This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in s...This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in spontaneous fermentation.Low-salt groups had lower pH and higher titratable total acid.In the low-salt groups,the dominant genera were Lactobacillus and Lactococcus,whereas Staphylococcus,Weissella,and Tetragenococcus were dominant in the high-salt groups.Higher total free amino acids and essential amino acids,organic acids,hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups.The RDA analysis revealed that Lactococcus was closely related to product quality,with the S3F10(3%salt and 10%rice f lour)group outperforming the others in the sensory evaluation.Therefore,3%salt and 10%rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.展开更多
The development of a method for the quantitative determination of the sericin content ratio(SCR)is urgently needed for silk refining and the purification of silk fibroin for biomedical applications.In this work,a seri...The development of a method for the quantitative determination of the sericin content ratio(SCR)is urgently needed for silk refining and the purification of silk fibroin for biomedical applications.In this work,a series of sericin/fibroin mixed samples with known SCRs were prepared by mixing initial samples of extracted sericin and fibroin from Bombyx mori silk.Significant differences were found in the contents of characteristic hydrophilic amino acids abundant in sericin and hydrophobic amino acids abundant in fibroin,and several linear relation-ships of SCR associated with the content ratios of Ser/Ala,Asp/Ala,Lys/Ala,Asp/Gly and Ser/Gly were estab-lished by amino acid analysis.Subsequently,the linear equation expressing SCR(%)as a function of the Asp to Ala content ratio X(%)was established as SCR=2.5634X−12.5587(R 2=0.9972).The results indicated that the SCR of degummed silks calculated by the equation is more objective and effective than the results obtained by the traditional weight loss method.Our study provides a novel approach for the sensitive and quantitative detection of the sericin content within the detection limit in unknown silks,which can contribute to quality control in the silk production process.展开更多
For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understa...For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating lactating dairy cows' nitrogen losses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattle in the US include variable efficiencies of absorbed essential AA for milk protein production. This first separation from a purely substrate-based system, standing on the old limiting AA theory, recognizes the ability of the cow to alter the metabolism of AA. In this review we summarize a compelling amount of evidence suggesting that AA requirements for milk protein synthesis are based on a demand-driven system. Milk protein synthesis is governed at mammary level by a set of transduction pathways, including the mechanistic target of rapamycin complex 1(mTORC1), the integrated stress response(ISR), and the unfolded protein response(UPR). In tight coordination, these pathways not only control the rate of milk protein synthesis, setting the demand for AA, but also manipulate cellular AA transport and even blood flow to the mammary glands, securing the supply of those needed nutrients. These transduction pathways, specifically mTORC1, sense specific AA, as well as other physiological signals, including insulin, the canonical indicator of energy status. Insulin plays a key role on mTORC1 signaling, controlling its activation, once AA have determined mTORC1 localization to the lysosomal membrane.Based on this molecular model, AA and insulin signals need to be tightly coordinated to maximize milk protein synthesis rate. The evidence in lactating dairy cows supports this model, in which insulin and glucogenic energy potentiate the effect of AA on milk protein synthesis. Incorporating the effect of specific signaling AA and the differential role of energy sources on utilization of absorbed AA for milk protein synthesis seems like the evident following step in nutrient requirement systems to further improve N efficiency in lactating dairy cow rations.展开更多
Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets de...Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants.In this study,we investigated the effects of adding sodium dichloroacetate(DCA)to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera(PDV)and liver of pigs.To measure nitrogen balance,18 barrows(40±1.0 kg)were fed one of three diets(n=6 per group):18%crude protein(CP,control),13.5%CP(LP),and 13.5%CP+100 mg DCA/kg dry matter(LP-DCA).To measure amino acid metabolism in the PDV and liver,15 barrows(40±1.0 kg)were randomly assigned to one of the three diets(n=5 per group).Four essential amino acids(Lys,Met,Thr,and Trp)were added to the LP diets such that these had amino acid levels comparable to those of the control diet.Results:The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet(P<0.05),without any negative effects on nitrogen retention(P>0.05).There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs(P>0.05).The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets(P<0.05).Conclusion:The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.展开更多
The nitrogen (N) metabolic experiments were made to estimate separately amino acid requirements of 4348 weeks old layers for maintenance, for protein accretion to estabolish models to estimate digestible amino acid re...The nitrogen (N) metabolic experiments were made to estimate separately amino acid requirements of 4348 weeks old layers for maintenance, for protein accretion to estabolish models to estimate digestible amino acid requirements. The regression relationship of nitrogen retention vs amino acid intake was estimated for each amino acid by giving, at rate of N intake of 091, 052, 015 and 0007gkg-1 body-weight (W075) per d, the semi-synthetic diets was made specially deficient in one amino acid. From the regression coefficients, it was calculated that, for the accretion of 1 g protein, the dietary digestible amino acid requirements were (mg) Thr 631, Val 1004, Met 399, Ile 886, Leu 1143, Phe 632, Lys 870, His 205, Arg 879, Trp 214, Met+Cys 776, and Phe+Tyr 1143. Daily amino acid requirements for N equilibrium were estimated to be (mgkg-1W075 per day) Thr 506, Val 747, Met 303, ILe 667 Leu 814, Phe 448, Lys 605 His 147, Arg 739 ,Trp 173, Met+Cys 586, and Phe+Tyr 839 The dietary degestible amino acid patterns for protein accretion and N equilibrium were also proposed. The models of estimating digestible amino acid requirements for the different productions were developed.展开更多
