Objectives:Cold-acclimated organisms accumulate low molecular weight organic solutes such as sugar alcohols and soluble sugars.This study aimed to compare the efficacy of five sugar alcohols and 14 soluble sugars in s...Objectives:Cold-acclimated organisms accumulate low molecular weight organic solutes such as sugar alcohols and soluble sugars.This study aimed to compare the efficacy of five sugar alcohols and 14 soluble sugars in stabilizing proteins under freezing,freeze-drying,and air-drying stresses.Materials and methods:Glucose-6-Phosphate Dehydrogenase(G6PD)was used as the model protein.G6PD solutions with or without sugar alcohols and or sugars were subjected to freezing,freeze-drying,and air-drying stresses.The recovery of G6PD activity was measured to evaluate the protective efficacy of these compounds.Results:Without stabilizers,freezing G6PD at-20℃ or-80℃ reduced enzyme activity by around 24%,while freeze-drying or air-drying reduced activity by 90%-95%.Among the five sugar alcohols tested,pinitol,quebrachitol and sorbitol stabilized G6PD,whereas mannitol and myo-inositol destabilized it.Among 14 soluble sugars,trehalose and raffinose showed slightly lower enzyme recovery after repeated freeze-thaw cycles at-20℃.Most soluble sugars(except arabinose and xylose)protected G6PD during freeze-drying,with di-,tri-,and oligosaccharides generally outperforming monosaccharides.During air-drying,lactose was ineffective,while arabinose,galactose,and xylose were detrimental.Conclusion:The study highlights the diverse mechanisms of sugar alcohols and sugars in protein stabilization under stress,offering insights for formulating stable protein-and cell-based drugs.展开更多
Sugars are one of the major metabolites and are essential for nucleic acid synthesis and energy production.In addition,sugars can act as signaling molecules.To study sugar signaling at the systemic level,there is an u...Sugars are one of the major metabolites and are essential for nucleic acid synthesis and energy production.In addition,sugars can act as signaling molecules.To study sugar signaling at the systemic level,there is an urgent need to systematically identify sugar-sensing proteins and nucleic acids.I propose the terms“swodkoreceptor”and“swodkocrine signaling,”derived from the Polish word“slodki”meaning“sweet,”to comprise all sugar-sensing proteins and signaling events,respectively,regardless of their cellular location and signaling domains.This proposal is intended to facilitate the inclusion of proteins such as the Escherichia coli Lac I repressor as an allolactose receptor,human glucokinase regulatory protein(GCKR)as a fructose receptor,and other sugar-binding based allosterically regulated enzymes and transcription factors as sugar-sensing receptors.In addition,enzyme-interacting proteins whose interaction state is regulated by sugar binding have also been proposed as sugar receptors.The systemic study of protein-and nucleic-acid-based swodkoreceptors may help to identify organelle-specific swodkoreceptors and to also address receptor duality.The study of intra-and inter-organism swodkocrine signaling and its crosstalk with gasocrine signaling may help to understand the etiology of diseases due to dysregulation in sugar homeostasis and signaling.展开更多
The content of soluble sugars is a vital parameter that indicates the quality of fleshy fruits such as apple(Malus domestica Borkh.).Studying the patterns of accumulation of soluble sugars and regulatory mechanisms as...The content of soluble sugars is a vital parameter that indicates the quality of fleshy fruits such as apple(Malus domestica Borkh.).Studying the patterns of accumulation of soluble sugars and regulatory mechanisms associated with fruit development is crucial for breeding improved fruit varieties.Here,we report that MdCIbHLH1,a low temperature-induced b HLH transcription factor,inhibits the accumulation of soluble sugars by regulating sugar-metabolizing enzyme activities,photosynthetic performance,and the expression of sugar-related genes in developing apple fruits.MdCIbHLH1 inhibits MdFBP and MdPEPCK expression,thus blocking the conversion of acids to sugars in apple fruits.We also discovered that MdCIbHLH1 decreases the photosynthetic rate and carbohydrate accumulation in apple leaves.Our results suggest that soluble sugar accumulation in apple fruits is influenced by multiple factors,including metabolic status,photosynthesis,and carbohydrate allocation.MdCIbHLH1 is critically involved in controlling the accumulation of soluble sugars by coordinating carbohydrate synthesis and allocation,thus influencing sugar transport and its metabolism during the development of apple fruits.展开更多
Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic...Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H^(2)) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.展开更多
Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most ...Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.展开更多
Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes fou...Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes four key hypotheses explaining sugar-mediated protection of dehydrated bilayers:the Water Replacement Hypothesis(WRH),Hydration Force Hypothesis(HFH),Headgroup Bridging Hypothesis(HBH),and Vitrification Hypothesis(VH).We argue that these mechanisms are not mutually exclusive but instead operate synergistically under different cellular contexts.We propose that these hypotheses are not mutually exclusive but likely operate under different cellular contexts.Future studies should prioritize the development of biologically realistic membrane models-incorporating diverse lipids,proteins,and asymmetric leaflets-to elucidate the exact roles and mechanisms of sugars in membrane stabilization.Such advancements will enhance our understanding of anhydrobiosis and inform cryopreservation strategies for mammalian cells.展开更多
