两个新水稻 Dwarf18 基因强等位突变体的表型分析及分子鉴定  

Phenotypic Analysis and Molecular Characterization of Two Allelic Mutants of the Dwarf18 Gene in Rice

作　　者：侯雷[1,2] 袁守江 尹亮 赵金凤[2] 万国峰[1] 张文会[1] 李学勇[2] 

机构地区：[1]聊城大学生命科学学院,山东聊城252059 [2]中国农业科学院作物科学研究所/农作物基因资源与基因改良国家重大科学工程,北京100081 [3]山东省水稻研究所,山东济南250100

出　　处：《作物学报》2012年第8期1416-1424,共9页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB100200)资助

摘　　要：通过EMS诱变日本晴获得了s2-9和s1-146a两个矮秆突变体,其植株矮小,成熟期株高分别为日本晴的26.3%和19.2%;苗期叶片较宽,叶色深绿;穗型仍为散穗但穗长变短,粒型未发生改变。对水稻胚乳的α-淀粉酶诱导实验表明,这2个矮秆突变体与GA的信号传导途径无关,外源活性GA3对水稻幼苗株高的促进实验显示它们应与赤霉素的生物合成有关。利用突变体与籼稻品种Dular分别杂交构建了F2群体,精细定位表明这2个突变体的表型与水稻Dwarf18(D18)基因紧密连锁。序列分析发现这2个矮秆突变体的D18基因均发生了突变,在s2-9突变体中D18基因的内含子3'拼接点发生单碱基突变,s1-146a中D18基因编码区的单碱基突变导致提前终止密码子的出现。RT-PCR结果显示,在s1-146a中D18基因表达明显增强,但在s2-9中未检测到D18基因的表达。We identified two strong dwarf mutants from Nipponbare by EMS mutagenesis, designated as s2-9 and s1-146a. The plant height of these two mutants was 26.3% and 19.2% of that of Nipponbare at the mature stage. They also had wider and dark green leaf at seedling stage. The GA3 treatment of seedling and α-amylase activity analysis in endosperm showed that the mutated gene was involved in GA biosynthesis. Fine mapping showed that the mutant phenotype was tightly linked with the D18 locus. There was a single nucleotide substitution at the 3’-splicing site between the first intron and the 2nd exon in s2-9, whereas there was a single nucleotide substitution in the 2nd exon in s1-146a, which caused a premature stop codon. Semi quantitative RT-PCR revealed that transcript of the D18 gene was up-regulated in s1-146a as compared to WT, but was not detected in s2-9.

关 键 词：水稻 矮秆突变体 Dwarf18 赤霉素 精细定位 

分 类 号：S511[农业科学—作物学]