自由基种类及其在植物抗病分子调控中的作用

Reactive oxygen species (ROS) acts as activating cells death and defense genes expression in plant

当生物生命代谢中受到各种应激时,由于出现了超量的具有高度活性的自由基,因而使其代谢发生重大变化。研究表明,植物在各种逆境下在细胞内产生的诸如氧化氮、单线态氧、过氧化氢等活性氧自由基对植物抗逆性调控因子的表达和细胞死亡调控具有重要意义。本文对植物逆境代谢中产生的自由基种类及其性质、抗氧化酶种类及其基因的多态性进行了总结,同时对部分重要的自由基对植物抗病基因表达的调控作用和对细胞死亡的调控作用进行了表述。

Oxidative stress is induced by a wide range of environmental factors including UV stress, pathogen invasion, herbicide action. Oxygen stress in plant cells will changed plant metabolization. Of the reactive oxygen species (ROS), hydrogen peroxide (H_2O_2), superoxide ([XCO.TIF;P]), hydraoxyl radicals ([XCOH.TIF;P]) and singlet oxygen (~1O_2), also nitric oxygen ([XCNO.TIF;P]) et al., are produced in a number of cellular reactions. The main cellular components susceptible to damage by these free radicals are lipids (peroxidation of unsaturated fatty acids in membranes), proteins (denaturation), carbohydrates and nucleic acids. Moreover, these ROS are involved as early messenger molecules in signaling cascades activated by external and development stimuli. It is an importance that these free radicals to activate bio-metabolize and the most metabolic program in biology.