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1.
The effect of 2(N‐morpholino)ethane)sulfonic acid (MES) on the growth of cucumber (Cucumis sativa L. var. Marketer) in hydroponic culture was determined at 0, 1, 5, and 10 mM concentrations. The effect of adding the MES to the solution at the time of transfer to hydroponic culture or waiting one week was also determined. MES was observed to strongly affect plant growth with increasing concentration in nutrient solution. Tissue and nutrient solution analysis determined that MES affects manganese (Mn) uptake. MES appears to be reduced by Mn, precipitating the Mn out of solution. The suitability of MES as a pH buffer in hydroponic culture is discussed in terms of this effect.  相似文献   

2.
Volatile compounds of cajá and taperebá fruits, both classified as Spondias mombin, but from different geographic origins, were extracted (and analyzed) using solid phase microextraction (SPME) and simultaneous distillation and extraction (SDE). Forty-eight compounds were identified in taperebá and 47 in cajá by SPME using a DVB/CAR/PMDS fiber. (E)-Caryophyllene (18.7%), ethyl butyrate (10.0%), and ethyl hexanoate (7.0%) were the most abundant components in taperebá volatiles extracted by SPME, whereas myrcene (41.1%) and beta-phellandrene (8.5%) were the major compounds in cajá. In the taperebá SDE extract, 46 substances were identified, and (Z)-caryophyllene (13.2%) and limonene (9.5%) were predominant. From the 42 substances found in the SDE extract of cajá, the major components were myrcene (38.0%) and p-cymene (6.2%). The two fruits showed similar chromatograms upon the use of SDE and SPME. These methods made it possible to determine 30 identical components in both fruits by using SDE and 32 by using SPME.  相似文献   

3.
LIU Yuan  LI Zhongyi  XU Renkou 《土壤圈》2019,29(5):656-664
Distribution of chemical forms of manganese(Ⅱ)(Mn(Ⅱ))on plant roots may affect Mn(Ⅱ)absorption by plants and toxicity of Mn(Ⅱ)to plants at its high level.The chemical forms of Mn(Ⅱ)on soybean roots were investigated to determine the main factors that affect their distribution and relationship with Mn(Ⅱ)plant toxicity.Fresh soybean roots were reacted with Mn(Ⅱ)in solutions,and Mn(Ⅱ)adsorbed on the roots was differentiated into exchangeable,complexed,and precipitated forms through sequential extraction with KNO_3,EDTA,and HCl.The exchangeable Mn(Ⅱ)content on the roots was the highest,followed by the complexed and precipitated Mn(Ⅱ)contents.Mn(Ⅱ)toxicity to the roots was greater at pH 5.5 than at pH 4.2 due to the larger amount of exchangeable Mn(Ⅱ)at higher pH.The cations Al~(3+),La~(3+),Ca~(2+),Mg~(2+),and NH_4~+competed with Mn(Ⅱ)for cation exchange sites on the root surfaces and thus reduced exchangeable Mn(Ⅱ)on the roots,in the order Al~(3+),La~(3+)Ca~(2+),Mg~(2+)NH_4~+.Al~(3+) and La~(3+) at 100μmol L~(-1) decreased exchangeable Mn(Ⅱ)by 80%and 79%,respectively,and Ca~(2+) and Mg2+at 1 mmol L~(-1) decreased exchangeable Mn(Ⅱ)by 51%and 73%,respectively.Organic anions oxalate,citrate,and malate reduced free Mn(Ⅱ)concentration in solution through formation of complexes with Mn(Ⅱ),efficiently decreasing exchangeable Mn(Ⅱ)on the roots;the decreases in exchangeable Mn(Ⅱ)on the roots were 30.9%,19.7%,and 10.9%,respectively,which was consistent with the complexing ability of these organic anions with Mn(Ⅱ).Thus,exchangeable Mn(Ⅱ)was the dominant form of Mn(Ⅱ)on the roots and responsible for Mn(Ⅱ)toxicity to plants.The coexisting cations and organic anions reduced the exchangeable Mn(Ⅱ)content,and thus they could alleviate Mn(Ⅱ)toxicity to plants on acid soils.  相似文献   

