@article{dimkovikj_fisher_hutchison_van hoewyk_2015, title={Stuck between a ROS and a hard place: Analysis of the ubiquitin proteasome pathway in selenocysteine treated Brassica napus reveals different toxicities during selenium assimilation}, volume={181}, ISSN={["1618-1328"]}, DOI={10.1016/j.jplph.2015.04.003}, abstractNote={During the selenium assimilation pathway, inorganic selenate and selenite are reduced to form selenocysteine (Sec). Tolerance to selenium in plants has long been attributable to minimizing the replacement of cysteine with selenocysteine, which can result in nonspecific selenoproteins that are potentially misfolded. Despite this widely accepted assumption, there is no evidence in higher plants demonstrating that selenocysteine induces toxicity by resulting in malformed proteins. In this study, we use Brassica napus to analyze the ubiquitin-proteasome pathway, which is capable of removing misfolded proteins. Sec rapidly increased proteasome activity and levels of ubiquitinated proteins, strongly indicating that selenocysteine induces protein misfolding. Proteasome inhibition increased the amount of selenium in protein in Sec-treated plants. Collectively, these data provide a mechanism that accounts for Sec toxicity. Additionally, Sec did not cause oxidative stress as judged by examining levels of superoxide using fluorescent microscopy. Therefore, the cellular response to Sec is different compared to selenite, which was recently shown to increase antioxidant metabolism in response to elevated mitochondrial superoxide that ultimately impaired proteasome activity. Therefore, plants must contend with two divergent modes of cytotoxicity during selenium assimilation. Selenite can result in oxidative stress, but increased flux of selenite reduction can yield Sec that in turn can cause protein misfolding.}, journal={JOURNAL OF PLANT PHYSIOLOGY}, author={Dimkovikj, Aleksandar and Fisher, Brian and Hutchison, Kim and Van Hoewyk, Doug}, year={2015}, month={Jun}, pages={50–54} }
 @article{shah_hutchison_hesterberg_grabow_huffman_hardy_parsons_2009, title={Leaching of Nutrients and Trace Elements from Stockpiled Turkey Litter into Soil}, volume={38}, ISSN={["1537-2537"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-66649083862&partnerID=MN8TOARS}, DOI={10.2134/jeq2007.0639}, abstractNote={In addition to nutrients, poultry are fed trace elements (e.g., As) for therapeutic purposes. Although a large proportion of the nutrients are assimilated by the birds, nearly all of the As is excreted. Hence, turkey litter constituents can leach into the soil and contaminate shallow ground water when it is stockpiled uncovered on bare soil. This study quantified the leaching of turkey litter constituents from uncovered stockpiles into the underlying soil. Four stockpiles were placed on Orangeburg loamy sand in summer 2004 for 162 d; 14 d after their removal, four stockpiles were created over the same footprints and left over winter for 162 d. Soil samples at depths of 7.6 to 30.5 cm and 30.5 to 61 cm adjacent to and beneath the stockpiles were compared for pH, electrical conductivity, total C, dissolved organic C, N species, P, water‐extractable (WE)‐P, As, WE‐As, Cu, Mn, and Zn. All WE constituents affected the 7.6‐ to 30.5‐cm layer, and some leached deeper; for example, NH4+–N concentrations were 184 and 62 times higher in the shallow and deep layers, respectively. During winter stockpiling, WE‐As concentrations beneath the stockpiles tripled and doubled in the 7.6‐ to 30.5‐cm and 30.5‐ to 61‐cm layers, respectively, with WE‐As being primarily as As(V). Heavy dissolved organic C and WE‐P leaching likely increased solubilization of soil As, although WE‐As concentrations were low due to the Al‐rich soil and low‐As litter. When used as drinking water, shallow ground water should be monitored on farms with a history of litter stockpiling on bare soil; high litter As; and high soil As, Fe, and Mn concentrations.}, number={3}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Shah, Sanjay B. and Hutchison, Kimberly J. and Hesterberg, Dean L. and Grabow, Garry L. and Huffman, Rodney L. and Hardy, David H. and Parsons, James T.}, year={2009}, pages={1053–1065} }
 @article{hutchison_hesterberg_2004, title={Dissolution of phosphate in a phosphorus-enriched ultisol as affected by microbial reduction}, volume={33}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2004.1793}, abstractNote={ABSTRACT}, number={5}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Hutchison, KJ and Hesterberg, D}, year={2004}, pages={1793–1802} }
