水稻分离群体中半矮秆和致死性黄苗突变体的形成机理研究

Generation Mechanism of A Semi-dwarf Mutant and A Lethal Yellow Seedling Mutant in A Rice Segregating Progeny Lines

[目的]鉴定sdwrky和lysrcc1突变体的Ds插入突变基因,初步分析sdwrky和lysrcc1突变体形成的分子机理。[方法]采用TAIL-PCR技术,分别从sdwrky突变体和lysrcc1突变体克隆Ds侧翼基因序列,并进行序列分析。[结果]Ds分别插入sdwrky突变体4号染色体Os04g0597300(sdwrky)基因和lysrcc1突变体3号染色体Os03g0599600(lysrcc1)基因,导致sdwrky和lysrcc1基因突变。[结论]sdwrky基因编码包含WRKY结构域的蛋白质(SDWRKY),推测SDWRKY与OsWRKY24具相似功能,作为糊粉层细胞内ABA和GA信号传导途径中共同的抑制因子,调控水稻种子萌发及幼苗生长,Sdwrky基因突变导致形成sdwrky突变体。lysrcc1基因编码包含RCC1结构域的蛋白质(LYSRCC1),LYSRCC1可能作为RanGEF参与核质运输,影响叶绿体合成的某一环节,lysrcc1基因隐性突变导致形成ylrcc1突变体。

[Objective] The study aimed to identify the Ds-tagged genes of the mutants sdwrky and lysrcc1,and to analyze their molecular mechanism.[Method] The Ds-flanking sequences were cloned from the two mutants by using TAIL-PCR amplification technique.[Result] Analysis of the Ds-flanking sequences indicated that one Ds element was inserted into the Os03g0599600 gene（sdwrky）of rice chromosome 4 in the sdwrky mutant;Another Ds element was inserted into the Os04g0597300 gene（lysrcc1）of rice chromosome 3 in the lysrcc1 mutant.[Conclusion] The sdwrky gene encoded a WRKY domain containing protein.SDWRKY probably had the similar function of OsWRKY24 which was a negative regulator encoded by a rice WRKY gene repressing both ABA and GA signaling in aleurone cells.The sdwrky gene mutation resulted in the sdwrky mutant phenotypes.The lysrcc1 gene encoded a regulator of chromosome condensation（RCC1）repeat containing protein（LYSRCC1）.As a Ran GEF,YLRCC1 probably played an important role in the regulation of nucleocytoplasmic transport,which was essential for chloroplast synthesis.The lysrcc1 mutant was probably caused by a single recessive mutation of the lysrcc1 gene.