[Biological characteristics of an Hog1 MAPK homologous gene FoHog1 knock-out mutant of Fusarium oxysporum f. sp. cubense].

Objective: This study was aimed to obtain a mitogen-activated protein kinase (MAPK) gene namely FoHog1 from Fusarium oxysporum f. sp. cubense and to verify its function.

Methods: We amplified FoHog1 gene by PCR and RT-PCR methods and analyzed it through bioinformatics method. PEG-mediated protoplast transformation was used to create the deletion mutants of FoHog1 gene. We analyzed different biological characteristics between knock-out strain and wild-type strain.

Results: FoHog1 gene encoding a putative protein of 357 amino acids and its genetic relationship with different Fusarium' s protein. Compared with the wild-type strain, FoHog1 deletion mutants have loose hyphae colony, less spores production, lower dry weight of hyphae and more sensitive to temperature, pH and osmotic stress. FoHog1 deletion mutants also have reduced colonization ability compared with the wild-type strain.

Conclusion: FoHog1 gene participated in mycelial growth, sporulation, catabolism of sodium acetate and ammonium chloride, osmotic stress response and pathogenic process with Fusarium oxysporum f. sp. cubense Race 4.