The aim of the project was to study the transcriptome of a Botrytis cinerea mutant deficient in production of two phytotoxic metabolites (botrydial and botcinin) during infection on tomato leaves upon inoculation in medium lacking or containing yeast extract. The first condition results in primary necrotic lesions that do not expand (incompatible interaction, infection fails) while the second condition results in expanding lesions (compatible interaction, infection succeeds). The wild type Botrytis cinerea is able to cause expanding lesions (compatible interaction) under both inoculation conditions. The mutant and wild type were also grown in vitro in the same inoculation medium lacking or containing yeast extract. Infected leaves and in vitro mycelium were sampled at several time points and used for RNA extraction and sequencing.