野油菜黄单胞菌效应蛋白 AvrXccC抑制鞭毛蛋白诱导的植物免疫反应

摘要

野油菜黄单胞菌III型分泌效应蛋白AvrXccC在拟南芥 rar1突变体上发挥毒性功能，然而，AvrXccC是如何发挥毒性功能的，目前还不清楚。本研究构建了A6vrXccC在 rar1突变体上的转基因植株，通过接种DC3000 hrcC突变体，发现 AvrXc‐cC／rar1转基因植株可以促进hrcC的毒性功能。进一步研究发现，AvrXccC／rar1转基因植株抑制细菌鞭毛蛋白激发的活性氧爆发、胼胝体沉积及下游 N HO1和FRK1基因的表达；但AvrXccC不抑制鞭毛蛋白诱导的MAPK激酶活性。研究表明，AvrX‐ccC抑制植物先天免疫反应可能独立于MAPK信号通路之外，为将来分离AvrXccC在植物体内的毒性靶标奠定了基础。%AvrXccC ,a type III effector protein of X anthomonas campestris pv .campestris (Xcc) ,acts as a virulence factor in rar1 mutant .However ,little is known about the virulence mechanisms of AvrXccC .In this study ,we demonstrated that AvrXc‐cC/rar1 transgenic plants enhance the DC3000 hrcC virulence and suppress flg22‐induced oxidative burst and callose deposition , as well as FRK1 and NHO1 gene expression .Interestingly , AvrXccC/rar1 transgenic plants cannot inhibit flg22‐induced MAPKs activity ,suggesting that AvrXccC is capable of inhibiting signaling of plant immunity in a MAPK independent manner . Overall ,this study provides a basis for future research aimed at isolating virulence targets of AvrXccC in plants .