Water stress-induced abscisic acid accumulation triggers the increased generation of reactive oxygen species and up-regulates the activities of antioxidant enzymes in maize leaves
Water stress-induced abscisic acid accumulation triggers the increased generation of reactive oxygen species and up-regulates the activities of antioxidant enzymes in maize leaves
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DOI：
10.1093/jxb/erf090
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发表时间：
2002-12-01
影响因子：
6.9
通讯作者：
Zhang, JH
中科院分区：
文献类型：
--
作者：
Jiang, MY;Zhang, JH
以离体玉米（Zea mays L.）叶片为材料，研究了水分胁迫诱导的脱落酸（阿坝）积累、活性氧（ROS）产生以及超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）活性之间的相互关系。用聚乙二醇（PEG 6000）诱导的-0.7MPa水分胁迫处理植物。水分胁迫下叶片阿坝含量、ROS产生和抗氧化酶活性的时程分析表明，阿坝含量的显著增加先于ROS的增加，随后这些抗氧化酶活性显著增加。用阿坝生物合成抑制剂钨酸盐预处理显著抑制了水分胁迫下叶片中阿坝的积累，同时也降低了ROS的产生和这些抗氧化酶的上调。百草枯诱导的轻度氧化胁迫，产生O-2（-），然后H2 O2，导致在非水分胁迫叶片中的抗氧化酶的活性显着增强。用Tiron和DMTU等活性氧清除剂和DPI等NAD（P）H氧化酶抑制剂预处理，几乎完全抑制了水分胁迫或阿坝处理引起的活性氧和抗氧化酶活性的增加。这些数据表明，水分胁迫诱导的阿坝积累触发了ROS的产生增加，这反过来又导致了抗氧化防御系统的上调。
The interrelationship among water-stress-induced abscisic acid (ABA) accumulation, the generation of reactive oxygen species (ROS), and the activities of several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) was investigated in leaves of detached maize (Zea mays L.) plants exposed to -0.7 MPa water stress induced by polyethylene glycol (PEG 6000). Time-course analyses of ABA content, the production of ROS, and the activities of antioxidant enzymes in water-stressed leaves showed that a significant increase in the content of ABA preceded that of ROS, which was followed by a marked increase in the activities of these antioxidant enzymes. Pretreatment with an ABA biosynthesis inhibitor, tungstate, significantly suppressed the accumulation of ABA, and also reduced the increased generation of ROS and the up-regulation of these antioxidant enzymes in water-stressed leaves. A mild oxidative stress induced by paraquat, which generates O-2(-) and then H2O2, resulted in a significant enhancement in the activities of antioxidant enzymes in non-water-stressed leaves. Pretreatment with some ROS scavengers, such as Tiron and dimethylthiourea (DMTU), and an inhibitor of NAD(P)H oxidase, diphenyleneiodonium (DPI), almost completely arrested the increase in ROS and the activities of these antioxidant enzymes induced by water stress or ABA treatment. These data suggest that water stress-induced ABA accumulation triggers the increased generation of ROS, which, in turn, leads to the up-regulation of the antioxidant defence system.