外源油菜素内酯对镉胁迫下龙葵（solanum - 应用与环境生物学报.doc

外源表油菜素内酯对镉胁迫下龙葵（Solanum nigrum L.）的缓解作用* 李 洋 金晓霞 丁国华 朱 宏 于丽杰** 哈尔滨师范大学生命科学与技术学院 哈尔滨 150025 摘 要：为了解外源表油菜素内酯（EBL）对龙葵镉(Cd)胁迫的，100 μmol L-1 Cd胁迫7 d和20 d龙葵喷施10-9、10-5 mol L-1 EBL生长状况、生理以及泛素基因Rma1、BUB、UBC）的表达。结果表明：Cd胁迫下龙葵叶片和根MDA含量、抗氧化酶（PODSOD、CAT）活性升高与Cd胁迫相比，外源EBL10-9、10-5 mol L-1处理龙葵株高、根长、干重、鲜重显著增加，而叶绿素含量增加不显著。Cd胁迫7 d相比，EBL10-9、10-5 mol L-1+Cd处理组叶片和根抗氧化酶活性增加不显著10-9 mol L-1 EBL+Cd处理组叶片MDA含量显著降低泛素基因UBC、Rma1表达上调10-5 mol L-1 EBL+Cd处理组叶片Rma1表达上调与Cd胁迫20 d相比，10-9 mol L-1 EBL+Cd处理组叶片和根MDA含量降低显著，叶片和根SOD、CAT活性以及叶片POD活性增加显著Rma1基因和根部BUB、UBC基因表达上调；10-5 mol L-1 EBL+Cd处理组。本研究表明Cd胁迫后，EBL通过提高叶片和根抗氧化酶系统活性，减轻膜脂过氧化程度来缓解Cd胁迫对龙葵的，并且Rma1、BUB、UBC基因参与该过程当Cd胁迫20 d时，以10-9 mol L-1 EBL的作用更为显著 关键词 表油菜素内酯；龙葵；Cd胁迫；泛素基因； Solanum nigrum L. by exogenous epibrassionlide * Li Yang, Jin Xiaoxia, Ding Guohua, Zhu Hong Yu Lijie** College of Life Science and Technology, Harbin Normal University, Harbin 150025, China Abstract Objectives: To reveal the regulatory role of the exogenous epibrassionlide in the process of S.nigrum by Cd stress. Methods: Applying to research the growth conditions, physiological and biochemical changes of different organs as well as the expression of three ubiquitin gene (Rma1, BUB, UBC) of S.nigrum under 100 μmol L-1 Cd for 7 and 20 days through spraying 10-9, 10-5 mol L-1 EBL for 7 days. Results: The results showed that compared with the control, the MDA content and activity of antioxidant enzymes (POD, SOD, CAT) of the leaves and roots under Cd stress increased, indicating that Cd has toxic effects on S.nigrum. Compared with single Cd stress, exogenous (10-9, 10-5 mol L-1) EBL significantly increased plant height, root length, dry weight, fresh weight, while the chlorophyll content was slightly effected. In which, compared with single Cd stress for 7 days, (10-9, 10-5 mol L-1) EBL + Cd-treatment group was not significant on antioxidant enzyme activity of leaves and roots, of which MDA content of leaves significantly decreased and the expression of UBC, Rma1 was upregulated