期刊
PLANT JOURNAL
卷 37, 期 1, 页码 21-33出版社
WILEY
DOI: 10.1046/j.1365-313X.2003.01930.x
关键词
active oxygen species; glutathione peroxidase; transgenic plants; oxidative stress
To evaluate the physiological potential of the defense system against hydroperoxidation of membrane-lipid components caused by environmental stresses in higher plants, we generated transgenic tobacco plants expressing a glutathione peroxidase (GPX)-like protein in the cytosol (TcGPX) or chloroplasts (TpGPX). The activities toward alpha-linolenic acid hydroperoxide in TcGPX and TpGPX plants were 47.5-75.3 and 32.7-42.1 nmol min(-1) mg(-1) protein, respectively, while no activity was detected in wild-type plants. The transgenic plants showed increased tolerance to oxidative stress caused by application of methylviologen (MV: 50 mum) under moderate light intensity (200 muE m(-2) sec(-1)), chilling stress under high light intensity (4degreesC, 1000 muE m(-2) sec(-1)), or salt stress (250 mM NaCl). Under these stresses, the lipid hydroperoxidation (the production of malondialdehyde (MDA)) of the leaves of TcGPX and TpGPX plants was clearly suppressed compared with that of wild-type plants. Furthermore, the capacity of the photosynthetic and antioxidative systems in the transgenic plants remained higher than those of wild-type plants under chilling or salt stress. These results clearly indicate that a high level of GPX-like protein in tobacco plants functions to remove unsaturated fatty acid hydroperoxides generated in cellular membranes under stress conditions, leading to the maintenance of membrane integrity and increased tolerance to oxidative stress caused by various stress conditions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据