title: Subfunctionalization of duplicate MYB genes in Solanum commersonii generated the cold-induced ScAN2 and the anthocyanin regulator ScAN1.
abstract: Wild potato species are useful sources of allelic diversity and loci lacking in the cultivated potato. In these species, the presence of anthocyanins in leaves has been associated with a greater tolerance to cold stress. However, the molecular mechanisms that allow potatoes to withstand cold exposure remain unclear. Here, we show that the expression of AN2, a MYB transcription factor, is induced by low temperatures in wild, cold-tolerant Solanum commersonii, and not in susceptible Solanum tuberosum varieties. We found that AN2 is a paralog of the potato anthocyanin regulator AN1, showing similar interaction ability with basic helix-loop-helix (bHLH) co-partners. Their sequence diversity resulted in a different capacity to promote accumulation of phenolics when tested in tobacco. Indeed, functional studies demonstrated that AN2 is less able to induce anthocyanins than AN1, but nevertheless it has a strong ability to induce accumulation of hydroxycinnamic acid derivatives. We propose that the duplication of R2R3 MYB genes resulted in subsequent subfunctionalization, where AN1 specialized in anthocyanin production and AN2 conserved the ability to respond to cold stress, inducing mainly the synthesis of hydroxycinnamic acid derivatives. These results contribute to understanding the evolutionary significance of gene duplication on phenolic compound regulation.
authors.affiliation: Department of Agricultural Sciences, University of Naples Federico II, Portici, 80055, Italy.
authors.forename: Vincenzo
authors.identifier: 0000-0002-8548-6825
authors.initials: V
authors.lastname: D'Amelia
authors.affiliation: Department of Agricultural Sciences, University of Naples Federico II, Portici, 80055, Italy.
authors.forename: Riccardo
authors.identifier: 0000-0002-4041-3702
authors.initials: R
authors.lastname: Aversano
authors.affiliation: National Research Council of Italy, Institute of Biosciences and Bioresources, Research Division Portici (CNR-IBBR), Portici, 80055, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ruggiero
authors.affiliation: National Research Council of Italy, Institute of Biosciences and Bioresources, Research Division Portici (CNR-IBBR), Portici, 80055, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Batelli
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Ingo
authors.initials: I
authors.lastname: Appelhagen
authors.affiliation: Department of Agricultural Sciences, University of Naples Federico II, Portici, 80055, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Dinacci
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Lionel
authors.initials: L
authors.lastname: Hill
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Cathie
authors.initials: C
authors.lastname: Martin
authors.affiliation: Department of Agricultural Sciences, University of Naples Federico II, Portici, 80055, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Carputo
mesh_terms: D000872:Anthocyanins / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D003373:Coumaric Acids / Q000378:metabolism; D020131:Genes, Duplicate; D009997:Osmotic Pressure; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D032322:Solanum / Q000235:genetics* / Q000502:physiology; D013312:Stress, Physiological; D014026:Nicotiana / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D051792:Basic Helix-Loop-Helix Proteins; D003373:Coumaric Acids; D010940:Plant Proteins; D014157:Transcription Factors; C004999:ferulic acid
keywords: ferulic acid; hydroxycinnamic acid; osmotic stress; paralog genes; potato; transcription factors