CRF12 specifically regulates the flowering time of Arabidopsis thaliana under non‐inductive conditions

SUMMARY The flowering time of Arabidopsis thaliana , a model plant, is significantly accelerated when exposed to long‐day (LD) conditions, as it is a typical LD plant. Consequently, the investigation of the flowering regulatory network in A. thaliana under LD conditions has garnered considerable attention in the study of flowering signals, resulting in a significant breakthrough. While many LD plants, including A. thaliana , exhibit delayed flowering under non‐inductive short‐day (SD) conditions, they are still capable of flowering. Nevertheless, research on the regulation of flowering induction in LD plants under non‐inductive SD conditions has been limited. This study demonstrated the involvement of CYTOKININ RESPONSE FACTORS 12 (CRF12) in the regulation of flowering in A. thaliana under non‐inductive conditions. Analysis of the expression patterns revealed that the activation of CRF12 expression and protein stability occurred exclusively in non‐inductive environments. Molecular and genetic analyses revealed that under a non‐inductive photoperiod of 12 h of light and 12 h of darkness, CRF12, CONSTANS (CO), and TARGET OF EAT 1/2 (TOE1/2) engage in competitive interactions to regulate flowering time, while in a SD photoperiod of 8 h of light and 16 h of darkness, CRF12 modulates flowering time by inhibiting the activity of TOE1/2.