title: OsNF-YC2 and OsNF-YC4 proteins inhibit flowering under long-day conditions in rice.
abstract: OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response through the modulation of three flowering-time genes ( Ehd1, Hd3a , and RFT1 ) in rice. Plant NUCLEAR FACTOR Y (NF-Y) transcription factors control numerous developmental processes by forming heterotrimeric complexes, but little is known about their roles in flowering in rice. In this study, it is shown that some subunits of OsNF-YB and OsNF-YC interact with each other, and among them, OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response of rice. Protein interaction studies showed that the physical interactions occurred between the three OsNF-YC proteins (OsNF-YC2, OsNF-YC4 and OsNF-YC6) and three OsNF-YB proteins (OsNF-YB8, OsNF-YB10 and OsNF-YB11). Repression and overexpression of the OsNF-YC2 and OsNF-YC4 genes revealed that they act as inhibitors of flowering only under long-day (LD) conditions. Overexpression of OsNF-YC6, however, promoted flowering only under LD conditions, suggesting it could function as a flowering promoter. These phenotypes correlated with the changes in the expression of three rice flowering-time genes [Early heading date 1 (Ehd1), Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1)]. The diurnal and tissue-specific expression patterns of the subsets of OsNF-YB and OsNF-YC genes were similar to those of CCT domain encoding genes such as OsCO3, Heading date 1 (Hd1) and Ghd7. We propose that OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response by interacting directly with OsNF-YB8, OsNF-YB10 or OsNF-YB11 proteins in rice.
authors.affiliation: Division of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-Gu, Seoul, 136-701, Republic of Korea.|Center for Desert Agriculture, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Soon-Kap
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Division of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-Gu, Seoul, 136-701, Republic of Korea.
authors.forename: Hyo-Young
authors.initials: HY
authors.lastname: Park
authors.affiliation: Division of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-Gu, Seoul, 136-701, Republic of Korea.
authors.forename: Yun Hee
authors.initials: YH
authors.lastname: Jang
authors.affiliation: Division of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-Gu, Seoul, 136-701, Republic of Korea.
authors.forename: Keh Chien
authors.initials: KC
authors.lastname: Lee
authors.affiliation: Department of Genetic Engineering, Dong-A University, Busan, 604-714, Republic of Korea.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Chung
authors.affiliation: Department of Bioresource Engineering and Plant Engineering Research Institute, Sejong University, 98 Gunja-dong, Gwangjin-Gu, Seoul, 143-747, Republic of Korea. jhwanlee90@sejong.ac.kr.
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-Gu, Seoul, 136-701, Republic of Korea. jkkim@korea.ac.kr.
authors.forename: Jeong-Kook
authors.initials: JK
authors.lastname: Kim
mesh_terms: D000483:Alleles; D023081:CCAAT-Binding Factor / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects; D017440:Photoperiod; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D025941:Protein Interaction Mapping; D055503:Protein Multimerization; D013997:Time Factors
chemical_list: D023081:CCAAT-Binding Factor; D010940:Plant Proteins; C402244:nuclear factor Y
keywords: Flowering time; NUCLEAR FACTOR Y (NF-Y); Photoperiodic flowering; Rice; Transcription