title: Water uptake in barley grain: Physiology; genetics and industrial applications.
abstract: Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3;1,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3;1,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3;1,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries.
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Suong
authors.initials: S
authors.lastname: Cu
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Collins
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Natalie S
authors.initials: NS
authors.lastname: Betts
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: March
authors.affiliation: Cargill Malt, Cargill, 65 Magill Road, Stepney SA 5069, Australia.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Janusz
authors.affiliation: Coopers Brewery, 461 South Rd, Regency Park SA 5010, Australia.
authors.forename: Doug C
authors.initials: DC
authors.lastname: Stewart
authors.affiliation: Carlsberg Group Research, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark.
authors.forename: Birgitte
authors.initials: B
authors.lastname: Skadhauge
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Eglinton
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Bianca
authors.initials: B
authors.lastname: Kyriacou
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Alan
authors.initials: A
authors.lastname: Little
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Burton
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia. Electronic address: geoffrey.fincher@adelaide.edu.au.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Fincher
mesh_terms: D001692:Biological Transport / Q000502:physiology; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping / Q000379:methods; D032461:Chromosomes, Plant / Q000235:genetics; D002523:Edible Grain / Q000235:genetics / Q000378:metabolism*; D056625:Endosperm / Q000235:genetics / Q000378:metabolism*; D019649:Food Industry / Q000379:methods; D005838:Genotype; D005936:Glucans / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011134:Polysaccharides / Q000378:metabolism; D040641:Quantitative Trait Loci / Q000235:genetics; D034622:RNA Interference; D014867:Water / Q000378:metabolism*
chemical_list: D005936:Glucans; D010940:Plant Proteins; D011134:Polysaccharides; D014867:Water; D005964:Glucosyltransferases; C040232:glucan synthase
keywords: Cell walls; Mutant library; QTL analysis; Starchy endosperm; Transgenic barley