南京农业大学学报2018，Vol.41Issue(2)：231-239,9.DOI:10.7685/jnau.201706007
水稻心白突变体whc的理化性质和基因定位
Physicochemical properties and gene mapping of white-core mutant whc in rice
摘要
Abstract
[Objectives]Starch accounts for about 80% of the total dry matter content of rice endosperm,and composition and content of starch as well as starch granule structure in the endosperm have important influence on the rice quality. Therefore,it is important to clarify the molecular mechanism of starch synthesis in rice. [Methods]A stable white core endosperm mutant(whc)was obtained by mutagenesis of 60Co-γ in a japonica rice variety'Zhonghua 11'(ZH11)background. Analysis of phenotypic traits,physicochemical properties,and starch structure was carried out. Further,genetic linkage analysis was performed using an F2population derived from whc and'N22'cross. [Results]Compared to the wild type,the mutant showed floury and opaque in the center of endosperm.In contrast to the increased grain width and effective panicle number,the whc had 14.5% less 1 000-grain weight than its wild type.Meanwhile,the amylose content in the mature seeds of the whc was 24.7% decreased,whereas the total protein content showed no significant difference. Scanning electron microscopy analysis of endosperm cross section showed that starch granules in the floury part of the mutant were abnormal,relative to its wild type. The extreme individual was selected and the whc locus was delimited between the RM349 and d1 molecular markers on the long arm of chromosome 4,with a physical distance of 158 kb. Sequence analysis revealed that coding region of a tetratricopeptide repeat(TPR)domain protein had a single nucleotide substitution,leading to premature termination of protein translation. Quantitative RT-PCR indicated that expression levels of genes encoding the AGPase subunits and other starch synthesis-related enzymes in the whc mutant endosperm had changed. [Conclusions]The phenotype of the whc was likely controlled by the gene encoding a TPR domain containing protein.关键词
水稻/心白突变体/淀粉/理化性质/基因定位Key words
rice/white core(whc)mutant/starch/physicochemical properties/gene mapping分类
农业科技引用本文复制引用
刘子文,胡曼曼,王致远,张瑜竣,谷晗,游佳,王益华,江玲,刘玲珑..水稻心白突变体whc的理化性质和基因定位[J].南京农业大学学报,2018,41(2):231-239,9.基金项目
国家重点研发项目(2016YFD0100101) （2016YFD0100101）
江苏省科技支撑计划项目(BE2015355-1) （BE2015355-1）
江苏省农业科技自主创新资金课题(CX(16)1029) （CX(16）
国家自然科学基金项目(31571629) （31571629）
