| The Phytophthora capsici and Phytophthora sojae are important members of Phytophthora,which not only seriously affect food security,but also cause huge losses to the economy and society.Phytophthora completes the infection by secreting a large number of effector molecules into the host to destroy its immune system.Studying the interaction between pathogen effectors and host plant proteins is crucial for understanding the pathogenesis of pathogens.In this study,we got the identification of the interactional proteins of the three effectors in Phytophthora capsici and Phytophthora sojae and the preliminary exploration of the function of effector molecules with DNA-binding domains,which provided a basis for further research to the molecular mechanism of Phytophthora.The main research is as follows:Identification of PsCRN108 interacting protein in Phytophthora sojae:There are very few reports of Phytophthora with effector molecules directly bind to conserved sequences of host plant DNA to interfere with their immune response.Preliminary research in the laboratory had found that there is an effector molecule PsCRN108 in Phytophthora sojae that can directly bind to the promoter of the host plant HSP gene,inhibiting the transcription and translation of the HSP gene and interfering with the HSP protein-mediated plant immune response.In this study.the yeast two-hybrid screening library was used to screen PsCRN 108 in the soybean cDNA library,and 84 candidate proteins were identified.Among them 18 candidate proteins were selected for one-toone verification of yeast two-hybrid,and we found two proteins that interact with PsCRN108,PUB23 and CAMTA2.Identification of PsCRN78 interaction protein in Phytophthora sojae:PsCRN78 is an effector molecule with secretory function in Phytophthora sojae,which has a kinase domain and may participate in its activity of inhibiting plant immune response during infection.This study found that PsCRN78 was toxic to yeast and could not use the yeast system for protein interaction identification:then.we used the immunoprecipitation of PsCRN78 and LC-MS/MS identification,combined with the phosphorylation data analysis of Arabidopsis mutants that stably transformed PsCRN78.As a result,we found that a class of aquaporins PIP2;7 in plants interact with PsCRN78,and therefore may participate in the pathogenic process of the PsCRN78 effector.Identification of PcRxLR242 interaction protein in Phytophthora capsici:PcRxLR242 is a type of effector molecule that has polymorphism in different strains of Phytophthora capsici.Previous studies had found that different PcRxLR242 homologues have a certain effect on the differentiation of host plant induced cell death and plant resistance.We transiently expressed PcRxLR242 through the agrobacteriummediated transient expression system,combined with immunoprecipitation and LC-MS/MS technology.We analysed results found that there was an interaction between the Rab subfamily members of a small G protein family and RxLR242.And verified by yeast two-hybrid one-to-one verification and luciferase complementation experiment,the results show that RxLR242 and RabE have a clear interaction relationship.A preliminary study on the effector function of DNA-binding activity in Phytophthora:To investigate the effect of DNA-binding domain of effctors on the pathogenicity of host plants in Phytophthora.Early research predicted DNA-binding effector molecules in oomycetes used biological information analysis,we selected 10 candidate effector molecules for further research.We constructed the pBin-GFP 2 plant expression vector,and observed the cell localization by transient expression of N.leaves;Pseudomonas and P.capsici was inoculated on N.benthamiana leaves of transient expression of candidate effector molecules.As a result,we found that there were two candidate effector molecules can change the plant phenotype:PcAvh92 was more resistant to disease and PcCRN100 was more susceptible to host plant. |
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