Molecular Basis of Gametophytic Self-Incompatibility in Nicotiana and Petunia

拟议的项目是研究雌蕊的功能方面 配子体S蛋白与S基因表达调控 自交不亲和性利用烟草阿拉塔和矮牵牛， 高博士将建立直接证据，证明S蛋白是 负责自交不亲和反应，通过测试 对自交不亲和性的影响 将新的S-基因导入对于不同的S-等位基因纯合的植物中，或者 将反义S基因导入相同S等位基因纯合的植物中; 2） 鉴定S蛋白的S等位基因特异性结构域， 使用在转基因植物中表达的嵌合S蛋白; 3）测试 突变S-的保守半胱氨酸残基的效果 蛋白质的功能; 4）确定序列 控制组织特异性和发育调节 通过将S基因的5'上游序列融合到 报告基因，GUS，然后用顺序缺失法检测 转基因植株中GUS基因表达的影响; 5）鉴定 一种与S基因座的花柱活动部分相关的蛋白质 利用N.阿拉塔。的 这些实验的结果将产生重要的信息， 自交不亲和的分子基础 %%% 许多高等植物有一种称为自交不亲和的机制， 它能阻止植物的花粉自交 同一植物的雌性组织（雌蕊）。基因控制 这种自交不亲和性已经被确定， 由此发生不相容性是未知的。除了其 对于植物生物学家来说， 在农业上的应用有助于理解这一过程。

The proposed project is to study the functional aspects of pistil S-proteins and regulation of S-gene expression in gametophytic self-incompatibility. Using Nicotiana alata and Petunia inflata, Dr. Kao will 1) establish direct evidence that S-proteins are responsible for the self-incompatibility reaction by testing the effect on self-incompatibility behavior of introducing either a new S-gene into plants homozygous for a different S-allele, or an antisense S-gene into plants homozygous for the same S-allele; 2) identify the s-allele specificity domain of the S-protein by using chimeric S-proteins expressed in transgenic plants; 3) test the effect of mutating the conserved cysteine residues of S- proteins on their function; 4) determine the sequences controlling tissue specific and developmentally regulated expression of S-genes by fusing their 5' upstream sequences to a reporter gene, GUS, and then using sequential deletion to test the effect on expression of GUS in transgenic plants; 5) identify a protein associated with the style activity part of the S-locus using a unique self-compatible style-part mutant of N. alata. The result of these experiment will yield important information on the molecular basis of self-incompatibility. %%% Many higher plants have a mechanism, termed self-incompatibility, with prevents the pollen from a given plant from self fertilizing the female tissue (pistil) of the same plant. Genes controlling this self- incompatibility have been identified but the mechanism whereby the incompatibility occurs is unknown. In addition to its inherent interest to plant biologists, there are clear applications to agriculture to an understanding of this process.