《植物生理学报》 2018, 54(4): 607-617

一氧化氮参与外源谷胱甘肽对盐胁迫下番茄幼苗抗氧化损伤的调控

温泽林^1,2, 刘慧英^1,2,*, 周艳^1,2, 陈仙君^1,2, 冯玉龙^1,2

¹石河子大学农学院园艺系, 新疆石河子832003; ²新疆生产建设兵团特色果蔬栽培生理与种植资源利用重点实验室, 新疆石河子832003

通信作者：刘慧英；E-mail: hyliuok@aliyun.com

摘　要：

采用营养液水培, 研究外源谷胱甘肽(GSH)对NaCl和NaCl+Hb (牛血红蛋白, 一种一氧化氮清除剂)处理下番茄(Lycopersicon esculentum)幼苗叶片中一氧化氮合酶(NOS)活性及其一氧化氮(NO)水平、膜脂过氧化程度、活性氧(ROS)积累和ROS清除能力的影响。结果表明: 施用Hb使盐胁迫下番茄幼苗叶片的氧化损伤程度加剧, NO含量下调, 但对GSH含量无显著影响。外源GSH的施用显著提高了盐胁迫下番茄幼苗叶中内源GSH与NO水平, 单脱氢抗坏血酸还原酶(MDHAR)和硝酸还原酶(NR)活性, 超氧化物歧化酶(SOD)活性(除72 h), 过氧化氢酶(CAT)活性(除48 h), 处理48和72 h的谷胱甘肽还原酶(GR)、抗坏血酸过氧化物酶(APX)和脱氢抗坏血酸还原酶(DHAR)活性; 降低电解质渗透率、硫代巴比妥酸(TBARS)含量以及处理48和72 h的过氧化氢(H₂O₂)和超氧阴离子(O₂ ^¯· )含量。外源喷施GSH亦显著提高NaCl+Hb处理下番茄叶中抗坏血酸(AsA)、GSH和NO水平, CAT和APX活性, 处理24和48 h的NR活性以及处理48和72 h的NOS活性; 降低电解质渗透率及H₂O₂和TBARS含量。表明外源GSH通过介导内源GSH和NO水平上调, 提高抗氧化酶活性和ROS的清除能力来缓解NaCl和NaCl+Hb处理导致的氧化损伤。因此, NO参与了外源GSH对盐胁迫下番茄幼苗抗氧化损伤的调控。

关键词：GSH; Hb; 盐胁迫; 番茄幼苗; 抗氧化系统

收稿：2017-10-09   修定：2018-03-26

资助：国家自然科学基金(31360478)和兵团国际合作项目(2014BC002)。

The involvement of nitric oxide in exogenous glutathione regulates antioxidant defense capacity against salt stress in tomato seedlings

WEN Ze-Lin^1,2, LIU Hui-Ying^1,2,*, ZHOU Yan^1,2, CHEN Xian-Jun^1,2, FENG Yu-Long^1,2

¹Department of Horticulture, College of Agronomy, Shihezi University, Shihezi, Xinjiang 832003, China; ²Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Crops, Shihezi, Xinjiang 832003, China

Corresponding author: LIU Hui-Ying; E-mail: hyliuok@aliyun.com

Abstract:

A hydroponic experiment was performed to investigate the effects of exogenous glutathione (GSH) on nitric oxide (NO) levels, the activities of key enzymes related to NO synthesis, the lipid peroxidation level, production of reactive oxygen species (ROS), and the ROS scavenging capacity in leaves of tomato (Lycopersicon esculentum) seedlings under NaCl and NaCl+Hb (NO scavenger) treatments. Our results showed that the application of Hb increased the oxidative damage and decreased the NO level, but had no significant effect on GSH contents in the leaves of salt-stressed tomato seedlings. Exogenous GSH application significantly increased the contents of GSH and NO and the activities of nitrate reductase (NR), monodehydroascorbate reductase (MDHAR), superoxide dismutase (SOD) (except 72 h), and catalase (CAT) (except 48 h) during the whole sampling period, as well as the activities of glutathione reductase (GR), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) at 48 and 72 h after treatments, and decreased the electrolyte permeability, the contents of thiobarbituric acid reactive substance (TBARS) and hydrogen peroxide (H₂O₂) during the whole sampling period and superoxide anion (O₂ ^¯· ) at 48 and 72 h in leaves of salt-stressed tomato seedlings. The application of GSH also significantly increased the levels of GSH, ascorbic acid (AsA) and NO, the activities of CAT and APX at all three sampling dates, and the activities of NR at 24 and 48 h and nitric oxide synthase (NOS) at 48 and 72 h, and decreased the electrolyte permeability and the contents of TBARS and H₂O₂ in leaves of tomato seedlings under NaCl+Hb treatment. These results indicate that exogenous GSH could alleviate the oxidative damage induced by NaCl or NaCl+Hb treatments by up-regulating the levels of GSH and NO, and increasing the activities of antioxidant enzymes and the ROS scavenging capacity. In conclusion, NO is involved in the regulation of antioxidant defense capacity against salt stress in tomato seedlings by exogenous GSH.

Key words: GSH; Hb; salt stress; tomato seedling; antioxidant system