在本氏烟中瞬时表达效应因子PsCRN127基因提高其对寄生疫霉的抗性

Transient expression of the Ps CRN127 effector gene enhances Nicotiana benthamiana resistance to Phytophthora parasitica

[目的]本研究对一个具有植物细胞死亡抑制活性的大豆疫霉效应因子Ps CRN127进行功能分析,为认识疫霉菌的致病机制和利用效应因子来提高植物抗病性提供参考。[方法]利用农杆菌介导的瞬时表达技术,分析Ps CRN127的细胞死亡调控活性;利用寄生疫霉游动孢子接种本氏烟离体叶片评估Ps CRN127对植物防卫反应的影响;利用实时定量RT-PCR检测本氏烟中激素抗病信号途径标记基因的表达;利用DAB染色检测本氏烟接种叶片中过氧化氢的积累;利用与GFP融合的方法观察Ps CRN127的亚细胞定位。[结果]在本氏烟中表达Ps CRN127可以抑制由INF1、Psoj NIP、Ps CRN63、Bax和Avh241诱导的植物细胞死亡,并且可以提高其对寄生疫霉的抗性;Ps CRN127可能通过提高激素抗性信号途径相关基因的表达和过氧化氢的积累来提高植物抗病性;Ps CRN127定位于植物的细胞质和细胞核中。[结论]大豆疫霉可能通过分泌具有广泛细胞死亡抑制活性的CRN效应因子Ps CRN27来调控植物的细胞死亡和防卫反应;可以直接应用这些疫霉菌效应因子提高植物的抗病性。

[Objectives]This study characterized a broad cell-death-suppression effector PsCRN127 from Phytophthora sojae,in order to gain information of Phytophthora pathogenesis and guidance to promote plant resistance. [Methods]The Agrobacterium-mediated transient expression method was used to analyze cell death manipulation activity of PsCRN127. Inoculation assay on detached Nicotiana benthamiana leaves using zoospores was conducted to evaluate the effect of PsCRN127 expression on plant defense. Real-time RT-PCR was performed to determine the expression of genes in plant hormone signaling pathways. DAB staining approach was adopted to detect the accumulation of hydrogen peroxide in plants. The subcellular localization of GFP：PsCRN127 fusion was analyzed by using a fluorescent microscope. [Results]Expression of PsCRN127 suppressed cell death induced by INF1,PsojNIP,PsCRN63,Bax and Avh241 in N.benthamiana;PsCRN127 may promote plant disease resistance by regulating hormone signaling and inducing accumulation of hydrogen peroxide. PsCRN127 is localized within plant cytoplasm and nucleus. [Conclusions]P.sojae may secrete broad cell-death-suppression effectors such as PsCRN127 to manipulate plant cell death and immunity,and they could be used directly to enhance plant disease resistance.