4.
5.
Berries and seeds of two subspecies (ssp. sinensis and mongolica) of sea buckthorn (Hippopha? rhamnoides L.) were compared in terms of triacylglycerols, glycerophospholipids, tocopherols, and tocotrienols. The berries of ssp. mongolica contained less oleic acid (4.6 vs 20.2%, p < 0.001) and more palmitic (33.9 vs 27.4%, p < 0.01) and palmitoleic (32.8 vs 21.9%, p < 0.05) acids in triacylglycerols than those of ssp. sinensis. The proportions of linoleic acid (32.1 vs 22.2%, p < 0.01, in berries; 47.7 vs 42.7%, p < 0.05, in seeds) and palmitic acid (21.1 vs 16.4%, p < 0.001, in berries; 17.0 vs 14.1%, p < 0.05, in seeds) in glycerolphospholipids were higher in ssp. mongolica than in ssp. sinensis, and vice versa with oleic acid (4.3 vs 18.5% in berries, 10.0 vs 22.2% in seeds, p < 0.001). A higher proportion of alpha-linolenic acid was also found in the glycerophospholipids of ssp. sinensis berries (16.2 vs 10.1%, p < 0.001). alpha-, beta-, gamma-, and delta-tocopherols constituted 93-98% of total tocopherols and tocotrienols in seeds, and alpha-tocopherol alone constituted 76-89% in berries. The total contents of tocopherols and tocotrienols varied within the ranges of 84-318 and 56-140 mg kg(-1) in seeds and whole berries, respectively. The seeds of ssp. mongolica were a better source of tocopherols and tocotrienols than those of ssp. sinensis (287 vs 122 mg kg(-1), p < 0.001). The compositional differences between the two subspecies should be considered when the berries are bred and exploited for nutritional purposes.  相似文献   

6.
Two previous studies have reported that pu-erh tea contains a high level of γ-aminobutyric acid (GABA), which is the major inhibitory neurotransmitter in the central nervous system and has several physiological functions. However, two other researchers have demonstrated that the GABA content of several pu-erh teas was low. Due to the high value and health benefits of GABA, analysis of mass-produced pu-erh tea is necessary to determine whether it is actually enriched with GABA. A high-performance liquid chromatography (HPLC) method was developed for the determination of GABA in tea, the results of which were verified by amino acid analysis using an Amino Acid Analyzer (AAA). A total of 114 samples of various types of Chinese tea, including 62 pu-erh teas, 13 green teas, 8 oolong teas, 8 black teas, 3 white teas, 4 GABA teas, and 16 process samples from two industrial fermentations of pu-erh tea (including the raw material and the first to seventh turnings), were analyzed using HPLC. Statistical analysis demonstrated that the GABA content in pu-erh tea was significantly lower than that in other types of tea (p < 0.05) and that the GABA content decreased during industrial fermentation of pu-erh tea (p < 0.05). This mass analysis and comparison suggested GABA was not a major bioactive constituent and resolved the disagreement GABA content in pu-erh tea. In addition, the GABA content in white tea was found to be significantly higher than that in the other types of tea (p < 0.05), leading to the possibility of producing GABA-enriched white tea.  相似文献   

7.
8.
Red–yellow (Pisum fulvum Sibth. et Sm.) and Ethiopian (Pisum abyssinicum A. Br.) peas have become of increasing interest to breeders in the last decade, as they have been found to be partially or completely tolerant to various biotic stresses, such as to attack by pea weevil, mildew blight or rust. A trial was carried out at the Institute of Field and Vegetable Crops at Rimski ?an?evi from 2005 to 2007, with 13 accessions each of red–yellow and Ethiopian peas sown at 100 viable seeds m?2, in plots of 0.5 m2. Seed yield per plant in red–yellow pea was significantly and positively correlated with seed number per plant (r = 0.881**), pod number per plant (r = 0.839**) and number of fertile nodes (r = 0.820**). The highest positive correlation among the agronomic characteristics in Ethiopian pea was between number of fertile nodes and number of pods (r = 0.937**). Seed yield in Ethiopian pea was highly significantly correlated with number of seeds (r = 0.807**), pods (r = 0.692*), and fertile nodes (r = 0.638*). The results suggest that plant morphology of the progenies between red–yellow or Ethiopian peas and grain-type common pea could not differ significantly from that of individual parents. That means that it could be possible to develop hybrid lines that could keep the desirable morphological traits of grain-type common pea, such as lodging-tolerance and high seed yields, and to make an introgression of a specific resistance from wild pea taxa, especially by back-crosses with the former. However, one must always be aware of unpredicted outcomes as a result of rather different genetic basis of individual seed yield components.  相似文献   