The compositions and contents of soluble sugars highly determine the flavor and quality of fleshy fruits.In the present study,we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus...The compositions and contents of soluble sugars highly determine the flavor and quality of fleshy fruits.In the present study,we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus enhanced sucrose concentration while decreased fructose and glucose concentration in transgenic apple calli and ripening tomato fruits.To comprehensively understand the effects of the MdWRKY126 on the content of various soluble sugars in apple and tomato fruits,enzyme activities and related essential genes associated with the sugar metabolism and transportation pathway in MdWRKY126-overrexpressed apple and tomato lines were analyzed.The results indicated that the overexpression of MdWRKY126 upregulated sucrose phosphate synthase(SPS)activity and the gene expression levels of SPS and sucrose transporter SUT,which was conducive to a large accumulation of sucrose in fruit cells.Meanwhile,MdWRKY126 overexpression downregulated the activity of enzymes involved in sucrose decomposition including cell wall invertase(CWINV),sucrose synthase(SUSY)and the corresponding gene expressions,as well as inhibited the expression levels of hexose transporter(HTs)and tonoplast sugar transporter(TSTs)that transport hexose into vacuoles,resulting in a reduced hexose level in apple calli and tomato fruit.These findings enrich our understanding of the metabolism and regulation of soluble sugars in apple fruits.展开更多
In Shandong,the special folk activity of blowing sugar figures during the Spring Festival has a long history.It is said that this skill can be traced back to the Tang Dynasty.At that time,as sugar-making technology im...In Shandong,the special folk activity of blowing sugar figures during the Spring Festival has a long history.It is said that this skill can be traced back to the Tang Dynasty.At that time,as sugar-making technology improved a lot,smart folk craftsmen(工匠)began to use sugar to create various small items.Once heated,sugar turns soft and malleable(可塑的).展开更多
Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects ...Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects the quality.The hormone abscisic acid(ABA)plays a crucial role in plant responses to abiotic stresses.Previous studies showed that exogenous ABA promotes floret closure,although the molecular mechanisms and effects of endogenous ABA on floret closure remain unknown.In this study,the effect of endogenous ABA on floret closure and the molecular mechanism by which ABA promotes floret closure through sugar transporters were investigated by changing the expression levels of OsNCED3 and OsPYL1 in rice.The results showed that overexpression(OE)-OsNCED3increased the endogenous ABA level of florets.Florets closed 5.91 min earlier and OsNCED3 gene knockout line delayed the closure of florets by 5.08 min compared with the wild type.In addition,OsPYL1 regulated the endogenous ABA content and changed the sensitivity to ABA such that the floret closure times for OE and CRISPR-Cas9(CR)were 9.84 min earlier and 12.78 min later,respectively,resulting in an increase in the split husk rate to 15.4%.The gene expression levels of some sugar transporters(STs)changed.The OsPYL1 and OsSWEET4proteins could interact on the cell membrane.These results indicate that ABA promotes the closure of rice florets and the enhanced sensitivity to ABA promotes this effect even more.The molecular mechanism is mainly related to downstream sugar transporters that respond to the ABA signaling pathway,especially OsSWEET4.展开更多
For the purpose of satisfying high demands for taste,color,flavor,and storage of meat products,water retention agents(WRAs)play an important role.Phosphate has been widely used as an attractive functional material for...For the purpose of satisfying high demands for taste,color,flavor,and storage of meat products,water retention agents(WRAs)play an important role.Phosphate has been widely used as an attractive functional material for water retention in current practical applications.However,excessive phosphate addition and longterm consumption may be harmful impacts on health and the environment.Therefore,it is vital to develop safe and efficient phosphate-free WRAs for further improving water-holding capacity(WHC)efficacy and edible safety,especially in meat products.In particular,sugar water retention agents(SWRAs)are increasingly popular because of their perfect safety,excellent WHC,and superior biological properties.This review discusses the inducements and mechanisms underlying water loss in meat products.In addition,we focused on the research progresses and related mechanisms of SWRAs in the WHC of meat products and its unique biological functions,as well as the extraction technology.Finally,the future application and development of SWRA were prospected.展开更多
The early responsive to dehydration-like(ERDL or ERD)subfamily,subclade within the monosaccharide transporter(MST)superfamily,is crucial in the regulation of growth and seed yield in Arabidopsis.Here,we identified Os ...The early responsive to dehydration-like(ERDL or ERD)subfamily,subclade within the monosaccharide transporter(MST)superfamily,is crucial in the regulation of growth and seed yield in Arabidopsis.Here,we identified Os ERD5 as an At ERDL6 homologue and explored the function of Os ERD5.We found that Os ERD5 overexpression significantly enhanced the tiller number and grain yield of rice.Os ERD5 was widely expressed in aboveground tissues,encoded a tonoplast-localized protein,and exhibited transport activities for fructose,glucose and mannose when expressed in yeast.Expression character assay revealed that Os ERD5 mediated hexose efflux across tonoplasts and participated in maintaining the diurnal rhythm-regulated intracellular hexose homeostasis.Additional physiological and molecular evidence showed that Os ERD5 overexpression promoted vacuolar glucose efflux,enhanced sucrose synthesis and transport,increased sugar content in the shoot base,and promoted rice tillering by activating the synthesis of cytokinin simultaneously repressing strigolactone and gibberellin signaling.This study elucidates the function of Os ERD5 and the mechanism underlying the overexpression of Os ERD5 increasing rice tillering and yield.展开更多
Drought is becoming a common threat to crop production.Identifying and utilizing excellent droughtresistant genes is crucial to combating this stress and ensuring global food security by developing droughtresistant cr...Drought is becoming a common threat to crop production.Identifying and utilizing excellent droughtresistant genes is crucial to combating this stress and ensuring global food security by developing droughtresistant crop varieties.Although sugar transporters are involved in stress tolerance in many plants,the sugar transporter gene family of Tartary buckwheat has yet to be systematically analyzed.This study identified 140 sugar transporter genes from the‘Pinku'Tartary buckwheat genome and classified them into 10 subfamilies.Structural analysis showed that subfamily SGB/pGlcT had the highest number of introns compared to other subfamilies,and abundant abiotic stress-related cis-acting elements existed in the promoter region.Collinear analysis revealed relatively ancient genes FtSUT7,FtSTP28,FtPLT1,and FtINT2.The expression of sugar transporter genes was screened under various abiotic stresses,which revealed the association of stress tolerance with different sugar transporter genes,i.e.,FtERD23,FtINT2,FtpGlcT2,and FtSTP27.Further,we observed that the overexpression of FtERD23 maintains osmotic pressure through glucose transport,which may enhance drought stress tolerance.Moreover,gene co-expression analyses using weighted gene coexpression network analysis(WGCNA)and fuzzy c-means algorithm(FCMA)identified six transcription factors that may regulate FtERD23 expression and are involved in plant drought tolerance.Our systematic analysis provides a theoretical basis for the further functional characterization of sugar transporter genes to improve drought tolerance in Tartary buckwheat and its related species.展开更多
