title: Cytosolic glutamine synthetase is important for photosynthetic efficiency and water use efficiency in potato as revealed by high-throughput sequencing QTL analysis.
abstract: WUE phenotyping and subsequent QTL analysis revealed cytosolic GS genes importance for limiting N loss due to photorespiration under well-watered and well-fertilized conditions. Potato (Solanum tuberosum L.) closes its stomata at relatively low soil water deficits frequently encountered in normal field conditions resulting in unnecessary annual yield losses and extensive use of artificial irrigation. Therefore, unraveling the genetics underpinning variation in water use efficiency (WUE) of potato is important, but has been limited by technical difficulties in assessing the trait on individual plants and thus is poorly understood. In this study, a mapping population of potatoes has been robustly phenotyped, and considerable variation in WUE under well-watered conditions was observed. Two extreme WUE bulks of clones were identified and pools of genomic DNA from them as well as the parents were sequenced and mapped to reference potato genome. Following a novel data analysis approach, two highly resolved QTLs were found on chromosome 1 and 9. Interestingly, three genes encoding isoforms of cytosolic glutamine synthase were located in the QTL at chromosome 1 suggesting a major contribution of this enzyme to photosynthetic efficiency and thus WUE in potato. Indeed, Glutamine synthetase enzyme activity of leaf extracts was measured and found to be correlated with contrasting WUE phenotypes.
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Øst, Denmark. kac@bio.aau.dk.|Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Øst, Denmark. kac@bio.aau.dk.
authors.forename: Kacper Piotr
authors.initials: KP
authors.lastname: Kaminski
authors.affiliation: Department of Agroecology, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark. kirstenk.sorensen@agrsci.dk.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Kørup
authors.affiliation: Department of Agroecology, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark. mathiasn.andersen@agrsci.dk.
authors.forename: Mathias Neumann
authors.initials: MN
authors.lastname: Andersen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Øst, Denmark. mson@bio.aau.dk.
authors.forename: Mads
authors.initials: M
authors.lastname: Sønderkær
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Øst, Denmark. msa@bio.aau.dk.
authors.forename: Mette Sondrup
authors.initials: MS
authors.lastname: Andersen
authors.affiliation: Danish Potato Breeding Foundation, Grindstedvej 55, 7184, Vandel, Denmark. hgk@lkfvandel.dk.
authors.forename: Hanne Grethe
authors.initials: HG
authors.lastname: Kirk
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Øst, Denmark. kln@bio.aau.dk.
authors.forename: Kåre Lehmann
authors.initials: KL
authors.lastname: Nielsen
mesh_terms: D002874:Chromosome Mapping; D003600:Cytosol / Q000201:enzymology; D018744:DNA, Plant / Q000235:genetics; D005974:Glutamate-Ammonia Ligase / Q000235:genetics / Q000502:physiology*; D059014:High-Throughput Nucleotide Sequencing; D010641:Phenotype; D010788:Photosynthesis; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D014867:Water / Q000502:physiology*
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D014867:Water; D005974:Glutamate-Ammonia Ligase