外源表油菜素内酯对镉胁迫下龙葵(Solanum nigrum L.)的缓解作用  

Alleviation of Cd stress in Solanum nigrum L.by exogenous epibrassionlide

作　　者：李洋[1] 金晓霞[1] 丁国华[1] 朱宏[1] 于丽杰[1] 

机构地区：[1]哈尔滨师范大学生命科学与技术学院,哈尔滨150025

出　　处：《应用与环境生物学报》2015年第4期717-724,共8页Chinese Journal of Applied and Environmental Biology

基　　金：黑龙江省教育厅面上项目(12531178;12531204);哈尔滨师范大学青年学术骨干资助计划项目(KGB201218);"植物生物学"黑龙江省高校重点实验室开放课题(ZK201205);哈尔滨师范大学硕士研究生创新科研项目资助~~

摘　　要：为了解外源表油菜素内酯(EBL)对龙葵镉(Cd)胁迫的调节作用,对100μmol L-1 Cd胁迫处理7 d和20 d后的龙葵喷施10-9、10-5 mol L-1 EBL 7 d,研究其生长状况、不同器官的生理生化作用以及3个泛素基因(Rma1、BUB、UBC)的表达变化.结果表明:与对照相比,Cd胁迫下龙葵叶片和根部MDA含量、抗氧化酶(POD、SOD、CAT)活性升高,表明Cd对龙葵有一定的毒害作用.与单一Cd胁迫相比,外源EBL(10-9、10-5 mol L-1)处理下龙葵株高、根长、干重、鲜重显著(P<0.05)增加,而叶绿素含量增加不显著.与单一Cd胁迫7 d相比,EBL(10-9、10-5 mol L-1)+Cd处理组叶片和根部抗氧化酶活性增加不显著,其中10-9 mol L-1 EBL+Cd处理组叶片MDA含量显著(P<0.05)降低,泛素基因UBC、Rma1表达上调;10-5 mol L-1EBL+Cd处理组叶片Rma1表达上调.与单一Cd胁迫20 d相比,10-9 mol L-1 EBL+Cd处理组叶片和根部MDA含量降低显著(P<0.05),叶片和根部SOD、CAT活性以及叶片POD活性增加显著(P<0.05),叶片Rma1基因和根部BUB、UBC基因表达上调;10-5 mol L-1 EBL+Cd处理组叶片BUB、UBC基因和根部UBC基因表达上调.本研究表明Cd胁迫后,EBL通过提高叶片和根部抗氧化酶系统活性,减轻膜脂过氧化程度来缓解Cd胁迫对龙葵的损伤,并且泛素Rma1、BUB、UBC基因参与该过程,且表达存在时空特异性;当Cd胁迫20 d时,以10-9 mol L-1 EBL对龙葵的缓解作用更为显著.This study aimed to reveal the regulatory role of the exogenous epibrassionlide （EBL） in alleviating Cd stress of Solanum nigrum. We sprayed EBL of 10-9 and 10-5 mol L-1 concentrations for 7 days on S.nigrum under 100 μmol L-1 Cd treatment for 7 and 20 days, then observed the plants for their growth conditions, physiological and biochemical changes of different organs as well as the expression of three ubiquitin gene （Rma1, BUB, UBC）. Compared with the control, Cd stress increased the MDA content and activity of antioxidant enzymes （POD, SOD, CAT） of the leaves and roots, indicating that Cd has toxic effects on S.nigrum. Compared with single Cd stress, exogenous EBL （10-9, 10-5 mol L-1） significantly increased plant height, root length, dry weight, fresh weight, and slightly increased chlorophyll content. In comparison with single Cd stress for 7 days, （10-9, 10-5 mol L-1） EBL ＋ Cd-treatment group showed no significant change of antioxidant enzyme activity of leaves and roots. In 10-9 mol L-1 EBL ＋ Cd-treatment group MDA content of leaves was significantly decreased and the expression of UBC, Rma1 upregulated; while in 10-5 mol L-1 EBL ＋ Cd-treatment group the expression of Rma1 was upregulated. Compared with single Cd stress for 20 days, 10-9 mol L-1 EBL ＋ Cd-treatment significantly decreased MDA content of leaves and roots, significantly increased the activity of SOD, CAT of leaves and roots and POD of leaves, and significantly upregulated the expression of Rma1 of leaves and BUB, UBC of roots; the 10-5 mol L-1 EBL ＋ Cd-treatment upregulated the expression of BUB, UBC of leaves and UBC of roots. The research suggested that EBL relieved Cd stress on S. nigrum by increasing the activity of antioxidant enzyme system and reducing the degree of membrane lipid peroxidation of the leaves and roots. Three ubiquitin genes （Rma1, BUB, UBC） are involved in the process with temporal and spatial specificity of expression. The alleviate effect of 10-9 mol L-1 EBL is more remarkable for S. n

关 键 词：表油菜素内酯(EBL) 龙葵 CD胁迫 泛素基因 缓解作用 

分 类 号：Q945.78[生物学—植物学]