Sugar cane juice is a popular refreshing drink in most part of Bangladesh. It has great taste and health benefits;also it is available most of the public places at reasonable prices which consumed by road side custome...Sugar cane juice is a popular refreshing drink in most part of Bangladesh. It has great taste and health benefits;also it is available most of the public places at reasonable prices which consumed by road side customers including general public, shopping personals, tourists, students. In our country, street vendors crushing sugarcane between roller crusher and sold without any heat treatment or preservative, also served with or without added ice and lemon juice. The study aimed to identify and compare the physico-chemical and microbial quality of sugarcane juice. The chemical qualities of juices including moisture, P<sup>H</sup>, ash, total soluble solid, total sugar, reducing sugar and titrable acidity were found slightly different in Mymensingh, Gazipur and Narayangonj areas. The highest and lowest value of moisture, ash, P<sup>H</sup>, total soluble solids, total sugar, reducing sugar and titrable acidity were found in 84.33% - 79.26% (Gazipur-Mymensingh), 0.57% - 0.04% (Mymensingh-Gazipur), 5.9 - 2.9 (Gazipur-Narayangonj), 17.48% - 4.98% (Mymensingh-Narayangonj), 21.9% - 6.56% (Mymensingh-Gazipur), 3.7 - 2.1 (Gazipur-Mymensingh) and 0.523% - 0.007% (Narayangonj-Gazipur) respectively. For microbiological analysis, the total viable count of sugar cane juice in Mymensingh, Gazipur and Narayangonj were ranged from 0.6 × 10<sup>5</sup> - 43.6 × 10<sup>5</sup> cfu/ml, 4.6 × 10<sup>5</sup> - 21.6 × 10<sup>5</sup> cfu/ml and 3.6 × 10<sup>5</sup> - 36.6 × 10<sup>5</sup> cfu/ml respectively, where the permitted value is 1.0 × 10<sup>4</sup> cfu/ml, whereas the total coliform count was ranged from 0.4 × 10<sup>5</sup> - 6.4 × 10<sup>5</sup> cfu/ml, 0.6 × 10<sup>5</sup> - 8.4 × 10<sup>5</sup> cfu/ml and 0.00 - 8.4 × 10<sup>5</sup> cfu/ml, where the permitted value is 100 cfu/ml and total fungal count was ranged from 5.5 × 10<sup>5</sup> - 56.5 × 10<sup>5</sup> cfu/ml, 21.5 × 10<sup>5</sup> - 54.5 × 10<sup>5</sup> cfu/ml and 32.5 × 10<sup>5</sup> - 68.5 × 10<sup>5</sup> cfu/ml, where the permitted value is 1000 cfu/ml. According to the Gulf standard, the microbiological parameters of all the collected sugar cane juice were out of the permitted standards, so that a serious health outbreak can be caused anytime.展开更多
In order to enrich the germplasm resources of sugar beet resistant to damping-off and explore their physiological mechanisms in response to the disease,the previously isolated and purified Rhizoctonia solani were empl...In order to enrich the germplasm resources of sugar beet resistant to damping-off and explore their physiological mechanisms in response to the disease,the previously isolated and purified Rhizoctonia solani were employed to inoculate 112 main sugar beet varieties.The emergence rate,morbidity,mortality rate,peroxidase(POD)activity were investigated.The results showed that 112 main sugar beet varieties were divided into six levels according to the incidence rate:disease resistance(≤40%),high resistance(40%<to≤50%),medium resistance(50%<to≤60%),medium sensitivity(60%<to≤70%),high sensitivity(70%<to≤80%)and disease susceptibility(>80%).On the basis of this classification,5 disease resistant varieties,9 highly resistant varieties,9 moderately resistant varieties,20 moderately susceptible varieties,21 highly susceptible varieties,and 48 susceptible varieties were classified.Moreover,it was found that POD of disease-resistant varieties was significantly different from that of susceptible varieties.This approach provides a theoretical basis for the rational breeding of sugar beet varieties resistant to sugar beet damping-off,and have certain reference value for the development of the domestic sugar beet planting industry.展开更多
A general situation of the sugar beet industry and business in the European Union(EU) has been presented. It included the quotas of sugar production there, its prices and changes on the market. The latest sugar produc...A general situation of the sugar beet industry and business in the European Union(EU) has been presented. It included the quotas of sugar production there, its prices and changes on the market. The latest sugar production data in the world was also given. The main companies carrying out activities on the Polish sugar and sugar beet seeds were also presented.New circumstances after liberating the sugar market in the EU in October, 2017, were also presented. Nowadays, Poland has been a great potential country for further technological progress in agricultural holdings and growing performance in sugar processing and production industry. As food export from Poland increases, it will be followed by increasing use of sugar. Examples are given to improve sugar beet productivity.展开更多
Crop yield depends on biomass,which is primarily associated with photosynthesis.We previously demonstrated that two photorespiratory bypasses,i.e.,GOC(glycolate oxidase+oxalate oxidase+catalase)and GCGT(glycolate oxid...Crop yield depends on biomass,which is primarily associated with photosynthesis.We previously demonstrated that two photorespiratory bypasses,i.e.,GOC(glycolate oxidase+oxalate oxidase+catalase)and GCGT(glycolate oxidase+catalase+glyoxylate carboligase+tartronic semialdehyde reductase),significantly increased photosynthesis,biomass,and grain yield,but decreased seed-setting rates in rice.This study explored the underlying mechanism of how elevated photosynthetic efficiency impacted the seed-setting.First,pollen germination assessed in vivo and in vitro,revealed a reduced germination rate in GCGT rice.Subsequent analysis found that photosynthates highly accumulated in the leaves and stems;sucrose and soluble sugar levels were increased but the starch level was reduced in the anthers.Uridine diphosphate glucose(UDP-Glc)was increased but uridine diphosphate galactose(UDP-Gal)was unaltered,thus causing an imbalance in the UDP-Glc/UDP-Gal ratio in GCGT anthers.Most anthers in GCGT plants had two locules in contrast to four in the wild-type(WT).Pollen tapetum was developmentally abnormal,and genes related to sucrose synthesis,transport,and tapetal programmed cell death(PCD)were upregulated,whereas those involved in starch synthesis and conversion were downregulated in GCGT anthers.Taken together,our results demonstrated that an increase in sugar content was the primary factor causing reduced seed-setting rates in high photosynthetic efficiency rice,during which metabolic disorder of sugars and UDP sugar imbalance in anthers lead to impaired pollen fertility.展开更多
