MaGA2ox12基因在香蕉中的克隆、亚细胞定位及表达分析

Cloning,Expression and Subcellular Localization Analysis of Ma GA2ox12Gene from Banana

为了比较MaGA2ox12在威廉斯香蕉(Musa acuminata,AAA group)‘8818’及其矮化突变体‘8818-1’的序列差异和表达差异,本研究分别以威廉斯‘8818’及‘8818-1’的假茎为试材,同源克隆MaGA2ox12基因的g DNA及启动子序列,比较它们在基因组测序品种DH-Pahang以及威廉斯‘8818’和‘8818-1’中的序列差异。结果表明‘,8818’和‘8818-1’间MaGA2ox12的g DNA与启动子序列的相似性分别为99.93%和99.86%,而威廉斯品种与DH-Pahang间,MaGA2ox12基因无论g DNA序列还是启动子序列均存在较大差异(分别为98.13%和87.14%),且MaGA2ox12的启动子存在较多光响应和激素响应元件。MaGA2ox12具备GA2ox基因家族的特征,同源进化分析发现其与海枣、油棕亲缘关系最近,属于C20-GA2ox类型。亚细胞定位显示MaGA2ox12蛋白定位于细胞核上。RT-qPCR结果表明,MaGA2ox12在巴西、贡蕉、‘8818’果实发育时期下调表达,在‘88181-1’中上调表达,调控具有品种特异性,Ma GA2ox12极其可能是调控果实和假茎中赤霉素含量的主要酶之一。

To compare the sequence differences and expression differences of MaGA2ox12 in Williams’8818’(Musa acuminata,AAA Group)and its mutant’8818’,the g DNA and promoter sequences of MaGA2ox12 gene were cloned homogeneously in the pseudostem of’8818’and’8818’,and their sequence differences in genome-sequencing variety DH-Pahang,’8818-1’and’8818-1’were compared.The results showed that the g DNA and promoter sequence similarities of MaGA2ox12 between’8818’and’8818-1’were 99.93%and 99.86%,respectively.However,the g DNA sequence and promoter sequence of MaGA2ox12 gene were significantly different between Williams cultivar and DH-Pahang(98.13%and 87.14%,respectively),and the promoter of MaGA2ox12 had a lot of light response and hormone response elements.Ma GA2ox12 has the characteristics of GA2ox gene family.Homologous evolution analysis shows that Ma GA2ox12 is most closely related to Cocos nucifera,Phoenix dactylifera and belongs to C20-GA2ox type.The subcellular localization of MaGA2ox12 showed that it was located in the nucleus.The RT-qPCR results showed that MaGA2ox12 expression was down-regulated in the fruit development stage of BX,GJ and’8818’,and up-regulated in’8818-1’.The regulation was cultivar-specific.MaGA2ox12 was probably one of the main enzymes regulating gibberellin content in both fruit and pseudostem.