小麦耐逆基因-TaLEA3的克隆及在酵母中的功能分析

Cloning of a Novel Stress-tolerant Gene-TaLEA3 from Wheat and the Functional Analysis in Yeast

LEA蛋白 (late embryogenesis abundantprotein) ,是指胚胎发生后期种子中大量积累的一类蛋白质 ,它广泛存在于高等植物中 ,且受发育阶段、脱落酸 (ABA)和脱水信号的调节 ,其中第 3组LEA蛋白与作物耐逆性密切相关。通过RT PCR从小麦中克隆了一个新的第 3组LEA蛋白基因 ,TaLEA3。该蛋白主要定位于细胞质。TaLEA3的表达受高盐、低温和外源激素ABA的诱导 ,根中表达量一般高于叶中 ,且在不同胁迫下该基因表达模式存在差异。在所检测的一对同核异质小麦品种中 ,该基因的表达与耐旱性呈正相关。TaLEA3在酵母中过量表达 。

Expression of the genes encoding group 3 LEA proteins is thought to be relating with desiccation tolerance in young seedling. A novel gene in the group 3 Lea genes, named as TaLEA3, was cloned from wheat in the present study. TaLEA3 was mainly located in cytoplasm as revealed by the green fluorescent protein (GFP) fused to it. The gene was induced by high salt, low temperature and exogenous ABA treatments. The mRNA level of TaLEA3 was positively related to the drought tolerance of cultivars when its expression was compared in a pair of near isogenic lines of wheat. Substantially, the expression of TaLEA3 was higher in roots than that in leaves and their expression patterns were different under different stresses. Overexpression of TaLEA3 improved stress tolerance in transgenic yeast cells when cultured in medium containing sorbitol, or salt and under -20℃ freezing treatment.