title: Genetic Diversity and Genome Wide Association Study of β-Glucan Content in Tetraploid Wheat Grains.
abstract: Non-starch polysaccharides (NSPs) have many health benefits, including immunomodulatory activity, lowering serum cholesterol, a faecal bulking effect, enhanced absorption of certain minerals, prebiotic effects and the amelioration of type II diabetes. The principal components of the NSP in cereal grains are (1,3;1,4)-β-glucans and arabinoxylans. Although (1,3;1,4)-β-glucan (hereafter called β-glucan) is not the most representative component of wheat cell walls, it is one of the most important types of soluble fibre in terms of its proven beneficial effects on human health. In the present work we explored the genetic variability of β-glucan content in grains from a tetraploid wheat collection that had been genotyped with a 90k-iSelect array, and combined this data to carry out an association analysis. The β-glucan content, expressed as a percentage w/w of grain dry weight, ranged from 0.18% to 0.89% across the collection. Our analysis identified seven genomic regions associated with β-glucan, located on chromosomes 1A, 2A (two), 2B, 5B and 7A (two), confirming the quantitative nature of this trait. Analysis of marker trait associations (MTAs) in syntenic regions of several grass species revealed putative candidate genes that might influence β-glucan levels in the endosperm, possibly via their participation in carbon partitioning. These include the glycosyl hydrolases endo-β-(1,4)-glucanase (cellulase), β-amylase, (1,4)-β-xylan endohydrolase, xylanase inhibitor protein I, isoamylase and the glycosyl transferase starch synthase II.
authors.affiliation: Department of Soil, Plant and Food Sciences, Section of Genetics and Plant Breeding, University of Bari 'Aldo Moro', Via G. Amendola 165/A, 70126, Bari, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Marcotuli
authors.affiliation: The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland.
authors.forename: Kelly
authors.initials: K
authors.lastname: Houston
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Julian G
authors.initials: JG
authors.lastname: Schwerdt
authors.affiliation: The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland.
authors.forename: Robbie
authors.initials: R
authors.lastname: Waugh
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Fincher
authors.affiliation: Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Burton
authors.affiliation: Department of Soil, Plant and Food Sciences, Section of Genetics and Plant Breeding, University of Bari 'Aldo Moro', Via G. Amendola 165/A, 70126, Bari, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Blanco
authors.affiliation: Agricultural and Environmental Science, University of Bari 'Aldo Moro', Via G. Amendola 165/A, 70126, Bari, Italy.
authors.forename: Agata
authors.initials: A
authors.lastname: Gadaleta
mesh_terms: D014644:Genetic Variation; D055106:Genome-Wide Association Study; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000378:metabolism; D057891:Tetraploidy; D014908:Triticum / Q000235:genetics* / Q000378:metabolism; D047071:beta-Glucans
chemical_list: D010940:Plant Proteins; D047071:beta-Glucans