FLOWERING LOCUS T Paralogs Control the Annual Growth Cycle in Populus Trees

Here, we show that the three Populus three FLOWERING LOCUS T (FT) paralogs are important regulators of phenology and essential for vegetative growth, albeit in different tissues at different times of the year. FT2a has been established as an important regulator of autumn phenology previously, but not much was known about FT2b. It is now clear that both FT2s act together to regulate SD-induced growth cessation. The role of FT1 during winter was so far unclear and we show that FT1 is indispensable for the continuation of growth after winter, probably through the release of dormancy.