机械伤害诱导的植物防御机制和信号转导

Mechanism of Wound-induced Defense Response and Signal Transduction in Plants

茉莉酸是植物伤反应的特异激素,在植物伤反应中具有核心作用,其下游调控机制已经比较清晰。在番茄(Lycopersicon esculentum)伤反应中,系统素和茉莉酸协同启动相关基因的表达,行使系统性防御功能。拟南芥(Arabidopsis thaliana)信号肽是新发现的一类信号物质,可以激活植物的初始免疫反应,但其在伤反应中的作用机制有待进一步研究。脱落酸位于茉莉酸上游,单独或者协同茉莉酸参与植物的防御反应。另外,植物中还存在以核糖核酸酶为代表的且不依赖于茉莉酸的伤反应信号转导途径。该文对植物伤反应的防御机制和信号转导做了详细概述。

Jasmonic acid(JA) is the specific phytohormone responding to plant wounding and plays a central function in both plant local and systemic wounding signaling.However,an 18-amino acid polypeptide system has been identified in tomato for initiating systemic JA production and defense gene expression in undamaged distal tissues.Arabidopsis AtPEPs(a class of short peptides) can activate transcription of the defense gene defensin(PDF1.2) and be induced by wounding,JA and ethylene,which are potentially connected to the wounding response.Both antagonistic and synergistic interactions occur between abscisic acid(ABA) and JA signaling in Arabidopsis.The deficiency in activation of JA-induced genes in ABA-deficient mutants indicates that ABA precedes or cooperates with JA in activating the defense response.In addition,plants have a JA-independent wounding signal pathway,overrepresented by RNase.We review recent advances in investigating the mechanism and signal transduction in the wounding response of plants.