Using Genomic Tools to Identify Interspecific Reproductive Barriers in the Tomato Clade

PI：Patricia A.贝丁格（科罗拉多州立大学）联合PI：布鲁斯A。麦克卢尔（密苏里州大学），罗杰T。Chetelat（加州大学戴维斯分校）和Jocelyn Rose（康奈尔大学）合作者：Stephen Stack（科罗拉多州立大学）和Esther货车der Knaap（俄亥俄州州立大学）开花植物是陆地环境中最成功的生物之一。它们的成功很大程度上归功于高度进化的控制交配的机制。这些机制有助于避免近亲繁殖以及种间交配，这可能导致不育或其他问题。通常，这些机制需要花粉（雄性）和雌蕊（雌性）之间的特定分子水平的相互作用。人们在理解防止近亲交配的机制方面已经取得了很大进展，例如兄弟姐妹之间;雌蕊识别并拒绝这种花粉，从而防止近亲繁殖。然而，遗传上不同的植物之间更复杂的相互作用的分子基础（即，不同的物种）长期以来一直是棘手的。尚未解决的问题包括：生殖障碍在何处以及何时起作用？这些屏障的分子本质是什么？这些障碍是否可以通过下调或添加特定基因来规避或创造？基因组学和蛋白质组学工具与番茄家族的生物学、遗传学和生物化学研究的悠久传统相结合，现在有可能以新的方式解决控制种间授粉的机制。本计画将借由直接观察种间授粉行为，来决定番茄科授粉障碍物的发育时间与作用地点。负责识别和排斥种间花粉的基因[即，种间生殖障碍（IRB）基因]将通过蛋白质组学分析和番茄基因组学项目使作图方法成为可能。最后，通过将候选IRB基因转化到新的遗传背景中并检测授粉行为的变化来确定其在种间授粉中的功能。更广泛的影响控制植物繁殖的机制具有重大的经济意义。例如，操纵生殖过程对于大多数杂交作物的生产是必不可少的。该项目旨在了解植物物种之间的生殖障碍，与调节物种之间的基因转移直接相关，既有可取的（将重要的农艺性状从野生物种转移到驯化物种），也有不可取的（将转基因从转基因作物转移到野生物种）。该项目还将基因组学扩展到生物多样性研究，比较驯化和野生物种的生殖基因。该项目将对研究基础设施作出重要贡献，开发一种新的工具（突变FISH盒），广泛应用于基因组学研究。该项目还将在教育方面产生重大影响。在每一个主办组织发展一个强大的本科生培训计划将给予高度重视。除了一对一的教师指导的本科研究，一个多头脑的组成部分（研究纳入本科实验室课程）的项目将在新生和高级本科水平开发。 该项目产生的数据和生物资源将通过项目网站“番茄种间生殖障碍”（IRBT）（待开发）和SOL基因组学网络（SGN）网站（http：//www.example.com）提供。www.sgn.cornell.edu

PI: Patricia A. Bedinger (Colorado State University)Co-PIs: Bruce A. McClure (University of Missouri), Roger T. Chetelat (UC Davis), and Jocelyn Rose (Cornell University)Collaborators: Stephen Stack (Colorado State University) and Esther van der Knaap (Ohio State University)The flowering plants are among the most successful organisms in terrestrial environments. Much of their success can be attributed to highly evolved mechanisms for controlling mating. These mechanisms help avoid inbreeding as well as interspecific matings that could result in sterility or other problems. Often, these mechanisms entail specific molecular-level interactions between the pollen (male) and pistil (female). Much progress has been made toward understanding mechanisms for preventing matings between closely related individuals such as between siblings; the pistil recognizes and rejects such pollen and thus, prevents inbreeding. However, the molecular basis of the more complex interactions between genetically dissimilar plants (i.e., different species) has long been intractable. Unresolved questions include: Where and when do reproductive barriers operate? What is the molecular nature of these barriers? Can these barriers be circumvented or created by the down-regulation or addition of specific genes? Genomic and proteomic tools combined with a long tradition of biological, genetic and biochemical studies of the tomato family now make it possible to address the mechanisms controlling interspecific pollination in new ways. This project will determine the developmental time and place of action of pollination barriers in the tomato family by direct observation of interspecific pollinations. The genes responsible for recognition and rejection of interspecific pollen [i.e., Interspecific Reproductive Barrier (IRB) genes] will be identified through proteomic analysis and mapping approaches made possible by tomato genomics projects. Finally, the function of candidate IRB genes in interspecific pollination will be determined by transforming them into new genetic backgrounds and testing for changes in pollination behavior. Broader ImpactsThe mechanisms controlling plant reproduction have major economic importance. For example, manipulation of reproductive processes is essential for the production of most hybrid crop plants. This project - to understand reproductive barriers between plant species - is directly relevant to regulating gene transfer between species, both desirable (transferring agronomically important traits from wild to domesticated species) and undesirable (transfer of transgenes from genetically modified crops into wild species). The project also expands genomics into biodiversity studies with the comparison of reproductive genes of domesticated and wild species. The project will make an important contribution to research infrastructure with the development of a new tool (the FISH Cassette for Mutagenesis) that will have wide application in genomics research. This project will also have a significant impact in terms of education. The development of a strong undergraduate training program at each host organization will be given high priority. In addition to one-on-one faculty mentored undergraduate research, a Many Minds component (incorporation of research into undergraduate lab courses) to the project will be developed at the both freshman and advanced undergraduate level. Data and biological resources generated by this project will be available through the project website, Interspecific Reproductive Barriers in Tomato (IRBT)(to be developed) and through the SOL Genomics Network (SGN) website (http://www.sgn.cornell.edu).