show Abstracthide AbstractA functional circadian clock was previously characterized in Botrytis cinerea and demonstrated the crucial role of BcFRQ, the ortholog of core clock component FREQUENCY from Neurospora crassa. It was previously shown that the corresponding knockout mutant ?bcfrq displayed an abnormal developmental phenotype (always-sclerotia) when grown on potato dextrose agar. In the present study, we demonstrate that this phenotype can be reversed back to macroconidia production by adding primary nitrogen sources, suggesting an extra-circadian role for BcFRQ in nitrogen metabolism. We performed an RNAseq study of wildtype and knockout mutant ?bcfrq under varying nutritional and light conditions, to identify the genes involved in 1) perturbed nitrogen metabolism in the mutant ?bcfrq and 2) additional extra-circadian functions of BcFRQ. Overall design: Comparative gene expression profiling analysis of RNA-seq data for Botrytis cinerea strains (B05.10 and DeltaBcFRQ1) on CM media without nitrogen sources and complemented with Glutamine 0.1M as a primary source of Nitrogen. Samples were treated with constant light (LL), constant darkness (DD) or a light pulse (LP, 4 hours) and harvested at 48 hours.