Non-coding regulation in seasonal flowering control - Insights from FLC

As sessile organisms, plants must adapt to fluctuating environmental conditions, with temperature serving as a key driver of developmental transitions. The ability to accurately perceive and respond to seasonal temperature fluctuations is critical for plant survival and reproductive success. In many species, prolonged exposure to the low temperatures of autumn and winter triggers vernalization, enabling flowering to occur under favourable spring conditions. This process has been extensively characterized in Arabidopsis thaliana, particularly through studies of the floral repressor FLOWERING LOCUS C (FLC). In this mini review, we summarize recent advances in understanding the genetic basis of vernalization, focusing on how non-coding polymorphisms influence FLC transcript accumulation and expression of long non-coding RNAs, thereby altering vernalization requirement and efficiency. Variation in the quantitative expression of FLC and its homologs has shaped the evolution of diverse life-history strategies of Arabidopsis relatives within the Brassicaceae family. Dissecting how naturally occurring non-coding variants reconfigure the cis-regulatory landscape of FLC-like genes will be key to understanding the molecular basis of phenological diversity. Such insights not only illuminate the evolutionary dynamics of flowering time control but also holds promise to provide targets for crop improvement under changing climatic conditions.