@article{israel_taliercio_kwanyuen_burton_dean_2011, title={Inositol Metabolism in Developing Seed of Low and Normal Phytic Acid Soybean Lines}, volume={51}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2010.03.0123}, abstractNote={While inositol has key roles in phytic acid and raffi nosaccharide synthesis, its concentration in developing seed of low phytic acid soybean [Glycine max (L.) Merr.] lines derived from CX1834 (Wilcox et al., 2000) has not been compared to that of normal lines. Concentrations of metabolites in the phytic acid and raffi nosaccharide biosynthesis have been measured in mature seed of CX1834-derived lines but not throughout seed development. Our objective was to compare concentrations of inositol and metabolites associated with phytic acid and raffi nosaccharide synthesis in developing seed of CX1834-derived and normal lines. Plants were cultured with complete nutrient solutions in growth chambers with 650 to 700 μmol m −2 s −1 of photosynthetically active radiation and a 26/22°C day/night temperature. Seed inositol concentrations were high (60 to 90 mmol kg −1 seed dry wt.) at 20 d after fl owering (DAF) and decreased 95% by maturity in both normal and low phytic acid lines. In two of three experiments, low phytic acid lines had signifi cantly (p ≤ 0.05) greater seed inositol concentrations than normal lines at the fi rst two sampling dates, but differences at maturity were not signifi cant. Seeds of low phytic acid and normal lines had statistically similar concentrations (p > 0.05) of partially phosphorylated inositol intermediate (inositol triphosphate [IP3]), stachyose, raffi nose, and phytase activity throughout development. These results corroborate previous studies that ruled out defects in genes coding myo-inositol1-P synthase, inositol kinases, and phytase as the basis for the low seed phytic acid trait in CX1834-derived lines.}, number={1}, journal={CROP SCIENCE}, author={Israel, Daniel W. and Taliercio, Earl and Kwanyuen, Prachuab and Burton, Joseph W. and Dean, Lisa}, year={2011}, pages={282–289} }
 @article{kwanyuen_burton_2010, title={A Modified Amino Acid Analysis Using PITC Derivatization for Soybeans with Accurate Determination of Cysteine and Half-Cystine}, volume={87}, ISSN={["1558-9331"]}, DOI={10.1007/s11746-009-1484-2}, abstractNote={Breeding efforts to change the amino acid profile of seed protein and the assessment of genetic variation for amino acid composition among soybean germplasm resources have been hampered by lack of a rapid and inexpensive method for amino acid determination. A modified procedure presented here is partly based on a gas-phase hydrolysis and precolumn derivatization for HPLC analysis. The procedure accurately measured cysteine and half-cystine in samples. The method was also proven to be accurate using a reference protein with known amino acid composition. It is reliable and can be automated for daily analysis with a large number of samples. The method was also tested with soybean seeds harvested from a two-replicate multi-location soybean field experiment. It was found that no soybean cultivar by location interaction was significant for any of the amino acids which demonstrate that amino acid compositions were generally stable across a range of environments, and that the repeatability of the measurement itself was high. The error associated with the determination was also low as demonstrated by the analysis of variance.}, number={2}, journal={JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY}, author={Kwanyuen, Prachuab and Burton, Joseph W.}, year={2010}, month={Feb}, pages={127–132} }
 @article{carter_rzewnicki_burton_villagarcia_bowman_taliercio_kwanyuen_2010, title={Registration of N6202 Soybean Germplasm with High Protein, Favorable Yield Potential, Large Seed, and Diverse Pedigree}, volume={4}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2009.08.0462.crg}, abstractNote={N6202' soybean (Glycine max (L.) Merr.) (Reg. No. GP-366, PI 658498) was cooperatively developed and released by the USDA-ARS and the North Carolina Agricultural Research Service in October 2009 as a mid-Maturity Group VI germplasm with high-protein seed, favorable yield potential, large seed size, and diverse pedigree. The unusual combination of high protein and favorable yield in this germplasm, plus its diverse genetic background, makes it a potentially desirable breeding stock for both specialty and commodity breeding programs. N6202 was developed through conventional breeding and is adapted to the southern United States. Average seed protein level was 457 g kg -1 (zero moisture basis), which was 33 g kg -1 greater (p < 0.05) than that of the control cultivar NC-Roy. Average yield of N6202 was more than 90% of NC-Roy over 65 environments. The 100-seed weight of N6202 (21.4 g) was signifi cantly greater (p < 0.05) than that of the largest- seeded control cultivar Dillon (15.2 g).Twenty-fi ve percent of N6202's pedigree is derived from Japanese cultivar Fukuyataka. Fukuyataka is not known to be related to the genetic base of U.S. soybean. An additional 25% of N6202's pedigree traces to the Japanese cultivar Nakasennari, which appears in the pedigree of only one cultivar (its parent 'N6201'). Thus, the release of N6202 broadens the genetic range of materials adapted for soybean breeding in the United States. N6202 exhibits a moderate level of the bleeding hilum trait in some environments.