Time-Course Transcriptome Analysis Unveils the CoFKF1-CoMYB4-CoFT1 Regulatory Module in Flowering Control of Camellia oleifera Abel.

Camellia oleifera Abel. (C. oleifera) represents a significant woody edible oil species predominantly distributed in southern China. Timely flowering is essential for the growth, development and tea oil production of C. oleifera. However, the mechanisms underpinning this process remain insufficiently understood. In this study, it was demonstrated through time-course transcriptome analysis that we revealed that CoFKF1-like1 (CoFKF1) serves as a central regulatory gene in the flowering process of C. oleifera. The ectopic expression of CoFKF1 resulted in the induction of early flowering. Furthermore, it was observed that CoFKF1 interacts with the transcription factor CoMYB4 in a blue-light-dependent manner, facilitating its ubiquitination and subsequent degradation. Genetically, CoMYB4 was identified as functioning downstream of CoFKF1 by directly binding to the promoter of CoFT1 and repressing its promoter activity. In conclusion, these findings elucidate that CoFKF1 promotes flowering by reducing the stability of the CoMYB4 protein, thereby enhancing CoFT1 promoter activity. Collectively, the results provide critical insights into the flowering mechanisms of C. oleifera and present a promising avenue to optimise its flowering period via the CoFKF1-CoMYB4-CoFT1 module.