Mitogen-activated protein kinases are associated with the regulation of physiological traits and virulence in Fusarium oxysporum f. sp. cubense

• Published in: PloS one 2015-04, Vol.10 (4), p.e0122634-e0122634
• Main Authors: Ding, Zhaojian, Li, Minhui, Sun, Fei, Xi, Pinggen, Sun, Longhua, Zhang, Lianhui, Jiang, Zide
• Format: Article
• Language: English
• Subjects: Acids; Analysis; Aspergillus fumigatus; Attenuation; Beauvericin; Biochemical analysis; Biosynthesis; Candida albicans; Cell Wall - metabolism; Chitin; Computational Biology; Depletion; Depsipeptides - biosynthesis; Disease control; Disruption; Fruits; Fungi; Fusaric acid; Fusaric Acid - biosynthesis; Fusarium; Fusarium - cytology; Fusarium - enzymology; Fusarium - genetics; Fusarium - pathogenicity; Fusarium oxysporum; Gene expression; Gene regulation; Genes; Genomes; Hydrogen peroxide; Hyphae - cytology; Hyphae - enzymology; Hyphae - genetics; Hyphae - pathogenicity; Iron; Kinases; Laboratories; MAP kinase; Metabolism; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - metabolism; Mitogens; Molecular modelling; Mutation; Oxidative stress; Pathogens; Peroxidase; Physiology; Phytotoxins; Plant diseases; Plant pathology; Protein kinases; Proteins; Saccharomyces cerevisiae; Siderophores - biosynthesis; Signal transduction; Signs and symptoms; Stress response; Transcription; Transcription, Genetic; Virulence; Virulence (Microbiology); Wilt
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0122634

Fusarium oxysporum f. sp. cubense (FOC) is an important soil-borne fungal pathogen causing devastating vascular wilt disease of banana plants and has become a great concern threatening banana production worldwide. However, little information is known about the molecular mechanisms that govern the expression of virulence determinants of this important fungal pathogen. In this study, we showed that null mutation of three mitogen-activated protein (MAP) kinase genes, designated as FoSlt2, FoMkk2 and FoBck1, respectively, led to substantial attenuation in fungal virulence on banana plants. Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid. Biochemical analysis further confirmed the essential role of MAP kinases in modulating the production of fusaric acid, which was a crucial phytotoxin in accelerating development of Fusarium wilt symptoms in banana plants. Additionally, we found that the MAP kinase FoSlt2 was required for siderophore biosynthesis under iron-depletion conditions. Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2. Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence.