Rht12矮秆小麦GA3ox基因的克隆与表达分析  

Cloning and Expression Analysis of GA3ox Genes from Rht12 Dwarfing Wheat

作　　者：刘颖[1] 阳文龙[2] 郭小丽[3] 翟晓[3] 刘冬成[2] 孙家柱[2] 夏石头[1] 张爱民[2] 

机构地区：[1]湖南农业大学植物激素与生长发育湖南省重点实验室,生物科学技术学院,长沙410128 [2]中国科学院遗传与发育生物学研究所植物细胞与染色体工程国家重点实验室,北京100101 [3]中国农业大学生物学院,北京100193

出　　处：《分子植物育种》2015年第2期241-253,共13页Molecular Plant Breeding

基　　金：973项目(2014CB138100);国家自然科学基金项目(90717118)共同资助

摘　　要：赤霉素3-氧化酶(GA3ox)是赤霉素生物合成途径中的一种关键酶,在茎的伸长中起着重要的作用。为探讨GA3ox基因和Rht12矮秆小麦矮化之间的关系,本研究利用同源克隆方法分离得到了小麦品种中国春和宁98-2105(含矮秆基因Rht12)的GA3ox1和GA3ox2基因,并对其在茎的不同部位进行了表达模式分析。研究结果表明,小麦GA3ox1和GA3ox2均含有3个外显子和2个内含子,其编码的蛋白具有2-酮戊二酸依赖性的双加氧酶典型的保守结构域,但中国春和宁98-2105的GA3ox1和GA3ox2之间存在部分碱基的差异。实时定量表达分析结果显示,GA3ox1和GA3ox2在中国春和宁98-2105茎的不同部位的表达趋势基本一致,但表达量具有较大差异,GA3ox1和GA3ox2在宁98-2105茎的倒一节结节中的转录水平显著高于中国春,推测宁98-2105中赤霉素的信号转导通路可能受到了影响,即矮秆基因Rht12可能影响了赤霉素信号的传导。本研究结果为进一步研究矮秆基因Rht12的致矮机理和利用提供了理论依据。GA 3-oxidase（GA3ox） is a key enzyme which catalyzes endogenous bioactive gibberellins formation and plays crucial roles in stem elongation.To gain insight into the relationships between GA3 ox and Rht12 dwarfing wheat,we isolated GA3ox1 and GA3ox2 from wheat varieties Chinese Spring and Ning 98-2105（containing Rht12gene） by homologous cloning,and analyzed their expression patterns in different parts of stems.The results showed that there were two introns and three exons in each of GA3ox1 and GA3ox2,the deduced amino acid sequences of GA3ox1 and GA3ox2 had typical conserved domain of ketoglutarate-dependent dioxygenase,but several SNPs existed in GA3ox1 and GA3ox2 between Chinese Spring and Ning 98-2105.Quantitative PCR analysis indicated that GA3ox1 and GA3ox2 had similar expression patterns in different stem parts of Chinese Spring and Ning98-2105,but their transcript levels were very different,the expression levels of GA3ox1 and GA3ox2 in the uppermost node of Ning 98-2105 was significantly higher than those of Chinese Spring,which suggested that the gibberellins signaling pathway might be affect ed in Rht12 dwarfing wheat Ning 98-2105.These results lay afoundation for utility and further investigating dwarfing mechanism of Rht12 in wheat.

关 键 词：小麦 GA3ox 基因克隆 表达分析 

分 类 号：S512.1[农业科学—作物学]