识别系统的变异在个体之间高度相关。本研究涉及详细的遗传调查的分子机制，导致花粉雌蕊识别和不亲和性之间的相关性的原因。具体来说，这项研究结合了定量遗传解剖的变化不兼容，全基因组的基因表达分析，和人工选择实验，以发现新的机制，花粉雌蕊相互作用的一个物种，已经发展自我和外来的不兼容的模式植物系统中发现的。这项研究将得到与当地自然历史博物馆有关的外联活动的补充。科学家们将为小学和高中学生创造教育活动，提供有关花卉多样性的教师专业发展研讨会，并组织植物科学的公开讲座。本项目调查了长期存在的假说，即自我和异源花粉雌蕊不亲和性系统是机械连接解剖的分子基础上的不亲和性的变化在一个非模式的野花物种。具体而言，本研究将确定是否自我和异源识别共享遗传机制，如果自我和异源不亲和性的崩溃涉及多个基因，包括自我身份位点以外的基因，以及自我和异源不亲和性之间的相关性是否可以限制花粉雌蕊识别的进化。为了实现这些目标，本研究将通过全基因组基因表达分析确定不相容的分子机制，通过遗传图谱实验表征自交和异源花粉识别崩溃的遗传结构，并量化不相容性之间的相关性所施加的遗传约束使用人工选择实验。这项综合性研究将测试有关植物中不相容的遗传基础的特定假设，同时发现花粉雌蕊识别的新机制。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。