title: Acclimation of metabolism to light in Arabidopsis thaliana: the glucose 6-phosphate/phosphate translocator GPT2 directs metabolic acclimation.
abstract: Mature leaves of plants transferred from low to high light typically increase their photosynthetic capacity. In Arabidopsis thaliana, this dynamic acclimation requires expression of GPT2, a glucose 6-phosphate/phosphate translocator. Here, we examine the impact of GPT2 on leaf metabolism and photosynthesis. Plants of wild type and of a GPT2 knockout (gpt2.2) grown under low light achieved the same photosynthetic rate despite having different metabolic and transcriptomic strategies. Immediately upon transfer to high light, gpt2.2 plants showed a higher rate of photosynthesis than wild-type plants (35%); however, over subsequent days, wild-type plants acclimated photosynthetic capacity, increasing the photosynthesis rate by 100% after 7 d. Wild-type plants accumulated more starch than gpt2.2 plants throughout acclimation. We suggest that GPT2 activity results in the net import of glucose 6-phosphate from cytosol to chloroplast, increasing starch synthesis. There was clear acclimation of metabolism, with short-term changes typically being reversed as plants acclimated. Distinct responses to light were observed in wild-type and gpt2.2 leaves. Significantly higher levels of sugar phosphates were observed in gpt2.2. We suggest that GPT2 alters the distribution of metabolites between compartments and that this plays an essential role in allowing the cell to interpret environmental signals.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK.
authors.forename: Beth C
authors.initials: BC
authors.lastname: Dyson
authors.affiliation: School of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester, M1 7DN, UK.
authors.forename: J William
authors.initials: JW
authors.lastname: Allwood
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Feil
authors.affiliation: School of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester, M1 7DN, UK.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Miller
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK.
authors.forename: Caroline G
authors.initials: CG
authors.lastname: Bowsher
authors.affiliation: School of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester, M1 7DN, UK.
authors.forename: Royston
authors.initials: R
authors.lastname: Goodacre
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany.
authors.forename: John E
authors.initials: JE
authors.lastname: Lunn
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK.
authors.forename: Giles N
authors.initials: GN
authors.lastname: Johnson
mesh_terms: D000064:Acclimatization; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D055786:Gene Knockout Techniques; D019298:Glucose-6-Phosphate / Q000378:metabolism; D008027:Light; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D030821:Plants, Genetically Modified; D013213:Starch / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C000592795:GPT2 protein, Arabidopsis; D009004:Monosaccharide Transport Proteins; D019298:Glucose-6-Phosphate; D013213:Starch
keywords: high light; photosynthesis; sugar signalling