Chemical induction of silent biosynthetic pathway for the expansion of the terpenome in Botrytis cinerea

The recent availability of the B. clnerea genome at the Genoscope (http://www.genoscope.cns.fr/) and at the Broad Institute (http://www.broad.mit.edu/annotation/fgi/) provided the opportunity to investigate secondary metabolism gene clusters including those putatively involved in sesquiterpene biosynthesis. Although only two families of toxins have been isolated and reported, the sequencing of the genomes of the B05–10 and T4 strains revealed an abundance of novel biosynthetic gene clusters. Genomic data revealed that B. cinerea has 43 key enzymes some of them are specific of this phytopathogen. Within the genome, 6 genes coding for putative sesquiterpene cyclases have been identified, including 2 diterpene cyclases. To study them, we have undertaken different approaches: chemical- and molecular-based epigenetic studies, comparative genomic study and gene inactivation. As a result new molecules with novel structures were found. The isolation and characterization of these molecules are under study and their structures and biosynthetic pathway, using deuterated acetate and labelled glucose experiments, are shedding light on new biological targets.