拟南芥NAD激酶3(NADK3)参与调节镉胁迫响应  

NAD kinase 3 (NADK3) plays a role in response to cadmium stress in Arabidopsis thaliana

作　　者：王晓阳[1] 孙立荣[1] 李珊珊[1] 胡盼盼[1] 郝福顺[1] 

机构地区：[1]河南大学生命科学学院 植物逆境生物学重点实验室,河南开封475004

出　　处：《河南科技学院学报（自然科学版）》2013年第5期13-17,共5页Journal of Henan Institute of Science and Technology(Natural Science Edition)

基　　金：河南省教育厅自然科学基金项目(2007180004;2010B180004)

摘　　要：以拟南芥野生型(WT)、NAD激酶3(NADK3)基因纯合缺失突变体nadk3和超表达该基因的植物为材料,研究了NADK3在Cd胁迫下的作用.结果表明:nadk3对Cd胁迫敏感;正常生长条件下,nadk3根长与WT及超表达植物没有明显差别,但在Cd胁迫下,nadk3根长显著短于WT及超表达植物;用CdCl2处理幼苗后,WT植株中NADK3基因的表达量明显增加;与WT相比,Cd胁迫下nadk3根中H2O2水平也增加;抗氧化酶活性测定发现,Cd胁迫下该突变体与WT中过氧化氢酶和超氧化物歧化酶活性没有显著差异,但突变体中抗坏血酸过氧化物酶和谷胱甘肽还原酶的活性明显低于WT;Cd胁迫下突变体中Cd2+含量的增加值显著高于WT.NADK3可通过降低拟南芥中活性氧水平和Cd2+的积累在拟南芥应答Cd胁迫反应中发挥作用.The functions of NAD kinase3 （NADK3） in response to cadmium （Cd） stress in Arabidopsis were investigated by the null mutant nadk3,transgenic plants overexpressing NADK3 and wild-type （WT） plants.The results showed that nadk3 was sensitive to Cd stress.Under normal growth conditions,nadk3 had similar roots in length to WT and the overexpressors.However,the primary root length of nadk3 was significantly shorter than that of WT and the transgenie plants under Cd stress.The transcript level of NA DK3 in WT increased clearly after treatment with CdCl2.Moreover,The H2O2 level in roots of nadk3 enhanced remarkably compared with WT.The activities of some antioxidative enzymes such as ascorbate peroxidase （APX）,eatalase （CAT）,superoxide dismutase （SOD） and glutathione reductase （GR） were assayed.There were not significant different in the activities of CAT and SOD between WT and nadk3 under Cd stress.However, the activities of APX and GR markedly reduced in the mutant relative to that in WT after treatment with CdCl2.Besides,the increase in Cd content of nadk3 seedlings were significantly higher than that of WT after exposure to Cd.Ahogether,these results show that NADK3 plays roles in adaptation to Cd stress through decreasing levels of reactive oxygen species and Cd accumulation in A rabidopsis.

关 键 词：拟南芥 NADK3 CD胁迫 活性氧 抗氧化酶 

分 类 号：Q505[生物学—生物化学]