一个耐受镉毒害的拟南芥突变体的筛选

从甲基磺酸乙酯(EMS)诱变获得的拟南芥M2代群体(Columbia型)中筛选获得一个耐受镉Cd2 毒害能力显著增强的拟南芥突变体(命名为cdr1-1).遗传分析表明,该突变性状为隐性单基因突变,与野生型相比,cdr1-1突变体在不同发育时期均能耐受Cd2 毒害,且其对Cd2 的积累能力也显著高于野生型.此外,还发现cdr1-1突变体体内的还原型谷胱甘肽(GSH)水平显著高于野生型,用GSH合成抑制剂丁硫氨酸亚矾胺处理cdr1-1突变体,导致其耐受Cd2 毒害能力显著下降,几乎接近野生型水平,表明cdr1-1突变体对Cd2 的耐受性至少部分依赖于GSH介导的途径.

Screening for an Arabidopsis mutant with enhanced tolerance to cadmium toxicity

An Arabidopsis mutant (designated cdr1-1) was identified that had enhanced tolerance to cadmium (Cd 2 ) toxicity by screening ethyl methanesulfonate-mutagenized Arabidopsis M2 seedlings (ecotype Columbia). Genetic analysis indicated that the cdr1-1 mutation was recessive and segregated as a single gene. At different development stages, cdr1-1 showed enhanced tolerance to Cd 2 toxicity compared with the wild type. Also, a higher Cd 2 accumulation was detected in cdr1-1 seedlings than that in wild-type seedlings. In addition, it was also found that glutathion (GSH) content was enhanced significantly in cdr1-1plants. Treatment with BSO, an inhibitor of GSH biosynthesis, resulted in a significantly decreased tolerance of the cdr1-1 mutant to Cd 2 toxicity, which was comparable to that of the wild type, suggesting that the enhanced tolerance of cdr1-1 to Cd 2 toxicity is dependent, at least in part, on a GSH-medicated pathway.