Botrytis cinerea: the cause of grey mould disease

Introduction: Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is an airborne plant pathogen with a necrotrophic lifestyle attacking over 200 crop hosts worldwide. Although there are fungicides for its control, many classes of fungicides have failed due to its genetic plasticity. It has become an important model for molecular study of necrotrophic fungi. Taxonomy: Kingdom: Fungi, phylum: Ascomycota, subphylum: Pezizomycotina, class: Leotiomycetes, order: Helotiales, family: Sclerotiniaceae, genus: Botryotinia. Host range and symptoms: Over 200 mainly dicotyledonous plant species, including important protein, oil, fibre and horticultural crops, are affected in temperate and subtropical regions. It can cause soft rotting of all aerial plant parts, and rotting of vegetables, fruits and flowers post-harvest to produce prolific grey conidiophores and (macro)conidia typical of the disease. Pathogenicity: B. cinerea produces a range of cell-wall-degrading enzymes, toxins and other low-molecular-weight compounds such as oxalic acid. New evidence suggests that the pathogen triggers the host to induce programmed cell death as an attack strategy. Resistance: There are few examples of robust genetic host resistance, but recent work has identified quantitative trait loci in tomato that offer new approaches for stable polygenic resistance in future.