Pre-harvest water deficit(PHWD)plays an important role in sugar accumulation of citrus fruit.However,the mechanism is not known well.Here,it was confirmed that PHWD promoted sucrose accumulation of citrus fruit,but ha...Pre-harvest water deficit(PHWD)plays an important role in sugar accumulation of citrus fruit.However,the mechanism is not known well.Here,it was confirmed that PHWD promoted sucrose accumulation of citrus fruit,but had limited effect on fructose,glucose and total acid.A sucrose transporter,Cs SUT1,which localizes to the plasma membrane,was demonstrated to function in sucrose transport induced by PHWD.Compared to wild-type,Cs SUT1 overexpression in citrus calli stimulated sucrose,fructose and glucose accumulation,while its silencing in juice sacs reduced sucrose accumulation.Increased sugar accumulation in transgenic lines enhanced plant drought tolerance,and resulted in decreased electrolyte leakage,malondialdehyde and hydrogen peroxide contents,as well as increased superoxide dismutase activity and proline contents.An abscisic acid(ABA)-responsive transcription factor,Cs ABF3,was found with a same expression pattern with Cs SUT1 under PHWD.Yeast one-hybrid,electrophoretic mobility shift assay and dual-luciferase assays all revealed that Cs ABF3 directly bound with the Cs SUT1 promoter by ABA responsive elements.When Cs ABF3 was overexpressed in citrus calli,the sucrose,fructose and glucose concentration increased correspondingly.Further,transgenic studies demonstrated that Cs ABF3 could affect sucrose accumulation by regulating Cs SUT1.Overall,this study revealed a regulation of Cs ABF3 promoting Cs SUT1 expression and sucrose accumulation in response to PHWD.Our results provide a detail insight into the quality formation of citrus fruit.展开更多
Sucrose phosphate synthase(SPS)is a rate-limiting enzyme that works in conjunction with sucrose-6-phosphate phosphatase(SPP)for sucrose synthesis,and it plays an essential role in energy provisioning during growth and...Sucrose phosphate synthase(SPS)is a rate-limiting enzyme that works in conjunction with sucrose-6-phosphate phosphatase(SPP)for sucrose synthesis,and it plays an essential role in energy provisioning during growth and development in plants as well as improving fruit quality.However,studies on the systematic analysis and evolutionary pattern of the SPS gene family in apple are still lacking.In the present study,a total of seven MdSPS and four MdSPP genes were identified from the Malus domestica genome GDDH13 v1.1.The gene structures and their promoter cis-elements,protein conserved motifs,subcellular localizations,physiological functions and biochemical properties were analyzed.A chromosomal location and gene-duplication analysis demonstrated that whole-genome duplication(WGD)and segmental duplication played vital roles in MdSPS gene family expansion.The Ka/Ks ratio of pairwise MdSPS genes indicated that the members of this family have undergone strong purifying selection during domestication.Furthermore,three SPS gene subfamilies were classified based on phylogenetic relationships,and old gene duplications and significantly divergent evolutionary rates were observed among the SPS gene subfamilies.In addition,a major gene related to sucrose accumulation(MdSPSA2.3)was identified according to the highly consistent trends in the changes of its expression in four apple varieties(‘Golden Delicious’,‘Fuji’,‘Qinguan’and‘Honeycrisp’)and the correlation between gene expression and soluble sugar content during fruit development.Furthermore,the virus-induced silencing of MdSPSA2.3 confirmed its function in sucrose accumulation in apple fruit.The present study lays a theoretical foundation for better clarifying the biological functions of the MdSPS genes during apple fruit development.展开更多
Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakth...Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.展开更多
Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs...Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs), and phylogenetic analysis revealed that the Md SUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively. The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs. SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. After assessing four different tissues, Md SUS1 s and Md SUS2.1 showed the highest expression in fruit, whereas Md SUS2.2/2.3 and Md SUS3 s exhibit the highest expression in shoot tips. Most Md SUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both Md SUS2.1 and Md SUS1.4 displayed opposite expression profiles. These results suggest that different Md SUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.展开更多
Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose an...Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.展开更多
Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12...Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg.mL^-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg.mL^-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.展开更多
A robust voltammetric method has been developed and validated for the determination of Fe(Ⅱ) and Fe(Ⅲ) in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concen...A robust voltammetric method has been developed and validated for the determination of Fe(Ⅱ) and Fe(Ⅲ) in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe(Ⅱ) and Fe(Ⅲ) composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.展开更多
We evaluated the effects of neutral detergent soluble fiber (NDSF) and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulatio...We evaluated the effects of neutral detergent soluble fiber (NDSF) and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC). The experiment had a 2x2 factorial design with two dosages of sucrose, low (ca. 0.26 g d-1, low-sucrose) and high (ca. 1.01 g d-1, high-sucrose), and two dosages of supplied NDSF, low (1.95 g d-1, Iow-NDSF) and high (2.70 g d-1, high-NDSF). Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber (NDF) and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.展开更多
