标题：Copper Suppresses Abscisic Acid Catabolism and Catalase Activity, and Inhibits Seed Germination of Rice
作者：Ye, Nenghui;Li, Haoxuan;Zhu, Guohui;Liu, Yinggao;Liu, Rui;Xu, Weifeng;Jing, Yu;Peng, Xinxiang;Zhang, Jianhua
作者机构：[Ye, N] Shenzhen Research Institute, Chinese University of Hong Kong, Shenzhen, China;[ Li, H] State Key Laboratory of Agrobiotechnology, Chinese Univ 更多
通讯作者地址：[Zhang, JH]Chinese Univ Hong Kong, Shenzhen Res Inst, Shenzhen, Peoples R China.
来源：Plant and cell physiology
关键词：Abscisic acid (ABA);Catalase;Copper;Reactive oxygen species;Rice (Oryza sativa);Seed germination
摘要：Although copper (Cu) is an essential micronutrient for plants, a slight excess of Cu in soil can be harmful to plants. Unfortunately, Cu contamination is a growing problem all over the world due to human activities, and poses a soil stress to plant development. As one of the most important biological processes, seed germination is sensitive to Cu stress. However, little is known about the mechanism of Cu-induced inhibition of seed germination. In the present study, we investigated the relationship between Cu and ABA which is the predominant regulator of seed germination. Cu at a concentration of 30 mu M effectively inhibited germination of rice caryopsis. ABA content in germinating seeds under copper stress was also higher than that under control conditions. Quantitative real-time PCR (qRT-PCR) revealed that Cu treatment reduced the expression of OsABA8ox2, a key gene of ABA catabolism in rice seeds. In addition, both malondialdehyde (MDA) and H2O2 contents were increased by Cu stress in the germinating seeds. Antioxidant enzyme assays revealed that only catalase activity was reduced by excess Cu, which was consistent with the mRNA profile of OsCATa during seed germination under Cu stress. Together, our results demonstrate that suppression of ABA catabolism and catalase (CAT) activity by excess Cu leads to the inhibition of seed germination of rice.