photoperiodism
Photoperiodism is the ability of plants to sense and respond to the relative lengths of day and night across the seasons, using this information to regulate key developmental processes such as flowering, dormancy, and tuber formation. This mechanism allows plants to synchronize reproduction and growth with the most favorable times of year, ensuring survival and reproductive success. Understanding how plants perceive and interpret daylength signals is central to crop improvement efforts, particularly in adapting varieties to different latitudes and climate conditions.
open_in_new WikipediaPubMed · 2026-05-04
A protein called Florigen (FT) acts as a seasonal timing signal in plants, traveling from leaves to growing tips to trigger flowering, tuber formation, and bud growth. This review synthesizes how FT works across many species and reveals a relay mechanism that helps plants commit to and sustain major developmental changes.
The FT florigen protein is produced in leaf veins in response to day length, then moves through the plant's vascular system to the shoot tip to trigger flowering or tuber formation across diverse species including cereals, tomato, potato, and trees.
FT forms a functional complex with bZIP transcription factors and 14-3-3 proteins to activate target genes, while closely related 'anti-florigen' proteins (TFL1 paralogs) act as negative regulators that fine-tune the timing of developmental transitions.
A newly described relay mechanism shows that FT genes (or close relatives) are re-activated at the shoot tip after FT protein arrives — identified in cereals, tomato, Arabidopsis, and potato stolons — suggesting this amplification loop helps sustain and lock in the photoperiod-induced developmental switch.
