镉胁迫对拟南芥幼苗错配修复基因表达的影响  

Effects of cadmium stress on expression of mismatch repair gene in Arabidopsis thaliana seedlings

作　　者：张巧丽[1] 刘宛[1] 李培军[1] 韩艳萍[1] 

机构地区：[1]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2008年第7期1173-1180,共8页Chinese Journal of Ecology

基　　金：国家重点基础研究发展计划项目(2004CB418506);中国科学院知识创新重大项目(KZCX1-YW-06-03);国家环保局"全国土壤现状调查及污染防治专项"资助项目

摘　　要：采用半定量反转录聚合酶链式反应(RT-PCR)技术研究了Cd胁迫对拟南芥(Arabidopsis thaliana)幼苗错配修复和增殖细胞核抗原基因表达的影响,并结合幼苗的形态和生理指标,选取Cd胁迫敏感的生物标记物。结果表明:不同浓度(0.25、0.5、1.0 mg.L-1)Cd处理对拟南芥幼苗叶片数、地上部鲜质量影响不大;Cd浓度为0.25 mg.L-1时,地上部分可溶性蛋白质含量明显升高(P<0.05),Cd浓度为0.5和1.0 mg.L-1时,可溶性蛋白质含量明显降低(P<0.05);叶绿素含量随着Cd浓度的增加而微弱增加(P>0.05)。Cd浓度为0.25 mg.L-1时,以18S rRNA为内参照,PCNA1、PCNA2、MSH2、MSH3、MSH6、MSH7 6个基因均出现了诱导表达,当Cd浓度增加到1.0 mg.L-1时,除了MSH6持续表达诱导及MSH3基因与对照相比表达抑制外,其他基因的表达依然出现诱导,但都低于0.5 mg.L-1Cd处理下的基因表达水平。以上结果表明,基因表达的改变可作为检测Cd污染对植物遗传毒性效应潜在有用的生物标记物。Using semi-quantitative reverse transcription-polymerase chain reaction （RT-PCR）, the effects of cadmium （Cd） stress on the mismatch repair and proliferating cell nuclear antigen gene expression of Arabidopsis thaliana seedlings were studied and linked to the morphological and physiological indices of A. thaliana seedlings , aimed to choose the biomarkers sensitive to Cd stress. The results indicated that under Cd stress, no significant changes were observed in leaf number and shoot fresh mass of A. thaliana seedlings. The total soluble protein content of the shoots increased significantly when exposed to 0.25 mg Cd ·L^-1 （ p 〈 0. 05 ） but decreased significantly at 0. 5 and 1.0 mg Cd ·L^-1 （P 〈0. 05）, while the chlorophyll content had a slight in- crease with increasing Cd concentration （P 〉0. 05）. Using 18S rRNA as the internal standard, the expression of PCNA1, PCNA2, MSH2, MSH3, MSH6 and MSH7 genes in shoots was significantly induced at 0. 25 mg Cd ·L^-1. When the Cd concentration increased to 1.0 mg ·L^-1, the expression of the genes was still induced, except that MSH6 was persistently induced and MSH3 was repressed compared with the control, but the expression was lower than that at 0. 5 mg·L^-1 of Cd. The above results suggested that specific gene expression could serve as the potential and useful biomarker for the detection of genotoxic effects of Cd pollution on plants.

关 键 词：Cd 生物标记物 错配修复基因 增殖细胞核抗原 半定量RT—PCR 

分 类 号：X173[环境科学与工程—环境科学]