拟南芥受Cd2+诱导表达基因的筛选及其在Cd2+胁迫下的功能

镉是一种毒性很大的重金属。土壤溶液中即使存在极低浓度Cd2+也能对植物造成伤害。早在植物做出结构和代谢的调整以适应逆境之前，由于Cd2+的刺激，植物的基因表达已经发生了变化。这里我们采用一种新的基于引物退火控制技术的差异显示方法来筛选受镉离子诱导表达的基因。获得的19条差异条带代表着18个基因。经过RT-PCR方法验证，其中6个基因确实是受Cd2+诱导表达，包括LEA(胚胎发育晚期丰富蛋白), AtGSTF2(谷胱甘肽-S-转移酶2), AtGSTF6(谷胱甘肽-S-转移酶6), HSP70(热激蛋白70), sHSP17.6B-CI(17.6 kDa 类型 I小分子热激蛋白)和sHSP17.6-CII(17.6 kDa类型II 小分子热激蛋白)。 这些结果有助于研究植物对镉离子胁迫的解毒机制。其中的三个热激蛋白基因的启动子也能考虑用于植物修复。

A Set of Genes Up-regulated by Cadmium Ions and Their Function under Cadmium Stress in Arabidopsis thaliana

Cadmium is a kind of highly toxic heavy metals. Even very low concentration of Cd2 + in soil solutions can result in toxic effects to plants. To survive, plants must change their metabolism to cope with cadmium exposure. Before that a lot of genes had changed their expression. A novel differential display PCR method was adopted that is based on annealing control primers (ACPs) to identify up-regulated genes of Arabidopsis by Cd2+ exposure. Nineteen differentially expressed bands were isolated and sequenced. They represent eighteen genes. Among them, six genes were identified by RT-PCR that they were really induced by cadmium treatment, including LEA (late embryogenesis abundant rotein), AtGSTF2 ( Glutathione S-transferase 2 ), AtGSTF6 ( Glutathione S-transferase 6 ),HSP70(heat shock protein 70), sHSP17. 6B-CI( 17.6 kDa class Ⅰ small heat shock protein) and sHSP17. 6-CII( 17.6 kDa class Ⅱ small heat shock protein). The results will help us to understand detoxification mechanism of plant to cadmium. And promoters of these three SPs could be used for phytoremediation of cadmium pollution.