Far-red enriched light delays tomato transcriptome modulations in response to Botrytis cinerea infection

We performed a transcriptome analysis of a 30 -hour infection time course aiming to unravel hormonal and metabolic pathways affected by FR which would in turn modulate disease resistance. Our data show that supplemental FR, received before pathogen inoculation, triggers the FR-induced susceptibility, which is associated with a delay in pathogen recognition and defense activation via JA and possibly ethylene signaling. The transcriptome analysis highlighted a set of six PROTEINASE INHIBITOR genes (PI) that are induced only in WL-treated samples. As PI genes are described to be JA-responsive genes, the FR-induced susceptibility in tomato is possibly due to a dampening of JA-mediated gene induction and expression affecting defense responses resulting in more susceptible plants. We examined the transcriptional response of tomato leaves subjected to either white or far-red enriched light prior to inoculation with the necrotrophic fungus Botrytis cinerea or a mock solution. We then followed the transcriptome changes through time (every 6 hours from 0 to 30 hours post inoculation).