Mechanism Research On Phytophthora Infestans RxLR Effector Promoting Late Blight Disease By Interaction With Host Protein

Potato(Solanum tuberosum subsp.Tuberosum)is becoming more and more important as the fourth staple food.Potato late blight is caused by Phytophthora infestans,one of the most destructive fungal oomycete diseases.As the development of late blight bacteria is relatively rapid,physiological races are becoming more and more complicated,and the resistance genes of disease-resistant varieties can be quickly overcome after the pathogenic bacteria are mutated,so that the disease-resistant varieties that are selected and bred by traditional breeding lose their resistance.The effector protein is produced by the interaction between the phytopathogenic microorganism and the host plant.The protein function is divided into two kinds,toxic and non-toxic,and can be specifically recognized by the plant NBS-LRR resistance protein.When Phytophthora infestans infects host cells,it interacts with the host to make the plant itself produce an immune response.This paper is that 11 RxLR effector proteins of P.infestans have been used as the research object to explore whether it can promote the infection of late blight.In this thesis,the functional proteins were identified by using Agrobacterium transient expression(ATTA),subcellular localization and PVX-agroinfection analysis.The results of the study are as follows:(1)GFP expression vector was constructed by GFP fusion of 11 effector genes Pi04266,Pi08174,Pi12737,Pi14788,Pi15110,Pi22757,Pi00821,Pi15679,Pi07689,Pi18609,RD24,and protein coding region gene sequences.Mediated by Agrobacterium-mediated transfection of N.benthamiana,using GFP empty vector as a control,Agrobacterium transient expression test,the results show that: 11 effector proteins significantly promote the infection of late blight,a class of effector proteins worthy of study.(2)In vivo observation using confocal fluorescence microscope Confocal confirmed that the effector protein RD24 was located in the nucleus and formed a ring around the nucleus of the cell nucleus.(3)The gene silencing technique was used to construct the myrGFP·RD24mut expression vector and mediate Agrobacterium transfection in N.benthamiana.GFP-RD24 was used as a positive control and GFP empty vector was used as a negative control.Agrobacterium transient expression test was performed.The results showed that myr GFP·RD24mut could not promotethe infection of late blight.(4)The preliminary results of the natural induction identification of the 10 tested potato germplasm resources in the field were as follows: Cooperation 88,gck11-5,930,gck11-3,Belgium 105,72-7,gck12-10,North Korea The resistance of Citation 4 reached a high level of resistance,Belgium 4 was a middle resistance,and Eugene was a susceptible one.(5)The RD24 gene PVX virus transient expression vector pGR106·RD24 was constructed.The 9 potato germplasm resources were infected by Agrobacterium tumefaciens and the RD24 gene was transiently expressed in potato.The results showed that the system was able to induce co-operative 88,930 deaths in potato resistant germplasm resources.Cooperative 88,930 strains are resistant to the effector protein RD24 and contain resistance genes.