香蕉枯萎镰刀菌4号生理小种FoSP1基因功能的初步分析OA北大核心CSTPCD

Banana Fusarium wilt is a fungal disease which is the most harmful and difficult to control in banana produc-tion in China.Due to the influence of banana Fusarium wilt,the banana planting area in China has been decreasing year by year in recent years,which has brought huge economic losses to the subtropical and tropical banana industries in China.The disease occurred because the vascular bundle of banana was invaded by Fusarium oxysporum f.sp.cubense(Foc),and its propagation speed was fast,which caused the yellowing of banana leaves and plant wilting.By comparing the genome and transcriptome sequences of Foc race 1(Foc1,N2)and race 4(Foc4,B2),a secreted protein FoSP1 lo-cated in the lineage-specific region with high expression was screened out.The results showed that the open reading frame of FoSP1 gene was 387 bp,encoding 129 amino acids,and its signal peptide cleavage site was located between the 20th and 21st amino acid residues,and the protein had no known domain and functional site,so it was inferred that FoSP1 was a new secreted protein.In order to study the biological function of the protein in Foc4 strain,the split-marker method was used to knock out the FoSP1 gene of B2 strain,and the phenotype analysis and pathogenicity determination of the correctly knocked-out mutant were carried out.The results showed that compared with wild-type B2 strain,there was no significant difference in the vegetative growth of FoSP1 gene knockout mutants,and they were insensitive to exogenous stresses such as NaCl,D-sorbitol and H2O2,but the conidial yield and germination rate of knockout mutants were significantly reduced,and their pathogenicity to Brazilian banana was significantly weakened.It is inferred that the secreted protein FoSP1 does not participate in the vegetative growth of B2 strain,but plays an im-portant role in the process of sporulation and pathogenicity.This result lays a foundation for further study on the patho-genic mechanism of secreted proteins in the genome lineage-specific region of Foc4.