9.
Effects of (1) the addition of 35 kg N ha-1yr-1(as NH4NO3) and (2) interception of throughfall and litterfall by means of a roof on concentrations, chemical characteristics and dynamics of dissolved organic matter (DOM) in acid forest soils (podzols) were studied at Gårdsjön, Sweden. A non-manipulated catchment served as a reference. After 4 yr of treatment no significant effects of either manipulation were found on concentrations and characteristics of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON). The variability of these parameters within catchments appeared to be of the same order of magnitude as the variability between catchments. At all sites, DON contributed more than 70% of the total dissolved nitrogen. In general, the proportion of hydrophilic DOC increased with depth. In contrast, to other studies the C/N ratio of DOM at Gårdsjön did not show a clear pattern with depth. Other studies in SE U.S.A. have suggested that relatively low C/N ratios at depth are due to increased contribution of hydrophilic neutrals to DOC. However, this fraction appears to be small in temperate and boreal spruce forest soils, including Gårdsjön.  相似文献   

10.
The aim of this study was the detailed characterization of the phenolic composition and the determination of the antioxidant activity of the Bord? grape (Vitis labrusca) cultivated in South Brazil. The edible parts of Bord? grapes (flesh and skin) contained 1130 mg/kg of total phenolic compounds (as gallic acid), mainly located in the skins. Anthocyanin content in the skins was high, largely as 3,5-diglucosides (1359 mg/kg, as malvidin 3,5-diglucoside). Total flavonols accounted for 154 μmol/kg, mainly located in the skins and with myricetin 3-glucoside as the principal flavonol in both grape parts. Very low amounts of flavan-3-ol monomers and dimers and low amounts of polymeric proanthocyanidins, with a composition similar to that reported for V. vinifera grape varieties, were found in Bord? grape skins. Hydroxycinnamic acid derivatives mainly derived from caffeic acid and were found in the skins in high amounts, ten times higher than in the flesh (total amount: 483 μmol/kg). Finally, the Bord? grape cultivar can be considered a high resveratrol producer (10.91 mg/kg) and also exhibited a high value of total antioxidant capacity (37.6 ± 1.0 mmol/kg, as Trolox).  相似文献   

11.
In the assessment of the antioxidant properties of edible plants, the widely consumed Vitis × labruscana cv. 'Isabella', known in Italy as "fragola" (strawberry) grape, was of interest. Phenol and flavonoid contents of the methanolic extracts of peel, pulp, seed, leaf, and stalk components of the plant were determined. The metabolic profile of the extracts was performed by 1D and 2D NMR. Quantitative analysis, obtained in the presence of 0.01% of internal standard trimethylsilyl propionate, evidenced the presence of catechins in both stalk and seed extracts, whereas caffeic acid and quercetin were the main metabolites of the leaf extract. Furthermore, the extracts were tested for their radical scavenging and reducing capacities by measuring their capacity to scavenge DPPH(?) and ABTS(?+) and to reduce Fe(III) and Mo(VI) salts. The antioxidant efficacy of the extracts in cell-free systems and their antiproliferative activity toward HepG2 and A549 cells were also evaluated. Seed and stalk components are able to reduce by 39.6 and 40.6%, respectively, the amount of the metabolically active HepG2 cells after only 24 h of exposure.  相似文献   

12.
OPG是一种分泌型糖蛋白,属于TNF受体超家族成员,可抑制破骨细胞分化的最终阶段以及成熟破骨细胞的活性并诱导其凋亡(Simonet et al.,1997;Yasuda et al.,1998)。目前,国内外尚未见有关鸡OPG克隆的相关研究报道。本实验在体外成功地培养鸡胚额骨成骨细胞的基础上(张胶和侯加法,2  相似文献   