}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Carter, T. E., Jr. and Rzewnicki, P. E. and Burton, J. W. and Villagarcia, M. R. and Bowman, D. T. and Taliercio, Earl and Kwanyuen, P.}, year={2010}, month={Jan}, pages={73–79} }
 @article{leytem_kwanyuen_plumstead_maguire_brake_2008, title={Evaluation of phosphorus characterization in broiler ileal digesta, manure, and litter samples: P-31-NMR vs. HPLC}, volume={37}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2007.0134}, abstractNote={Using 31-phosphorus nuclear magnetic resonance spectroscopy (31P-NMR) to characterize phosphorus (P) in animal manures and litter has become a popular technique in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with 31P-NMR compared to other accepted methods such as high performance liquid chromatography (HPLC). To evaluate the use of 31P-NMR to quantify myo-inositol hexakisphosphate (phytate) in ileal digesta, manure, and litter from broilers, we compared results obtained from both 31P-NMR and a more traditional HPLC method. The quantification of phytate in all samples was very consistent between the two methods, with linear regressions having slopes ranging from 0.94 to 1.07 and r2 values of 0.84 to 0.98. We compared the concentration of total monoester P determined with 31P-NMR with the total inositol P content determined with HPLC and found a strong linear relationship between the two measurements having slopes ranging from 0.91 to 1.08 and r2 values of 0.73 to 0.95. This suggests that 31P-NMR is a very reliable method for quantifying P compounds in manure/litter samples.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Leytem, A. B. and Kwanyuen, P. and Plumstead, P. W. and Maguire, R. O. and Brake, J.}, year={2008}, pages={494–500} }
 @article{carrao-panizzi_kwanyuen_erhan_negrao lopes_2008, title={Genetic variation and environmental effects on beta-conglycinin and glycinin content in Brazilian soybean cultivars}, volume={43}, ISSN={["1678-3921"]}, DOI={10.1590/S0100-204X2008000900002}, abstractNote={The objective of this work was to determine genetic and environmental effects on beta-conglycinin and glycinin content in Brazilian soybean cultivars. The concentrations of these protein fractions were analyzed by scanning densitometry after electrophoresis, in 90 Brazilian soybean cultivars sown in Ponta Grossa, PR, in 2001. The effects of the sowing location were determined in the cultivar MG/BR 46 (Conquista), sown in 16 locations of Goiás and Minas Gerais states (Central Brazil), and in the cultivar IAS 5, sown in 12 locations of Paraná and São Paulo states (Southern Brazil), in 2002 soybean season. A significant variability for beta-conglycinin (7S) and glycinin (11S) protein fractions ratio was observed among the 90 Brazilian soybean cultivars. 'MS/BRS 169' (Bacuri) and 'BR-8' (Pelotas) presented the highest and the lowest 11S/7S ratios (2.76 and 1.17, respectively). Beta-conglycinin protein fractions presented more variability than glycinin protein fractions. Grouping test classified 7S proteins in seven groups, 11S proteins in four groups, and protein fraction ratios (11S/7S) in nine groups. Significant effect of sowing locations was also observed on protein fractions contents. There is a good possibility of breeding for individual protein fractions, and their subunits, without affecting protein content.}, number={9}, journal={PESQUISA AGROPECUARIA BRASILEIRA}, author={Carrao-Panizzi, Mercedes Concordia and Kwanyuen, Prachuab and Erhan, Sevim Zeynep and Negrao Lopes, Ivani de Oliveira}, year={2008}, month={Sep}, pages={1105–1114} }
