| Rice false smut is one of the three major diseases of rice caused by U st ilaginoidea v irens,which poses a great threat to the yield and qualit y of rice.Studies on the pathogenic mechanis m of rice false smut is of great significa nce to the development of new fungic ide s and the formula t io n of new funga l disease prevention and control strategies.In this study,the funct io n of ester cyclase gene and 7 C C HC-type zinc finger protein genes which were significa nt ly upregulated on the 6th day after U.v irens infect io n were studie d.The main results are as follows :1.In this study,through the knockout of gene U v EC 1 contain i n g Polyketide cyclase Snoa L-like domain of U.v irens,it was found that the deletion of U v EC 1 could significa nt l y increase the mycelia l growth rate,spore production and cell wall sensitivit y of U.v irens.The pathogenic it y of U v EC1 gene knockout transforma nt s was significa nt l y lower than that of wild type.Observation of subcellular localization revealed that Uv EC1 appeared to be mainly localized in the cytoplasm of various tissues.To further study the regulat o r y mechanis m of U v EC 1 in U.v irens,233 differe nt ia l ly expressed proteins were identified by proteomic analys is of U v EC 1 knockout mutant and wild type strain.Bioinfo r ma t ic s analys is of these identified proteins s howed that differe nt ia ll y expressed proteins were mainly involved in catalytic activit y,binding,transmembra ne transport,cellular stress response and relate d metabolic processes.Further analysis showed that 28 of the differe nt ia l l y expressed proteins we re predicted to be secreted proteins,5 proteins were related to the spliceosome pathway of U.v irens.The results of proteome data analysis and q RT-PC R verifica t io n showed that the expression of proteins involved in ustila gino id ins biosynthes is was signif ica nt l y increased in U v EC1 gene knockout mutants.Biologica l assay showed that the culture filtra te of mutant strains signif ica nt ly inhib ited the growth of rice seed germ,which ma y be related to the increase of ustila gino id i ns.These results suggest that Uv EC 1gene is involved in the regulat io n of growth,sporulatio n,pathogenic it y and mult ip le metabolic pathways of U.v irens.2.The funct io na l study of 7 genes with C C HC-type zinc finger doma in protein in U.v irens showed that the seven genes had differen t effects on the growth,sporulatio n and pathogenic it y of U.v irens.The deletions of U v C C HC1,U v C C HC 2,U v C C HC 3 and U v C C HC 4 genes signif ica nt ly affected the mycel ia l growth rate of the transforma nts.The deletions of U v C C HC 4,U v C C HC5,U v C C HC 6 and U v C C HC 7 increased or decreased the spore production and pathogenic it y of U.v irens.The U v C C HC 5 gene knockout transforma nts could not form rice balls after inoculat io n,which may be related to the decreased utilizat io n effic ie nc y of stachyose and sucrose by U.v irens.The expression of these seven genes were signif ica nt ly up-regulated on the 1st,3rd and 5th day after U.v irens infect io n,suggest ing that these genes were involved in the attachment and growth of U.v irens hyphae on the surface of rice glume and to establishi the parasitic relations hip by invading floral organs. |
