Read this pathogen profile to understand the full background of Botrytis cinerea, also known as grey mould; a generalist necrotrophic fungal pathogen found on important fruits, vegetables, and flowers worldwide.
If you observe signs of decay on your fruits and vegetables, accompanied by the growth of fuzzy grey-brown mould, chances are it is Botrytis cinerea. B. cinerea is a cosmopolitan fungus that infects more than 1500 plant species, ranging from dicots, monocots, gymnosperms, and even non-vascular plant species. Both individual isolates and the species show this extensive host range in contrast to other broad-host pathogens with narrow-range isolates. Key hosts include important crops like strawberries, tomatoes, grapes, lily, onions, and pine trees. This notorious pathogen causes both pre-and post-harvest losses by infecting all parts of the plant and causing an estimated loss of $10 to 100 billion annually worldwide.
B. cinerea can spread from one plant to another by wind, water, or even on insects and enter host tissue either by direct penetration or through natural openings. To assist invasion across such a diverse range of hosts, this fungus employs a multitude of strategies. One major contributing factor is the extensive genetic diversity among B. cinerea strains and their polygenic architecture, where standing genetic variation in numerous genes can collectively contribute to specific phenotypes. Additionally, B. cinerea deploys a broad range of molecular weapons, including the secretion of cell wall-degrading enzymes and toxins that break down host cell walls. The pathogen also activates diverse signalling pathways as a defence against host resistance mechanisms and produces virulence factors to infect the host. Notably, recent observations show that B. cinerea sends immune-suppressing small RNA molecules to the host, effectively silencing host genes by manipulating their RNA interference machinery possibly creating a mass confusion attack on the plant rather than a specific targeted attack.
The pathogen’s global distribution, genetic diversity, and ability to be stratospherically spread pose challenges for disease management. Farmers primarily rely on integrated strategies, combining cultural practices, chemical and biological controls, and the cultivation of tolerant/resistant varieties. Current research endeavours aim to thoroughly understand the genetic and molecular diversity of B. cinerea, aiming to formulate effective strategies to combat B. cinerea infections and mitigate their repercussions on agriculture. In our pathogen profile entitled: “Genetic and molecular landscapes of the generalist phytopathogen Botrytis cinerea”, we summarized the current understanding of genetic and molecular mechanisms employed by the fungus to attack its hosts and also discuss recent innovative strategies to combat B. cinerea.
Ritu Singh, Celine Caseys, Daniel J. Kliebenstein published this study in Molecular Plant Pathology Journal:
TITLE IMAGE: Phylogenetic tree representing the wide host range of B. cinerea.