系统素、茉莉酸在番茄系统伤反应中的作用

Role of systemin and jasmonic acid in systemic wounding response of tomato

当植物受到机械损伤或昆虫伤害时,植物体会在受伤部位产生伤信号分子启动防御基因的系统表达,蛋白酶抑制剂基因是防御基因的一典型代表。番茄是研究植物系统伤信号很好的模式植物,目前,三种类型的番茄系统伤信号突变体被鉴定出来,通过对番茄系统伤信号突变体进行功能分析并在它们之间进行相互嫁接实验,研究结果表明系统素和茉莉酸通过同一信号通路来激活防御基因的系统表达。系统素(或它的前体原系统素)在受伤部位激活茉莉酸的合成,使之达到系统反应的水平,应对外来伤害;茉莉酸或其衍生物是重要的系统伤信号分子,它诱导伤防御基因的系统表达。植物的系统伤反应可比做动物的炎症反应,它们之间有许多相似之处。

Plants produce systemic wounding signals in the wounding site which leads to the expression of systemic defense gene when plants receive the mechanical wounding or insect attack. Among the systemic defense gene,protease inhibitor gene is a representative sample. Tomato is a good model plant in studying the systemic wound response. Three type of wound-response mutants have been identified in tomato plant at present time, through the function analysis of the tomato wound-response mutants and the reciprocal grafting experiment among them, the results indicate that systemin and jasmonie acid activate defence gene systemic expression through a common signaling pathway . Systemin or its precursor protein prosystemin act at or near the site of wounding to increase jasmonate acid synthesis to a level that is required for the systemic response and jasmonie acid or its derivatives act as a mobile wound signal to induce the systemic defense gene expression. The systemic wound signal pathway in plant can be regarded as the inflammatory response in animal, they have rots of similarities.