帚枝霉属内生真菌激发子蛋白SbES诱导辣椒抗棒孢叶斑病作用机理

为明确帚枝霉属Sarocladium内生生防真菌HND5菌株外泌激发子蛋白SbES的诱导辣椒抗病作用机理，通过构建SbES蛋白的毕赤酵母Pichia pastoris重组蛋白表达菌株，利用纯化后的SbES重组蛋白处理辣椒植株，检测辣椒对棒孢叶斑病的抗性，以及相关抗病反应与抗病基因表达的变化。结果表明，0.1 mg/mL SbES重组蛋白可有效诱导辣椒产生对棒孢叶斑病的抗性，可激发辣椒叶片活性氧爆发、微过敏反应和胼胝质积累等抗病反应；并能有效提高辣椒叶片中与活性氧爆发、过敏性反应、胼胝质合成和植保素合成等抗病反应相关基因，以及水杨酸、茉莉酸和乙烯信号传导关键基因的表达。推测帚枝霉属内生真菌激发子蛋白SbES可通过激活多种抗病信号传导途径来激发辣椒产生对棒孢叶斑病的抗性。

Study on the mechanism of disease resistance induced by the elicitor protein SbES from endophytic fungus Sarocladium strain in chilli pepper Capsicum annuum

In order to elucidate the activity of the elicitor protein SbES, produced by endophytic biocontrol fungi Sarocladium spp. HND5 in inducing disease resistance of pepper and its mechanism, a recombinant Pichia pastoris strain expressing SbES protein was constructed and purified SbES recombinant protein was used to treat pepper plants. The resistance to Corynespora cassiicola and changes of resistance response and resistance gene expression after the SbES protein treatment were detected. The results showed that 0.1 mg/mL SbES recombinant protein could effectively induce resistance of pepper to Corynespora leaf spot, stimulate reactive oxygen species (ROS) burst, micro-HR reaction and callose accumulation in pepper leaves. In addition, SbES protein treatment effectively improved the expression of broad-spectrum resistance genes, and other resistance response (including ROS burst, hypersensitive reaction, callose synthesis, phytoalexin synthesis, as well as salicylic acid, jasmonic acid and ethylene signal transduction) -related genes in pepper leaves. The results showed that the SbES elicitor protein can stimulate pepper resistance to Corynespora cassiicola.