南京农业大学学报2017，Vol.40Issue(5)：780-788,9.DOI:10.7685/jnau.201703043
水稻胚乳突变体b140的表型分析及基因克隆
Phenotyping and gene cloning of a floury endosperm mutant b140 in rice
摘要
Abstract
[Objectives] We analyzed the phenotype of a rice floury endosperm mutant b140 and cloned this gene to lay the foundation for the mechanism of starch biosynthesis.[Methods] Related agronomic traits,dry matter accumulation during grain filling and physicochemical properties of wild type and b140 grains were measured and the structure of starch granules were observed.A hybrid F2 population of b140 and'Nanjing 11'was developed and the recessive individuals were selected to map the locus.qRT-PCR was conducted to analyze the expression of genes related to starch biosynthesis.The activities of related enzymes were measured.[Results] The grain width,grain thickness and 1 000-grain weight of b140 significantly decreased compared with the wild type.There was no detectable change in grain length and other agronomic traits of b140 compared with the wild type.Total starch content and amylose content in mature seeds of b140 decreased compared with wild-type.The content of soluble sugars was significantly higher than that of wild type.Scanning electron microscopy analysis showed that the mutant endosperm contained loosely packed irregular compound starch granules.The b140 locus was delimited to a 56 kb region on Chromosome 1.Sequence analysis revealed that the coding region of Os01g0179400,an already reported gene,had a mutation.The results of qRT-PCR indicated that the expression levels of some genes participating in starch synthesis were down-regulated in b140.The analysis of enzymatic activity showed that the activity of adenosine diphosphoglucose pyrophosphprylase in b140 was significantly lower than that in wild type.[Conclusions] Os01g0179400 contained a single nucleotide substitution in b140,leading to floury endosperm.Os01g0179400 might play an important role in the synthesis and regulation of starch in rice and affect the activity of adenosine diphosphoglucose pyrophosphprylase.The discovery of b140 has certain significance for the understanding of starch synthesis and regulation mechanism.关键词
水稻/粉质胚乳突变体/精细定位/淀粉Key words
rice/floury endosperm mutant/fine mapping/starch分类
农业科技引用本文复制引用
汪国湘,蔡跃,尤小满,燕海刚,王亮,金洁,张文伟,江玲..水稻胚乳突变体b140的表型分析及基因克隆[J].南京农业大学学报,2017,40(5):780-788,9.基金项目
江苏省科技支撑计划项目(BE2015363) （BE2015363）
江苏省自主创新课题资助项目(CX(16)1029) （CX(16）
安徽省科技重大专项(16030701068) （16030701068）
