小麦中编码未知蛋白的热胁迫响应基因TaWTF1的克隆和功能分析

WTF1 (What’s this factor 1)是包含“Domain of Unknown Function 860”(DUF860)的一类蛋白, 特异定位于植物细胞叶绿体或线粒体中, 在内含子的剪切中发挥作用。在研究小麦(Triticum aestivum)热胁迫转录谱时发现一个包含该结构域的探针受高温诱导表达。通过对其所编码的基因TaWTF1进行克隆并详细分析, 发现该基因的启动子区包含HSE、干旱、GA及SA等胁迫和激素响应元件, 且该基因在苗期和开花期均受热胁迫诱导表达。在开花期, TaWTF1在普通叶中的表达显著高于包括旗叶在内的其它组织器官。进一步将该基因在拟南芥(Arabidopsis thaliana)中超表达, 显著提高了转基因植株在热胁迫下的成活率, 说明TaWTF1参与了植物耐热性。该研究为解析植物耐热性分子机理开辟了新的领域, 并为作物耐热性分子育种提供了候选基因。

Isolation and Functional Characterization of Heat-stressresponsive Gene TaWTF1 from Wheat

What’s this factor 1 genes (WTF1s) encode a group of proteins with Domain of Unknown Function 860 which are localized specifically in the plant chloroplast and mitochondria and play an important role in intron splicing. Previously, a heat-responsive probe with this conserved domain was identified in the Affymetrix Wheat Genome Array. With the probe sequence, the open reading frame was cloned from wheat and was named TaWTF1. Bioinformatics analysis showed that the promoter of TaWTF1 contained some stress- and hormone-responsive elements including a heat-shock element. TaWTF1 gene expression was induced by heat treatments at the seedling and flowering stages. Moreover, the expression of this gene was higher in the common leaves. Importantly, overexpression of TaWTF1 improved the survival rate of Arabidopsis under heat stress. This study provides valuable information to understand more about the molecular mechanism of thermotolerance in plants.