Journal Article

Evolutionary diversification of galactinol synthases in Rosaceae: adaptive roles of galactinol and raffinose during apple bud dormancy

Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Universidade Federal do Rio Grande do Sul [Porto Alegre] (UFRGS), Porto, Diogo Denardi, Falavigna, Vitor, 'Financiadora de Estudos e Projetos' (FINEP) : 0107009700 ; Embrapa : 02.12.12.003.00.02 ; 'Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior' (CAPES, Ministry of Education) ; 'Conselho Nacional de Desenvolvimento Cientifico e Tecnologico' (CNPq) : 309869/2012-9, 304991/2014-7, Empresa Brasileira de Pesquisa Agropecuária (Embrapa) ; Ministério da Agricultura, Pecuária e Abastecimento [Brasil] (MAPA) ; Governo do Brasil-Governo do Brasil, Miotto, Yohanna Evelyn, Dias de Oliveir

2018

Overview

Galactinol synthase (GolS) is a key enzyme in the biosynthetic pathway of raffinose family oligosaccharides (RFOs), which play roles in carbon storage, signal transduction, and osmoprotection. The present work assessed the evolutionary history of GolS genes across the Rosaceae using several bioinformatic tools. Apple (Malus x domestica) GolS genes were transcriptionally characterized during bud dormancy, in parallel with galactinol and raffinose measurements. Additionally, MdGolS2, a candidate to regulate seasonal galactinol and RFO content during apple bud dormancy, was functionally characterized in Arabidopsis. Evolutionary analyses revealed that whole genome duplications have driven GolS gene evolution and diversification in Rosaceae speciation. The strong purifying selection identified in duplicated GolS genes suggests that differential gene expression might define gene function better than protein structure. Interestingly, MdGolS2 was differentially expressed during bud dormancy, concomitantly with the highest galactinol and raffinose levels. One of the intrinsic adaptive features of bud dormancy is limited availability of free water; therefore, we generated transgenic Arabidopsis plants expressing MdGolS2. They showed higher galactinol and raffinose contents and increased tolerance to water deficit. Our results suggest that MdGolS2 is the major GolS responsible for RFO accumulation during apple dormancy, and these carbohydrates help to protect dormant buds against limited water supply.

• Publisher: Oxford University Press (OUP),CCSD,Oxford University Press
• Subject: apples / Arabidopsis / biochemical pathways / bioinformatics / buds / carbon sequestration / dormancy / evolution / gene expression regulation / genes / inositol 3-alpha-galactosyltransferase / Life Sciences / Malus domestica / protein structure / raffinose / Research Papers / signal transduction / transcription (genetics) / transgenic plants / Vegetal Biology / water supply
• ISBN: 0004261472000