Pollen-pistil Interactions in the Genus Nicotiana

烟草属花粉-雌蕊相互作用

• 批准号: 9982686
• 负责人: Bruce McClure
• 金额: $ 39万
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9982686&HistoricalAwards=false
• 关键词: Pollen; pistil; Interactions; Genus; Nicotiana

The goal of this project is to identify and characterize factorsthat contribute to S-allele-specific pollen recognition in Nicotiana alata.In this species, the S-locus controls intraspecific compatibility. Pollenis rejected when the S-allele in the pollen is the same as one of theS-alleles expressed in the pistil. S-RNases control the specificity ofpollen rejection, but other factors contribute to S-allele-specific pollenrecognition in other ways. Our main objective is to identify andcharacterize these non-S-RNase factors. HT-protein is one such factor that appears to be an unstablecomponent of the stylar extracellular matrix. Antisense suppression of HTprevents S-allele-specific pollen rejection, but its precise function isunknown. We propose experiments to determine the abundance of HT-proteinduring style development, and why it is so unstable. We have found that twospecific stylar proteins bind to S-RNase in vitro. One is a previouslycharacterized protein, NaTTS, that is implicated in growth of compatiblepollen tubes. The second, designated p11, has not been well characterized.NaTTS and p11 are putative non-S-RNase factors that may be implicated inboth pollen rejection and in supporting compatible pollen tube growth. Gelfiltration and protein blot analysis are proposed to determine the molecularweight and composition of NaTTS/S-RNase/p11 complexes. NaTTS and p11 willbe also expressed in bacteria and then used to test for interactions invitro. Antisense methods will be used to determine whether p11 affectscompatible or incompatible pollinations in vivo. To identify newnon-S-RNase factors, we have generated populations that segregate for theability to perform S-allele-specific pollen rejection. cDNA AFLP will beused to screen for new sequences associated with pollen rejection phenotype. The impact of this research will be to provide a betterunderstanding of the genetic mechanisms for pollen recognition andrejection. This is of practical significance to biotechnologists who wishto manipulate plant breeding behavior.

本研究的目的是鉴定和表征影响烟草阿拉塔S等位基因特异性花粉识别的因素。 当花粉中的S等位基因与雌蕊中表达的S等位基因之一相同时，花粉被拒绝。 S-RNases控制花粉排斥的特异性，但其他因素以其他方式促进S等位基因特异性花粉识别。 我们的主要目标是鉴定和表征这些非S-RNase因子。 HT-蛋白就是这样一个因子，它似乎是花柱细胞外基质的不稳定成分。 反义抑制HT可防止S等位基因特异性花粉排斥，但其确切功能尚不清楚。 我们提出了实验来确定丰富的HT-蛋白质在风格的发展，以及为什么它是如此不稳定。 我们在离体条件下发现两种特异的花柱蛋白与S-RNase结合。 一个是先前表征的蛋白质，NaTTS，它与相容性花粉管的生长有关。 NaTTS和p11是推测的非S-RNase因子，可能与花粉排斥和支持亲和花粉管生长有关。 凝胶过滤法和蛋白质印迹法测定了NaTTS/S-RNase/p11复合物的分子量和组成。 NaTTS和p11也将在细菌中表达，然后用于测试体外相互作用。 反义方法将用于确定p11是否影响体内的亲和或不亲和授粉。 为了鉴定新的非S-RNase因子，我们已经产生了能够进行S等位基因特异性花粉排斥的分离群体。 cDNA AFLP将用于筛选与花粉排斥表型相关的新序列。这项研究的影响将提供一个更好的理解花粉识别和排斥的遗传机制。 这对希望操纵植物育种行为的生物技术工作者具有实际意义。