Long-range mobile signals mediate seasonal control of shoot growth

Significance In perennial plants such as long-lived trees growing in boreal and temperate forest, transition from summer to winter is associated with induction of growth cessation and bud set at the shoot apex. Where in the plant these seasonal shifts are perceived and how these are communicated to the shoot apex remain unresolved. We identify leaves as a site for perception of seasonal shifts and reveal that components of floral transition such as FLOWERING LOCUS T ( FT ) and plant hormone GA have been recruited to function as long-range signals to communicate seasonal changes perceived in leaves to the shoot apical meristem to control its activity to synchronize bud set with the change of seasons in perennials.