水稻白条纹突变体st13的表型分析及基因定位

发布时间：2018-08-02 13:25

【摘要】：【目的】叶色突变相关基因鉴定和克隆有助于研究光合作用,补充并完善叶绿体发育机理和色素合成代谢途径,为开展水稻的高光效育种提供理论依据。【方法】从粳稻品种Dongjin的组培后代中分离出一个白条纹突变体st13,成熟期测定野生型和st13的主要农艺性状,苗期测定色素含量并观察叶绿体的超微结构;将st13和Dongjin进行正反交,观察F_1植株表型,并对F_2表型分离进行卡方检验,对st13进行遗传分析;利用st13×南京11(籼稻品种)的F_2和F_(2:3)群体,对st13突变基因定位;采用qPCR分析叶绿体发育和叶绿素合成相关基因在st13与野生型相对表达量。【结果】与野生型Dongjin相比,该突变体的株高、单株有效穗数、穗长、结实率和千粒重等主要农艺性状显著下降。苗期的色素含量降低,分蘖期无差异。突变体的叶绿体中既有含丰富的类囊体膜结构的正常叶绿体,也存在无类囊体结构的叶绿体。遗传分析和基因定位结果表明,st13的突变表型受1对隐性核基因控制,突变基因位于第3条染色体长臂InDel(Insertion-Deletion)标记I3-21和I3-22之间。进一步在这两个标记之间设计了6对InDel标记,最终将基因定位在94kb区间内,此区间共有8个候选基因。【结论】这8个候选基因中,有5个假定的蛋白,其他三个都是有功能注释的蛋白,而这三个蛋白在水稻中均未见报道,因此,st13突变是由一个新的叶色基因突变引起的;同时st13中叶绿体发育、叶绿素合成和光合系统相关基因的表达也发生了显著改变,推测ST13可能是调控叶绿体发育的关键基因。
[Abstract]:[objective] Identification and cloning of genes related to leaf color mutation are helpful to study photosynthesis, complement and perfect the mechanism of chloroplast development and the pathway of pigment biosynthesis. [methods] A white stripe mutant st13 was isolated from the tissue culture progeny of japonica rice variety Dongjin, and the main agronomic characters of wild type and st13 were determined at maturity. The pigments content and chloroplast ultrastructure were observed at seedling stage, st13 and Dongjin were crossed positively and inversely, the phenotypes of FStu1 plants were observed, and the phenotypes of FSC2 were detected by chi-square test, and the genetic analysis of st13 was carried out. St13 脳 Nanjing 11 (Indica rice variety) was used to localize the st13 mutant gene, and qPCR was used to analyze the relative expression of chloroplast development and chlorophyll synthesis related genes between st13 and wild type. [results] compared with wild type Dongjin, st13 mutation gene was located in F _ 2 and F _ (2:3) populations of st13 脳 Nanjing 11 (indica rice variety). The main agronomic characters such as plant height, effective panicle number per plant, ear length, seed setting rate and 1000-grain weight were significantly decreased. Pigment content in seedling stage decreased, but there was no difference at tillering stage. Both normal chloroplasts with abundant thylakoid membrane structure and chloroplasts without thylakoid structures were found in the chloroplasts of the mutant. Genetic analysis and gene mapping showed that the mutant phenotype of st13 was controlled by a pair of recessive nuclear genes, and the mutant genes were located between the long arm InDel (Insertion-Deletion) markers I3-21 and I3-22 on chromosome 3. Further, six pairs of InDel markers were designed between the two markers. Finally, the gene was located in the 94kb region, which had 8 candidate genes. [conclusion] among the 8 candidate genes, there are five hypothetical proteins. The other three are functionally annotated proteins, none of which have been reported in rice, so the mutation of st13 was caused by a new leaf color gene mutation, and chloroplast development in st13. Chlorophyll synthesis and the expression of photosynthesis-related genes also changed significantly, suggesting that ST13 may be the key gene regulating chloroplast development.
【作者单位】：南京农业大学作物遗传与种质创新国家重点实验室/农业部长江中下游粳稻生物学与遗传育种重点实验室/长江流域杂交水稻协同创新中心/江苏省现代作物生产中心;江苏丘陵地区镇江农业科学研究所;中国农业科学院作物科学研究所;
【基金】：国家重点研发项目七大农作物育种专项(2016YFD0100101-08) 国家863计划资助项目(2014AA10A603-15) 江苏省科技支撑计划资助项目(BE2014394,BE2015363) 江苏省农业科技自主创新资金资助课题[CX(16)1029]
【分类号】：S511

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