植物抗病反应的信号传导网络

植物由抗病基因介导的防卫过程存在一系列生理生化和分子生物学反应，这些反应从病原菌侵染点开始的超敏反应(HR)并延伸到远处组织的系统抗性或获得性抗性(SAR)，受制于一种信号传导网络的调控。这个信号系统由抗病蛋白和病原菌非毒性蛋白在一种配体-受体的互作模式下激发，并由信号分子H2O2,NO和系统信号分子SA，JA和乙烯和通过关键调控基因传递和放大，最终诱导一系列防卫反应基因的表达和代谢的变化而产生抗性。植物防卫信号的产生有类似于动物免疫系统因子的介导，并可由非寄主病原菌或诱导子诱发。这些信号途径所产生的广谱抗性为植物抗病基因工程的应用奠定了基础。

Signal Network of Plant Disease Resistance

Plant R gene mediated defense responses include a series of physiological, biochemical and molecular activities. These responses begin with the initial hypersensitive response at the site of pathogen attack and end with systemic defenses or acquired resistance in tissues distant from the invasion sites. These responses are controlled by a defense signaling network, which is activated by the recognition of a plant resistance gene encoded protein, R protein, and a pathogen avirulence gene encoded protein, Avr protein, in a model of the receptor ligand recognition. The signal of the perception of the Avr protein by the R protein is transduced and amplified by the signal molecules, H 2O 2, NO and the systemic molecules SA, JA and ethylene to induce numerous defense related genes and metabolism enhancement, resulting in disease resistance. Plant defense probably uses similar mechanisms used in the animal immunity system. Increasing information about plant defense provides approaches to manipulate broad spectrum disease resistance in crops. Possible progresses of plant defense research in the near future are discussed in this review.