In this paper amino acids synthesis in aqueous solution induced by ion implantation, which was possibly ubiquitous on primitive Earth, is investigated. As a discharge using a graphite rod as the anode under a nitrogen...In this paper amino acids synthesis in aqueous solution induced by ion implantation, which was possibly ubiquitous on primitive Earth, is investigated. As a discharge using a graphite rod as the anode under a nitrogen atmosphere was performed against ammonia water, it was found that three kinds of amino acids were produced. They were glycine, serine and alanine. By introducing ion implantation into the carboxylate solution, ammonia and amino acids were also formed via nitrogen deposition/fixation. Another isotopic experiment showed that both OH and H radicals played a crucial role in the arc-discharge-promoted reactions in aqueous solution Therefore, we believe that the impact of ions in the original atmospheric conditions might have functioned as a promoter in the chemical origin and evolution of life.展开更多
BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate t...BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids (EAA) during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine (L-NA) reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE: By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid (GABA) in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN: A randomized and controlled experiment SETTING : Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS: A total of 42 male healthy SD rats (grade Ⅱ, weighting 250-300 g) were provided by the Experimental Animal Center of Hebei Province (Certification: 04036). Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride (TTC) were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS: The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups: sham-operated group (n = 6), ischemic group (n = 18), L-NA group (n = 18). The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups (n = 6 for each): drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion (MCAO) respectively. L-NA (20 mg/kg, ip) was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain (IV%) in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett's test. MAIN OUTCOME MEASURES: (1) The volume of cerebral infarction; (2) The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS : All 42 rats were involved in the final analysis. (1) Infarcted volume: Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was (20.13±3.59)% and (23.12±5.84)% in L-NA group, which was not similar to that in ischemic group [(22.10±3.98)%, (25.38± 5.37)%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [(26.11±3.55)% and (37.15±3.58)%, P 〈 0.01]. Changes of amino acid content: At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group ( P〈 0.05-0.01). However, contents in L-NA group were similar to those in ischemic group (P 〉 0.05). At 12 hours after ischemia, the contents of aspartate [(0.21 ±0.06), (0.36±0.05), (0.29±0.12) mg/g] and glutamate [(0.55±0.06), (0.78±0.10), (0.52±0.10) mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [(0.49±0.17), (0.63± 0.03), (0.51±0.15) mg/g; (0.98±0.30), (1.15±0.15), (0.93±0.15) mg/g, P〈 0.05-0.01]. Glycine in hippocampus was (0.40±0.07) mg/g, which was higher than that in ischemic group [(0.21±0.07) mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was (0.93±0.10), (0.62±0.12) and (0.81 ±0.10) mg/g, respectively, which was higher than that in ischemic group [(0.60±0.08), (0.37±0.17), (0.59±0.10) mg/g, P 〈 0.05-0.01]. CONCLUSION : It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.展开更多
Background:To compare the nutritional value and digestibility of five quality protein maize(QPM) hybrids to that of white and yellow maize,two experiments were carried out in growing pigs.In experiment 1,the energy...Background:To compare the nutritional value and digestibility of five quality protein maize(QPM) hybrids to that of white and yellow maize,two experiments were carried out in growing pigs.In experiment 1,the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize.In experiment 2,the apparent and standardized ileal digestibility(AID and SID,respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize.In both experiments,the comparisons were conducted using contrasts.Results:The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids(P 〈 0.05) than in the pigs fed white or yellow maize.Energy digestibility(P 〈 0.001) and metabolizability(P 〈 0.01) were higher in the pigs fed the white and yellow maize diets than in those fed the QPM diets.The AID of lysine was higher(P〈 0.01) in the QPM diets than in the white and yellow maize.The AIDs of leucine,isoleucine,valine,phenylalanine,and methionine were lower in the QPM diets than those of maize(white and yellow)(all P 〈 0.05).Maize(white and yellow) had greater SIDs of leucine,isoleucine,valine,phenylalanine,glutamic acid,serine,alanine,tyrosine,and proline(P 〈 0.05).Conclusions:Based on these results,it was concluded that QPM had a lower metabolizable energy content and a higher amount of digestible lysine than normal maize.展开更多
[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of larg...[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field (HPEF). [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.展开更多
The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by u...The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by using the independent non-homologous protein database. It is shown that the average absolute errors for resubstitution test are 0.070 and 0.068 with the standard deviations 0.049 and 0.047 for the prediction of the content of α-helix and β-sheet respectively. For cross-validation test, the average absolute errors are 0.075 and 0.070 with the standard deviations 0.050 and 0.049 for the prediction of the content of α-helix and β-sheet respectively. Compared with the other methods currently available, the BP neural network method combined with the amino acid composition and the biased auto-correlation function features can effectively improve the prediction accuracy.展开更多
