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ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Publications at this Location » Publication #313532

Research Project: Develop Improved Plant Genetic Resources to Enhance Pasture and Rangeland Productivity in the Semiarid Regions of the Western U.S.

Location: Forage and Range Research

Title: Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals

Author
item Yun, Lan - Inner Mongolian Agriculture University
item Larson, Steven
item Jensen, Kevin
item Staub, Jack
item Grossl, Paul - Utah State University

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2015
Publication Date: 7/10/2015
Citation: Yun, L., Larson, S.R., Jensen, K.B., Staub, J.E., Grossl, P.R. 2015. Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals. Plant and Soil. doi: 10.1007/s11104-015-2583-5.

Interpretive Summary: Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a population derived from two perennial grass species, Leymus cinereus and L. triticoides, grown on phytotoxic and fertile soils. These QTLs were aligned to the genome sequence of barley (Hordeum vulgare) for comparison to genes and QTLs controlling heavy metal accumulation in other plants. Three of four Zn QTLs were conserved across different test soils and aligned to Zn QTLs of barley, but QTLs controlling arsenic, copper, lead, and other heavy metals did not correspond with other species and showed strong plant QTL - soil interactions. Two homoeologous molybdenum QTLs were closely associated with MOT1 orthogenes, which encode one of two known molybdate transporters in plants, and multiple possible candidate gene associations were identified for other heavy metals. Significant QTL variation and plant QTL - soil interactions demonstrated opportunities and pitfalls, respectively, to modify elemental profiles in grasses through breeding. Results also suggest that the MOT1 gene is a potentially robust genetic marker for molybdenum uptake variation in plants.

Technical Abstract: Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Chromosome regions known as quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a population derived from two perennial grass species, basin wildrye (Leymus cinereus) and creeping wildrye (L. triticoides), grown on phytotoxic and fertile soils. These QTLs were aligned to the genome sequence of barley (Hordeum vulgare) for comparison to genes and QTLs controlling heavy metal accumulation in other plant species. Three of four Zn QTLs were conserved across different test soils and aligned to Zn QTLs of barley, but QTLs controlling arsenic, copper, lead, and other heavy metals did not correspond with other species and were not consistent between different soils, which demonstrated significant plant QTL - soil interaction. Two molybdenum QTLs located on slightly different copies of the same chromosome (homoeologous chromosomes) were closely associated with the same MOT1 gene, which encodes one of two known molybdate transporters in plants, and multiple possible candidate gene associations were identified for other heavy metals. Significant QTL variation and plant QTL - soil interactions demonstrated opportunities and pitfalls, respectively, to modify elemental profiles in grasses through breeding. Results also suggest that the MOT1 gene is a potentially robust genetic marker that can be used for breeding higher or lower molybdenum uptake in plants.