Self-Incompatibility in Nicotiana Alata

阿拉塔烟草的自交不亲和性

• 批准号: 9316152
• 负责人: Bruce McClure
• 金额: $ 33万
• 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: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316152&HistoricalAwards=false
• 关键词: Self; Incompatibility; Nicotiana; Alata

9316152 McClure In solanaceous plants with gametophytic self-incompatibility (GSI), S-allele pollen recognition and rejection are controlled by a single genetic locus, the S-locus. Pollen is rejected if its single S-allele matches either S-allele in the pistil. Information is communicated about the allelic constitution of the S-locus in the sporophyte and in the gametophyte. The products of the S-locus are the carriers of this information. The S-locus products expressed in the pistil comprise a series of allelic ribonucleases, the S-RNases. It has been shown that each S- allele encodes a different S-RNase. However, it is not known how these differences lead to S-allele specific recognition. No S-allele specific product has yet been identified in the male gametophyte (i.e., pollen-S). This proposal seeks to develop an understanding of the molecular basis for S-allele specific recognition and rejection. The first step will be to develop a system in which S-allele specific recognition and rejection can be manipulated. Cloned S-RNases from Nicotiana alata will be used to introduce new allelic specificity into transgenic plants. Using the expression system, it will be possible to manipulate cloned S-RNase sequences in vitro and assess the effects on pollination behavior in vivo. The choice of plant materials for use as transgene recipient is very important. The transformation efficiency of N. alata is too low to generate the necessary number of transformants. Therefore, transgenes will be introduced into a plant such as Nicotiana plumbaginifolia and crossed into N. alata or into a transformable F1 hybrid capable of S-allele specific pollen rejection. In either case, the inherent specificity of the SI reaction provides excellent controls. Dr. McClure will look for the introduction of, or modification of, a new specificity in the transgenic plants. Identification of the pollen-S product is a major goal of this proposal. A combined genetic and molecul ar biological approach is proposed. A large F2 population segregating for two S- alleles has been generated. Plants homozygous for a given S- allele will be pooled. Using these pooled materials, subtractive hybridization and differential mRNA display will be used to identify a putative pollen-S cDNA. GSI has the potential to help understand plant cell-cell communication. To realize its potential, GSI research must move into an analytical phase. This proposal aims to accomplish this by developing a system for direct analysis of the allelic specificity function of S-RNases, and identifying the product responsible for allele specific recognition in pollen. ***

9316152在具有配子体自交不亲和性的茄科植物中，S等位基因对花粉的识别和排斥是由单个遗传座位控制的，即S座位。如果花粉的单个S等位基因与雌蕊中的任何一个S等位基因匹配，则拒绝花粉。关于S基因座在孢子体和配子体中的等位基因构成的信息是相互传递的。S轨迹的产品是这一信息的载体。在雌蕊中表达的S位点产物包括一系列等位基因核糖核酸酶，即S核糖核酸酶。已有研究表明，每个S等位基因编码不同的S核糖核酸酶。然而，这些差异是如何导致S等位基因特异性识别的尚不清楚。在雄配子体中还没有发现S等位基因的特异产物(即花粉S)。这一建议旨在加深对S-等位基因特异性识别和排斥的分子基础的理解。第一步将是开发一个可以操纵S等位基因特异性识别和排斥的系统。从烟草中克隆的S核糖核酸酶将被用于向转基因植物中引入新的等位基因特异性。利用该表达系统，可以在体外操纵克隆的S核糖核酸酶序列，并在体内评估其对授粉行为的影响。选择用作转基因受体的植物材料是非常重要的。转化子的转化效率太低，无法产生所需数量的转化子。因此，转基因将被导入到白花烟草等植物中，并与北美烟草杂交，或进入能够产生S等位基因特异花粉排斥的可转化的F1杂种中。在任何一种情况下，SI反应的固有特异性都提供了很好的控制。麦克卢尔博士将在转基因植物中寻找一种新的特异性的引入或修饰。鉴定花粉-S产品是这项提案的主要目标。提出了一种遗传和分子生物学相结合的方法。产生了一个大的分离两个S等位基因的F2群体。对于给定的S等位基因，纯合的植物将被汇集。利用这些汇集的材料，消减杂交和差异显示将被用来鉴定一个可能的花粉-S。GSI具有帮助理解植物细胞间通讯的潜力。为了实现其潜力，GSI研究必须进入分析阶段。这项建议旨在通过开发一个系统来直接分析S核糖核酸酶的等位基因特异性功能，并确定负责花粉中等位基因特异性识别的产物来实现这一点。***