Functional Characterization Of MAPK Signal Pathway Of Fomps1Gene In Fusarium Oxysporum F.sp.Cubense

Fusarium wilt of banana,also known as Panama disease of banana or Yellow leaf disease,is because Fusarium oxysporum f. sp. cubense(Foc) infect banana tissue caused by vascular diseases and fungal soil borne diseases. The results to research the molecular basis of this disease help us to understand the pathogen-host plant interaction, provide new targets for exploiting new fungicide, help us to make some novel control strategies in future. mpsl encoding a mitogen-activated protein kinase(MAPK) of F. oxysporum, MAPK pathway plays an important role in the pathogen pathogenicity and infect. This study deals with the method of reverse genetics Fompsl gene function has carried on the preliminary study, the main research results are as follows:1、To understand its role in pathogenesis of Foc, the DNA fragments from the upstream and downstream of open read frame were amplified by PCR, respectively. They were cloned into the pCT74to construct the vector for homologous recombination, then was transferred into Foc B2strain by the PEG-Mediated Protoplast Transformation. At last, several transformants with seletcion marker of GFP and hph cassette were obtained. Among them, three transformants were confirmed to be the Fompsl gene-deletiong mutants(△Fompsl) by PCR with four pairs of the gene-specific primers.2、By biology characteristic observation of the△Fompsl mutant, colony morphology is irregular shaped;under the microscope,hyphae is the fracture shape; Spore production rate is reduce;△Fompsl mutant have obvious reduction in growth rate; The hetero caryon rate of hyphae is increased. Hyphae have infiltration. In different carbon source medium, wild type and mutant in galactosyl as carbon source of the culture medium can produce a large number of aerial hyphae, but in other medium colony almost no aerial hyphae.3、△Fomps1mutant unable to perforation the cellophane. Knockout mutants lacking Fomps1reduce the pathogenicity of banana. In the infection test,we find the spore of△Fomps1mutant can’t attached in the root of banana,also did not find hyphae into the root.By the crude toxin pathogenicity test and the result of HPLC, knockout mutants lacking Fompsl lead to toxin-producing ability is reduced.4、Knockout mutants lacking Fompsl made of cellulose, lignin peroxidase, pectinase enzyme activity is reduced, but increase the laccase activity. By quantitative fluorescence analysis, we find the expression quantity of Foc4-xyl4, Foc4-Lac,Foc4-102is increased, but the expression quantity of Foc4-pl, Foc4-CHS3, Foc4-Lip, Foc4-835is decreased.5、Complement of△Fompsl mutant with the original Fompsl gene, the pathogenicity and biologic characteristics of complementary strain were recover.The results showed that the Fompsl gene is an important pathogenic genes of Fusarium wilt of banana, relevant experiment results to guide the banana blight certain theoretical basis for the prevention and cure.