title: Transcriptional and Post-transcriptional Mechanisms Limit Heading Date 1 (Hd1) Function to Adapt Rice to High Latitudes.
abstract: Rice flowering is controlled by changes in the photoperiod that promote the transition to the reproductive phase as days become shorter. Natural genetic variation for flowering time has been largely documented and has been instrumental to define the genetics of the photoperiodic pathway, as well as providing valuable material for artificial selection of varieties better adapted to local environments. We mined genetic variation in a collection of rice varieties highly adapted to European regions and isolated distinct variants of the long day repressor HEADING DATE 1 (Hd1) that perturb its expression or protein function. Specific variants allowed us to define novel features of the photoperiodic flowering pathway. We demonstrate that a histone fold domain scaffold formed by GRAIN YIELD, PLANT HEIGHT AND HEADING DATE 8 (Ghd8) and several NF-YC subunits can accommodate distinct proteins, including Hd1 and PSEUDO RESPONSE REGULATOR 37 (PRR37), and that the resulting OsNF-Y complex containing Hd1 can bind a specific sequence in the promoter of HEADING DATE 3A (Hd3a). Artificial selection has locally favored an Hd1 variant unable to assemble in such heterotrimeric complex. The causal polymorphism was defined as a single conserved lysine in the CCT domain of the Hd1 protein. Our results indicate how genetic variation can be stratified and explored at multiple levels, and how its description can contribute to the molecular understanding of basic developmental processes.
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.|Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
authors.forename: Daniela
authors.identifier: http://orcid.org/0000-0003-3996-0204
authors.initials: D
authors.lastname: Goretti
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.|Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, United Kingdom.
authors.forename: Damiano
authors.identifier: http://orcid.org/0000-0002-6207-0974
authors.initials: D
authors.lastname: Martignago
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Landini
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.|Department of Agricultural and Environmental Sciences-Production, Territory, Agroenergy, University of Milan, Via Celoria 2, Milan, Italy.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Brambilla
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Jorge
authors.initials: J
authors.lastname: Gómez-Ariza
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Nerina
authors.identifier: http://orcid.org/0000-0002-2465-8881
authors.initials: N
authors.lastname: Gnesutta
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Francesca
authors.identifier: http://orcid.org/0000-0003-2984-2933
authors.initials: F
authors.lastname: Galbiati
authors.affiliation: Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
authors.forename: Silvio
authors.identifier: http://orcid.org/0000-0002-9603-0882
authors.initials: S
authors.lastname: Collani
authors.affiliation: Iwate Biotechnology Research Center and Laboratory of Crop Evolution, Graduate School of Agricultural Sciences, Kyoto University, Mozume, Muko, Kyoto, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takagi
authors.affiliation: Iwate Biotechnology Research Center and Laboratory of Crop Evolution, Graduate School of Agricultural Sciences, Kyoto University, Mozume, Muko, Kyoto, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Terauchi
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mantovani
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy.
authors.forename: Fabio
authors.identifier: http://orcid.org/0000-0002-1050-0477
authors.initials: F
authors.lastname: Fornara
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D018556:Crops, Agricultural / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D006657:Histones / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D011485:Protein Binding; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D006657:Histones; D010940:Plant Proteins; D014157:Transcription Factors