FB (AT1G22770) — Arabidopsis thaliana

Summary

AT1G22770 (GI, also known as FB or gigantea) in Arabidopsis thaliana encodes the GIGANTEA protein, which has been annotated with DNA-binding transcription repressor activity, peptide-O-fucosyltransferase activity, and multiple other molecular functions including calcium-dependent protein phosphatase and blue light photoreceptor activity. GI is associated with the regulation of circadian rhythm, including photoentrainment, temperature compensation, and downregulation of the circadian clock. It is linked to photoperiod sensitivity, flowering time, and shoot development, as well as responses to drought, salinity, and paraquat toxicity. The gene has been connected to traits such as harvest index, leaf area, seedling vigor, and fruit number, along with processes including carotenoid and xanthophyll metabolism, abscisic acid regulation, and miRNA processing. GI localizes to nuclear bodies, the tonoplast, and chloroplast envelope, and interacts with SPY and FB in pathways regulating circadian gene expression and photoperiodic flowering.