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961.
962.
The conformation of oat globulin dispersions (10% in D2O) under the influence of pH, chaotropic salts, protein structure perturbants, and heating conditions was studied by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectrum of oat globulin showed major bands from 1670 to 1634 cm(-1), corresponding to the four major types of secondary structures, that is, beta-turns, beta-sheets, alpha-helices, and random coils. At extreme acidic and alkaline pH conditions, there were changes in intensity in the bands attributed to beta-sheet structures (1626, 1634, and 1682 cm(-1)), and shifts of the bands to higher or lower wavenumbers, indicating changes in conformation. In the presence of some chaotropic salts, the 1626 and 1634 cm(-1) bands were shifted upward, with a marked decrease in the intensity of the 1634 cm(-1) peak. The addition of several protein structure perturbants led to a slight shift in the alpha-helix/random coil bands and a marked reduction in the beta-sheet peaks, suggesting protein unfolding. Heating under aggregating conditions led to slight shifts in all of the major bands and progressive changes in the intensity of the alpha-helix, beta-sheet, and beta-turn peaks, suggesting protein denaturation. This was accompanied by marked increases in intensity of the two intermolecular beta-sheet bands (1682 and 1624-1626 cm(-1)) associated with the formation of aggregated strands. The IR spectra of soluble and insoluble aggregates showed a redistribution of native and extensively denatured proteins in the two fractions. 相似文献
963.
J. Kittler H. Krüger D. Ulrich B. Zeiger W. Schütze Ch. Böttcher A. Krähmer G. Gudi U. Kästner H. Heuberger F. Marthe 《Genetic Resources and Crop Evolution》2018,65(5):1517-1527
Lemon balm (Melissa officinalis L.) is used since ancient times because of its sedative, spasmolytic and antiviral effects. Its therapeutic impact is due to the content of essential oil and rosmarinic acid. A set of 68 M. officinalis genotypes was evaluated for content and composition of essential oil and the content of rosmarinic acid. For all genotypes the level of ploidy was determined. The 68 genotypes were clone plants grown and evaluated for two years at Quedlinburg. For analysis of secondary metabolites distillation, gas chromatography and high performance liquid chromatography was used. The content of essential oil varied in this study in ranges from 0.03 to 0.33% for the second cut 2010 and 0.01–0.35% for the second cut 2011. The rosmarinic acid content ranged in the year 2010 from 3.67 to 7.55% and in the year 2011 from 4.92 to 8.07%. Via statistical analyses two chemotypes of essential oil were found: chemotype citral and chemotype β-caryophyllene oxide. Ploidy was determined for all genotypes and two cytotypes were found: diploid 2n = 2x = 32 (62 of 68 genotypes) and triploid 2n = 3x = 48 (6 of 68 genotypes). 相似文献
964.
965.
?ukasz?J.??uczajEmail author Ingvar?Svanberg Piotr?K?hler 《Genetic Resources and Crop Evolution》2011,58(5):783-793
The aim of this article is to study the geographical distribution and historical patterns of use of a little known root crop
native to Europe—marsh woundwort Stachys palustris L. The species grows in wet grasslands and arable fields. It produces edible tubers. Both ethnographic literature and archival
sources were searched. Seventeen reliable references concerning the consumption of S. palustris in southern and south–eastern Poland were found. The tubers were usually dried and powdered, and then added to soups or to
bread dough. They were also eaten as raw snacks. The plant was used mainly during food shortages in spring, until the turn
of the nineteenth and twentieth century, and later only as an occasional raw snack until the 1970s. Marsh woundwort was also
eaten in western Ukraine (one reference). There are many references to the edibility of marsh woundwort in the eighteenth
and nineteenth century European economic botany literature, particularly in Sweden and Great Britain. These publications tried
to popularize the use of S. palustris as food. However, there is no firm evidence from these countries that marsh woundwort was used as food there. Marsh woundwort
was also used, throughout northern and central Europe, as pig fodder and as a medicinal plant, particularly for healing wounds.
Further studies on the nutritive value of this forgotten crop should be undertaken, particularly that there is little knowledge
of the chemical composition of both marsh woundwort and its Asian relative Stachys affinis widely cultivated in China as a vegetable. 相似文献
966.
