Expression of barley BAX Inhibitor-1 in carrots confers resistance to Botrytis cinerea

BAX Inhibitor-1 (BI-1) is a protein that controls heterologous BAX-induced cell death, the hypersensitive reaction and abiotic stress-induced cell death in plants. When over-expressed in epidermal cells of barley, barley BI-1 induces susceptibility to the biotrophic fungal pathogen Blumeria graminis. When we expressed barley BI-1 in carrot susceptible to the necrotrophic fungus Botrytis cinerea, we obtained BI-1-mediated resistance to fungus-induced leaf cell death and less fungal spreading on the leaves. Barley BI-1 also mediated resistance to Chalara elegans in carrot roots. The results support the idea that cell death inhibition is an applicable approach to control cell-death-inducing pathogens in crop plants.