Plant signalling components EDS1 and SGT1 enhance disease caused by the necrotrophic pathogen Botrytis cinerea

Botrytis cinerea is a necrotrophic fungus that causes grey mould on a wide range of food plants, especially grapevine, tomato, soft fruits and vegetables. This disease brings about important economic losses in both pre- and postharvest crops. Successful protection of host plants against this pathogen is severely hampered by a lack of resistance genes in the hosts and the considerable phenotypic diversity of the fungus. The aim of this study was to test whether B. cinerea manipulates the immunity-signalling pathways in plants to restore its disease. We showed that B. cinerea caused disease in Nicotiana benthamiana through the activation of two plant signalling genes, EDS1 and SGT1, which have been shown to be essential for resistance against biotrophic pathogens; and more interestingly, virus-induced gene silencing of these two plant signalling components enhanced N. benthamiana resistance to B. cinerea. Finally, plants expressing the baculovirus antiapoptotic protein p35 were more resistant to this necrotrophic pathogen than wild-type plants. This work highlights a new strategy used by B. cinerea to establish disease. This information is important for the design of strategies to improve plant pathogen resistance.