Sensing the epigenome

Recent studies of plant development and environmental stress responses have converged on the roles of RNA and its metabolism as primary regulators of gene action. This RNA-based system appears to represent a versatile platform both for maintaining epigenetic memory and for reprogramming gene control in response to external signals. The fast-paced research reviewed here highlights exciting new trends in plant research relating to mechanisms and roles of the RNA-dependent epigenome in both development and evolution.