B. Lothenbach R. Krebs G. Furrer S. K. Gupta & R. Schulin 《European Journal of Soil Science》1998,49(1):141-148
We investigated the potential of montmorillonite, Al-montmorillonite and gravel sludge to immobilize polluting heavy metals in agricultural soil. Batch experiments showed that both Al-montmorillonite and montmorillonite immobilized zinc and cadmium. Zinc was bound specifically on Al-montmorillonite and became increasingly incorporated into the interlayer hydroxy-Al polymer, whereas there was no specific sorption on montmorillonite. Cadmium was bound on montmorillonite and Al-montmorillonite unspecifically by cation exchange, but there was no incorporation into the lattice. In pot experiments montmorillonite, Al-montmorillonite, or gravel sludge were added to a soil contaminated with zinc and cadmium. Increasing doses of these agents decreased the concentrations of NaNO3-extractable zinc and cadmium. Aluminium-montmorillonite and gravel sludge were more efficient than montmorillonite in immobilizing both zinc and cadmium. Remobilization tests at pH between 4 and 5.5 showed that cadmium and zinc desorbed more easily from montmorillonite than from Al-montmorillonite. Gravel sludge application increased the buffer capacity of the contaminated soil substantially. The binding agents decreased zinc concentrations in red clover (Trifolium pratense), and gravel sludge also reduced the cadmium concentrations. 相似文献
967.
968.
T. Ueno S. G. Stevenson K. R. Preston M. J. Nightingale B. M. Marchylo 《Cereal Chemistry》2002,79(1):155-161
A simple, highly efficient and reproducible two‐step extraction procedure using dilute acetic acid without (AN) and then with sonication (AS) has been developed for the fractionation of wheat flour protein. Approximately 97% of total protein was extracted from a Canadian hard red spring wheat flour; an additional 1.2% protein could be recovered by further extraction with 1% DDT and 50% 1‐propanol (AR). Size‐exclusion HPLC (SE‐HPLC) and flow field‐flow fractionation (flow FFF) showed that the AN extract, which accounted for most of the total extractable protein (AN + AS + AR), consisted primarily of monomeric protein. The AS extract was composed primarily of polymeric proteins. Flow FFF showed that AN polymeric protein, including that eluting at the SE‐HPLC void volume, showed smaller Stokes diameters than AS polymeric protein. Flow FFF profiles of AS SE‐HPLC subfractions showed that the void volume subfraction contained monomeric and small polymeric protein in addition to large polymeric protein, indicating formation of larger complexes through interaction between some or all of the components. AN and AS extracts, as well as SE‐HPLC and flow FFF fractions thereof, showed a fairly wide range of values among 12 Canadian hard red and white spring wheat cultivars. The proportion of total protein in the AS extract and in the larger sized polymeric protein fractions from SE‐HPLC and flow FFF were highly positively correlated to farinograph mixing time. 相似文献
969.
Jagadeesh Mosali Kefyalew Desta Roger K. Teal Kyle W. Freeman Kent L. Martin Jason W. Lawles 《Journal of plant nutrition》2013,36(12):2147-2163
ABSTRACT One would expect foliar applied phosphorus (P) to have higher use efficiencies than when applied to the soil, but limited information is available concerning this. Experiments were conducted in 2002, 2003, and 2004 to determine the effect of foliar applications of P on winter wheat grain yields, P uptake, and use efficiency. Twelve treatments containing varying foliar P rates (0, 1, 2, and 4 kg ha? 1 in 2002 and 2003 and additional 8, 12, 16, and 20 kg ha? 1 in 2004) with and without pre-plant rates of 30 kg ha? 1 were evaluated. Foliar applications of P at Feekes 7 generally increased grain yields and P uptake versus no foliar P. Use efficiency was higher when P was applied at Feekes 10.54. Results from this study suggested that low rates of foliar applied P might correct mid-season P deficiency in winter wheat, and that might result in higher P use efficiencies. 相似文献
970.
Sujit?K.?GhoshEmail author 《Journal of Agricultural, Biological & Environmental Statistics》2003,8(3):367-382
This article considers statistical modeling of a simplified version of Darwinian evolution which involves only two genes encoding
one molecule. In particular, we consider a process known as affinity maturation that is carried out in the germinal center reaction (GCR). We use a statistical model, developed earlier, that enables us to tease apart the effects of mutation rate and selection
in B cell populations undergoing an immune response. Standard classical statistical approaches that use large-sample theory
may lead to misleading conclusions when sample size is very small. The data collection in many biological systems, including
the immune response of vertebrate organisms, is both time consuming and often results in relatively small datasets. Therefore,
this article takes a Bayesian perspective that produces finite-sample estimates of the mutation rates and is flexible in extending
the models to more complicated processes. The method is illustrated using sequence data obtained from Gen bank that carried
the experiment over two years. 相似文献