 @article{plumstead_leytem_maguire_spears_kwanyuen_brake_2008, title={Interaction of calcium and phytate in broiler diets. 1. Effects on apparent prececal digestibility and retention of phosphorus}, volume={87}, ISSN={["1525-3171"]}, DOI={10.3382/ps.2007-00231}, abstractNote={Phytate P utilization from soybean meal (SBM) included in broiler diets has been shown to be poor and highly dependent on dietary Ca intake. However, the effect of Ca on P utilization and on the optimal ratio of Ca to nonphytate P (Ca:NPP) when diets contained varying levels of phytate has not been clearly shown and was the objective of this research. A factorial treatment structure was used with 4 dietary Ca levels from 0.47 to 1.16% and 3 levels of phytate P (0.28, 0.24, and 0.10%). Varying dietary phytate P levels were obtained by utilizing SBM produced from 3 varieties of soybeans with different phytate P concentrations. Ross 508 broiler chicks were fed 1 of 12 diets from 16 to 21 d of age. Excreta were collected from 16 to 17 d and from 19 to 20 d of age and ileal digesta was collected at 21 d of age. Apparent prececal P digestibility decreased when dietary Ca concentration increased and was higher when diets contained low-phytate SBM. The apparent digestibility of Ca and percentage of phytate P hydrolysis at the distal ileum were not reduced when dietary phytate P concentration increased. Including low-phytate SBM in diets reduced total P output in the excreta by 49% compared with conventional SBM. The optimum ratio of Ca:NPP that resulted in the highest P retention and lowest P excretion was 2.53:1, 2.40:1, and 2.34:1 for diets with 0.28, 0.24, and 0.10% phytate P. These data suggested that increased dietary Ca reduced the extent of phytate P hydrolysis and P digestibility and that the optimum Ca:NPP ratio at which P retention was maximized was reduced when diets contained less phytate P.}, number={3}, journal={POULTRY SCIENCE}, author={Plumstead, P. W. and Leytem, A. B. and Maguire, R. O. and Spears, J. W. and Kwanyuen, P. and Brake, J.}, year={2008}, month={Mar}, pages={449–458} }
 @article{leytem_plumstead_maguire_kwanyuen_burton_brake_2008, title={Interaction of calcium and phytate in broiler diets. 2. Effects on total and soluble phosphorus excretion}, volume={87}, ISSN={["0032-5791"]}, DOI={10.3382/ps.2007-00229}, abstractNote={Dietary Ca has been reported to influence the amount of phytate excreted from broilers and affect the solubility of P in excreta. To address the effects of dietary Ca and phytate on P excretion, 12 dietary treatments were fed to broilers from 16 to 21 d of age. Treatments consisted of 3 levels of phytate P (0.10, 0.24, and 0.28%) and 4 levels of Ca (0.47, 0.70, 0.93, and 1.16%) in a randomized complete block design. Feed phytate concentrations were varied by formulating diets with 3 different soybean meals (SBM): a low-phytate SBM, a commercial SBM, and a high phytate Prolina SBM having phytate P concentrations of 0.15 to 0.51%. Fresh excreta was collected from cages during 2 separate 24-h periods; collection I commenced after the start of dietary treatments (16 to 17 d) and collection II followed a 3-d adaptation period (19 to 20 d). Ileal samples were also collected at 21 d. Excreta samples were analyzed for total P, water soluble P (WSP), and phytate P, whereas ileal samples were analyzed for total P and phytate P. Results indicated that excreta total P could be reduced by up to 63% and WSP by up to 66% with dietary inclusion of low-phytate SBM. There was a significant effect of dietary Ca on both the excreta WSP and the ratio of WSP:total P. As dietary Ca increased, the excreta WSP and WSP:total P decreased, with the effects being more pronounced following a dietary adaptation period. There was a linear relationship between the slope of the response in WSP to dietary Ca and feed phytate content for excreta from collection II (r 2 = 0.99). There was also a negative correlation between excreta phytate concentration and excreta WSP during both excreta collections. The response in WSP to dietary manipulation was important from an environmental perspective because WSP in excreta has been related to potential for off-site P losses following land application.}, number={3}, journal={POULTRY SCIENCE}, author={Leytem, A. B. and Plumstead, P. W. and Maguire, R. O. and Kwanyuen, P. and Burton, J. W. and Brake, J.}, year={2008}, month={Mar}, pages={459–467} }
 @article{cramp_kwanyuen_daubert_2008, title={Molecular interactions and functionality of a cold-gelling soy protein isolate}, volume={73}, ISSN={["1750-3841"]}, DOI={10.1111/j.1750-3841.2007.00583.x}, abstractNote={A soy protein isolate (SPI) was thermally denatured at a critical concentration of 8% protein for 3 h at 95 degrees C, resulting in a powder that was readily reconstituted at ambient temperature and that demonstrated improved heat stability and cold-set gel functionality when compared to a control SPI. When SPI was heated at 3% protein equivalently, prior to reconstitution to 8% protein, the final viscosity was about 3 orders of magnitude less than the original sample. The viscosity of SPI heated at 3% protein was still nearly 2 orders of magnitude less than the original sample after both samples were reheated at 8% protein. These results suggested that heat denaturation at low protein concentrations limited network formation even after the protein concentration and interaction sites increased, impacting the isolate's cold gelling ability. Gelation was prevented upon treatment of SPI with iodoacetamide, which carbaminomethylated the cysteine residues, establishing the role of disulfide bonds in network formation. The viscosity of the 8% protein dispersion was also reduced by 2 orders of magnitude when treated with 8 M urea, and when combined with 10 mM DTT the gel viscosity was decreased by another order of magnitude. These results suggested that hydrophobic interactions played a primary role in gel strength after disulfide bonds form. The need for a higher concentration of protein during the heating step indicated that the critical disulfide bonds are intermolecular. Ultimately, the functionality produced by these protein-protein interactions produced a powdered soy protein isolate ingredient with consistent cold-set and thermal gelation properties.