Background The associations between sugary beverages and genetic predisposition to depression risk remain unclear.Aims This study aimed to investigate the associations of sugar-sweetened beverages(SSBs),artificially s...Background The associations between sugary beverages and genetic predisposition to depression risk remain unclear.Aims This study aimed to investigate the associations of sugar-sweetened beverages(SSBs),artificially sweetened beverages(ASBs)and natural juices(NJs)with depression and to assess whether these associations were modified by genetic predisposition.Methods We used data from the UK Biobank of 180599 individuals aged 39-72 years who were depression-free at baseline.Dietary intake of SSBs,ASBs and NJs was accessed by a 24-hour dietary recall between 2009 and 2012.The Polygenic Risk Score for depression was estimated and categorised as low(lowest tertile),intermediate(tertile 2)and high(highest tertile),.Cox proportional hazard and substitution models were conducted to evaluate hazard ratios(HRs)and 95%Cls.Results Over the 12-year follow-up,4915 individuals developed depression.Higher consumption(>2 units/day)of SSBs(HR:1.26,95%CI 1.12 to 1.43)and ASBs(HR:1.40,95%Cl 1.23 to 1.60)were both associated with an increased risk of depression.However,moderate consumption(>0-1 units/day)of NJs was associated with a lower risk of depression(HR:0.89,95%CI 0.83 to 0.95).Furthermore,genetic predisposition did not modify these associations(p interaction>0.05).In substitution models,the HRs for depression risk were 0.94(95%CI 0.89 to 0.99)and 0.89(95%CI 0.85 to 0.94),respectively,when 1 unit/day of SSBs or ASBs was replaced by an equivalent intake of NJs.Conclusions Higher consumption of SSBs and ASBs was associated with an increased risk of depression;in contrast,moderate consumption of NJs was inversely associated with a lower risk of depression.In theory,substituting SSBs and ASBswith NJs would suppose a reduction of depression risk.展开更多
With the advancement of agricultural mechanization,soil compaction has become a serious environmental problem.Soil compaction can increase soil bulk density and firmness,reduce porosity and permeability,and deteriorat...With the advancement of agricultural mechanization,soil compaction has become a serious environmental problem.Soil compaction can increase soil bulk density and firmness,reduce porosity and permeability,and deteriorate soil structure,ultimately inhibit sugar beet growth and reduce both root yield and sugar content.However,few farmers recognize the link between soil compaction and these adverse effects.Soil compaction has a cumulative effect,with significant differences observed in the vertical range of compaction accumulation.The most significant soil compaction occurs in the topsoil of 0-10 cm,and the influence depth can reach 70 cm,but it is small in deep soil,and the inflection point is at a soil depth of 10 cm.The degree of soil compaction is related to soil type,water content,tractor shaft load,tyre type,tyre pressure and operation speed,etc.Therefore,in the production process of sugar beet,it is advisable to avoid high-humidity operations,use low pressure tyres,reduce the number of tractor-units passes over the farmland,and implement agricultural and agronomic measures to minimize soil compaction.These practices will help protect the soil environment and ensure sustainable production of sugar beets.展开更多
The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and...The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date.展开更多
Sugar aminotransferases(SATs)catalyze the installation of chiral amines onto specific keto sugars,pro-ducing bioactive amino sugars.Their activity has been utilized in artificial reactions,such as using the SAT WecE t...Sugar aminotransferases(SATs)catalyze the installation of chiral amines onto specific keto sugars,pro-ducing bioactive amino sugars.Their activity has been utilized in artificial reactions,such as using the SAT WecE to transform valienone into the valuable a-glucosidase inhibitor valienamine.However,the low thermostability and limited activity on non-natural substrates have hindered their applications.Simultaneously improving stability and enzyme activity is particularly challenging owing to the acknowledged inherent trade-off between stability and activity.A customized combinatorial active-site saturation test-iterative saturation mutagenesis(CAST-ISM)strategy was used to simultaneously enhance the stability and activity of WecE toward valienone.Fourteen hotspots related to improving the stability-\activity trade-off were identified based on evolutionary conservation and the average mutation folding energy assessment of 57 residues in the active site of WecE.Positive mutagenesis and combinatorial mutations of these specific residues were accomplished via site-directed saturation mutagenesis(SSM)and iterative evolution cycles.Compared with those of the wild-type(WT)WecE,the quadruple mutant M4(Y321F/K209F/V318R/F319V)displayed a 641.49-fold increase in half-life(t_(1/2))at 40℃ and a 31.37-fold increase in activity toward the non-natural substrate valienone.The tri-ple mutant M3(Y321F/K209F/V318R)demonstrated an 83.04-fold increase in(t_(1/2))at 40℃and a 37.77-fold increase in activity toward valienone.The underlying mechanism was dependent on the strengthened interface interactions and shortened transamination reaction catalytic distance,compared with those of the WT,which improved the stability and activity of the obtained mutants.Thus,we accomplished a general target-oriented strategy for obtaining stable and highly active SATs for artificial amino-sugar biosynthesis applications.展开更多
基金supported by a research grant from the National University of Singapore to WQS(RP-3960366)a collaborative research grant from Sichuan Zhongke Organ Co.Ltd(Chengdu,China).
