Functional Studies Of The Effector Protein Gene Pep1 In Sporisorium Scitamineum

Sporisorium scitamineum is a dimorphic fungus of basidiomycetes.The sugarcane smut caused by it is the most important disease in sugarcane production in China,which seriously affects the development of sugarcane industry in China.The pathogenic mechanism of S.scitamineum is currently not fully understood,but there is evidence that effector proteins may play an important role in the pathogenic process.In this study,the following research was carried out based on the knockout of the disease-related gene pep1 in the laboratory,Such as signal peptide function identification,pressure stress response,gene expression analysis,pathogenicity identification,DAB analysis after inoculation,protein interaction in vitro,yeast two-hybrid.The main results were as follows:1.The signal peptide of Pep1 protein had the ability to guide secretion of a protein,indicating that Pep1 may be an effector;2.Deletion of pep1 gene had no obvious effect on the growth of S.scitamineum on normal medium,did not change its stress response to stress conditions under high osmotic pressure,oxidative conditions and cell wall integrity;3.The transcription level of the genes bE,bW,pra,mfa and prf,essential for sexual mating,was significantly down-regulated in of Δ35-pep1,and the mating efficiency of the mutant was significantly lower than that of the wild-type strain;4.Disruption of pep1 in a mating-type strain significantly reduced the pathogenicity of the mating-derived diploid mycelia;5.Pep1-null mutant Δ35-pep1 enhanced the ROS burst response at the inoculation sites on the sugarcane leaves;6.Prokaryotic-expressed Pep1 inhibited the activity of peroxidase Pod-1a from the sugarcane,but did not interact with Pod-1a in vitro.The study of gene pep1 knockout strain found that the deletion of the gene had an effect on the growth,coordination and pathogenicity of S.scitamineum;The study of the interaction between Pep1 and the host protein found the mechanism of Pep1 protein in the infection of sugarcane.This study aims to reveal the pathogenic mechanism of S.scitamineum and provide a theoretical basis for the prevention and treatment of Sugarcane smut.