DHD4, a CONSTANS-like family transcription factor, delays heading date by affecting the formation of the FAC complex in rice

Heading date (or flowering time) is one of the most important agronomic traits in rice, influencing its regional adaptability and crop yield. Many major-effect genes for rice heading have been identified, but practice they are difficult to be used molecular breeding because their dramatic effects on date. Genes with minor date, which more desirable fine-tuning time without significant yield penalty, were seldom reported. In this study, we identified a new minor-effect repressor, Delayed Date 4 (DHD4). The dhd4 mutant shows slightly earlier phenotype notable penalty compared wild-type plants under natural long-day conditions. DHD4 encodes CONSTANS-like transcription factor localized nucleus. Molecular, biochemical, genetic assays show that can compete 14-3-3 interact OsFD1, thus affecting formation Hd3a-14-3-3-OsFD1 tri-protein FAC complex, resulting reduced expression OsMADS14 OsMADS15, ultimately delaying flowering. Taken together, these results shed light regulation provide promising target improve rice.