Bioinformatics And Functional Analysis Of CFEM Gene Family In Fusarium Graminearum

Fusarium graminearum can infect wheat,barley,corn and other cereal crops,causing serious yield loss.More serious is Fusarium graminearum can produce a variety of mycotoxins,serious threat to human and animal health.Among them,Deoxynivalenol(DON)toxin was the most common.Therefore,effective control of Fusarium graminearum in wheat is very important for food production and safety.Existing studies have shown that filamentous fungi CFEM protein plays an important role in the pathogenesis.At present,there are very few studies on Fusarium graminearum CFEM protein,and the specific functions of this gene family in its pathogenicity,growth and development are still unclear,and the relevant regulation mechanism remains to be further studied.In this paper,the CFEM gene family of Fusarium graminearum was systematically analyzed by bioinformatics,and the biological function of the gene family was further studied by targeted gene knockout technology.The main results obtained are as follows:(1)Through multiple rounds of comparative analysis,a total of 23 CFEM genes(named Fg CFEM1-23 respectively)were identified in Fusarium graminearum genome.All 23 Fg CFEM genes and encoded proteins were systematically analyzed using relevant tools,including signal peptide analysis,subcellular localization,transmembrane domain analysis,GPI modification site identification,effector prediction,etc.Two new conserved domains were identified in Fusarium graminearum CFEM gene family,named CFEM＿WR and CFEM＿KF,respectively.(2)Transcriptome analysis was conducted on Fusarium graminearum after artificial inoculation of wheat materials.The results showed that all 23 CFEM genes were expressed after inoculation of wheat,and the expression levels of 7 CFEM genes were significantly up-regulated.Combined with bioinformatics analysis,Fg CFEM11 and Fg CFEM23 were identified as candidate effector factors,which may play an important role in the pathogenesis of Fusarium graminearum.This study provides a theoretical basis for further analysis of the effects of CFEM effector on plant pathogenic fungi.(3)Twenty-three FgCFEMs targeted knockout mutants were constructed and phenotypic analysis was performed.The results showed that compared with the wildtype strain PH-1,some mutants have defects in growth rate(ΔFgcfem2,ΔFgcfem18 andΔFgcfem21),sporulation capacity(ΔFgcfem8 and ΔFgcfem18),pathogenicity(ΔFgcfem3,ΔFgcfem4,ΔFgcfem6,ΔFgcfem8,ΔFgcfem11 and ΔFgcfem16),toxicity(ΔFgcfem1,ΔFgcfem3,ΔFgcfem5 and ΔFgcfem18)and etc.The results showed that the CFEM protein was related to the growth and development,sporulation,pathogenicity and toxicity of Fusarium graminearum,which provided an important basis for further study on the growth and development and pathogenicity mechanism of Fusarium graminearum.