}, number={1}, journal={JOURNAL OF FOOD SCIENCE}, author={Cramp, G. L. and Kwanyuen, P. and Daubert, C. R.}, year={2008}, pages={E16–E24} }
 @article{xue_upchurch_kwanyuen_2008, title={Relationships between oleic and linoleic acid content and seed colonization by Cercospora kikuchii and Diaporthe phaseolorum}, volume={92}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-92-7-1038}, abstractNote={Compared with standard cultivars, seed of mid-oleic soybean genotypes sometimes have shown increased colonization by Cercospora kikuchii in the field as judged by increased levels of purple-stained seed. To examine relationships between oleic and linoleic acid levels in soybean seed and postharvest seed colonization by two fungal seed pathogens, we inoculated seed with differing oleic:linoleic acid (O/L) ratios. Seed with defined O/L ratios were produced by allowing seed development of two isogenic soybean lines to occur in three different air temperature environments. Seed produced in these environments were harvested, individually analyzed for fatty acid composition, and inoculated with mycelium preparations of the fungal seed pathogens C. kikuchii or Diaporthe phaseolorum var. sojae. Fungal biomass of infected seed was quantified by measuring in vitro ergosterol content. For both soybean lines, colonization by C. kikuchii was positively correlated with the O/L ratio (r = 0.55, P < 0.03) and oleic acid content (r = 0.61, P < 0.02), and negatively correlated with linoleic (r = –0.60, P < 0.02) and linolenic (r = –0.58, P < 0.03) acid content. No association was found between the extent of seed colonization by D. phaseolorum and the seed O/L ratio. Our data suggest that the O/L ratio may be related to soybean seed colonization by C. kikuchii, but there is no evidence of a relationship with D. phaseolorum var. sojae colonization.}, number={7}, journal={PLANT DISEASE}, author={Xue, H. Q. and Upchurch, R. G. and Kwanyuen, P.}, year={2008}, month={Jul}, pages={1038–1042} }
 @article{naegle_kwanyuen_burton_carter_rufty_2008, title={Seed nitrogen mobilization in soybean: Effects of seed nitrogen content and external nitrogen fertility}, volume={31}, ISSN={["1532-4087"]}, DOI={10.1080/01904160801894921}, abstractNote={ABSTRACT Soybean breeding programs have developed genetic lines with relatively low seed protein, which could negatively impact early seedling growth in low fertility conditions commonly encountered in the field. In these experiments, seed protein mobilization and its regulation in situ in soybean lines with different seed protein levels was investigated. The results showed that rates of nitrogen (N) release from cotyledons were much lower with decreasing levels of N in seed. Patterns of proteolysis of the storage proteins glycinin and β -conglycinin and their subunits were not different, but breakdown rates were slower. Seed N release rates increased somewhat when external N was supplied to roots of the developing seedlings, suggesting the involvement of source/sink controls. The effect appeared to be down-stream from proteolysis, as rates of protein breakdown were not altered. The results indicate that low seed protein levels will lead to reduced seedling fitness in low fertility soil conditions unless ...}, number={2}, journal={JOURNAL OF PLANT NUTRITION}, author={Naegle, Erin and Kwanyuen, Prachuab and Burton, Joseph and Carter, Thomas and Rufty, Thomas}, year={2008}, pages={367–379} }
