Live and let die: the smart lifestyle of Botrytis cinerea

It becomes increasingly apparent that interactions between plants and necrotrophic fungi are surprisingly subtle and complex, and host plants in fact play a much more active role in disease than previously anticipated. Just causing ‘death’ isn’t good enough, the execution of programmed cell death by a host plant in response to a pathogen is crucial for many necrotrophs to be successful. Botrytis cinerea is a ubiquitous pre- and post-harvest pathogen infecting a wide range of host plants and tissues. I will present an overview of current knowledge on pathogenicity factors of B. cinerea, with emphasis on phytotoxic metabolites and proteins that can cause (programmed?) plant cell death. I will subsequently discuss processes occurring in the host plant during the interaction, with emphasis on the formation of Reactive Oxygen Species and nitric oxide, as well as on cell death pathways. Examples will be presented of host defense responses during B. cinerea infection, that contribute to (partial) resistance. The capacity of B. cinerea to counteract the growth inhibitory activity of defence compounds, by a combination of enzymatic detoxification and secretion mechanisms, also contributes to its successful lifestyle.