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蛋白磷酸化在植物细胞脱落酸(ABA)介导的信号转导中起重要作用。然而,很多参与ABA信号途径的蛋白元件仍不清楚。使用改进的体外激酶试验方法的研究结果表明,在玉米叶片中,ABA和H2O2能够快速活化蛋白激酶总活性和Ca2+依赖型蛋白激酶总活性;ABA诱导的蛋白激酶总活性增加可以被活性氧的抑制剂和清除剂抑制,蛋白激酶抑制剂不仅可以降低ABA和H2O2诱导的激酶活性增加,而且也可以弱化它们对抗氧化防护酶活性的诱导作用;ABA和H2O2引发的蛋白磷酸化作用显著居先于它们诱导的抗氧化防护作用。使用凝胶激酶试验方法进行研究发现,一组分子量分别为66kDa,52kDa,49kDa和35kDa的蛋白激酶可能介导了ABA和H2O2诱导的抗氧化防护反应,并且66kDa和49kDa的蛋白激酶可能在ROS的下游起作用,而52kDa和35kDa的蛋白激酶可能在ABA和ROS的下游起作用。
Protein phosphorylation plays an important role in plant cell abscisic acid (ABA) -mediated signal transduction. However, many protein elements involved in the ABA signaling pathway remain unclear. The results of the in vitro kinase assays using improved assays show that ABA and H2O2 rapidly activate both total protein kinase activity and total Ca2 + -dependent protein kinase activity in maize leaves; the increase in ABA-induced total protein kinase activity can be inhibited by reactive oxygen species And protein kinase inhibitors, protein kinase inhibitors can not only reduce the ABA and H2O2-induced kinase activity, but also weaken their induction of antioxidant enzyme activity; ABA and H2O2-induced protein phosphorylation precedes them Induced anti-oxidant protective effect. A series of protein kinases with molecular weights of 66kDa, 52kDa, 49kDa and 35kDa, respectively, were found to mediate ABA and H2O2-induced antioxidant protective responses using the gel kinases assay, and the 66kDa and 49kDa protein kinases may be involved in ROS Downstream, while 52kDa and 35kDa protein kinases may act downstream of ABA and ROS.