[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedlings under Hg2+ stress at different concentrations.[Result]① There were no obvious effects on the growth of seedlings when the concentration of Hg2+ was lower than 0.10 mmol/L.However,toxic effects on the growth of seedling were observed when the concentration of Hg2+ was higher than 0.10 mmol/L.② Different tissues showed different resistant ability in response to Hg2+ stress.The leaves and roots of wheat seedlings were more insensitive to Hg2+ toxicity.③ CAT was more sensitive to Hg2+ stress compared to POD and SOD.[Conclusion]The toxic effect was related to the concentration of Hg2+(0.10 mmol/L).The higher concentration of Hg2+ could affect the expression of POD,CAT,and SOD isozymes in the leaves,roots of wheat seedlings and germinated seeds,which further affect the normal metabolism of membrane lipid and inhibit the growth of wheat seedlings at last.
从成熟心里美萝卜肉质根的皮中提取总RNA,采用RT-PCR方法获得过氧化物酶基因RsPrx1的cDNA,将其克隆到pGEM-T载体中,并构建毕赤酵母重组表达载体pPIC9KH-RsPrx1。用L iC l法转化野生型毕赤酵母GS115获得重组转化子。用不同浓度的NaC l和H2O2处理重组毕赤酵母转化子,结果表明该转化子具有一定的抗盐和抗氧化能力。建立了RsPrx1重组毕赤酵母表达体系,能够有效表达具有生物活性的外源过氧化物酶。
