Mapping of ionomic traits in Mimulus guttatus reveals Mo and Cd QTLs that colocalize with MOT1 homologues

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Borrowed alleles and convergence in serpentine adaptation

ACKNOWLEDGMENTS. We thank members of the L.Y. and K.B. laboratories for helpful discussions. This work was supported through the European Research Council Grant StG CA629F04E (to L.Y.); a Harvard University Milton Fund Award (to K.B.); Ruth L. Kirschstein National Research Service Award 1 F32 GM096699 from the NIH (to L.Y.); National Science Foundation Grant IOS-1146465 (to K.B.); NIH National Institute of General Medical Sciences Grant 2R01GM078536 (to D.E.S.); and Biotechnology and Biological Sciences Research Council Grant BB/L000113/1 (to D.E.S.)Peer reviewedPublisher PD

Genome-wide association studies identify heavy metal ATPase3 as the primary determinant of natural variation in leaf cadmium in Arabidopsis thaliana

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Single-kernel ionomic profiles are highly heritable indicators of genetic and environmental influences on elemental accumulation in maize grain (Zea mays)

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Mapping and validation of quantitative trait loci associated with concentrations of 16 elements in unmilled rice grain

Acknowledgments This research was supported in part by the US National Science Foundation, Plant Genome Research Program (Grant #IOS 0701119) awarded to D.E.S, M.L.G and S.R.M.P. We acknowledge Dr. Kathleen Yeater for consultation on analyzing marker-trait associations using SAS JMP Genomics. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture or Texas A&M AgriLife Research, and does not imply its approval to the exclusion of other products that also can be suitable. USDA is an equal opportunity provider and employer.Peer reviewedPublisher PD

Variation in sulfur and selenium accumulation is controlled by naturally occurring isoforms of the key sulfur assimilation enzyme ADENOSINE 5′-PHOSPHOSULFATE REDUCTASE2 across the arabidopsis species range

Natural variation allows the investigation of both the fundamental functions of genes and their role in local adaptation. As one of the essential macronutrients, sulfur is vital for plant growth and development and also for crop yield and quality. Selenium and sulfur are assimilated by the same process, and although plants do not require selenium, plant-based selenium is an important source of this essential element for animals. Here, we report the use of linkage mapping in synthetic F2 populations and complementation to investigate the genetic architecture of variation in total leaf sulfur and selenium concentrations in a diverse set of Arabidopsis (Arabidopsis thaliana) accessions. We identify in accessions collected from Sweden and the Czech Republic two variants of the enzyme ADENOSINE 5′-PHOSPHOSULFATE REDUCTASE2 (APR2) with strongly diminished catalytic capacity. APR2 is a key enzyme in both sulfate and selenate reduction, and its reduced activity in the loss-of-function allele apr2-1 and the two Arabidopsis accessions Hodonín and Shahdara leads to a lowering of sulfur flux from sulfate into the reduced sulfur compounds, cysteine and glutathione, and into proteins, concomitant with an increase in the accumulation of sulfate in leaves. We conclude from our observation, and the previously identified weak allele of APR2 from the Shahdara accession collected in Tadjikistan, that the catalytic capacity of APR2 varies by 4 orders of magnitude across the Arabidopsis species range, driving significant differences in sulfur and selenium metabolism. The selective benefit, if any, of this large variation remains to be explored

Mutations in Arabidopsis \u3ci\u3eYellow Stripe-Like1\u3c/i\u3e and \u3ci\u3eYellow Stripe-Like3\u3c/i\u3e Reveal Their Roles in Metal Ion Homeostasis and Loading of Metal Ions in Seeds

Here, we describe two members of the Arabidopsis (Arabidopsis thaliana) Yellow Stripe-Like (YSL) family, AtYSL1 and AtYSL3. The YSL1 and YSL3 proteins are members of the oligopeptide transporter family and are predicted to be integral membrane proteins. YSL1 and YSL3 are similar to the maize (Zea mays) YS1 phytosiderophore transporter (ZmYS1) and the AtYSL2 iron (Fe)-nicotianamine transporter, and are predicted to transport metal-nicotianamine complexes into cells. YSL1 and YSL3 mRNAs are expressed in both root and shoot tissues, and both are regulated in response to the Fe status of the plant. β-Glucuronidase reporter expression, driven by YSL1 and YSL3 promoters, reveals expression patterns of the genes in roots, leaves, and flowers. Expression was highest in senescing rosette leaves and cauline leaves. Whereas the single mutants ysl1 and ysl3 had no visible phenotypes, the ysl1ysl3 double mutant exhibited Fe deficiency symptoms, such as interveinal chlorosis. Leaf Fe concentrations are decreased in the double mutant, whereas manganese, zinc, and especially copper concentrations are elevated. In seeds of double-mutant plants, the concentrations of Fe, zinc, and copper are low. Mobilization of metals from leaves during senescence is impaired in the double mutant. In addition, the double mutant has reduced fertility due to defective anther and embryo development. The proposed physiological roles for YSL1 and YSL3 are in delivery of metal micronutrients to and from vascular tissues

Root Suberin Forms an Extracellular Barrier That Affects Water Relations and Mineral Nutrition in Arabidopsis

Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model that suberin acts to form a chemical barrier limiting the extracellular, or apoplastic, transport of water and solutes in plant roots. Using the newly characterized enhanced suberin1 (esb1) mutant, we established a connection in Arabidopsis thaliana between suberin in the root and both water movement through the plant and solute accumulation in the shoot. Esb1 mutants, characterized by increased root suberin, were found to have reduced day time transpiration rates and increased water-use efficiency during their vegetative growth period. Furthermore, these changes in suberin and water transport were associated with decreases in the accumulation of Ca, Mn, and Zn and increases in the accumulation of Na, S, K, As, Se, and Mo in the shoot. Here, we present direct genetic evidence establishing that suberin in the roots plays a critical role in controlling both water and mineral ion uptake and transport to the leaves. The changes observed in the elemental accumulation in leaves are also interpreted as evidence that a significant component of the radial root transport of Ca, Mn, and Zn occurs in the apoplast.</p