Nitrogen(N)is an essential plant growth nutrient whose coordinated distribution from source to sink organs is crucial for seed development and overall crop yield.We compared high and low N use efficiency(NUE)Brassica ...Nitrogen(N)is an essential plant growth nutrient whose coordinated distribution from source to sink organs is crucial for seed development and overall crop yield.We compared high and low N use efficiency(NUE)Brassica napus(rapeseed)genotypes.Metabonomics and transcriptomics revealed that leaf senescence induced by N deficiency promoted amino acid allocation from older to younger leaves in the high-NUE genotype at the vegetative growth stage.Efficient source to sink remobilization of amino acids elevated the numbers of branches and pods per plant under a N-deficiency treatment during the reproductive stage.A15N tracer experiment confirmed that more amino acids were partitioned into seeds from the silique wall during the pod stage in the high-NUE genotype,owing mainly to variation in genes involved in organic N transport and metabolism.We suggest that the greater amino acid source-to-sink allocation efficiency during various growth stages in the high-NUE genotype resulted in higher yield and NUE under N deficiency.These findings support the hypothesis that strong amino acid remobilization in rapeseed leads to high yield,NUE,and harvest index.展开更多
The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated accord...The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated according to FAO/WHO amino acid recommendations. The results showed that the mean protein content for WRS was 16.67%, which was 23.21% higher than that for the control. The mean contents (g 100 g^-1 protein) of most amino acids for WRS were lysine 2.74%, threonine 2.83%, phenylalanine 4.17%, isoleucine 3.42%, valine 3.90%, histidine 2.81%, glutamic acid 29.96%, proline 9.12%, glycine 3.59%, alanine 3.37%, and cysteine 1.57%, which were higher than those for the control. The contents of the other 6 amino acids for WRS were lower than those for the control. The materials (Triticum monococcum L., Triticum carthlicum Nevski, and Triticum turgidum L.) contained relatively high concentration of the most deficient EAAs (lysine, threonine, and methionine). Comparing with FAO/WHO amino acid recommendations, the amino acid scores (AAS) of lysine (49.8%), threonine (70.7%), and sulfur-containing amino acids (74.8%) were the lowest, which were considered as the main limiting amino acids in WRS. It was observed that the materials with Triticum urartu Turn. (AA) and Aegilops speltoides Tausch. (SS) genomes had relatively high contents of protein and EAA. The contents of protein (16.91%), phenylalanine (4.78%), isoleucine (3.53%), leucine (6.16%), and valine (4.09%) for the diploid materials were higher than those for the other materials. These results will provide some information for selecting parents in breeding about nutrient quality and utilization of fine gene in wheat.展开更多
The phenotypes of protein and amino acid contents were measured in an F9 recombinant inbred line population derived from a cross between Zhenshan 97B and Delong 208. A total of 48 and 64 QTLs were identified in 2004 a...The phenotypes of protein and amino acid contents were measured in an F9 recombinant inbred line population derived from a cross between Zhenshan 97B and Delong 208. A total of 48 and 64 QTLs were identified in 2004 and 2005, respectively. The contribution of each QTL to the phenotypic variation ranged from 4.0% to 43.7%. Most QTLs co-localized, forming 29 QTL clusters on the chromosomes with three major ones detected in both years, which were mapped on chromosomes 1, 7 and 9, respectively. The two QTL clusters for amino acid content, qAa1 and qAa7, influenced almost all the traits with the allele from Zhenshan 97B, and the third QTL cluster for amino acid content, qAa9, increased the lysine content with the allele from Delong 208. A wide coincidence was found between the QTL detected under this study and the loci involved in amino acid metabolism pathways in nitrogen assimilation and transport, or protein biosynthesis. The results would facilitate the identification of candidate genes and could be used in marker-assisted selection for the favorable allele in rice quality improvement.展开更多
Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate redu...Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate reduction,and ammonium assimilation.Many amino acid transporters(AATs)mediating transfer processes of amino acids have been functionally characterized in Arabidopsis,whereas the function and regulation of the vast majority of AATs in rice(Oryza sativa L.)and other crops remain unknown.In this review,we summarize the current understanding of amino acids in the rhizosphere and in metabolism.We describe their function as signal molecules and in regulating plant architecture,flowering time,and defense against abiotic stress and pathogen attack.AATs not only function in root acquisition and translocation of amino acids from source to sink organs,regulating N uptake and use efficiency,but also as transporters of non-amino acid substrates or as amino acid sensors.Several AAT genes show natural variations in their promoter and coding regions that are associated with altered uptake rate of amino acids,grain N content,and tiller number.Development of an amino acid transfer model in plants will advance the manipulation of AATs for improving rice architecture,grain yield and quality,and N-use efficiency.展开更多
Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gil...Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P &gt; 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.展开更多
On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve i...On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve internal quality of fruit, and excessive nitrogen application can reduce soluble solid and sugar contents of fruit, increase organic acid content, reduce fruit aroma, increase protein and amino acid contents, and increase or reduce vitamin C content. Relevant issues were discussed.展开更多
