Ultraviolet-B-induced oxidative stress and antioxidant defense system responses in ascorbate-deficient vtc1 mutants of Arabidopsis thaliana
Ultraviolet-B-induced oxidative stress and antioxidant defense system responses in ascorbate-deficient vtc1 mutants of Arabidopsis thaliana
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DOI：
10.1016/j.jplph.2007.04.002
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发表时间：
2008-02-01
影响因子：
4.3
通讯作者：
Zhang, Lixin
中科院分区：
文献类型：
--
作者：
Gao, Qjan;Zhang, Lixin
紫外线b （UV-B）辐射对植物细胞有负面影响，并导致活性氧（ROS）的产生。为了进一步了解UV-B对抗氧化过程的影响，我们研究了抗坏血酸缺乏的拟南芥突变体vtc1对短期增加的UV-B暴露的反应。在补充UV-B后，vtc1突变体表现出氧化损伤。损害的证据包括H2O2含量的增加和硫代巴比妥酸反应物质（TBARS）的产生；叶绿素含量和叶绿素荧光参数也有所下降。在UV-B处理的第一天，vtc1突变体的总谷胱甘肽含量高于野生型（WT）。我们发现谷胱甘肽/总谷胱甘肽的比例降低，脱氢抗坏血酸/总谷胱甘肽的比例增加。与WT植物相比，vtc1突变体中抗坏血酸的含量更高。此外，与WT植株相比，vtc1突变体中负责清除ROS的酶，包括超氧化物歧化酶、过氧化氢酶和抗坏血酸过氧化物酶的活性不足。据报道，在vtc1突变体中，负责抗坏血酸和谷胱甘肽再生的酶（包括单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶和谷胱甘肽还原酶）的活性也同样降低。这些结果表明，抗坏血酸缺乏突变体vtc1对补充UV-B处理比WT植物更敏感，抗坏血酸可以被认为是一种重要的抗UV-B辐射的抗氧化剂。(c) 2007 Elsevier GmbH版权所有。
Ultraviolet-B (UV-B) radiation has a negative impact on plant cells, and results in the generation of reactive oxygen species (ROS). In order to increase our understanding of the effects of UV-B on antioxidant processes, we investigated the response of an ascorbate-deficient Arabidopsis thaliana mutant vtc1 to short-term increased UV-B exposure. After UV-B supplementation, vtc1 mutants exhibited oxidative damage. Evidence for damage included an increase in H2O2 content and the production of thiobarbituric acid reactive substances (TBARS); a decrease in chlorophyll content and chlorophyll fluorescence parameters were also reported. The vtc1 mutants had higher total glutathione than the wild type (WT) during the first day of UV-B treatment. We found reduced ratio of glutathione/total glutathione and increased ratio of dehydroascorbate/total. ascorbate in the vtc1 mutants, compared to the WT plants. In addition, the enzymes responsible for ROS scavenging, including superoxide dismutase, catalase, and ascorbate peroxidase, had insufficient activity in the vtc1 mutants, compared to the WT plants. The same reduced activity in the vtc1 mutants was reported for the enzymes responsible for the regeneration of ascorbate and glutathione (including monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase). These results suggest that the ascorbate-deficient mutant vtc1 is more sensitive to supplementary UV-B treatment than WT plants and ascorbate can be considered an important antioxidant for UV-B radiation. (c) 2007 Elsevier GmbH. All rights reserved.