 @article{gao_shang_maroof_biyashev_grabau_kwanyuen_burton_buss_2007, title={A modified colorimetric method for phytic acid analysis in soybean}, volume={47}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2007.03.0122}, abstractNote={A quantitative, reproducible, and efficient phytic acid assay procedure is needed to screen breeding populations and support genetic studies in soybeans [Glycine max (L.) Merr.]. The objective of this study was to modify the colorimetric Wade reagent method and compare the accuracy and applicability of this new method in determining seed phytic acid content in soybean with three well-established phytic acid assay methods: anion exchange column (AEC), high-performance liquid chromatography (HPLC), and 31P nuclear magnetic resonance (NMR). The CV for repeated measurements of a low phytic acid soybean mutant, CX1834-1-6, ranged from 1.8 to 4.2% (n = 5), indicating the results were precise and reproducible. Phytic acid content of 42 soybean genotypes as determined by this method showed a correlation of 93.7 to 96.6% with the measurements by AEC, HPLC, and NMR. According to analysis of covariance, using inorganic P content as a predictor, phytic acid P content in a given sample analyzed by the four assay methods can be estimated with four linear regression models at the α = 0.01 level. Compared with HPLC, AEC, and 31P NMR, this modified colorimetric method is simpler and less expensive for assaying a large number of samples, allowing its effective application in breeding and genetic studies of low phytic acid soybean.}, number={5}, journal={CROP SCIENCE}, author={Gao, Y. and Shang, C. and Maroof, M. A. Saghal and Biyashev, R. M. and Grabau, E. A. and Kwanyuen, P. and Burton, J. W. and Buss, G. R.}, year={2007}, pages={1797–1803} }
 @article{israel_kwanyuen_burton_walker_2007, title={Response of low seed phytic acid soybeans to increases in external phosphorus supply}, volume={47}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2006.11.0691}, abstractNote={Commercialization of soybean [Glycine max (L.) Merr.] varieties with low seed phytic acid will depend on the stability of the trait when grown in soils with a wide range of P availabilities and on the impact of altered P composition on seed protein and oil concentrations. Impacts of deficient (0.05 mmol L-1) to excessive (0.9 to 1.2 mmol L -1 ) levels of external P on seed P composition of normal and low phytic acid lines and of altered seed P composition on seed protein and oil synthesis were evaluated. Soybean lines homozygous recessive (pha/pha) at one of two loci with genes that condition the low seed phytic acid trait had the same greater-than-threefold increase in phytic acid in response to increasing external P as their normal phytic acid parent, 'AGS Prichard-RR' (Pha/Pha). This supports the conclusion from previous inheritance studies that the low seed phytic acid trait in CX1834-1-2 is controlled by epistatic interaction between two independent recessive genes. The seed phytic acid concentration in the low phytic acid line Q03PHY-443 (derived from CX1834-1-2) was <2 g phytic acid P kg -1 dry wt. when grown under deficient to excessive external P. As the P supply increased, seed inorganic P concentrations for this line increased from 0.8 to 4.0 g kg -1 dry wt., compared to an increase of 0.2 to 0.6 g kg -1 dry wt. for the normal phytic acid lines. Seed protein and oil concentrations did not differ significantly between normal and low phytic acid lines. These results support continued development of varieties with low seed phytic acid and high yields.}, number={5}, journal={CROP SCIENCE}, author={Israel, D. W. and Kwanyuen, P. and Burton, J. W. and Walker, D. R.}, year={2007}, pages={2036–2046} }
 @article{leytem_plumstead_maguire_kwanyuen_brake_2007, title={What aspect of dietary modification in broilers controls litter water-soluble phosphorus: Dietary phosphorus, phytase, or calcium?}, volume={36}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2006.0334}, abstractNote={Environmental concerns about phosphorus (P) losses from animal agriculture have led to interest in dietary strategies to reduce the concentration and solubility of P in manures and litters. To address the effects of dietary available phosphorus (AvP), calcium (Ca), and phytase on P excretion in broilers, 18 dietary treatments were applied in a randomized complete block design to each of four replicate pens of 28 broilers from 18 to 42 d of age. Treatments consisted of three levels of AvP (3.5, 3.0, and 2.5 g kg−1) combined with three levels of Ca (8.0, 6.9, and 5.7 g kg−1) and two levels of phytase (0 and 600 phytase units [FTU]). Phytase was added at the expense of 1.0 g kg−1 P from dicalcium phosphate. Fresh litter was collected from pens when the broilers were 41 d of age and analyzed for total P, soluble P, and phytate P as well as P composition by 31P nuclear magnetic resonance (NMR) spectroscopy. Results indicated that the inclusion of phytase at the expense of inorganic P or reductions in AvP decreased litter total P by 28 to 43%. Litter water-soluble P (WSP) decreased by up to 73% with an increasing dietary Ca/AvP ratio, irrespective of phytase addition. The ratio of WSP/total P in litter decreased as the dietary Ca/AvP ratio increased and was greater in the phytase-amended diets. This study indicated that while feeding reduced AvP diets with phytase decreased litter total P, the ratio of Ca/AvP in the diet was primarily responsible for effects on WSP. This is important from an environmental perspective as the amount of WSP in litter could be related to potential for off-site P losses following land application of litter.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Leytem, A. B. and Plumstead, P. W. and Maguire, R. O. and Kwanyuen, P. and Brake, J.}, year={2007}, pages={453–463} }
