Functional Analysis Of Necrosis And Ethylene-Inducing Proteins Of Cytospora Chrysosperma

Poplar canker caused by Cytospora chrysosperma is a branch and trunk disease of forest trees,which seriously affects the normal growth of poplar,and occurs in most parts of China.Cvtospora chrysosperma is a dead trophic pathogenic fungus,which secretes toxins and enzymes when interacting with plants.Cytospora chrysosperma is a dead trophic pathogenic fungus that extracts nutrients from dead host tissues.Among the toxins secreted by the dead trophic pathogens are a new class of phytotoxic proteins,which can induce necrosis and ethylene production.They are called NLP proteins.NLP proteins can be used as pathogenic toxic factors to induce cell protoplast destruction leading to cell necrosis and death,as well as an elicitor of pathogen-related molecular activity?PAMP?,which can induce plant immune defense response and resist pathogenic bacteria infection.Therefore,NLP protein plays a very important role in plant-pathogen interaction.In this study,we identified the NLP genes of poplar canker fungi CCG₀6974 and CCG₀6928,and obtained NLP gene knockout mutants and overexpression strains by PEG-mediated genetic transformation technology.Pathogenicity test showed that the mutants had decreased pathogenicity and increased pathogenicity of overexpression,indicating that NLP was a toxic factor.Transient expression of NLP could not cause tobacco allergic necrosis,suggesting that poplar canker was caused by transient expression of NLP.The NLP gene of rot fungus has no inductive cell death activity.The toxicity of NLP from poplar canker was analyzed in this study.The results will help to reveal the molecular mechanism of interaction between poplar and rot fungus,and lay a theoretical foundation for the prevention and control of poplar canker.