MaohongCai, ShanshanZhu, MingmingWu, XiaomingZheng, JiachangWang, LiangZhou, TianhuiZheng, SongCui, ShirongZhou, ChaonanLi, HuanZhang, JuntaoChai, XinyueZhang, XinJin, ZhijunCheng, XinZhang, CailinLei, YulongRen, JianminWan

　　Molecular Plant, 24 November 2020, IF: 12.084

　　doi: 10.1016/j.molp.2020.11.013

　　https://doi.org/10.1016/j.molp.2020.11.013

　　Abstract

　　Heading date (or flowering time) is one of the most important agronomic traits in rice, which influences the regional adaptability and crop yield. Many major-effect genes have been identified on rice heading date, which influence heading date to a large extent, and they are hard to utilize in rice molecular breeding. While minor-effect genes on heading date which are more desirable for fine-tuning flowering time without significant yield penalty were less reported. Here, we identified a new minor-effect heading date repressor, Delayed Heading Date 4 (DHD4). The dhd4  mutant shows a slightly earlier flowering phenotype without a notable yield penalty compared with wild type plants under natural long day (NLD) conditions. DHD4  encodes a CONSTANS -like transcription factor localized in the nucleus. Molecular, biochemical and genetic assays show that DHD4 can compete with 14-3-3 to interact with OsFD1, thus affecting formation of the Hd3a-14-3-3-OsFD1 tri-protein FAC complex and causing reduced expression of OsMADS14  and OsMADS15 , and ultimately delayed flowering. These results shed new light on the regulation of flowering time in rice and provide a promising target for fine-tuning of flowering time to improve the regional adaptability of rice.