文摘Objectives:Cold-acclimated organisms accumulate low molecular weight organic solutes such as sugar alcohols and soluble sugars.This study aimed to compare the efficacy of five sugar alcohols and 14 soluble sugars in stabilizing proteins under freezing,freeze-drying,and air-drying stresses.Materials and methods:Glucose-6-Phosphate Dehydrogenase(G6PD)was used as the model protein.G6PD solutions with or without sugar alcohols and or sugars were subjected to freezing,freeze-drying,and air-drying stresses.The recovery of G6PD activity was measured to evaluate the protective efficacy of these compounds.Results:Without stabilizers,freezing G6PD at-20℃ or-80℃ reduced enzyme activity by around 24%,while freeze-drying or air-drying reduced activity by 90%-95%.Among the five sugar alcohols tested,pinitol,quebrachitol and sorbitol stabilized G6PD,whereas mannitol and myo-inositol destabilized it.Among 14 soluble sugars,trehalose and raffinose showed slightly lower enzyme recovery after repeated freeze-thaw cycles at-20℃.Most soluble sugars(except arabinose and xylose)protected G6PD during freeze-drying,with di-,tri-,and oligosaccharides generally outperforming monosaccharides.During air-drying,lactose was ineffective,while arabinose,galactose,and xylose were detrimental.Conclusion:The study highlights the diverse mechanisms of sugar alcohols and sugars in protein stabilization under stress,offering insights for formulating stable protein-and cell-based drugs.
基金supported by the National Science Centre grants,Grant/Award Number:SONATA-BIS 2020/38/E/NZ3/00090 and SONATA 2021/43/D/NZ3/01798。
文摘Sugars are one of the major metabolites and are essential for nucleic acid synthesis and energy production.In addition,sugars can act as signaling molecules.To study sugar signaling at the systemic level,there is an urgent need to systematically identify sugar-sensing proteins and nucleic acids.I propose the terms“swodkoreceptor”and“swodkocrine signaling,”derived from the Polish word“slodki”meaning“sweet,”to comprise all sugar-sensing proteins and signaling events,respectively,regardless of their cellular location and signaling domains.This proposal is intended to facilitate the inclusion of proteins such as the Escherichia coli Lac I repressor as an allolactose receptor,human glucokinase regulatory protein(GCKR)as a fructose receptor,and other sugar-binding based allosterically regulated enzymes and transcription factors as sugar-sensing receptors.In addition,enzyme-interacting proteins whose interaction state is regulated by sugar binding have also been proposed as sugar receptors.The systemic study of protein-and nucleic-acid-based swodkoreceptors may help to identify organelle-specific swodkoreceptors and to also address receptor duality.The study of intra-and inter-organism swodkocrine signaling and its crosstalk with gasocrine signaling may help to understand the etiology of diseases due to dysregulation in sugar homeostasis and signaling.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32122080,31972375)Shandong Province(Grant No.ZR2020YQ25)。
文摘The content of soluble sugars is a vital parameter that indicates the quality of fleshy fruits such as apple(Malus domestica Borkh.).Studying the patterns of accumulation of soluble sugars and regulatory mechanisms associated with fruit development is crucial for breeding improved fruit varieties.Here,we report that MdCIbHLH1,a low temperature-induced b HLH transcription factor,inhibits the accumulation of soluble sugars by regulating sugar-metabolizing enzyme activities,photosynthetic performance,and the expression of sugar-related genes in developing apple fruits.MdCIbHLH1 inhibits MdFBP and MdPEPCK expression,thus blocking the conversion of acids to sugars in apple fruits.We also discovered that MdCIbHLH1 decreases the photosynthetic rate and carbohydrate accumulation in apple leaves.Our results suggest that soluble sugar accumulation in apple fruits is influenced by multiple factors,including metabolic status,photosynthesis,and carbohydrate allocation.MdCIbHLH1 is critically involved in controlling the accumulation of soluble sugars by coordinating carbohydrate synthesis and allocation,thus influencing sugar transport and its metabolism during the development of apple fruits.
基金supported by the Specialty Crop Block Grant Program of the U.S. Department of Agriculture's (USDA), Agricultural Marketing Service (AMS) through the California Department of Food and Agriculture (SCB15015)partly also by funding from the California Leafy Greens Research Board and by Oak Ridge Institute for Science and Education (ORISE) Research Participation Program。
文摘Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H^(2)) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.
基金supported by the National Natural Science Foundation of China(Grant Nos.32302642,32272790)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(Grant No.SN-ZJU-SIAS-0011)+1 种基金Collaborative Promotion Program of Zhejiang Provincial Agricultural Technology of China(Grant No.2023ZDXT05)the Fundamental Research Funds for the Central Universities(Grant No.226-2022-00122).
文摘Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.
基金supported by the National Natural Science Foundation of China,China(Grant No.52376052)the Anhui Provincial Natural Science Foundation,China(Grant No.2308085ME174).
文摘Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes four key hypotheses explaining sugar-mediated protection of dehydrated bilayers:the Water Replacement Hypothesis(WRH),Hydration Force Hypothesis(HFH),Headgroup Bridging Hypothesis(HBH),and Vitrification Hypothesis(VH).We argue that these mechanisms are not mutually exclusive but instead operate synergistically under different cellular contexts.We propose that these hypotheses are not mutually exclusive but likely operate under different cellular contexts.Future studies should prioritize the development of biologically realistic membrane models-incorporating diverse lipids,proteins,and asymmetric leaflets-to elucidate the exact roles and mechanisms of sugars in membrane stabilization.Such advancements will enhance our understanding of anhydrobiosis and inform cryopreservation strategies for mammalian cells.
基金supported by the National Natural Science Foundation of China(Grant No.32172521)the Excellent Youth Science Foundation of Heilongjiang Province(Grant No.YQ2023C006)+1 种基金the China Postdoctoral Science Foundation(Grant No.2023MD744175)the Talent Introduction Programof Northeast Agricultural University of China,and the Collaborative Innovation System of the Agricultural Bioeconomy in Heilongjiang Province,China.
