Metabolic control of transcription: Light alters histone methylation in plants via nuclear a-ketoglutarate dehydrogenase

Abstract

Mechanisms that link environmental stimuli to organismal transcriptional responses facilitate adaptation and survival. Because it signals energy availability through photosynthesis, light is among the most important environmental signals for plants. On page 179 of this issue, Huang et al. (1) demonstrate that, in the plant Arabidopsis thaliana, light exposure stimulates chromatin-local depletion of the tricarboxylic acid (TCA) cycle metabolite α-ketoglutarate to orchestrate global gene expression by impairing demethylation of nucleosomal histone tails. These findings provide a molecular mechanism for how the Arabidopsis genome senses light. They also demonstrate how subcellular metabolism can be spatially reorganized to regulate chromatin structure and transcription.