Photoperiodic control of flowering in Arabidopsis

Flowering is a crucial event for most plants species and key to reproductive success. Among the environmental signals driving floral transition, day length plays a major role. In the model plant species Arabidopsis thaliana flowering is promoted by long days typical of spring or early summer, but delayed during short winter days. This response is mediated by the photoperiod pathway that comprises at its core the GIGANTEA - CONSTANS and FLOWERING LOCUS T genes. Here we summarize recent advances in our understanding of photoperiodic control of flowering, focusing on the gene regulatory cascade acting in leaves to generate a transmissible florigenic signal and on the molecular network required at the shoot apical meristem to respond to such signal.