Frances M. Dupont

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By contrast to chloroplasts, our knowledge of amyloplasts--organelles that synthesize and store starch in heterotrophic plant tissues--is in a formative stage. While our understanding of what is considered their primary function, i.e. the biosynthesis and degradation of starch, has increased dramatically in recent years, relatively little is known about(More)
Wheat grain yield and flour quality are strongly influenced by the effects of environment during grain fill. Environmental variables such as temperature, water and fertilizer influence the rate and duration of wheat grain development, protein accumulation and starch deposition in unique ways, and by different mechanisms. The effects of environment are(More)
Protein accumulation and composition in wheat grains: Effects of mineral nutrients and high temperature Frances M. Dupont a,∗, William J. Hurkman a, William H. Vensel a, Charlene Tanaka a, Kerry M. Kothari a, Okkyung K. Chung b, Susan B. Altenbach a a USDA Agricultural Research Service, Western Regional Research Center, 800 Buchanan Center, Albany, CA(More)
Wheat flour is one of the world's major food ingredients, in part because of the unique end-use qualities conferred by the abundant glutamine- and proline-rich gluten proteins. Many wheat flour proteins also present dietary problems for consumers with celiac disease or wheat allergies. Despite the importance of these proteins it has been particularly(More)
The ω-gliadins encoded on chromosome 1 of the A genome were purified from Triticum aestivum L. (2n=6x=42, AABBDD) cv. Butte86, nullisomic 1D-tetrasomic 1A of cv. Chinese Spring (CS N1DT1A), and the diploid T. urartu (2n=2x=14, AA). Reverse-phase high-performance liquid chromatography combined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis of(More)
Membrane fractions enriched in endoplasmic reticulum (ER), tonoplast and Golgi membranes (TG) and plasma membranes (PM) were prepared from barley (Hordeum vulgare L. cv CM 72) roots and the lipid compositions of the three fractions were analyzed and compared. Plants were grown in an aerated nutrient solution with or without 100 millimolar NaCl. Each(More)
Cereal Chem. 77(5):607–614 ω-Gliadins were purified from wheat (Triticum aestivum L. ‘Butte’) flour and characterized. Although reversed-phase HPLC (RP-HPLC) separated the 1B-encoded ω-gliadins into two fractions, 1B1 and 1B2, these fractions had nearly identical amino acid compositions, three similar protein bands in SDS-PAGE, 10 similar spots in(More)
Ionophore-stimulated ATPase activity and ATP-dependent quinacrine quench were enriched in parallel when microsomal vesicles were prepared from corn (Crow Single Cross Hybrid WF9-Mo17) roots and collected on a cushion of 10% dextran. Activities were highest in the apical 1.5 centimeters of the roots. Vesicles collected on the dextran cushion also contained(More)
Na(+)/H(+) exchange activity in barley (Hordeum vulgare cv CM-72) root tonoplast was induced by Na(+) even in the presence of inhibitors of protein synthesis. Induction occurred with a half-time of only 15 minutes. When salt-treated roots were transferred to a nutrient solution containing no Na(+), the activity disappeared with a similar time course. The(More)
The vacuolar H+-ATPase of higher plants is a member of the V-ATPase family, which comprises complex, multisubunit ATPases found in a11 eukaryotes. The electrochemical gradient created by the V-ATPase is thought to provide the driving force for the iecondary transport of other ions and metabolites (Taiz, 1992). In barley (Hordeum vulgare L.) roots this(More)