Spores, which are often termed conidia in some fungi, are an essential part of the developmental cycle of A. brassicicola and arise from the branching filaments or hyphae that make up the fungus. In the study, the investigators show that disruption of the AbNPS2 gene drastically impacts the integrity of the cell wall of fungal spores produced in the reproductive phase of A. brassicicola's life cycle. The AbNPS2 gene most likely directs the synthesis of a molecule that plays an essential role in maintaining the structure of the cell wall of the conidia.
Associate Professor Christopher Lawrence of the Virginia Bioinformatics Institute and the Department of Biological Sciences at Virginia Tech, director of the study, remarked: "Typical A. brassicicola spores are hydrophobic. Water droplets placed on a lawn of fungal hyphae bearing normal spores are repelled and easily roll off the surface. When the AbNPS2 gene is disrupted, the linkage of the outermost layer of the fungal spore cell wall to the middle layer appears to be disturbed, destroying the cell wall's regular architecture and making the spores permeable to water. This has drastic effects on the viability of the spores."
Kwang-Hyung Kim, doctoral student and the lead author on the paper, stated: "What we have been able to show is that mutation of the AbNPS2 gene is accompanied by structural