WRKY1 mediates transcriptional regulation of light and nitrogen signaling pathways
- Plant Physiology
- Plant responses to multiple environmental stimuli must be integrated to enable them to adapt their metabolism and development. Light (L) and nitrogen (N) are two such stimuli whose downstream signaling pathways must be intimately connected to each other to control plant energy status. Here, we describe the functional role of the WRKY1 transcription factor in controlling genome-wide transcriptional reprogramming of Arabidopsis (Arabidopsis thaliana) leaves in response to individual and combined L and N signals. This includes a cross-regulatory network consisting of 724 genes regulated by WRKY1 and involved in both N and L signaling pathways. The loss of WRKY1 gene function has marked effects on the L and N response of genes involved in N uptake and assimilation (primary metabolism) as well as stress response pathways (secondary metabolism). Our results at the transcriptome and at the metabolite analysis level support a model in which WRKY1 enables plants to activate genes involved in the recycling of cellular carbon resources when L is limiting but N is abundant and up-regulate amino acid metabolism when both L and N are limiting. In this potential energy conservation mechanism, WRKY1 integrates information about cellular N and L energy resources to trigger changes in plant metabolism.