铝胁迫条件下小麦根系特异表达基因的研究

Identification of Differential Genes in Wheat Roots under Aluminum Stress

利用尼龙膜点阵杂交技术,由耐铝胁迫小麦品系OK91G106根系构建的cDNA差减杂交文库中,鉴定出29个铝胁迫特异诱导基因,包括20个已知生物学功能的基因和9个功能未知基因。这20个已知功能基因归属于植物体内细胞信号转导、活性氧清除、维持膜结构稳定、苹果酸分泌和细胞保护等类别。表明在铝胁迫下,植株体内在短时间内发生了感受铝胁迫逆境信号并进行了信号转导,调控了植株对铝胁迫逆境响应的复杂分子生物学过程。Northern印迹对5个铝诱导基因转录本的检测结果与尼龙膜点阵技术获得的结果相一致。本研究鉴定出的铝诱导基因中含有1个苹果酸转运蛋白基因,表明苹果酸分泌量的增加可能是供试小麦响应和抵御铝胁迫逆境的重要机制之一。

Twenty-nine aluminum-induced genes were identified on the base of nylon filter arrays, which contained all clones from a suppression subtractive hybridization （SSH） cDNA library constructed from roots of OK91G106 （the wheat line with high ability of aluminum tolerance）. The induced genes included 20 known biological functions and 9 functions unknown by BLASTn analysis in international biological website NCBI. We found that the induced genes under aluminum stress could be classified into different groups according to the deduced biological function, including signal transduction, active oxygen scavenging, sustaining stability of membrane structure, secretion of malate, and protection of cellular function. It suggested that the wheat plants involved the perception and transduction of the signal of aluminum stress, by which to induce the expression of some genes response to aluminum stress in short time under aluminum stress condition. The results from Northern blot analysis for five induced genes were all similar to those from the nylon filter arrays. There was one malate transporter gene among the 29 aluminum-induced genes, indicating that the increase of malate secretion under aluminum stress condition is possibly an important mechanism for the tested wheat line to response and withstand the aluminum toxicity.