拟南芥抵抗丁香假单胞杆菌过程中AZI1基因功能研究

AZI1属于脂转移蛋白家族,它在拟南芥抵抗病原菌侵染过程中可能起着传递信号物质的作用。该实验以过表达和T-DNA插入突变体及野生型拟南芥植株为材料,通过RNA印迹、蛋白质免疫印迹和原位免疫组织化学方法,研究了拟南芥壬二酸诱导基因AZI1对丁香假单胞杆菌的抗性功能。结果表明:(1)AZI1基因可以被丁香假单胞杆菌、H2O2和乙烯利诱导,它可能参与水杨酸和乙烯介导的抗菌途径。(2)蛋白质免疫印迹实验结果显示,丁香假单胞杆菌侵染叶片的叶柄渗出液中存在AZI1蛋白及其同源物EARLI1,并能够与其他蛋白质形成复合体,说明AZI1有可能通过维管组织移动到个体的其他部位,与信号分子的转移有关。(3)AZI1及其同源物EARLI1主要在花序茎的木质化部位表达,过表达AZI1基因能够促进木质素的合成,提高拟南芥对丁香假单胞杆菌的抗性。

Function of AZI1 in Arabidopsis Resistance against Pseudomonas syringae

Function of AZI1 in Arabidopsis resistance to Pseudomonas syringae was analyzed using overexpressing,T-DNA knockout and wild-type lines.(1)The expression of AZI1 could be induced by P.syringae,H₂O₂ and ethephon,indicating AZI1 is involved in salicylic acid- and ethylene-mediated antimicrobial pathways.(2)Western blotting analyses showed that AZI1 and its paralog EARLI1 existed in petiole exudate.They could form complexes with other proteins.It suggested that AZI1 possibly moved to other sites of plants through vascular tissue and related with signal transduction.(3)AZI1 and its paralog EARLI1 mainly expressed in lignified tissues of inflorescence stems,overexpression of AZI1 could promote biosynthesis of lignin and enhance the resistance of Arabidopsis to P.syringae.AZI1 belongs to lipid transfer protein (LTP) family.It may play important functions in transduction of signal molecules during defense response of Arabidopsis to infection of P.syringae.