Pollen-pistil Interactions in the Genus Nicotiana

烟草属花粉-雌蕊相互作用

• 批准号: 9604645
• 负责人: Bruce McClure
• 金额: $ 36万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9604645&HistoricalAwards=false
• 关键词: Pollen; pistil; Interactions; Genus; Nicotiana

McClure 9604645 Pollen-pistil interactions provide an important avenue for controlling plant reproduction. The factors controlling intraspecific and interspecific pollen recognition in the genus Nicotiana provide an excellent system for exploring these interactions. A great deal is known about S-RNase mediated intraspecific pollen recognition in self-incompatible Nicotiana alata. Furthermore, the interspecific crossing relationships between N. alata and its self-compatible relatives have been well described. Both types of pollen recognition clearly entail interactions between the pollen and the pistil. This research project uses biochemical and molecular biological tools to understand the molecular details of these interactions. In the previous funding period, cloned S-RNase genes from N. alata were expressed in transgenic plants to examine their role in controlling pollination. The key results were: 1) that S-RNases control the specificity of intraspecific pollination, 2) that recognition information is diffusely encoded in the S-RNase molecule, 3) that at least three genetically distinct mechanisms contribute to controlling interspecific pollination between N. alata and its self-compatible relatives, and 4) that S-RNase was implicated in interspecific pollen recognition and rejection. These results are important because they imply that S-RNase helps to define a window of genetic relatedness for compatible pollination. It has a role in rejecting self-pollen, and thus prevents inbreeding. It also has a role in rejecting interspecific pollen, and so acts to prevent very wide crosses. The major goals in this new proposal are: 1) to identify and characterize non-SRNase factors that contribute to pollen recognition, and 2) to examine the specificity of RNase dependent interspecific pollen rejection. One putative factor has already been identified by differential cDNA cloning. This new sequence will be characterized using immunological and transgenic plant methods. The cDNA cloning appr oach will be extended to identify further non-S-RNase factors related to pollen recognition. The specificity of interspecific pollen recognition will be addressed by comparing the pollination behavior of transgenic plants expressing a bacterial RNase with plants expressing S-RNase or recognition defective S-RNase. By understanding the natural mechanisms that control intraspecific and interspecific pollen recognition in the genus Nicotiana, these studies may contribute to efforts to artificially manipulate the breeding behavior of economically important plants.

McClure 9604645 花粉-雌蕊相互作用为控制植物繁殖提供了重要途径。控制烟草属种内和种间花粉识别的因素为探索这些相互作用提供了一个极好的系统。人们对 S-RNase 介导的自交不亲和烟草种内花粉识别有很多了解。此外，N. alata 与其自交亲和近缘种之间的种间杂交关系已得到很好的描述。两种类型的花粉识别显然都需要花粉和雌蕊之间的相互作用。该研究项目使用生物化学和分子生物学工具来了解这些相互作用的分子细节。在之前的资助期间，来自N. alata的克隆S-RNase基因在转基因植物中表达，以检查它们在控制授粉中的作用。主要结果是：1) S-RNase 控制种内授粉的特异性，2) 识别信息广泛编码在 S-RNase 分子中，3) 至少三种遗传上不同的机制有助于控制 N. alata 及其自交亲和近缘种之间的种间授粉，4) S-RNase 参与种间花粉识别和排斥。这些结果很重要，因为它们意味着 S-RNase 有助于定义相容授粉的遗传相关性窗口。它具有拒绝自花花粉的作用，从而防止近亲繁殖。它还具有拒绝种间花粉的作用，因此可以防止非常广泛的杂交。这项新提案的主要目标是：1) 识别和表征有助于花粉识别的非 SRNase 因素，2) 检查 RNase 依赖性种间花粉排斥的特异性。差异 cDNA 克隆已经鉴定出一种推定因素。该新序列将使用免疫学和转基因植物方法进行表征。 cDNA 克隆方法将被扩展以进一步鉴定与花粉识别相关的非 S-RNase 因子。通过比较表达细菌 RNase 的转基因植物与表达 S-RNase 或识别缺陷 S-RNase 的植物的授粉行为，可以解决种间花粉识别的特异性。通过了解控制烟草属种内和种间花粉识别的自然机制，这些研究可能有助于人为操纵具有重要经济意义的植物的育种行为。