 @article{hesterberg_chou_hutchison_sayers_2001, title={Bonding of Hg(II) to reduced organic, sulfur in humic acid as affected by S/Hg ratio}, volume={35}, ISSN={["1520-5851"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035387905&partnerID=MN8TOARS}, DOI={10.1021/es001960o}, abstractNote={Organic matter is an important sorbent of heavy metals in soils and sediments. The heterogeneity of organic matter, including the presence of various reactive O-, N-, and S-bearing ligands, makes it difficult to precisely characterize the nature of metal-ligand binding sites. The objective of this research was to characterize the extent and nature of Hg(II) bonding with reduced organic S in soil organic matter. Sulfur-rich humic acid (0.7 +/- 0.1 mol of S kg-1) was extracted from samples of surface soil from a marine wetland. Synchrotron X-ray absorption near-edge structure (XANES) analysis at the S K edge indicated that 70 +/- 3 mol % of the organic S was in a reduced oxidation state. Aqueous solutions containing 2 mmol of Hg kg-1, 0.1 M NaNO3, and humic acid added at various S/Hg molar ratios at pH 5.60 +/- 0.02 were characterized using extended X-ray absorption fine structure (EXAFS) spectroscopy at the Hg LIII edge. Spectral fitting showed that as the total S/Hg ratio increased from 0.6 to 5.6 (reduced S/Hg of 0.4-4.0), the fraction of Hg-S bonding relative to Hg-O (or Hg-N) bonding increased from 0.4 to 0.9. Results demonstrated preferential bonding of Hg(II) to reduced organic S sites and indicated that multiple sulfur ligands were coordinated with Hg2+ ions at high S/Hg ratios, which corresponded to low levels of complexed Hg(II).}, number={13}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Hesterberg, D and Chou, JW and Hutchison, KJ and Sayers, DE}, year={2001}, month={Jul}, pages={2741–2745} }
 @article{hutchison_hesterberg_chou_2001, title={Stability of reduced organic sulfur in humic acid as affected by aeration and pH}, volume={65}, ISSN={["0361-5995"]}, DOI={10.2136/sssaj2001.653704x}, abstractNote={Reduced S groups in soil organic matter (OM) play an important role in the complexation of heavy metals. These complexation reactions are often studied using the humic acid component of OM. The objective of our study was to determine the effect of pH on humic acid yield and the effect of pH and exposure to O2 on the oxidation of reduced organic S. Humic acid was extracted at pH levels between 11.5 and 13.0 from a soil collected from a salt marsh. Also, aqueous samples of humic acid at different pH levels were aspirated with CO2‐free air for 4 or 44 h. X‐ray absorption near‐edge structure (XANES) spectroscopy was used to determine changes in S oxidation states for the various treatments. With increasing pH, the yield of humic acid increased from 1.3 to 4.6 g humic acid kg−1 soil, and the total S in these samples was 24 ± 1 g kg −1 humic acid. Linear‐combination fitting of XANES spectra showed that all of these humic acid samples contained ≈70% (mol/mol) reduced S (modeled as benzyl disulfide) and 30% (mol/mol) oxidized S (modeled as sulfonate and ester sulfate). For humic acid exposed to aeration for 4 h at pH levels between 11.5 and 13.0, reduced organic S was oxidized only at pH 13.0 (15% [mol/mol] of total S). Samples exposed to aeration for 44 h between pH 3.5 and 12.4 showed no detectable change in reduced organic S.}, number={3}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Hutchison, KJ and Hesterberg, D and Chou, JW}, year={2001}, pages={704–709} }
 @article{hesterberg_zhou_hutchison_beauchemin_sayers_1999, title={XAFS study of adsorbed and mineral forms of phosphate}, volume={6}, ISSN={["0909-0495"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033438322&partnerID=MN8TOARS}, DOI={10.1107/S0909049599000370}, abstractNote={The solubility of inorganic phosphorus in soils is regulated by surface-adsorbed phosphate or phosphate minerals. The objective of this study was to determine whether different phosphate species of relevance to soils showed distinguishing XAFS spectral features. Phosphorus KXANES spectra for Fe-phosphates were characterized by a unique pre-edge feature near -3 eV (relative energy) that increased in intensity with increasing mineral crystallinity and was very weak for phosphate adsorbed on goethite. Spectra of Ca-phosphates and a soil sample exhibited a distinct shoulder on the high-energy side of the absorption edge. Spectra of Al-phosphates were characterized by a weak pre-edge feature at -1 eV.}, number={1999 May 1}, journal={JOURNAL OF SYNCHROTRON RADIATION}, author={Hesterberg, D and Zhou, WQ and Hutchison, KJ and Beauchemin, S and Sayers, DE}, year={1999}, month={May}, pages={636–638} }