摘要： 旨在对水稻叶片早衰突变体osles3进行遗传分析与基因精细定位，探索水稻叶片衰老的分子机制。从粳稻中花11的自然变异突变体库中筛选到一个叶早衰突变体osles3 ，对该突变体及其野生型进行表型鉴定及农艺性状分析，构建突变体与籼稻ZS97的F₂群体，通过图位克隆的方法精细定位该基因，并利用生物信息学方法对其进行结构与功能分析。表型鉴定结果表明，osles3在分蘖后期开始出现水浸状衰老斑点，成熟时整株衰老；与野生型相比，osles3的株高、分蘖数、结实率、穗粒数及千粒质量等都极显著降低。遗传分析结果表明，该突变表型由1对核隐性基因控制，利用分子标记将目标基因定位于第3染色体长臂端，其与RM15524和RM15551的遗传距离分别为0.9，0.5 cM。序列多态性及生物信息学分析表明，OsLES3属于LSD1型锌指（Zinc finger）蛋白家族成员，其翻译起始位点（ATG）5'上游区存在988 bp片段插入及54 bp片段缺失。本研究完成了水稻叶早衰突变体osles3的精细定位，可能是DNA片段插入与缺失造成OsLES3功能缺失，从而导致该突变体表型的产生。

关键词: 水稻, 早衰突变体, 基因定位, 生物信息学

Abstract: Genetics analysis and fine mapping of osles3,a mutant with early senescent leaf in rice,were conducted to explore the molecular mechanism of rice leaf premature senescence.A leaf early senescence mutant osles3 was obtained from a natural mutant library of the Japonica variety Zhonghua 11.Phenotype and agronomic traits of osles3 and its wild-type were identified.The F₂ population from mutant crossed to ZS97(Indica cultivar) was used to mapping the gene OsLES3 by the map cloning method,and the structure and function of OsLES3 were analyzed by bioinformatics method.Phenotypic observation showed that the mutant began to have water-soaked senescence spots in the late tillering period,and the whole plant senescence at maturity. osles3 mutant showed extremely significantly decreased in plant height,tiller number,seed setting rate,grain number per panicle and 1000-grain weight compared to the wild-type plant.Genetic analysis revealed that the mutant phenotype was controlled by a pair of nuclear recessive gene on the long arm of chromosome 3,between two markers RM15524 and RM15551 with 0.9,0.5 cM genetic distance,respectively.Morever,sequence polymorphorism and bioinformatic analysis revealed that 988 bp fragment insertion and 54 bp fragment deletion in 5' Čupstream of translation initiation ATG of OsLES3,which encoded a LSD1 zinc finger domain containing protein.This research completed the fine mapping of the rice premature leaf senescence mutant osles3,and revealed that the mutant phenotype might be caused by some DNA fragment deletion and insertion in OsLES3 gene.

Key words: Rice, Early senescence mutant, Gene mapping, Bioinformatic

中图分类号: 

• Q78

• S511.03