Role of eisosomes in the necrotrophic fungus Alternaria brassicicola

lternaria brassicicola is a fungal necrotroph responsible for the Brassicaceae dark spot disease. This fungus is a seed-borne pathogen that only affects the aerial parts of host plants causing great damages with major incidence on yield and product quality. Its transmission to seed is a major component of pathogen fitness promoting the dispersal and long-term survival of the fungus. Recently, we showed that several eisosomal protein encoding genes were overexpressed when germinated spores of A.brassicicola were exposed to osmotic and hydric stresses, which are the main constraints encountered by the fungus during the seed colonization process. MCC/eisosomes are membrane microdomains whose function is still unclear. They have been proposed to participate in the plasma membrane function by regulating the homeostasis of lipids and would promote the recruitment of specific proteins and their subsequent protection from endocytosis. Here, we deciphered the potential involvement of eisosome in pathogenicity using a reverse genetic approach by generating and characterizing mutants deficient for key eisosomal proteinencoding genes (?pil1, ?nce102, ?lsp1 and ?pil1?lsp1). In parallel, these proteins have been fused to GFP to monitor their cellular location during the plant infection and following the exposure to stresses. Depending on the mutants, the leaf and silique colonization processes were impaired by comparison to the wild-type. We also showed a strong impact of MCC/eisosome proteinmutations on the generation of appressoria-like structures

Genome sequence of the necrotrophic plant pathogen Alternaria brassicicola Abra43

Alternaria brassicicola causes dark spot (or black spot) disease, which is one of the most common and destructive fungal diseases of Brassicaceae spp. worldwide. Here, we report the draft genome sequence of strain Abra43. The assembly comprises 29 scaffolds, with an N50 value of 2.1 Mb. The assembled genome was 31,036,461 bp in length, with a G+C content of 50.85%

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

Background 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 AbMak1 gene, which encodes a group A flavin monooxygenase in the plant pathogenic fungus Alternaria brassicicola, by generating a deficient mutant and examining its phenotype. Results 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 Δabmak1 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 Δabmak1 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 Δabmak1 strain. Conclusion This study sheds new light on the function of a fungal flavin-dependent monooxygenase, which plays an important role in melanization

Proteomics and the search for welfare and stress biomarkers in animal production in the one-health context

Stress and welfare are important factors in animal production in the context of growing production optimization and scrutiny by the general public. In a context in which animal and human health are intertwined aspects of the one-health concept it is of utmost importance to define the markers of stress and welfare. These are important tools for producers, retailers, regulatory agents and ultimately consumers to effectively monitor and assess the welfare state of production animals. Proteomics is the science that studies the proteins existing in a given tissue or fluid. In this review we address this topic by showing clear examples where proteomics has been used to study stress-induced changes at various levels. We adopt a multi-species (cattle, swine, small ruminants, poultry, fish and shellfish) approach under the effect of various stress inducers (handling, transport, management, nutritional, thermal and exposure to pollutants) clearly demonstrating how proteomics and systems biology are key elements to the study of stress and welfare in farm animals and powerful tools for animal welfare, health and productivity