文摘The compositions and contents of soluble sugars highly determine the flavor and quality of fleshy fruits.In the present study,we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus enhanced sucrose concentration while decreased fructose and glucose concentration in transgenic apple calli and ripening tomato fruits.To comprehensively understand the effects of the MdWRKY126 on the content of various soluble sugars in apple and tomato fruits,enzyme activities and related essential genes associated with the sugar metabolism and transportation pathway in MdWRKY126-overrexpressed apple and tomato lines were analyzed.The results indicated that the overexpression of MdWRKY126 upregulated sucrose phosphate synthase(SPS)activity and the gene expression levels of SPS and sucrose transporter SUT,which was conducive to a large accumulation of sucrose in fruit cells.Meanwhile,MdWRKY126 overexpression downregulated the activity of enzymes involved in sucrose decomposition including cell wall invertase(CWINV),sucrose synthase(SUSY)and the corresponding gene expressions,as well as inhibited the expression levels of hexose transporter(HTs)and tonoplast sugar transporter(TSTs)that transport hexose into vacuoles,resulting in a reduced hexose level in apple calli and tomato fruit.These findings enrich our understanding of the metabolism and regulation of soluble sugars in apple fruits.
文摘In Shandong,the special folk activity of blowing sugar figures during the Spring Festival has a long history.It is said that this skill can be traced back to the Tang Dynasty.At that time,as sugar-making technology improved a lot,smart folk craftsmen(工匠)began to use sugar to create various small items.Once heated,sugar turns soft and malleable(可塑的).
基金supported by the National Natural Science Foundation of China(32260780 and 31360297)the China Postdoctoral Science Foundation(2021M701513)+1 种基金the Jiangxi 2011 Collaborative Innovation Centre of Postharvest Key Technology and Quality Safety of Fruits and Vegetables,China(JXGS-05)the Gan Po 555 Engineering Excel ence Talents Project in Jiangxi Province,China。
文摘Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects the quality.The hormone abscisic acid(ABA)plays a crucial role in plant responses to abiotic stresses.Previous studies showed that exogenous ABA promotes floret closure,although the molecular mechanisms and effects of endogenous ABA on floret closure remain unknown.In this study,the effect of endogenous ABA on floret closure and the molecular mechanism by which ABA promotes floret closure through sugar transporters were investigated by changing the expression levels of OsNCED3 and OsPYL1 in rice.The results showed that overexpression(OE)-OsNCED3increased the endogenous ABA level of florets.Florets closed 5.91 min earlier and OsNCED3 gene knockout line delayed the closure of florets by 5.08 min compared with the wild type.In addition,OsPYL1 regulated the endogenous ABA content and changed the sensitivity to ABA such that the floret closure times for OE and CRISPR-Cas9(CR)were 9.84 min earlier and 12.78 min later,respectively,resulting in an increase in the split husk rate to 15.4%.The gene expression levels of some sugar transporters(STs)changed.The OsPYL1 and OsSWEET4proteins could interact on the cell membrane.These results indicate that ABA promotes the closure of rice florets and the enhanced sensitivity to ABA promotes this effect even more.The molecular mechanism is mainly related to downstream sugar transporters that respond to the ABA signaling pathway,especially OsSWEET4.
基金funded by National Natural Science Foundation of China(51901160)。
文摘For the purpose of satisfying high demands for taste,color,flavor,and storage of meat products,water retention agents(WRAs)play an important role.Phosphate has been widely used as an attractive functional material for water retention in current practical applications.However,excessive phosphate addition and longterm consumption may be harmful impacts on health and the environment.Therefore,it is vital to develop safe and efficient phosphate-free WRAs for further improving water-holding capacity(WHC)efficacy and edible safety,especially in meat products.In particular,sugar water retention agents(SWRAs)are increasingly popular because of their perfect safety,excellent WHC,and superior biological properties.This review discusses the inducements and mechanisms underlying water loss in meat products.In addition,we focused on the research progresses and related mechanisms of SWRAs in the WHC of meat products and its unique biological functions,as well as the extraction technology.Finally,the future application and development of SWRA were prospected.
基金supported by the National Natural Science Foundation of China(32401743)the Earmarked Fund for the China Agriculture Research System(CARS-01)+1 种基金the Hunan Natural Science Foundation Project(2021JJ40235)the Science and Technology Innovation Program of Hunan Province(2022RC3053)。
文摘The early responsive to dehydration-like(ERDL or ERD)subfamily,subclade within the monosaccharide transporter(MST)superfamily,is crucial in the regulation of growth and seed yield in Arabidopsis.Here,we identified Os ERD5 as an At ERDL6 homologue and explored the function of Os ERD5.We found that Os ERD5 overexpression significantly enhanced the tiller number and grain yield of rice.Os ERD5 was widely expressed in aboveground tissues,encoded a tonoplast-localized protein,and exhibited transport activities for fructose,glucose and mannose when expressed in yeast.Expression character assay revealed that Os ERD5 mediated hexose efflux across tonoplasts and participated in maintaining the diurnal rhythm-regulated intracellular hexose homeostasis.Additional physiological and molecular evidence showed that Os ERD5 overexpression promoted vacuolar glucose efflux,enhanced sucrose synthesis and transport,increased sugar content in the shoot base,and promoted rice tillering by activating the synthesis of cytokinin simultaneously repressing strigolactone and gibberellin signaling.This study elucidates the function of Os ERD5 and the mechanism underlying the overexpression of Os ERD5 increasing rice tillering and yield.
