Investigating the molecular components of a potential florigen signalling mechanism in maize.

摘要

Floral transition mechanisms in maize are poorly understood compared to other species. Maize indeterminate1 (id1) encodes a key flowering time regulator that acts in leaves to mediate the production or transmission of florigenic signals. In Arabidopsis, the FT protein is widely accepted as the archetypical florigen. Maize Zea CENTRORADIALIS genes (ZCN) encompass a large family of FT- related genes. This study examines whether one of these genes, ZCN8, encodes a maize florigen. My results show that id1 acts upstream of ZCN8 to control its expression, suggesting a new link to flowering control in temperate, day-neutral maize. In teosinte, a tropical progenitor of maize that requires short day photoperiods to induce flowering, ZCN8 is highly upregulated in leaves under inductive photoperiods. Moreover, vascular specific expression of ZCN8 in Arabidopsis rescues the ft-1 mutation, demonstrating that ZCN8 acts as a florigen that integrates endogenous and environmental signals in maize.