title: Genome-wide association of drought-related and biomass traits with HapMap SNPs in Medicago truncatula.
abstract: Improving drought tolerance of crop plants is a major goal of plant breeders. In this study, we characterized biomass and drought-related traits of 220 Medicago truncatula HapMap accessions. Characterized traits included shoot biomass, maximum leaf size, specific leaf weight, stomatal density, trichome density and shoot carbon-13 isotope discrimination (δ(13) C) of well-watered M. truncatula plants, and leaf performance in vitro under dehydration stress. Genome-wide association analyses were carried out using the general linear model (GLM), the standard mixed linear model (MLM) and compressed MLM (CMLM) in TASSEL, which revealed significant overestimation of P-values by CMLM. For each trait, candidate genes and chromosome regions containing SNP markers were found that are in significant association with the trait. For plant biomass, a 0.5 Mbp region on chromosome 2 harbouring a plasma membrane intrinsic protein, PIP2, was discovered that could potentially be targeted to increase dry matter yield. A protein disulfide isomerase-like protein was found to be tightly associated with both shoot biomass and leaf size. A glutamate-cysteine ligase and an aldehyde dehydrogenase family protein with Arabidopsis homologs strongly expressed in the guard cells were two of the top genes identified by stomata density genome-wide association studies analysis.
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Bioengineering Department, Kafkas University, Kars, 36100, Turkey.
authors.forename: Muhammet
authors.initials: M
authors.lastname: Sakiroglu
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Krom
authors.affiliation: Department of Biology, University of Vermont, Burlington, VT, 05405, USA.
authors.forename: John
authors.initials: J
authors.lastname: Stanton-Geddes
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Mingyi
authors.initials: M
authors.lastname: Wang
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN, 55108, USA.
authors.forename: Nevin D
authors.initials: ND
authors.lastname: Young
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Udvardi
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics; D018533:Biomass; D055864:Droughts; D056726:Genetic Association Studies; D055106:Genome-Wide Association Study; D023281:Genomics; D005721:Glutamate-Cysteine Ligase / Q000235:genetics; D016014:Linear Models; D015810:Linkage Disequilibrium; D046913:Medicago truncatula / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics; D018520:Plant Shoots / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D054046:Plant Stomata / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D020641:Polymorphism, Single Nucleotide
chemical_list: D010940:Plant Proteins; D000444:Aldehyde Dehydrogenase; D005721:Glutamate-Cysteine Ligase
keywords: GWAS; Medicago truncatula; biomass; compressed mixed linear model; drought; single nucleotide polymorphisms