Heat shock protein 70 regulates the abscisic acid-induced antioxidant response of maize to combined drought and heat stress
Heat shock protein 70 regulates the abscisic acid-induced antioxidant response of maize to combined drought and heat stress
复制标题
热休克蛋白 70 调节脱落酸诱导的玉米对干旱和热胁迫的抗氧化反应
DOI：
10.1007/s10725-009-9436-2
复制
发表时间：
2010-04-01
影响因子：
4.2
通讯作者：
Li, Chaohai
中科院分区：
文献类型：
--
作者：
Hu, Xiuli;Liu, Ruixia;Li, Chaohai
研究了热休克蛋白70（HSP70）和脱落酸（阿坝）诱导的玉米对干旱和高温复合胁迫的抗氧化反应之间的相互作用。首先，干旱诱导的超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR）和过氧化氢酶（CAT）等酶活性的增加幅度小于高温或干热复合胁迫，但个别情况除外（例如叶中的CAT、根中的GR）。干旱、高温及其复合胁迫下，HSP70合成和H2O2产生均显著增加，其中以干旱+高温复合胁迫诱导的叶片HSP70合成和H2O2产生的增加量最大，其次为高温和干旱，而根系HSP70合成和H2O2产生的增加量差异不明显。阿坝抑制剂、HSP70抑制剂和H2O2清除剂预处理显著抑制了胁迫诱导的叶片和根系抗氧化酶活性的增加，阿坝抑制剂和H2O2清除剂明显抑制了HSP70的合成，而HSP70抑制剂则略微促进了H2O2的积累。100 μM阿坝显著提高了胁迫下玉米幼苗抗氧化酶活性、HSP70表达和H2O2产生。因此，ABA诱导的H2O2的产生促进了HSP70的合成，上调了抗氧化酶的活性，从而抑制了细胞内活性氧（ROS）的水平。以上结果表明，HSP70在ABA诱导的玉米抗氧化防御中起着重要作用。
We investigated the interaction between heat shock protein 70 (HSP70) and abscisic acid (ABA)-induced antioxidant response of maize to the combination of drought and heat stress. First, the increased activities of enzymes, including superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) and catalase (CAT), induced by drought were less than those by heat or combined drought and heat stress, except some individual cases (e.g. CAT in leaves, GR in roots). Second, both HSP70 synthesis and H2O2production increased prominently under drought, heat or their combination stress; the increase in leaves induced by drought and heat combination was the highest, followed by heat and by drought, while the increase in roots had not visible difference. Third, either in leaves or roots, pretreatment with ABA inhibitor, HSP70 inhibitor and H2O2scavenger, significantly arrested the stress-induced increase of antioxidant enzyme activities, and ABA inhibitor and H2O2scavenger obviously suppressed HSP70 synthesis, while HSP70 inhibitor slightly heightened H2O2accumulation. Finally, 100 μM ABA significantly enhanced the activities of antioxidant enzymes, HSP70 expression and H2O2production under stresses in comparison with ABA-deficient mutantvp5maize plants without pretreatment. Thus, ABA-induced H2O2production enhances the HSP70 synthesis and up-regulates the activities of antioxidant enzymes, resulting in the suppression of cellular reactive oxygen species (ROS) levels. Our results suggest that HSP70 may play a crucial role in ABA-induced antioxidant defense of maize to drought and heat combination.