The eukaryotic translation initiation factor eIF4E regulates flowering and circadian rhythm in Arabidopsis

Translation initiation is a rate-limiting step in protein synthesis. The eukaryotic translation initiation factor 4E (eIF4E) plays an essential role in the translation initiation process. However, how eIF4E-dependent translation initiation regulates plant growth and development remains not fully understood. In this study, we have found that Arabidopsis eIF4E proteins distribute both in the nucleus and cytoplasm, and only cytoplasmic eIF4E is implicated in the control of flowering time. Results of profiling the genome-wide translation by Ribo-tag sequencing further reveal that eIF4E may regulate plant flowering by affecting homeostatic translation of flowering-time genes, including the Central Oscillator Genes (COGs). Consistent with the hypothesis that transcription-translation feedback loop is the core mechanism to drive the oscillation of circadian clock, we show that the eIF4E-dependent translation modulates the rhythmic oscillation of protein abundance of the clock-related genes (CCGs). Together, our study provides mechanistic insights into how the protein translation regulates multiple developmental processed in Arabidopsis including circadian clock and photoperiodic flowering. The differences of transcriptomes and translatomes between wild type and eif4e mutant were compared and analyzed