Function Analysis Of Effector Protein PITG＿07586 From Phytophthora Infestans

Potato（Solanum tuberosum L.）is an annual Solanum plant in Solanaceae.As the fourth largest food crop in the world,potato is widely planted all over the world and plays an important role in ensuring world food security.In the production process,late blight caused by Phytophthora infestans has caused great losses to potato industry.It was found that P.infestans suppress plant resistance by secreting effector proteins and targeting host proteins.At present,most studies focus on RxLR（R:Arginine;X:Any amino;L:Leucine）effector proteins,and there is a lack of research on non-RxLR domain effector proteins.In this study,the toxic molecular mechanism of PITG＿07586 was preliminarily analyzed by exploring the function and interaction protein of non-RxLR effector protein PITG＿07586.The results can provide new ideas for the prevention and control of potato late blight.The main results are as follows:（1）Protein structure analysis revealed that PITG＿07586 had a signal peptide at the N-terminus（1-21 amino acid）and a nuclear localization signal sequence at the C-terminus（110-120 amino acid）.（2）qRT-PCR results showed that PITG＿07586 was up-regulated during the inoculation of P.infestans on potato,suggesting that PITG＿07586 was involved in the process infection of plant by P.infestans.We found that transient expression of PITG＿07586 could promote the infection of P.infestans by in vitro leaf inoculation.（3）The GFP-PITG＿07586 fusion plasmid was constructed and it was found that PITG＿07586 was mainly located in the nucleus by agrobacterium-mediated gene expression.And PITG＿07586 did not suppress INFI-induced cell death when co-infiltrated with INF1.（4）Using the effector protein PITG＿07586 as bait protein,yeast two-hybrid technology was used to screen the c DNA library of potato cultivar ’Cooperative 88’,and three interacting proteins were preliminarily screened.It was potato POM30 protein,potato SRC2-like protein and voltage dependent anionic channel protein VDAC.The interaction between PITG＿07586 and three candidate proteins was further verified by luciferase complementation assay,and the results showed that PITG＿07586 could interact with three candidate proteins.（5）By using virus-induced gene silencing（VIGS）,PITG＿07586 candidate interaction proteins POM30、SRC2-like and VDAC were silenced on Nicotiana benthamiana.Compared with the control group TRV2-GFP,the area of disease area of silenced plants was significantly increased after inoculation.In summary,the non-RXLR effector protein PITG＿07586 was mainly located in the host nucleus,and it could suppress plant immunity system by interacting with potato POM30 protein,SRC2-like protein,and voltage dependent anionic channel protein VDAC.