Background:Low insecticidal protein expression at reproductive organs affect insect resistance in Bt transgenic cotton.In order to enhance flower insecticidal protein expression,the conventional cultivar Sikang1(S1)an...Background:Low insecticidal protein expression at reproductive organs affect insect resistance in Bt transgenic cotton.In order to enhance flower insecticidal protein expression,the conventional cultivar Sikang1(S1)and the hybrid cultivar Sikang3(S3)were used as experimental materials;the applications of selected 5 types of amino acids and 21 types of amino acids were sprayed on the flowers in 2016 and 2017 cotton growing seasons.Results:The flower Bt protein contents increased significantly under the two amino acid treatments in both cultivars,the Bt protein concentration increased by 15.2 to 25.8%compared with the control.However,no significant differences were detected between the two treatments of amino acid application.Increased amino acid and soluble protein contents,enhanced GPT,GOT,protease,and peptidase activities were observed under the amino acid application at the flowering stage.Conclusions:These results suggest that exterior application of the amino acids treatments could bolster the flower insecticidal protein expression.展开更多
Ascobin (compound composed of ascorbic acid and citric acid) is considered one of exogenous protectants which may alleviate the harmful effects of salinity stress. Pot experiments were performed at the screen greenhou...Ascobin (compound composed of ascorbic acid and citric acid) is considered one of exogenous protectants which may alleviate the harmful effects of salinity stress. Pot experiments were performed at the screen greenhouse of National Research Centre, Cairo, Egypt to study the effect of foliar treatment of two cultivars of wheat plant with different concentrations of ascobin (0, 200, 400 and 600 mg/l) on some biochemical parameters, antioxidant enzymes, element contents and amino acid constituents of two cultivars of wheat plant grown under different salinity levels (0.0, 3000 and 6000 mg/l) in 2011/2012 and 2012/2013. Salinity with different concentrations levels increased phenolic compounds contents of the two wheat cultivars. The activities of antioxidant enzymes (SOD, CAT, POD, PPO, AXP and GR) dramatically increased due to salinity stress. Amino acid content was increased in cultivar Sids 1, while the content was decreased in cultivar Giza 168 in all salinity treatments. Increments in the above mentioned parameters compared to the untreated plants at normal and stressed conditions. The magnitude of increments was much more pronounced in response to 600 mg/l of ascobin. It could be concluded that, foliar treatment of wheat cultivars with ascobin could partially alleviate the harmful effect of salinity especially at the lower levels of salinity of the two cultivars of wheat at most of the studied parameters.展开更多
Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid conte...Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid content in hybrid rice cultivar Lingliangyou 268 compared to Luliangyou 996.The results showed that total amino acid content in grains was 9%higher in Lingliangyou 268 than in Luliangyou 996.There was no significant difference in grain nitrogen(N)content between Lingliangyou 268 and Luliangyou 996,while ratio of amino acid to N was 6%higher in Lingliangyou 268 compared to Luliangyou 996.A total of 16 differentially expressed proteins related to amino acid metabolism(e.g.,erythronate-4-phosphate dehydrogenase domain containing protein)were identified in grains between Lingliangyou 268 and Luliangyou 996.The identified proteins were involved in 10 molecular functions.Six of the 10 defined functions were related to binding(heterocyclic compound binding,nucleoside phosphate binding,nucleotide binding,organic cyclic compound binding,protein binding,and small molecule binding)and the other 4 defined functions were catalytic activity,enzyme regulator activity,hydrolase activity,and transferase activity.These results indicate that the higher grain amino acid content in Lingliangyou 268 compared to Luliangyou 996 is attributed to increased efficiency of converting N to amino acid that results from altered expression of proteins related to amino acid metabolism.展开更多
Amino acids are important nitrogen carriers in biomass and entail a broad spectrum of industrial uses,most notably as food additives,pharmaceutical ingredients,and raw materials for bio-based plastics.Attaining detail...Amino acids are important nitrogen carriers in biomass and entail a broad spectrum of industrial uses,most notably as food additives,pharmaceutical ingredients,and raw materials for bio-based plastics.Attaining detailed information in regard to the fragmentation of amino acids is essential to comprehend the nitrogen transformation chemistry at conditions encountered during hydrothermal and pyrolytic degradation of biomass.The underlying aim of this review is to survey literature studies pertinent to the complex structures of amino acids,their formation yields from various categories of biomass,and their fragmentation routes at elevated temperatures and in the aqueous media.Two predominant degradation reactions ensue in the decomposition of amino acids,namely deamination and decarboxylation.Notably,minor differences in structure can greatly affect the fate for each amino acid.Moreover,amino acids,being nitrogen-rich compounds,play pivotal roles across various fields.There is a growing interest in producing varied types and configurations of amino acids.Microbial fermentation appears to a viable approach to produce amino acids at an industrial scale.One innovative method under investigation is catalytic synthesis using renewable biomass as feedstocks.Such a method taps into the inherent nitrogen in biomass sources like chitin and proteins,eliminating the need for external nitrogen sources.This environmentally friendly approach is in line with green chemistry principles and has been gathering momentum in the scientific community.展开更多
基金supported by the National Key Research and Development Project(2022YFD2100902)National Natural Science Foundation of China(32372363)+1 种基金Dalian High-level Talent Innovation Support Program(2021RQ093)the Basic Research Project of Education Department of Liaoning Province(LJKZ0544).
文摘This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in spontaneous fermentation.Low-salt groups had lower pH and higher titratable total acid.In the low-salt groups,the dominant genera were Lactobacillus and Lactococcus,whereas Staphylococcus,Weissella,and Tetragenococcus were dominant in the high-salt groups.Higher total free amino acids and essential amino acids,organic acids,hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups.The RDA analysis revealed that Lactococcus was closely related to product quality,with the S3F10(3%salt and 10%rice f lour)group outperforming the others in the sensory evaluation.Therefore,3%salt and 10%rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.