 @article{xue_upchurch_kwanyuen_2006, title={Ergosterol as a quantifiable biomass marker for Diaporthe phaseolorum and Cercospora kikuchii}, volume={90}, ISSN={["1943-7692"]}, DOI={10.1094/PD-90-1395}, abstractNote={The relationship between ergosterol content and biomass was determined for the soybean fungal pathogens Diaporthe phaseolorum (Cooke & Ellis) Sacc. var. sojae, causal agent of Phomopsis seed decay, and Cercospora kikuchii (Matsumoto & Tomoy.), causal agent of leaf blight and purple seed stain. Biomass was manipulated by varying incubation period, and ergosterol was quantified by high-pressure liquid chromatography. Fungal dry mass was linearly correlated with ergosterol content (r 2 = 0.90, P < 0.05 for D. phaseolorum, and r 2 = 0.95, P < 0.01 for C. kikuchii). In vitro ergosterol content of fungi was 3.16 μg/mg for D. phaseolorum and 2.85 μg/mg for C. kikuchii. Ergosterol content of inoculated seed was qualitatively correlated with observed seed colonization by both pathogens. Soybean variety had a significant effect on fungal colonization by D. phaseolorum and ergosterol content. Results show that ergosterol content can be used to quantify colonization of soybean seed by both pathogens.}, number={11}, journal={PLANT DISEASE}, author={Xue, H. Q. and Upchurch, R. G. and Kwanyuen, P.}, year={2006}, month={Nov}, pages={1395–1398} }
 @article{kwanyuen_burton_2005, title={A simple and rapid procedure for phytate determination in soybeans and soy products}, volume={82}, ISSN={["0003-021X"]}, DOI={10.1007/s11746-005-1046-9}, abstractNote={A rapid and simple analytical procedure to determine the phytate (myo-inositol hexaphosphate) content in soybeans and soy products is described. Minimal sample preparation and automated HPLC analysis were achieved for large numbers of samples. Determination of the phytate content in a variety of soybean samples, including animal feeds, demonstrated the simplicity, reliability, and economy of the procedure compared with other time-consuming, complicated, and laborious methods.}, number={2}, journal={JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY}, author={Kwanyuen, P and Burton, JW}, year={2005}, month={Feb}, pages={81–85} }
 @article{kwanyuen_allina_weissinger_wilson_2002, title={A new form of crystalline rubisco and the conversion to its common dodecahedral form}, volume={1}, ISSN={["1535-3893"]}, DOI={10.1021/pr025548e}, abstractNote={In this paper, we present a new purification procedure that yields a new crystalline form of rubisco and has enabled us to completely remove this most abundant protein from tobacco leaf extract. The crystals formed within 48 h after refrigeration at 4 degrees C at pH 5.6. However, these crystals were not well-ordered crystals and lacked well-defined facets or edges. The remaining leaf extract (fraction 2 protein) was void of rubisco. Conversion of this new crystalline form of rubisco to its common dodecahedral form was achieved by dialysing the protein solution in Tris buffer at pH 8.0 or purified water. Since the molecular size of its large subunit of rubisco (55 kD) is similar to that of the papillomavirus capsid protein, L1 (57 kD), its complete removal from fraction 2-protein may facilitate the detection, purification, and recovery of the Li protein.}, number={5}, journal={JOURNAL OF PROTEOME RESEARCH}, author={Kwanyuen, P and Allina, SM and Weissinger, AK and Wilson, RF}, year={2002}, pages={471–473} }
 @article{luck_lanier_daubert_kwanyuen_2002, title={Viscoelastic behavior of commercially processed soy isolate pastes during heating and cooling}, volume={67}, ISSN={["0022-1147"]}, DOI={10.1111/j.1365-2621.2002.tb10293.x}, abstractNote={The viscoelastic properties of soy isolate dispersions of Prolina and Brim cultivars, commercially processed, were compared during heating and cooling utilizing small deformation rheology. All isolates formed gels upon hydration. Heating to 90 °C yielded less rigid gels, as evidenced by a decreasing G'. Holding at 90 °C induced an increase in G' for Brim isolate, possibly as a result of increased hydrophobic and/or covalent bonding. Cooling to 25 °C generated a G' increase above initial levels for both cultivars, likely due to enhanced intermolecular hydrogen bonding. Mechanical spectra at 25 °C before and after heating, and at 90 °C before and after holding, confirmed these observations. A lower G' was consistently exhibited by Prolina gels throughout testing.}, number={4}, journal={JOURNAL OF FOOD SCIENCE}, author={Luck, PJ and Lanier, TC and Daubert, CR and Kwanyuen, P}, year={2002}, month={May}, pages={1379–1382} }
