长枝木霉聚合根肿菌多元RNAi靶标防治榨菜根肿病的研究

Research on the Control of Brassica juncea Clubroot by Trichoderma longiflorum Based on Poly-RNAi Target

榨菜根肿病是由芸薹根肿菌(Plasmodiophora brassicae)引起的一种土传性病害,在榨菜栽培过程中危害十分严重。研究构建了丝状真菌表达根肿菌3个MAPK基因的dsRNA载体,利用PEG介导的原生质体转化技术将dsRNA载体转化到对榨菜根肿病具有生防作用的长枝木霉菌株中,通过抗生素筛选和PCR鉴定筛选到阳性转化子(即转基因长枝木霉),并对3个MAPK基因dsRNA在转基因长枝木霉中的表达情况进行了检测,分析了转基因长枝木霉对榨菜根肿病的防治效果。结果表明:通过RNAi技术对该长枝木霉菌株中多个MAPK基因进行联合干扰,可增强长枝木霉对根肿病病原菌的抗性,显著抑制根肿菌中3个MAPK基因的表达,从而提高长枝木霉对榨菜根肿病的防效,降低榨菜根肿病的病情指数。该研究结果可为根肿病防治提供新的思路。

Brassica juncea clubroot is a soil-borne disease caused by Plasmodiophora brassicae,bringing serious damage to Brassica juncea production.In this study,the dsRNA vector(pDH-RH-MAPK)expressing three MAPK genes of Plasmodiophora brassicae was constructed,then was transformed into Trichoderma longiflorum that has biocontrol effect on Brassica juncea clubroot by PEG-mediated.The positive transformants(i.e.,transgenic Trichoderma longiflorum strains)were screened by antibiotic screening and PCR identification.The expression of dsRNA of three MAPK genes in transgenic Trichoderma longiflorum strains was detected.The control effect of transgenetic Trichoderma longiflorum on clubroot disease was investigated by dipping Brassica juncea roots.The results show that the expression of three MAPK genes in Plasmodiophora brassicae was significantly reduced by targeted RNAi via transgenic Trichoderma longiflorum,the control effect of Trichoderma longiflorum on Brassica juncea clubroot was improved,thus reducing the disease index.The results could provide a new idea for the prevention and treatment of clubroot disease.