A flavoprotein supports cell wall properties in the necrotrophic fungus Alternaria brassicicola

• Published in: Fungal biology and biotechnology 2017, Vol.4 (1), p.1-1, Article 1
• Main Authors: Pigné, Sandrine, Zykwinska, Agata, Janod, Etienne, Cuenot, Stéphane, Kerkoud, Mohammed, Raulo, Roxane, Bataillé-Simoneau, Nelly, Marchi, Muriel, Kwasiborski, Anthony, N'Guyen, Guillaume, Mabilleau, Guillaume, Simoneau, Philippe, Guillemette, Thomas
• Format: Article
• Language: English
• Subjects: Biochemistry, Molecular Biology; Life Sciences; Microbiology and Parasitology; Mycology
• ISSN: 2054-3085; 2054-3085
• DOI: 10.1186/s40694-016-0029-3

Flavin-dependent monooxygenases are involved in key biological processes as they catalyze a wide variety of chemo-, regio- and enantioselective oxygenation reactions. Flavoprotein monooxygenases are frequently encountered in micro-organisms, most of which require further functional and biocatalytic assessment. Here we investigated the function of the gene, which encodes a group A flavin monooxygenase in the plant pathogenic fungus , by generating a deficient mutant and examining its phenotype. Functional analysis indicates that the AbMak1 protein is involved in cell wall biogenesis and influences the melanization process. We documented a significant decrease in melanin content in the Δ strain compared to the wild-type and complemented strains. We investigated the cell wall morphology and physical properties in the wild-type and transformants using electron and atomic force microscopy. These approaches confirmed the aberrant morphology of the conidial wall structure in the Δ strain which had an impact on hydrophilic adhesion and conidial surface stiffness. However, there was no significant impairment in growth, conidia formation, pathogenicity or susceptibility to various environmental stresses in the Δ strain. This study sheds new light on the function of a fungal flavin-dependent monooxygenase, which plays an important role in melanization.