Molecular Genetic Basis of Self-Incompatibility in Petunia

矮牵牛自交不亲和性的分子遗传学基础

• 批准号: 9220145
• 负责人: Teh-hui Kao
• 金额: $ 45.4万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-05-01 至 1997-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9220145&HistoricalAwards=false
• 关键词: Molecular; Genetic; Basis; Self; Incompatibility

Self-incompatible Petunia inflata and a self-compatible cultivar of Petunia hybrida will be used as model systems in an ongoing study of the molecular, biochemical, and genetic bases of gametophytic self-incompatibility. The first objective is to provide direct evidence for the role of the S-gene (the gene encoding the pistil S-protein) in the recognition and rejection of self pollen. Two approaches will be taken: a) transgenic P. inflata plants obtained by introducing S1-gene into S3S3 genotype, and S3-gene into S1S1 genotype, will be tested to see whether the ability to reject pollen bearing S1-allele and S3-allele respectively has been conferred by the transgenes; b) antisense S1-gene will be introduced into P. inflata plants with S1S3 genotype to see whether the ability to reject S1-bearing pollen is annulled in the transgenic plants. The second objective is to determine the regulatory sequences for the pistil-specific expression of the S- gene and rnx2 gene (encoding RNase X2) by examining the expression of a series of promoter-GUS constructs via transient assays and in stable transformants. The third objective is to identify and characterize other components that participate in self- incompatibility interactions. PCR techniques will be used to investigate whether the S-gene is expressed in pollen during its growth in situ. Chromosome walking experiments will be used to identify sequences linked to the S-gene that might encode other components of the self-incompatibility system. An approach based on immunoprecipitation will be used to examine whether pollinated pistils contain any proteins that interact with S-proteins. These experiments may lead to identification of the long sought pollen component of the S-locus. The fourth and final objective is to determine the genetic basis for the breakdown of self- incompatibility in the self-compatible cultivar of P. hybrida. Genetic crosses have been designed to test a model implicating a modifier locus in the modulation of S-alleles activity in self- incompatibility interactions.

在正在进行的分子，生化和遗传碱基的配子性自我兼容性的研究中，自我兼容的矮牵牛足体和自我兼容的矮牵牛品种将用作模型系统。第一个目标是直接证明S-Gene（编码雌性S-蛋白质的基因）在识别和排斥自花粉中的作用。将采用两种方法：a）通过将S1基因引入S3S3基因型获得的转基因P.充气植物，并将S3-GENE在S1S1基因型中进行测试，以查看拒绝花粉轴承S1-Allele和S3-Allele的能力是否已由Transgenes授予； b）反义S1基因将被引入具有S1S3基因型的P. Optrata植物中，以查看是否在转基因植物中废除拒绝含S1含S1的花粉的能力。第二个目标是通过通过瞬态测定和稳定转化剂检查一系列启动子-GUS构建体的表达来确定S-基因和RNX2基因（编码RNase X2）的雌蕊特异性表达的调节序列。第三个目标是识别和表征参与自我不相容相互作用的其他组件。 PCR技术将用于研究S-Gene在原位生长期间在花粉中是否表达。染色体步行实验将用于识别与S-Gene相关的序列，该序列可能编码自我兼容系统的其他组件。基于免疫沉淀的方法将用于检查授粉的雌蕊是否包含与S蛋白相互作用的任何蛋白质。这些实验可能导致鉴定S-cocus长期寻求的花粉成分。第四个也是最终目标是确定杂种杂种自我兼容品种中自我不相容性的遗传基础。 遗传杂交已设计为测试一个模型，该模型暗示了在自我不兼容相互作用中S-learters活性调节中的修饰基因座。