 @article{kwanyuen_wilson_2000, title={Optimization of Coomassie staining for quantitative densitometry of soybean storage proteins in gradient gel electrophoresis}, volume={77}, ISSN={["1558-9331"]}, DOI={10.1007/s11746-000-0196-0}, abstractNote={Soybean (Glycine maxL. Merr., cv. Dare) protein subunits were separated by gradient gel electrophoresis and analyzed by two-dimensional densitometry with computer-aided volume integration. Significant differences in the time required to achieve equilibrium staining with Coomassie Blue were revealed among the various polypeptides. Bands corresponding to lipoxygenase reached staining equilibrium in 2.7 h, whereas longer periods were required for polypeptides of β-conglycinin (5.5 to 6.7 h) and of glycinin (8.6 to 9.2 h). These differences among polypeptides could be attributed in part to changes in gradient concentration within the polyacrylamide gel. Optimal staining intensity among all soluble proteins extracted from soybean seed was reached after staining for 8 h. Shorter than optimal staining times lead to significant underestimation of parameters such as the percentage of β-conglycinin and glycinin of total soluble protein.}, number={12}, journal={JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY}, author={Kwanyuen, P and Wilson, RF}, year={2000}, month={Dec}, pages={1251–1254} }
 @article{nakasathien_israel_wilson_kwanyuen_2000, title={Regulation of seed protein concentration in soybean by supra-optimal nitrogen supply}, volume={40}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2000.4051277x}, abstractNote={The physiological and biochemical basis for increased seed protein concentrations (SPC) observed in restriction-index, recurrent-selection breeding programmes with soyabean (Glycine max) are poorly understood. The hypothesis that soyabean SPC is regulated by the supply of nitrogenous substrates available to the seed was evaluated. Effects of supra-optimal external N on seed storage protein accumulation, amino acid concentration and composition in leaves and seeds at R5, and levels of specific storage protein subunits were measured. Genotypes with different SPC (NC 107, normal; N87-984-16, intermediate; and NC 111, high) were grown in controlled-environment chambers and supplied with 30 mM N as NH4NO3 from V5 to maturity or from R5 to maturity. Control plants received 10 mM N throughout the growth cycle. Relative to control, supra-optimal N increased SPC of NC 107 and N87-984-16 by an average of 28%. Greater enhancement of protein accumulation than of dry matter accumulation in the seed resulted in SPCs of 460 to 470 g kg-1, which are appreciably higher than concentrations reported for these cultivars grown in the field and outdoor pot culture. Supra-optimal N also increased SPC of the high protein line (NC 111) by 15%, but this increase resulted entirely from a decrease in yield. Supra-optimal N supplied to NC 107 and N87-984-16 from V5 until R5 increased total free amino acid concentrations in seeds and leaves at R5 by an average of 21 and 46%, respectively. Enhanced accumulation of the β subunit of β-conglycinin, which does not contain methionine and cysteine, accounted for the increase in SPC. While enhanced N availability increased the SPC of a normal protein line into the high range, availability of sulfur amino acids in the developing seed determined which storage protein subunits were synthesized from the extra N.}, number={5}, journal={CROP SCIENCE}, author={Nakasathien, S and Israel, DW and Wilson, RF and Kwanyuen, P}, year={2000}, pages={1277–1284} }
 @article{settlage_kwanyuen_wilson_1998, title={Relation between diacylglycerol acyltransferase activity and oil concentration in soybean}, volume={75}, DOI={10.1007/s11746-998-0225-2}, abstractNote={Diacylglycerol acyltransferase (EC 2.3.1.20; DGAT) catalyzes synthesis of triacylglycerol from acyl-CoA and diacylglycerol. Activity of this enzyme and developmental changes in oil accumulation were estimated at various stages of seed growth in soybean germplasm with phenotypic differences in oil content. Oil deposition in seed of these genotypes followed a sigmoid pattern that was modeled to predict incremental rates of oil accumulation during seed development. A strong positive correlation was found between the estimated peak rate of oil deposition (near the mid-term of seed development) and oil concentration in mature seed. At saturating substrate levels, DGAT activity measured near the peak rate of oil deposition also was correlated positively with oil phenotype. In the latter stages of seed development, a positive correlation between estimates of enzyme activity at or below the apparent K m for diolein and comparable oil accumulation rates was attributed to reduced synthesis of substrates and/or potential change in affinity for substrate as suggested by an