基金supported by the National Key Research and Development Program of China(2017YFC1103602).
文摘The development of a method for the quantitative determination of the sericin content ratio(SCR)is urgently needed for silk refining and the purification of silk fibroin for biomedical applications.In this work,a series of sericin/fibroin mixed samples with known SCRs were prepared by mixing initial samples of extracted sericin and fibroin from Bombyx mori silk.Significant differences were found in the contents of characteristic hydrophilic amino acids abundant in sericin and hydrophobic amino acids abundant in fibroin,and several linear relation-ships of SCR associated with the content ratios of Ser/Ala,Asp/Ala,Lys/Ala,Asp/Gly and Ser/Gly were estab-lished by amino acid analysis.Subsequently,the linear equation expressing SCR(%)as a function of the Asp to Ala content ratio X(%)was established as SCR=2.5634X−12.5587(R 2=0.9972).The results indicated that the SCR of degummed silks calculated by the equation is more objective and effective than the results obtained by the traditional weight loss method.Our study provides a novel approach for the sensitive and quantitative detection of the sericin content within the detection limit in unknown silks,which can contribute to quality control in the silk production process.
基金partially supported by the USDA National Institute of Food and Agriculture,Hatch project 1020476。
文摘For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating lactating dairy cows' nitrogen losses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattle in the US include variable efficiencies of absorbed essential AA for milk protein production. This first separation from a purely substrate-based system, standing on the old limiting AA theory, recognizes the ability of the cow to alter the metabolism of AA. In this review we summarize a compelling amount of evidence suggesting that AA requirements for milk protein synthesis are based on a demand-driven system. Milk protein synthesis is governed at mammary level by a set of transduction pathways, including the mechanistic target of rapamycin complex 1(mTORC1), the integrated stress response(ISR), and the unfolded protein response(UPR). In tight coordination, these pathways not only control the rate of milk protein synthesis, setting the demand for AA, but also manipulate cellular AA transport and even blood flow to the mammary glands, securing the supply of those needed nutrients. These transduction pathways, specifically mTORC1, sense specific AA, as well as other physiological signals, including insulin, the canonical indicator of energy status. Insulin plays a key role on mTORC1 signaling, controlling its activation, once AA have determined mTORC1 localization to the lysosomal membrane.Based on this molecular model, AA and insulin signals need to be tightly coordinated to maximize milk protein synthesis rate. The evidence in lactating dairy cows supports this model, in which insulin and glucogenic energy potentiate the effect of AA on milk protein synthesis. Incorporating the effect of specific signaling AA and the differential role of energy sources on utilization of absorbed AA for milk protein synthesis seems like the evident following step in nutrient requirement systems to further improve N efficiency in lactating dairy cow rations.
基金This study was funded by grants from the National Natural Science Foundation of China(31872370,31670123)the Fundamental Research Funds for the Central Universities(XDJK2019B014,XDJK2013C097)the Natural Science Foundation Project of CQ CSTC(cstc2018jcyjAX0025).
文摘Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants.In this study,we investigated the effects of adding sodium dichloroacetate(DCA)to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera(PDV)and liver of pigs.To measure nitrogen balance,18 barrows(40±1.0 kg)were fed one of three diets(n=6 per group):18%crude protein(CP,control),13.5%CP(LP),and 13.5%CP+100 mg DCA/kg dry matter(LP-DCA).To measure amino acid metabolism in the PDV and liver,15 barrows(40±1.0 kg)were randomly assigned to one of the three diets(n=5 per group).Four essential amino acids(Lys,Met,Thr,and Trp)were added to the LP diets such that these had amino acid levels comparable to those of the control diet.Results:The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet(P<0.05),without any negative effects on nitrogen retention(P>0.05).There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs(P>0.05).The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets(P<0.05).Conclusion:The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.
文摘The nitrogen (N) metabolic experiments were made to estimate separately amino acid requirements of 4348 weeks old layers for maintenance, for protein accretion to estabolish models to estimate digestible amino acid requirements. The regression relationship of nitrogen retention vs amino acid intake was estimated for each amino acid by giving, at rate of N intake of 091, 052, 015 and 0007gkg-1 body-weight (W075) per d, the semi-synthetic diets was made specially deficient in one amino acid. From the regression coefficients, it was calculated that, for the accretion of 1 g protein, the dietary digestible amino acid requirements were (mg) Thr 631, Val 1004, Met 399, Ile 886, Leu 1143, Phe 632, Lys 870, His 205, Arg 879, Trp 214, Met+Cys 776, and Phe+Tyr 1143. Daily amino acid requirements for N equilibrium were estimated to be (mgkg-1W075 per day) Thr 506, Val 747, Met 303, ILe 667 Leu 814, Phe 448, Lys 605 His 147, Arg 739 ,Trp 173, Met+Cys 586, and Phe+Tyr 839 The dietary degestible amino acid patterns for protein accretion and N equilibrium were also proposed. The models of estimating digestible amino acid requirements for the different productions were developed.
