title: OsFTIP1-Mediated Regulation of Florigen Transport in Rice Is Negatively Regulated by the Ubiquitin-Like Domain Kinase OsUbDKγ4.
abstract: Flowering time is a critical agronomic trait that determines successful seed production and adaptation of crop plants. Photoperiodic control of this process in flowering plants is mediated by the long-distance mobile signal called florigen partly encoded byFLOWERING LOCUS T(FT) inArabidopsis thalianaand its orthologs in other plant species. Despite the progress in understanding FT transport in the dicot model Arabidopsis, the mechanisms of florigen transport in monocots, which provide most of the biomass in agriculture, are unknown. Here, we show that rice FT-INTERACTING PROTEIN1 (OsFTIP1), a member of the family of multiple C2 domain and transmembrane region proteins (MCTPs) and the closest ortholog of Arabidopsis FTIP1, is required for export of RICE FLOWERING LOCUS T 1 (RFT1) from companion cells to sieve elements. This affects RFT1 movement to the shoot apical meristem and its regulation of rice flowering time under long days. We further reveal that a ubiquitin-like domain kinase γ4, OsUbDKγ4, interacts with OsFTIP1 and modulates its degradation in leaves through the 26S proteasome, which in turn affects RFT1 transport to the shoot apical meristem. Thus, dynamic modulation of OsFTIP1 abundance in leaves by a negative regulator OsUbDKγ4 is integral to the role of OsFTIP1 in mediating RFT1 transport in rice and provides key evidence for a conserved role of FTIP1-like MCTPs in mediating florigen transport in flowering plants.
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Shiyong
authors.identifier: http://orcid.org/0000-0002-0068-4807
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Ying
authors.identifier: http://orcid.org/0000-0003-1615-7494
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Bao
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
authors.forename: Zhi Wei Norman
authors.initials: ZW
authors.lastname: Teo
authors.affiliation: College of Life Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Chuanzao
authors.identifier: http://orcid.org/0000-0001-5126-2180
authors.initials: C
authors.lastname: Mao
authors.affiliation: College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Gan
authors.affiliation: Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore dbsyuhao@nus.edu.sg.
authors.forename: Hao
authors.identifier: http://orcid.org/0000-0002-9778-8855
authors.initials: H
authors.lastname: Yu
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060405:Florigen / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; D060405:Florigen; D010940:Plant Proteins