title: Quantitative Trait Loci and Inter-Organ Partitioning for Essential Metal and Toxic Analogue Accumulation in Barley.
abstract: The concentrations of both essential nutrients and chemically similar toxic analogues accumulated in cereal grains have a major impact on the nutritional quality and safety of crops. Naturally occurring genetic diversity can be exploited for the breeding of improved varieties through introgression lines (ILs). In this study, multi-element analysis was conducted on vegetative leaves, senesced flag leaves and mature grains of a set of 54 ILs of the wild ancestral Hordeum vulgare ssp. spontaneum in the cultivated variety Hordeum vulgare ssp. vulgare cv. Scarlett. Plants were cultivated on an anthropogenically heavy metal-contaminated soil collected in an agricultural field, thus allowing simultaneous localization of quantitative trait loci (QTL) for the accumulation of both essential nutrients and toxic trace elements in barley as a model cereal crop. For accumulation of the micronutrients Fe and Zn and the interfering toxin Cd, we identified 25, 16 and 5 QTL, respectively. By examining the gene content of the introgressions, we associated QTL with candidate genes based on homology to known metal homeostasis genes of Arabidopsis and rice. Global comparative analyses suggested the preferential remobilization of Cu and Fe, over Cd, from the flag leaf to developing grains. Our data identifies grain micronutrient filling as a regulated and nutrient-specific process, which operates differently from vegetative micronutrient homoeostasis. In summary, this study provides novel QTL for micronutrient accumulation in the presence of toxic analogues and supports a higher degree of metal specificity of trace element partitioning during grain filling in barley than previously reported for other cereals.
authors.affiliation: Department of Plant Physiology, Ruhr University Bochum, Bochum, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Reuscher
authors.affiliation: Department of Plant Physiology, Ruhr University Bochum, Bochum, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kolter
authors.affiliation: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Pillen
authors.affiliation: Department of Plant Physiology, Ruhr University Bochum, Bochum, Germany.
authors.forename: Ute
authors.identifier: http://orcid.org/0000-0001-7870-4508
authors.initials: U
authors.lastname: Krämer
mesh_terms: D017343:Genes, Plant; D056726:Genetic Association Studies; D001467:Hordeum / Q000737:chemistry / Q000187:drug effects / Q000235:genetics*; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D018977:Micronutrients; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D040641:Quantitative Trait Loci; D012639:Seeds / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity
chemical_list: D019216:Metals, Heavy; D018977:Micronutrients; D012989:Soil Pollutants