基金the National Natural Science Foundation of China(No.29772033)
文摘In this paper amino acids synthesis in aqueous solution induced by ion implantation, which was possibly ubiquitous on primitive Earth, is investigated. As a discharge using a graphite rod as the anode under a nitrogen atmosphere was performed against ammonia water, it was found that three kinds of amino acids were produced. They were glycine, serine and alanine. By introducing ion implantation into the carboxylate solution, ammonia and amino acids were also formed via nitrogen deposition/fixation. Another isotopic experiment showed that both OH and H radicals played a crucial role in the arc-discharge-promoted reactions in aqueous solution Therefore, we believe that the impact of ions in the original atmospheric conditions might have functioned as a promoter in the chemical origin and evolution of life.
基金the Natural Sci-ence Foundation of HebeiProvince, No. C2005000840
文摘BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids (EAA) during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine (L-NA) reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE: By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid (GABA) in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN: A randomized and controlled experiment SETTING : Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS: A total of 42 male healthy SD rats (grade Ⅱ, weighting 250-300 g) were provided by the Experimental Animal Center of Hebei Province (Certification: 04036). Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride (TTC) were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS: The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups: sham-operated group (n = 6), ischemic group (n = 18), L-NA group (n = 18). The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups (n = 6 for each): drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion (MCAO) respectively. L-NA (20 mg/kg, ip) was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain (IV%) in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett's test. MAIN OUTCOME MEASURES: (1) The volume of cerebral infarction; (2) The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS : All 42 rats were involved in the final analysis. (1) Infarcted volume: Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was (20.13±3.59)% and (23.12±5.84)% in L-NA group, which was not similar to that in ischemic group [(22.10±3.98)%, (25.38± 5.37)%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [(26.11±3.55)% and (37.15±3.58)%, P 〈 0.01]. Changes of amino acid content: At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group ( P〈 0.05-0.01). However, contents in L-NA group were similar to those in ischemic group (P 〉 0.05). At 12 hours after ischemia, the contents of aspartate [(0.21 ±0.06), (0.36±0.05), (0.29±0.12) mg/g] and glutamate [(0.55±0.06), (0.78±0.10), (0.52±0.10) mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [(0.49±0.17), (0.63± 0.03), (0.51±0.15) mg/g; (0.98±0.30), (1.15±0.15), (0.93±0.15) mg/g, P〈 0.05-0.01]. Glycine in hippocampus was (0.40±0.07) mg/g, which was higher than that in ischemic group [(0.21±0.07) mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was (0.93±0.10), (0.62±0.12) and (0.81 ±0.10) mg/g, respectively, which was higher than that in ischemic group [(0.60±0.08), (0.37±0.17), (0.59±0.10) mg/g, P 〈 0.05-0.01]. CONCLUSION : It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.
基金National Research Institute for Forestry,Crops and Livestock for the financial support given to this research project
文摘Background:To compare the nutritional value and digestibility of five quality protein maize(QPM) hybrids to that of white and yellow maize,two experiments were carried out in growing pigs.In experiment 1,the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize.In experiment 2,the apparent and standardized ileal digestibility(AID and SID,respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize.In both experiments,the comparisons were conducted using contrasts.Results:The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids(P 〈 0.05) than in the pigs fed white or yellow maize.Energy digestibility(P 〈 0.001) and metabolizability(P 〈 0.01) were higher in the pigs fed the white and yellow maize diets than in those fed the QPM diets.The AID of lysine was higher(P〈 0.01) in the QPM diets than in the white and yellow maize.The AIDs of leucine,isoleucine,valine,phenylalanine,and methionine were lower in the QPM diets than those of maize(white and yellow)(all P 〈 0.05).Maize(white and yellow) had greater SIDs of leucine,isoleucine,valine,phenylalanine,glutamic acid,serine,alanine,tyrosine,and proline(P 〈 0.05).Conclusions:Based on these results,it was concluded that QPM had a lower metabolizable energy content and a higher amount of digestible lysine than normal maize.
基金Supported by Scientific Research Fund from Department of Education of Yunnan Province(2012Z134C)~~
文摘[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field (HPEF). [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.
文摘The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by using the independent non-homologous protein database. It is shown that the average absolute errors for resubstitution test are 0.070 and 0.068 with the standard deviations 0.049 and 0.047 for the prediction of the content of α-helix and β-sheet respectively. For cross-validation test, the average absolute errors are 0.075 and 0.070 with the standard deviations 0.050 and 0.049 for the prediction of the content of α-helix and β-sheet respectively. Compared with the other methods currently available, the BP neural network method combined with the amino acid composition and the biased auto-correlation function features can effectively improve the prediction accuracy.
基金supported by the National Natural Science Foundation of China(U21A20236,32072664)Natural Science Foundation of Hunan Province(2021JJ0004)China Agriculture Research System,and the Hunan Postgraduate Scientific Research Innovation Project(CX20190505)。
文摘Nitrogen(N)is an essential plant growth nutrient whose coordinated distribution from source to sink organs is crucial for seed development and overall crop yield.We compared high and low N use efficiency(NUE)Brassica napus(rapeseed)genotypes.Metabonomics and transcriptomics revealed that leaf senescence induced by N deficiency promoted amino acid allocation from older to younger leaves in the high-NUE genotype at the vegetative growth stage.Efficient source to sink remobilization of amino acids elevated the numbers of branches and pods per plant under a N-deficiency treatment during the reproductive stage.A15N tracer experiment confirmed that more amino acids were partitioned into seeds from the silique wall during the pod stage in the high-NUE genotype,owing mainly to variation in genes involved in organic N transport and metabolism.We suggest that the greater amino acid source-to-sink allocation efficiency during various growth stages in the high-NUE genotype resulted in higher yield and NUE under N deficiency.These findings support the hypothesis that strong amino acid remobilization in rapeseed leads to high yield,NUE,and harvest index.
