Abstract: Traditionally, reactive oxygen species (ROS) were considered to be toxic by products of aerobic metabolism. However, in recent years , it has become apparent that plants actively produce ROS as signaling molecules to control processes such as programmed cell death , abiotic stress responses, pathogen defense and systemic signaling . Emerging evidence suggests that hormone signaling pathways regulated by abscisic acid, salicylic acid, jasmonic acid and ethylene , as well as ROS signaling pathways, play key roles in the crosstalk between biotic and abiotic stress signaling. Reactive oxygen species (ROS) were originally thought to only be released by phagocytic cells during their role in host defence . It is now clear that ROS have a cell signalling role in many biological systems , both in animals and in plants . ROS induce programmed cell death or necrosis, induce or suppress the expression of many genes, and activate cell signalling cascades, such as those involving . Recent biochemical and genetic studies confirm that hydrogen peroxide is a signalling molecule in plants that mediates responses to abiotic and biotic stresses . The synthesis and action of hydrogen peroxide appear to be linked to those of nitric oxide . Downstream signalling events that are modulated by hydrogen peroxide include calcium mobilization, protein phosphorylation and gene expression .

Key words: ROS

摘要： 越来越明显的证据表明, 植物体十分活跃的产生着活性氧并将之作为信号分子、进而控制着诸如细胞程序性死亡、非生物胁迫响应、病原体防御和系统信号等生命过程, 而不仅是传统意义上的活性氧是有氧代谢的附产物。日益增多的证据显示, 由脱落酸、水杨酸、茉莉酸与乙烯以及活性氧所调节的激素信号途径, 在生物和非生物胁迫信号的“交谈”中起重要作用。活性氧最初被认为是动物吞噬细胞在宿主防御反应时所释放的附产物, 现在的研究清楚的表明, 活性氧在动物和植物细胞信号途径中均起作用。活性氧可以诱导细胞程序性死亡或坏死、可以诱导或抑制许多基因的表达, 也可以激活上述级联信号。近来生物化学与遗传学研究证实过氧化氢是介导植物生物胁迫与非生物胁迫的信号分子, 过氧化氢的合成与作用似乎与一氧化氮有关系。过氧化氢所调节的下游信号包括钙“动员”、蛋白磷酸化和基因表达等。

关键词: 活性氧, MAPK, H2 O2 , 信号转导, 胁迫FONT