水稻肌醇加氧酶基因的表达分析及植物表达载体的构建

为研究水稻肌醇加氧酶基因在植物水分胁迫分子应答中的作用,采用RT-PCR技术克隆了水稻肌醇加氧酶基因的cDNA编码区,命名为OsMIOX。该基因由927个碱基组成,编码308个氨基酸,与拟南芥肌醇加氧酶的氨基酸序列相比,同源性为78%。将克隆的OsMIOX基因连接pCAMBIA-1301载体,成功构建了35 s启动子驱动的植物超表达载体。实时定量PCR分析结果表明,水分胁迫下OsMIOX基因在旱稻IRAT109中上调表达,在旱稻(IRAT109和毫格劳)中的表达量显著高于水稻(越富和日本晴)。这说明水稻和旱稻的水分胁迫分子反应机制的确存在差异,而这种差异很可能就是水、旱稻抗旱性不同的原因之一。

Expression analysis of rice myo-inositol oxygenase like gene and development of its plant expression vector

To understand the role of myo-inositol oxygenase gene in plant under water stress using RT-PCR,the cDNA of open read fragment of putative myo-inositol oxygenase gene(MIOX) in rice was successfully amplified to 927 bp in length and encoded 308 amino acids,named OsMIOX.Sequence analysis indicated that OsMIOX shared high homogeneity with the Arabidopsis thaliana MIOX gene.The cloned cDNA of OsMIOX gene was introduced into pCAMBIA-1301 vector,giving a plant expression vector containing OsMIOX gene linked with 35s promoter.Results of real-time PCR analysis showed that the OsMIOX gene was upregulated by PEG stress in upland rice cultivar IRAT109,and the expression level was higher in upland rice(IRAT109,Haogelao) than in lowland rice(Yuefu,Nipponbare) under PEG stress.This showed that the molecular mechanism under water stress was different between lowland rice and upland rice,perhaps due to differences in drought stress.The possible role of OsMIOX gene under drought stress was discussed.