13.
The oxygen isotope composition (δ(18)O), accumulation of minerals (ash content), and nitrogen (N) content in plant tissues have been recently proposed as useful integrative physiological criteria associated with yield potential and drought resistance in maize. This study tested the ability of near-infrared reflectance spectroscopy (NIRS) to predict δ(18)O and ash and N contents in leaves and mature kernels of maize. The δ(18)O and ash and N contents were determined in leaf and kernel samples from a set of 15 inbreds and 18 hybrids grown in Mexico under full irrigation and two levels of drought stress. Calibration models between NIRS spectra and the measured variables were developed using modified partial least-squares regressions. Global models (which included inbred lines and hybrids) accurately predicted ash and N contents, whereas prediction of δ(18)O showed lower results. Moreover, in hybrids, NIRS clearly reflected genotypic differences in leaf and kernel ash and N contents within each water treatment. It was concluded that NIRS can be used as a rapid, cost-effective, and accurate method for predicting ash and N contents and as a method for screening δ(18)O in maize with promising applications in crop management and maize breeding programs for improved water and nitrogen use efficiency and grain quality.  相似文献   

14.
Glycosylated α-galactosidase (melibiase) has been purified from white chickpea ( Cicer arietinum ) to 340-fold with a specific activity of 61 units/mg. Cicer α-galactosidase showed a M(r) of 45 kDa on SDS-PAGE and by MALDI-TOF. The optimum pH and temperature with pNPGal were 4.5 and 50 °C, respectively. The K(m) for hydrolysis of pNPGal was 0.70 mM. Besides hydrolyzing the pNPGal, Cicer α-galactosidase also hydrolyzed natural substrates such as melibiose, raffinose, and stachyose very effectively; hence, it can be exploited commercially for improving the nutritional value of soy milk. Galactose was found to be a competitive inhibitor. The property of this enzyme to cleave the terminal galactose residues can be utilized for converting the group B erythrocytes to group O erythrocytes.  相似文献   

15.

Purpose

A medium-term study of sedimentary aliphatic hydrocarbons in the Gulf of Trieste was performed. The content of the aliphatic hydrocarbons, including their spatial and temporal distributions and origins, was determined. The collected data on the content of these compounds for the period of 2004–2013 were then processed using different evaluation indices and statistical analyses.

Materials and methods

Sediment samples were collected using a gravity core sampler. Hydrocarbons were extracted with hexane and dichloromethane (1:1), and their concentrations were determined by gas chromatography (using an FID detector). Principal component analysis (PCA) was performed to establish the differences between the different sampling sites.

Results and discussion

The study’s results reveal spatial and temporal variabilities in the aliphatic hydrocarbons within the investigated area. The mean concentrations of total aliphatic hydrocarbons were in the range of 17.9–84.6 μg g?1 d.w., while the concentrations of n-alkanes from C12 to C34 were 934–5232 ng g?1 d.w. The results of the analyses show higher concentrations of hydrocarbons in the coastal areas, with a decrease toward the central part of the Gulf of Trieste. The interannual differences in hydrocarbon concentrations were generally larger close to river estuaries and pollution sources, where degradation processes are more intensive. Different evaluation indices revealed the hydrocarbons to have different origins. The temporal distribution of aliphatic hydrocarbons shows a decrease in concentrations over the past few years at certain sites. Important changes in the concentration and composition of the aliphatic fraction were observed in and after 2010, characterised by intensive fluvial input and long-lasting decreased salinity.

Conclusions

The content and distribution of aliphatic hydrocarbons are largely dependent on coastal sources of these compounds. Although the investigated area could be considered only slightly to moderately contaminated by hydrocarbons, the recently applied measures for pollution reduction should be continued and intensified.
  相似文献   

16.
Use of synthetic iron (Fe) chelates is the most common and effective way to treat Fe chlorosis in plants. Most commercial products contain Fe‐EDDHA or Fe‐EDDHMA but their efficacy can be quite different. Commercial products with EDDHA or EDDHMA as active components were chosen based on the data obtained by Lucena et al. (1992) in their chemical test. The chelates present extreme differences in behavior in the mentioned chemical tests. The analysis of the products revealed that the total Fe concentration is greater than the one indicated by the manufacturer in spite of a lesser amount of FeY present. The plant response to these commercial products was tested using short‐term greenhouse hydroponic cultures. Sunflower and corn were chosen because of their different behavior under Fe‐stress conditions. No significant difference between plants treated with Fe‐EDDHA or Fe‐EDDHMA chelates were observed. Since the purity index indicates there are too many differences between commercial formulations of the same type of chelate, the differentiation between groups cannot be determined with commercial products. Index I3, described by Lucena et al. (1992), does not correlate with the plant response because it did not consider the purity percentage of the products.  相似文献   

