小麦wzy2-1基因的克隆及功能分析

脱水素是一类植物胚胎发育后期丰富蛋白(late embryogenesis abundant protein, LEA蛋白)，属于LEA D-11家族，植物受非生物胁迫会大量表达。利用同源克隆技术，从郑引1号小麦中克隆了1个Kn型脱水素基因，命名为wzy2-1。该基因全长1740bp，编码579个氨基酸，含有9个保守的K片段，与大麦的Dhn5基因具有较高同源性。生物信息学预测该蛋白属于高度亲水性的无序蛋白。通过该蛋白对大肠杆菌的保护作用研究表明，WZY2-1蛋白能够提高大肠杆菌对低温、高温、高盐以及高渗胁迫的耐受性。荧光实时定量PCR分析表明，wzy2-1基因受低温、盐渍、干旱诱导表达，但不受外源ABA诱导，说明wzy2-1基因属于非ABA依赖型脱水素基因。

Cloning and Functional Analysis of wzy2-1Gene in Wheat

Dehydrins (DHNs) are identified as the group II of LEA proteins and involved in plant abiotic stress tolerance.In this study,we isolated a novel Kn-type dehydrin genefrom wheat cultivarZhengyin 1, which was designated wzy2-1.The full length of wzy2-1 is 1740bp,encoding 579 amino acids andcontaining nine conserved K-fragments.Sequence alignment indicated that wzy2-1hadhighhomologytoDhn5gene in Hordeumvulgare.The WZY2-1 protein waspredicted to be a highly-hydrophilic and disordered protein. The WZY2-1 protein was successfully expressed in E. coli strain BL21 (DE3). We found that WZY2-1 protein improved the tolerance to low or high temperature, salt and osmotic stressesin E. coli. The qRT-PCR assay indicated that the expression of wzy2-1gene was inducedby low temperature, PEG, and salt stresses rather than ABA. Thus, we conclude that wzy2-1 is an ABA-independent gene.