基金supported by the National Natural Science Foundation of China(30671270)the National 863 Program of China(2006AA 10Z1E9)the Project for Improved Variety of Shandong Provice,China(Lu Nong Liang Zhong Zi[2006]No.6).
文摘The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated according to FAO/WHO amino acid recommendations. The results showed that the mean protein content for WRS was 16.67%, which was 23.21% higher than that for the control. The mean contents (g 100 g^-1 protein) of most amino acids for WRS were lysine 2.74%, threonine 2.83%, phenylalanine 4.17%, isoleucine 3.42%, valine 3.90%, histidine 2.81%, glutamic acid 29.96%, proline 9.12%, glycine 3.59%, alanine 3.37%, and cysteine 1.57%, which were higher than those for the control. The contents of the other 6 amino acids for WRS were lower than those for the control. The materials (Triticum monococcum L., Triticum carthlicum Nevski, and Triticum turgidum L.) contained relatively high concentration of the most deficient EAAs (lysine, threonine, and methionine). Comparing with FAO/WHO amino acid recommendations, the amino acid scores (AAS) of lysine (49.8%), threonine (70.7%), and sulfur-containing amino acids (74.8%) were the lowest, which were considered as the main limiting amino acids in WRS. It was observed that the materials with Triticum urartu Turn. (AA) and Aegilops speltoides Tausch. (SS) genomes had relatively high contents of protein and EAA. The contents of protein (16.91%), phenylalanine (4.78%), isoleucine (3.53%), leucine (6.16%), and valine (4.09%) for the diploid materials were higher than those for the other materials. These results will provide some information for selecting parents in breeding about nutrient quality and utilization of fine gene in wheat.
基金supported by grants from the National Program on the Development of Basic Research (Grant No. 2011CB100200)the National Program of High Technology Development (Grant No. 2010AA101801)+1 种基金the National Program of Plant Transgenic Breeding (Grant No. 2008ZX08009-003)the National Natural Science Foundation of China (Grant No. 30671114)
文摘The phenotypes of protein and amino acid contents were measured in an F9 recombinant inbred line population derived from a cross between Zhenshan 97B and Delong 208. A total of 48 and 64 QTLs were identified in 2004 and 2005, respectively. The contribution of each QTL to the phenotypic variation ranged from 4.0% to 43.7%. Most QTLs co-localized, forming 29 QTL clusters on the chromosomes with three major ones detected in both years, which were mapped on chromosomes 1, 7 and 9, respectively. The two QTL clusters for amino acid content, qAa1 and qAa7, influenced almost all the traits with the allele from Zhenshan 97B, and the third QTL cluster for amino acid content, qAa9, increased the lysine content with the allele from Delong 208. A wide coincidence was found between the QTL detected under this study and the loci involved in amino acid metabolism pathways in nitrogen assimilation and transport, or protein biosynthesis. The results would facilitate the identification of candidate genes and could be used in marker-assisted selection for the favorable allele in rice quality improvement.
基金supported by the National Natural Science Foundation of China(31930101)National Key Research and Development Program of China(2016YFD0100700)+1 种基金Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization and the Innovative Research Team Development Plan of the Ministry of Education of China(IRT17R56 and KYT201802)the Priority Academic Program Development from Jiangsu Government。
文摘Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate reduction,and ammonium assimilation.Many amino acid transporters(AATs)mediating transfer processes of amino acids have been functionally characterized in Arabidopsis,whereas the function and regulation of the vast majority of AATs in rice(Oryza sativa L.)and other crops remain unknown.In this review,we summarize the current understanding of amino acids in the rhizosphere and in metabolism.We describe their function as signal molecules and in regulating plant architecture,flowering time,and defense against abiotic stress and pathogen attack.AATs not only function in root acquisition and translocation of amino acids from source to sink organs,regulating N uptake and use efficiency,but also as transporters of non-amino acid substrates or as amino acid sensors.Several AAT genes show natural variations in their promoter and coding regions that are associated with altered uptake rate of amino acids,grain N content,and tiller number.Development of an amino acid transfer model in plants will advance the manipulation of AATs for improving rice architecture,grain yield and quality,and N-use efficiency.
基金financially supported by the National Key Basic Research Program of China (2012CB124702, 2013CB127302)National Natural Science Foundation of China (31272452)the National Key Technology R&D Program of China (2011BAD26B01)
文摘Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P &gt; 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.
基金Supported by Key Technology R&D Program of Hebei Province(16226313D-3)Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2019-3-5-1,F18C10001,2018100201)Shijiazhuang Comprehensive Experimental Station of China Agro-industry(Peach Industry)Research System(CARS-31-Z-2)
文摘On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve internal quality of fruit, and excessive nitrogen application can reduce soluble solid and sugar contents of fruit, increase organic acid content, reduce fruit aroma, increase protein and amino acid contents, and increase or reduce vitamin C content. Relevant issues were discussed.
