FLOWERING LOCUS T paralogs control the annual growth cycle in Populus trees.

In temperate and boreal regions, perennials adapt their annual growth cycle to the change of seasons. These adaptations ensure survival in harsh environmental conditions, allowing growth at different latitudes and altitudes, and are therefore tightly regulated. Populus tree species cease growth and form terminal buds in autumn when photoperiod falls below a certain threshold.

Acts in Leaves to Modulate the Timing of Growth Cessation and Bud Set.

is an important regulator of in the thermosensory pathway of Arabidopsis. It is a negative regulator of flowering and represses transcription. In poplar trees, is central for the photoperiodic control of growth cessation, which also requires the decrease of bioactive gibberellins (GAs).