increase in apparent K m for diolein in older seed. These data indicated that DGAT activity may be a rate-limiting step in triacylglycerol synthesis. However, it is difficult to accept the idea of a single rate-limiting step at the end of a complex metabolic pathway. Because oil is a quantitatively inherited trait, several genes determine genotypic differences in oil content among soybeans. Hence, DGAT activity may be an indicator of coordinated genetic expression of gene-products in the entire glycerolipid synthetic pathway for a given genotype. In any case, results of this investigation demonstrated that genotypic differences in DGAT activity contributed to expression of genetic variation in oil content among soybean gemplasm.}, number={7}, journal={Journal of the American Oil Chemists Society}, author={Settlage, S. B. and Kwanyuen, P. and Wilson, R. F.}, year={1998}, pages={775–781} }
 @article{kwanyuen_pantalone_burton_wilson_1997, title={A new approach to genetic alteration of soybean protein composition and quality}, volume={74}, ISSN={["0003-021X"]}, DOI={10.1007/s11746-997-0015-2}, abstractNote={Although soybeans produce high-quality meal, modern animal and fish production systems often require synthetic essential amino acid supplements to fortify feed rations. However, biotechnology may enable development of soybeans with naturally adequate levels of certain essential amino acids for advanced feed formulations. One approach involves genetic manipulation of glycinin (11S) and β-conglycinin (7S) contents, the principal components of soybean storage proteins. Because 11S contains more cysteine and methionine than 7S protein, a higher 11S:7S ratio could lead to beneficial changes in the nutritional quality of soybean meal. Although genotypic variation for 11S:7S may be low among soybean [Glycine max (L.) Merr.] germplasm, ratios ranging from 1.7–4.9 were observed among accessions of the wild ancestor of cultivated soybean (Glycine soja Sieb, and Zucc.). Thus, wild soybean germplasm was evaluated as a potential source of genes that govern protein synthesis that may have been lost during the domestication of G. max. Change in the amount of 11S protein accounts for a significant portion of the genotypic variation in protein concentration and composition among wild soybeans. Strong positive correlation exists between the 11S:7S ratio and methionine or cysteine concentration of total protein. Moderate positive associations were found for threonine or tyrosine. A moderate negative correlation was found between lysine and 11S:7S. No association was found for leucine and phenylalanine or for total essential amino acid concentration. Based on these data, G. soja may contain a different complement of genes that influence expression of 11S and 7S proteins than G. max germplasm. Thus, through interspecific hybridization, wild soybeans may be a useful genetic resource for the further improvement of protein quality in cultivated soybeans.}, number={8}, journal={JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY}, author={Kwanyuen, P and Pantalone, VR and Burton, JW and Wilson, RF}, year={1997}, month={Aug}, pages={983–987} }
 @article{kwanyuen_wilson_1990, title={SUBUNIT AND AMINO-ACID-COMPOSITION OF DIACYLGLYCEROL ACYLTRANSFERASE FROM GERMINATING SOYBEAN COTYLEDONS}, volume={1039}, ISSN={["0006-3002"]}, DOI={10.1016/0167-4838(90)90227-7}, abstractNote={The subunit and amino acid composition of the enzyme that catalyses triacylglycerol synthesis was determined for the first time from plant tissues. Diacylglycerol acyltransferase (acyl-CoA:1,2-diacylglycerol O-acyltransferase, EC 2.3.1.20) purified from germinating soybean (Glycine max L. Merr. cv. Dare) cotyledons, dissociated into three nonidentical subunits having apparent molecular masses of 40.8, 28.7, and 24.5 kDa. The respective subunits occurred in a 1:2:2 molar ratio in the native enzyme. Five peptides in that molar ratio were assumed to constitute a monomer having a putative molecular mass of 153.1 kDa. Based upon the apparent molecular mass of purified diacylglycerol acyltransferase after delipidation (1539 kDa), there was a high probability that the complete structure of the native enzyme from soybean contained ten identical monomers. The polarity index of each subunit was less than 21%, far below the 40% boundary reported for membrane bound proteins. Hydrophobic amino acids accounted for greater than 48% of the composition in each subunit. It was predicted from these data that the native enzyme contained 12,525 amino acid residues, and that the two smaller subunits were more deeply embedded in the membrane than the 40.8 kDa subunit. Attempts to reactivate the denatured or delipidated protein were not successful.}, number={1}, journal={BIOCHIMICA ET BIOPHYSICA ACTA}, author={KWANYUEN, P and WILSON, RF}, year={1990}, month={May}, pages={67–72} }