基金supported by the Youth Innovation Program of the Chinese Academy of Agricultural Sciences(Y2022QC02)the National Natural Science Foundation of China(32161143005 and 32111540258)+1 种基金the European Union Horizon 2020 Project Planta SYST(SGA-CSA No.739582 under FPA No.664620)the Science and Technology Project of the Hebei Education Department,China(BJ2019022)。
文摘Drought is becoming a common threat to crop production.Identifying and utilizing excellent droughtresistant genes is crucial to combating this stress and ensuring global food security by developing droughtresistant crop varieties.Although sugar transporters are involved in stress tolerance in many plants,the sugar transporter gene family of Tartary buckwheat has yet to be systematically analyzed.This study identified 140 sugar transporter genes from the‘Pinku'Tartary buckwheat genome and classified them into 10 subfamilies.Structural analysis showed that subfamily SGB/pGlcT had the highest number of introns compared to other subfamilies,and abundant abiotic stress-related cis-acting elements existed in the promoter region.Collinear analysis revealed relatively ancient genes FtSUT7,FtSTP28,FtPLT1,and FtINT2.The expression of sugar transporter genes was screened under various abiotic stresses,which revealed the association of stress tolerance with different sugar transporter genes,i.e.,FtERD23,FtINT2,FtpGlcT2,and FtSTP27.Further,we observed that the overexpression of FtERD23 maintains osmotic pressure through glucose transport,which may enhance drought stress tolerance.Moreover,gene co-expression analyses using weighted gene coexpression network analysis(WGCNA)and fuzzy c-means algorithm(FCMA)identified six transcription factors that may regulate FtERD23 expression and are involved in plant drought tolerance.Our systematic analysis provides a theoretical basis for the further functional characterization of sugar transporter genes to improve drought tolerance in Tartary buckwheat and its related species.
文摘Sugar cane juice is a popular refreshing drink in most part of Bangladesh. It has great taste and health benefits;also it is available most of the public places at reasonable prices which consumed by road side customers including general public, shopping personals, tourists, students. In our country, street vendors crushing sugarcane between roller crusher and sold without any heat treatment or preservative, also served with or without added ice and lemon juice. The study aimed to identify and compare the physico-chemical and microbial quality of sugarcane juice. The chemical qualities of juices including moisture, P<sup>H</sup>, ash, total soluble solid, total sugar, reducing sugar and titrable acidity were found slightly different in Mymensingh, Gazipur and Narayangonj areas. The highest and lowest value of moisture, ash, P<sup>H</sup>, total soluble solids, total sugar, reducing sugar and titrable acidity were found in 84.33% - 79.26% (Gazipur-Mymensingh), 0.57% - 0.04% (Mymensingh-Gazipur), 5.9 - 2.9 (Gazipur-Narayangonj), 17.48% - 4.98% (Mymensingh-Narayangonj), 21.9% - 6.56% (Mymensingh-Gazipur), 3.7 - 2.1 (Gazipur-Mymensingh) and 0.523% - 0.007% (Narayangonj-Gazipur) respectively. For microbiological analysis, the total viable count of sugar cane juice in Mymensingh, Gazipur and Narayangonj were ranged from 0.6 × 10<sup>5</sup> - 43.6 × 10<sup>5</sup> cfu/ml, 4.6 × 10<sup>5</sup> - 21.6 × 10<sup>5</sup> cfu/ml and 3.6 × 10<sup>5</sup> - 36.6 × 10<sup>5</sup> cfu/ml respectively, where the permitted value is 1.0 × 10<sup>4</sup> cfu/ml, whereas the total coliform count was ranged from 0.4 × 10<sup>5</sup> - 6.4 × 10<sup>5</sup> cfu/ml, 0.6 × 10<sup>5</sup> - 8.4 × 10<sup>5</sup> cfu/ml and 0.00 - 8.4 × 10<sup>5</sup> cfu/ml, where the permitted value is 100 cfu/ml and total fungal count was ranged from 5.5 × 10<sup>5</sup> - 56.5 × 10<sup>5</sup> cfu/ml, 21.5 × 10<sup>5</sup> - 54.5 × 10<sup>5</sup> cfu/ml and 32.5 × 10<sup>5</sup> - 68.5 × 10<sup>5</sup> cfu/ml, where the permitted value is 1000 cfu/ml. According to the Gulf standard, the microbiological parameters of all the collected sugar cane juice were out of the permitted standards, so that a serious health outbreak can be caused anytime.
文摘In order to enrich the germplasm resources of sugar beet resistant to damping-off and explore their physiological mechanisms in response to the disease,the previously isolated and purified Rhizoctonia solani were employed to inoculate 112 main sugar beet varieties.The emergence rate,morbidity,mortality rate,peroxidase(POD)activity were investigated.The results showed that 112 main sugar beet varieties were divided into six levels according to the incidence rate:disease resistance(≤40%),high resistance(40%<to≤50%),medium resistance(50%<to≤60%),medium sensitivity(60%<to≤70%),high sensitivity(70%<to≤80%)and disease susceptibility(>80%).On the basis of this classification,5 disease resistant varieties,9 highly resistant varieties,9 moderately resistant varieties,20 moderately susceptible varieties,21 highly susceptible varieties,and 48 susceptible varieties were classified.Moreover,it was found that POD of disease-resistant varieties was significantly different from that of susceptible varieties.This approach provides a theoretical basis for the rational breeding of sugar beet varieties resistant to sugar beet damping-off,and have certain reference value for the development of the domestic sugar beet planting industry.
文摘A general situation of the sugar beet industry and business in the European Union(EU) has been presented. It included the quotas of sugar production there, its prices and changes on the market. The latest sugar production data in the world was also given. The main companies carrying out activities on the Polish sugar and sugar beet seeds were also presented.New circumstances after liberating the sugar market in the EU in October, 2017, were also presented. Nowadays, Poland has been a great potential country for further technological progress in agricultural holdings and growing performance in sugar processing and production industry. As food export from Poland increases, it will be followed by increasing use of sugar. Examples are given to improve sugar beet productivity.
基金supported by the National Key Research and Development Program of China (2020YFA0907600)the Major Program of Guangdong Basic and Applied Research (2019B030302006)+1 种基金the National Natural Science Foundation of China (32101647)the Double First-Class Discipline Promotion Project (2023B10564004).