基金The Projects#2017YFD0201306,#2018YFD0100406 supported by the National Key R&D Program of China#31671613 supported by National Natural Science Foundation of China+1 种基金Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)Project#2016PCTS-1 supported by the Chinese academy of agricultural sciences’engineering science and technology innovation fund
文摘Background:Low insecticidal protein expression at reproductive organs affect insect resistance in Bt transgenic cotton.In order to enhance flower insecticidal protein expression,the conventional cultivar Sikang1(S1)and the hybrid cultivar Sikang3(S3)were used as experimental materials;the applications of selected 5 types of amino acids and 21 types of amino acids were sprayed on the flowers in 2016 and 2017 cotton growing seasons.Results:The flower Bt protein contents increased significantly under the two amino acid treatments in both cultivars,the Bt protein concentration increased by 15.2 to 25.8%compared with the control.However,no significant differences were detected between the two treatments of amino acid application.Increased amino acid and soluble protein contents,enhanced GPT,GOT,protease,and peptidase activities were observed under the amino acid application at the flowering stage.Conclusions:These results suggest that exterior application of the amino acids treatments could bolster the flower insecticidal protein expression.
文摘Ascobin (compound composed of ascorbic acid and citric acid) is considered one of exogenous protectants which may alleviate the harmful effects of salinity stress. Pot experiments were performed at the screen greenhouse of National Research Centre, Cairo, Egypt to study the effect of foliar treatment of two cultivars of wheat plant with different concentrations of ascobin (0, 200, 400 and 600 mg/l) on some biochemical parameters, antioxidant enzymes, element contents and amino acid constituents of two cultivars of wheat plant grown under different salinity levels (0.0, 3000 and 6000 mg/l) in 2011/2012 and 2012/2013. Salinity with different concentrations levels increased phenolic compounds contents of the two wheat cultivars. The activities of antioxidant enzymes (SOD, CAT, POD, PPO, AXP and GR) dramatically increased due to salinity stress. Amino acid content was increased in cultivar Sids 1, while the content was decreased in cultivar Giza 168 in all salinity treatments. Increments in the above mentioned parameters compared to the untreated plants at normal and stressed conditions. The magnitude of increments was much more pronounced in response to 600 mg/l of ascobin. It could be concluded that, foliar treatment of wheat cultivars with ascobin could partially alleviate the harmful effect of salinity especially at the lower levels of salinity of the two cultivars of wheat at most of the studied parameters.
文摘Improving grain amino acid content of rice(Oryza sativa L.)is essential for the health of consumers.This study was conducted to identify the physiological processes that contribute to the higher grain amino acid content in hybrid rice cultivar Lingliangyou 268 compared to Luliangyou 996.The results showed that total amino acid content in grains was 9%higher in Lingliangyou 268 than in Luliangyou 996.There was no significant difference in grain nitrogen(N)content between Lingliangyou 268 and Luliangyou 996,while ratio of amino acid to N was 6%higher in Lingliangyou 268 compared to Luliangyou 996.A total of 16 differentially expressed proteins related to amino acid metabolism(e.g.,erythronate-4-phosphate dehydrogenase domain containing protein)were identified in grains between Lingliangyou 268 and Luliangyou 996.The identified proteins were involved in 10 molecular functions.Six of the 10 defined functions were related to binding(heterocyclic compound binding,nucleoside phosphate binding,nucleotide binding,organic cyclic compound binding,protein binding,and small molecule binding)and the other 4 defined functions were catalytic activity,enzyme regulator activity,hydrolase activity,and transferase activity.These results indicate that the higher grain amino acid content in Lingliangyou 268 compared to Luliangyou 996 is attributed to increased efficiency of converting N to amino acid that results from altered expression of proteins related to amino acid metabolism.
基金funding from the National Water and Energy Center at the United Arab Emirates University(UAEU)through the 12R124 grant.
文摘Amino acids are important nitrogen carriers in biomass and entail a broad spectrum of industrial uses,most notably as food additives,pharmaceutical ingredients,and raw materials for bio-based plastics.Attaining detailed information in regard to the fragmentation of amino acids is essential to comprehend the nitrogen transformation chemistry at conditions encountered during hydrothermal and pyrolytic degradation of biomass.The underlying aim of this review is to survey literature studies pertinent to the complex structures of amino acids,their formation yields from various categories of biomass,and their fragmentation routes at elevated temperatures and in the aqueous media.Two predominant degradation reactions ensue in the decomposition of amino acids,namely deamination and decarboxylation.Notably,minor differences in structure can greatly affect the fate for each amino acid.Moreover,amino acids,being nitrogen-rich compounds,play pivotal roles across various fields.There is a growing interest in producing varied types and configurations of amino acids.Microbial fermentation appears to a viable approach to produce amino acids at an industrial scale.One innovative method under investigation is catalytic synthesis using renewable biomass as feedstocks.Such a method taps into the inherent nitrogen in biomass sources like chitin and proteins,eliminating the need for external nitrogen sources.This environmentally friendly approach is in line with green chemistry principles and has been gathering momentum in the scientific community.