《植物生理学报》 2014, 50(1): 95-104

过表达单脱氢抗坏血酸还原酶基因提高番茄抗UV-B胁迫能力

王玉, 孔凡英, 尹波, 董新纯*, 孟庆伟

山东农业大学生命科学学院, 作物生物学国家重点实验室, 山东泰安271018

通信作者：董新纯；E-mail: sspp@sdau.edu.cn；Tel: 0538-8246298

摘　要：

以野生型(WT)和转正义叶绿体单脱氢抗坏血酸还原酶基因(LeMDAR)番茄为试材, 探讨了UV-B胁迫下过表达LeMDAR对番茄抗氧化能力的影响。测定了不同时间UV-B处理下番茄抗坏血酸(AsA)含量, 脱氢抗坏血酸(DHA)含量, 单脱氢抗坏血酸还原酶(MDAR)活性, 光合速率和叶绿素荧光参数等。在UV-B处理下, 转基因番茄植株的AsA含量、 MDAR酶及抗坏血酸过氧化物酶(APX)活性、H₂O₂和超氧阴离子清除速率、净光合速率(Pn)高于野生型番茄。此外, 紫外胁迫下, 转基因株系丙二醛(MDA)含量和相对电导率(REC)较野生型增加的少。上述结果表明, MDAR对抗坏血酸再生具有重要作用, 过表达LeMDAR提高了番茄植株抗氧化能力, 对光合机构有保护作用。

关键词：番茄; LeMDAR; UV-B胁迫; 抗坏血酸再生; 抗氧化能力

收稿：2013-09-22   修定：2013-11-15

资助：国家重点基础研究发展计划(2009CB118505)和国家自然科学基金(31071338和31171474)

Overexpression of Chloroplastic Monodehydroascorbate Reductase Gene Enhanced Tolerance to UV-B Stress in Tomato

WANG Yu, KONG Fan-Ying, YIN Bo, DONG Xin-Chun*, MENG Qing-Wei

College of Life Science, State Key Laboratory of Crop Biology, Shandon Agricultural University, Tai’an, Shandong 271018, China

Corresponding author: DONG Xin-Chun; E-mail: sspp@sdau.edu.cn; Tel: 0538-8246298

Abstract:

The wild type (WT) and transgenic tomato lines with overexpression of chloroplastic monodehydroascorbate reductase gene (LeMDAR) were used to investigate the antioxidant ability under UV-B stress. Contents of ascorbic acid (AsA) and dehydrogenation ascorbic acid (DHA), monodehydroascorbic acid reductase (MDAR) activities, net photosynthetic rate (Pn) and chlorophyll fluorescence parameters were measured under UV-B treatment. Compared with WT, AsA content, activities of APX and MDAR in transgenic plants increased and the contents of H₂O₂ and O2 ¯· decreased. In transgenic plants, the higher Pn, the lower MDA content and the relative electric conductivity (REC) were detected, compared with WT under UV-B. These results indicated that MDAR has an important role in AsA regeneration, and overexpression of LeMDAR improved the plant antioxidant ability and protected photosynthetic mechanism.

Key words: tomato; LeMDAR; UV-B stress; AsA regeneration; antioxidant ability