17.
In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. In this study, a novel, rapid, and nonintrusive method aimed to simultaneously determine the content in gaseous CO(2) and ethanol above a glass poured with champagne, using a micro-gas chromatography technique coupled with a thermal conductivity detector, was presented. The simultaneous quantification of CO(2) and ethanol in the headspace of a champagne glass was monitored, in real tasting conditions, all along the first 15 min following pouring, depending on whether or not the glass shows effervescence. Both CO(2) and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between rising bubbles and the release of gaseous CO(2) and volatile organic compounds.  相似文献   

18.
The possible adverse effects on health of diet-derived advanced glycation endproducts (AGEs) and advanced lipoxidation endproducts (ALEs) is of current interest. This study had the objective of determining the effects of the addition of AGE/ALE inhibitors and different types of sugar and cooking oil on Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) formation in model foods (sponge cakes). The cake baked using glucose produced the highest level of CML (2.07±0.24 mmol/mol lysine), whereas the cake baked using fructose produced the highest concentration of CEL (25.1±0.15 mmol/mol lysine). There were no significant differences between CML concentrations formed in the cakes prepared using different types of cooking oil, but significant differences (P<0.001) were observed between the cakes prepared using different proportions of cooking oil. The cakes containing oil generated greater concentrations of CML than sucrose. α-Tocopherol and rutin did not inhibit CML and CEL formation. In contrast, ferulic acid and thiamin, thiamin monophosphate, and thiamin pyrophosphate reduced CML and CEL formation.  相似文献   

19.
Cinnamaldehyde (CA), one of the active components of cinnamon, has been known to exert several pharmacological effects such as anti-inflammatory, antioxidant, antitumor, and antidiabetic activities. However, its antiobesity effect has not been reported yet. This study investigated the antidifferentiation effect of CA on 3T3-L1 preadipocytes, and the antiobesity activity of CA was further explored using high-fat-diet-induced obese ICR mice. During 3T3-L1 preadipocytes were differentiated into adipocytes, 10-40 μM CA was treated and lipid contents were quantified by Oil Red O staining, along with changes in the expression of genes and proteins associated with adipocyte differentiation and adipogenesis. It was found that CA significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding proteins α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1) in concentration-dependent manners. Moreover, CA markedly up-regulated AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), and these effects were blunted in the presence of AMPK inhibitor, compound C. In the animal study, weight gains, insulin resistance index, plasma triglyceride (TG), nonesterified fatty acid (NEFA), and cholesterol levels in the 40 mg/kg of CA-administered group were significantly decreased by 67.3, 55, 39, 31, and 23%, respectively, when compared to the high-fat diet control group. In summary, these results suggest that CA exerts antiadipogenic effects through modulation of the PPAR-γ and AMPK signaling pathways.  相似文献   

20.
This study aimed to achieve the conversion of cereal proteins to the alternative end products glutamate or γ-aminobutyrate (GABA). Rye malt, fungal proteases, and lactobacilli were employed to convert wheat gluten or barley proteins. Glutamate and GABA formations were strain-dependent. Lactobacillus reuteri TMW1.106 and Lactobacillus rossiae 34J accumulated glutamate; L. reuteri LTH5448 and LTH5795 accumulated GABA. Glutamate and GABA accumulation by L. reuteri TMW1.106 and LTH5448 increased throughout fermentation time over 96 h, respectively. Peptides rather than amino acids were the main products of proteolysis in all doughs, and barley proteins were more resistant to degradation by rye malt proteases than wheat gluten. However, addition of fungal protease resulted in comparable degradation of both substrates. Glutamate and GABA accumulated to concentrations up to 63 and 90 mmol kg(-1) DM, respectively. Glutamate levels obtained through bioconversion of cereal proteins enable the use of hydrolyzed cereal protein as condiment.  相似文献   

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