文摘Crop yield depends on biomass,which is primarily associated with photosynthesis.We previously demonstrated that two photorespiratory bypasses,i.e.,GOC(glycolate oxidase+oxalate oxidase+catalase)and GCGT(glycolate oxidase+catalase+glyoxylate carboligase+tartronic semialdehyde reductase),significantly increased photosynthesis,biomass,and grain yield,but decreased seed-setting rates in rice.This study explored the underlying mechanism of how elevated photosynthetic efficiency impacted the seed-setting.First,pollen germination assessed in vivo and in vitro,revealed a reduced germination rate in GCGT rice.Subsequent analysis found that photosynthates highly accumulated in the leaves and stems;sucrose and soluble sugar levels were increased but the starch level was reduced in the anthers.Uridine diphosphate glucose(UDP-Glc)was increased but uridine diphosphate galactose(UDP-Gal)was unaltered,thus causing an imbalance in the UDP-Glc/UDP-Gal ratio in GCGT anthers.Most anthers in GCGT plants had two locules in contrast to four in the wild-type(WT).Pollen tapetum was developmentally abnormal,and genes related to sucrose synthesis,transport,and tapetal programmed cell death(PCD)were upregulated,whereas those involved in starch synthesis and conversion were downregulated in GCGT anthers.Taken together,our results demonstrated that an increase in sugar content was the primary factor causing reduced seed-setting rates in high photosynthetic efficiency rice,during which metabolic disorder of sugars and UDP sugar imbalance in anthers lead to impaired pollen fertility.
基金supported by National Natural Science Foundation of China(7191010700,91746205).
文摘Background The associations between sugary beverages and genetic predisposition to depression risk remain unclear.Aims This study aimed to investigate the associations of sugar-sweetened beverages(SSBs),artificially sweetened beverages(ASBs)and natural juices(NJs)with depression and to assess whether these associations were modified by genetic predisposition.Methods We used data from the UK Biobank of 180599 individuals aged 39-72 years who were depression-free at baseline.Dietary intake of SSBs,ASBs and NJs was accessed by a 24-hour dietary recall between 2009 and 2012.The Polygenic Risk Score for depression was estimated and categorised as low(lowest tertile),intermediate(tertile 2)and high(highest tertile),.Cox proportional hazard and substitution models were conducted to evaluate hazard ratios(HRs)and 95%Cls.Results Over the 12-year follow-up,4915 individuals developed depression.Higher consumption(>2 units/day)of SSBs(HR:1.26,95%CI 1.12 to 1.43)and ASBs(HR:1.40,95%Cl 1.23 to 1.60)were both associated with an increased risk of depression.However,moderate consumption(>0-1 units/day)of NJs was associated with a lower risk of depression(HR:0.89,95%CI 0.83 to 0.95).Furthermore,genetic predisposition did not modify these associations(p interaction>0.05).In substitution models,the HRs for depression risk were 0.94(95%CI 0.89 to 0.99)and 0.89(95%CI 0.85 to 0.94),respectively,when 1 unit/day of SSBs or ASBs was replaced by an equivalent intake of NJs.Conclusions Higher consumption of SSBs and ASBs was associated with an increased risk of depression;in contrast,moderate consumption of NJs was inversely associated with a lower risk of depression.In theory,substituting SSBs and ASBswith NJs would suppose a reduction of depression risk.
基金Supported by China Agriculture Research System(Sugar Crops)of Ministry of Agriculture and Rural Affairs and Ministry of Finance(CARS-170601)Natural Science Foundation of Heilongjiang Province(C201239).
文摘With the advancement of agricultural mechanization,soil compaction has become a serious environmental problem.Soil compaction can increase soil bulk density and firmness,reduce porosity and permeability,and deteriorate soil structure,ultimately inhibit sugar beet growth and reduce both root yield and sugar content.However,few farmers recognize the link between soil compaction and these adverse effects.Soil compaction has a cumulative effect,with significant differences observed in the vertical range of compaction accumulation.The most significant soil compaction occurs in the topsoil of 0-10 cm,and the influence depth can reach 70 cm,but it is small in deep soil,and the inflection point is at a soil depth of 10 cm.The degree of soil compaction is related to soil type,water content,tractor shaft load,tyre type,tyre pressure and operation speed,etc.Therefore,in the production process of sugar beet,it is advisable to avoid high-humidity operations,use low pressure tyres,reduce the number of tractor-units passes over the farmland,and implement agricultural and agronomic measures to minimize soil compaction.These practices will help protect the soil environment and ensure sustainable production of sugar beets.
基金Financial support by Dual Initiative Project of Jiangsu Province and Changzhou University is gratefully acknowledgedSample analysis supported by Analysis and Testing Center,NERC Biomass of Changzhou University was also greatly acknowledged.
文摘The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date.
基金supported by the National Key Research and Development Program of China(2018YFE0200501 and 2020YFA0907700)the National Natural Science Foundation of China(32271306 and 21977067).
文摘Sugar aminotransferases(SATs)catalyze the installation of chiral amines onto specific keto sugars,pro-ducing bioactive amino sugars.Their activity has been utilized in artificial reactions,such as using the SAT WecE to transform valienone into the valuable a-glucosidase inhibitor valienamine.However,the low thermostability and limited activity on non-natural substrates have hindered their applications.Simultaneously improving stability and enzyme activity is particularly challenging owing to the acknowledged inherent trade-off between stability and activity.A customized combinatorial active-site saturation test-iterative saturation mutagenesis(CAST-ISM)strategy was used to simultaneously enhance the stability and activity of WecE toward valienone.Fourteen hotspots related to improving the stability-\activity trade-off were identified based on evolutionary conservation and the average mutation folding energy assessment of 57 residues in the active site of WecE.Positive mutagenesis and combinatorial mutations of these specific residues were accomplished via site-directed saturation mutagenesis(SSM)and iterative evolution cycles.Compared with those of the wild-type(WT)WecE,the quadruple mutant M4(Y321F/K209F/V318R/F319V)displayed a 641.49-fold increase in half-life(t_(1/2))at 40℃ and a 31.37-fold increase in activity toward the non-natural substrate valienone.The tri-ple mutant M3(Y321F/K209F/V318R)demonstrated an 83.04-fold increase in(t_(1/2))at 40℃and a 37.77-fold increase in activity toward valienone.The underlying mechanism was dependent on the strengthened interface interactions and shortened transamination reaction catalytic distance,compared with those of the WT,which improved the stability and activity of the obtained mutants.Thus,we accomplished a general target-oriented strategy for obtaining stable and highly active SATs for artificial amino-sugar biosynthesis applications.
