《植物生理学报》 2011, 47(10): 1010-1016

H₂O₂和MAPK介导油菜素内酯诱导番茄抗氧化防护酶SOD和CAT的信号途径

丁海东, 刘慧, 陈一, 王丹, 梁建生*

扬州大学生物科学与技术学院, 江苏扬州225009

通信作者：梁建生；E-mail: jssliang@126.com；Tel: 0514-87979320

摘　要：

本文以番茄为材料, 研究H2O2和MAPK在BR诱导的抗氧化防护系统中的作用。结果表明, 外源BR提高抗氧化防护酶 SOD和CAT活性; 而这种诱导机制被H2O2产生抑制剂二苯基碘(DPI)和MEK1/2专一抑制剂PD98059阻断。进一步研究发现: BR能够诱导细胞质外体H2O2的产生, 这种诱导被PD98059抑制; BR能够活化一种49 kDa MAPK, 这种活化被DPI抑制。本 研究结果证实细胞质外体H2O2和MAPK候选激酶(49 kDa MAPK)信号参与BR诱导的抗氧化防酶途径, 且两者之间存在交互作用。

关键词：番茄; 油菜素内酯; H2O2; MAPK; 抗氧化防护酶

收稿：2011-08-03   修定：2011-08-03

资助：国家自然科学基金(90917005)、江苏省高校自然科学 研究基金(10KJB180010)和扬州大学科技创新培育基金 (2010CXJ047)。

Involvements of H₂O₂ and Mitogen-Activated Protein Kinase Signals in Brassinosteroid-Activated Tomato Antioxidant Defense Enzymes Superoxide Dismutase and Catalase

DIng Hai-Dong, LIu Hui, CHEn Yi, WAng Dan, LIAng Jian-Sheng*

College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu 225009, China

Corresponding author: LIAng Jian-Sheng; E-mail: jssliang@126.com; Tel: 0514-87979320

Abstract:

In this study, the role of H₂O₂ and MAPK (mitogen-activated protein kinase) in BR (brassinosteroid)-induced antioxidant defense system were investigated in leaves of tomato, Lycopersicom esculentum Mill.. The results showed that exogenous BR increased antioxidant defense enzymes SOD and CAT activities. However, the induction mechanisms were blocked by pre-treatment with the apoplastic H₂O₂ production inhibitor DPI and the mitogen-activated protein kinase kinase (MEK1/2) specific inhibitor PD98059. Further studies showed that BR was able to induce the production of apoplastic H₂O₂ and the activation of a 49-kDa MAPK, which were inhibited by PD98059 and DPI, respectively. The results suggest that the interactive cross-talk between apoplastic H₂O₂ signal and a candidate MAPK kinase (48 kDa MAPK) signal are involved in BR-activated antioxidant defense enzymes.

Key words: Lycopersicom esculentum Mill.; brassinosteroid; H₂O₂; MAPK; antioxidant defense enzymes