The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the...The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the understanding of sucrose metabolism in microspores and the supporting tissues. The aims of the present work were to 1) follow the changes in total and relative concentrations of sucrose, glucose, fructose and starch in the stamen parts and microspores up until anthesis, 2) follow the activities of sucrose-metabolism-related enzymes, in the anther walls fraction and microspores of the crop plant tomato. Sucrose was found to be partially cleaved in the filament, decreasing by more than twofold in the anther wall layers and the locular fluid, and to accumulate in the mature pollen grains, constituting 80% of total soluble sugars. Thus, sucrose was both the starting sugar, supporting microspore development, and the main carbohydrate accumulated at the end of the pollen-development program. The major invertase found to be active in both the anther wall layers and in maturing microspores was cell-wall-bound invertase. High fructokinase 2 and sucrose phosphate synthase activities during pollen maturation coincided with sucrose accumulation. The potential importance of sucrose accumulation during pollen dehydration phase and germination is discussed.展开更多
The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constr...The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps(encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and csc B(encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing csc B only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.展开更多
Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature inc...Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.展开更多
Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this...Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this work was to study the effect of sucrose during pSSC cryopreservation and to find the most effective concentration in freezing medium, pSSCs were cryopreserved with freezing media containing different concentrations of sucrose (70, 140, 210, and 280 mmol L^-1) and a control group without sucrose. The survival rates, plasma membrane integrity, and mitochondrial membrane potential of thawed cells were detected by trypan blue (TB) staining, SYBR-14/propidium iodide (PI) dual staining, and JC-1 staining, respectively. All the staining results showed an obvious increase in cell survival in the sucrose-treated groups as compared to that in the control group, with the exception of 280 mmol L^-1 sucrose. Moreover, the 210 mmol L^-1 sucrose group yielded the highest survival rate among all the groups (P〈0.05). The results of SYBR-14/PI dual staining and JC-1 staining were consistent with those of TB staining as above described. Quantitative real-time PCR (qRT-PCR) indicated that the mRNA levels of three apoptosis-promoting genes (BAX, APAF1 and CASPASE9) were significantly higher in thawed cells than in cells before freezing (P〈0.05). Moreover, the mRNA level of one anti-apoptotic gene (XIAP) was significantly lower in thawed cells than in cells before freezing (P〈0.05). When comparing the mRNA expression of apoptosis-related genes in thawed cells, the mRNA level of the anti-apoptotic genes in the control group was significantly lower than that in the sucrose-treated groups (P〈0.05). Western blot analyses showed that the expression levels of cleaved CASPASE9, CASPASE3 and PARP-1 in the sucrose-treated groups were lower than those in the control group and were the lowest in the 210 mmol L-1 sucrose group. Both qRT-PCR and Western blot analyses suggested that sucrose inhibited cell apoptosis during freezing and thawing. Briefly, sucrose promoted pSSCs survival after freezing and thawing, especially at a concentration of 210 mmol L^-1, which possibly assisted pSSC dehydration and inhibited cell apoptosis. These findings hold great promise for further studies of the regulatory mechanism of proliferation and differentiation of pSSCs.展开更多
Changes in sucrose metabolism in response to salt (NaC1) and water (polyethylene glycol, PEG6000) iso-osmotic stresses were measured in tomato cultivar Liaoyuan Duoli (Solanum lycopersicum L.) and the objective ...Changes in sucrose metabolism in response to salt (NaC1) and water (polyethylene glycol, PEG6000) iso-osmotic stresses were measured in tomato cultivar Liaoyuan Duoli (Solanum lycopersicum L.) and the objective was to provide a new evidence for the relationship between salt and osmotic stresses. The carbohydrate contents, as well as sucrose metabolizing enzymes activities and transcript levels were determined. The results indicated that soluble sugar and hexoses accumulated to higher levels and the contents of sucrose and starch were lower in mature fruit under the two stress treatments. Salt and water stresses can enhance the invertase and sucrose synthase activities of tomato fruit in a long period of time (45-60 days after anthesis), and elevate the expression of soluble acid invertase mRNA. It showed that two different stresses could also regulate the soluble acid invertase activity by controlling its gene expression. The activity of sucrose synthase was linked to the changes in soluble sugar levels but not with transcript levels. The effects of salt and water stress treatments on sucrose phosphate synthase activities were weak.展开更多
In higher plants, sugars(mainly sucrose) are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and development. Sucrose tran...In higher plants, sugars(mainly sucrose) are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and development. Sucrose transporters, or sucrose carriers(SUCs), play an important role in the long-distance transportation of sucrose from source organs to sink organs, thereby affecting crop yield and quality.The identification, characterization, and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants. However, no relevant study has been reported on sucrose transporter genes in Brassica rapa var. rapa, a cruciferous root crop used mainly as vegetables and fodder.We identified and cloned 12 sucrose transporter genes from turnips, named BrrSUC1.1 to BrrSUC6.2according to the SUC gene sequences of B. rapa pekinensis. We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified. Real-time quantitative polymerase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip. These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.展开更多
This study investigates the effect of boric acid and sucrose on the germination and growth of Areca catechu L (areca palm). Using areca pollen from Hainan, China, this study determines the influence of culture media w...This study investigates the effect of boric acid and sucrose on the germination and growth of Areca catechu L (areca palm). Using areca pollen from Hainan, China, this study determines the influence of culture media with different concentrations of boric acid and sucrose on the germination and growth of areca pollen. Results show that the germination and growth of the pollen tube growth are highest under a boric acid concentration of 0.4 g/L to 0.6 g/L. The germination rate of areca pollen is highest in solid medium with a sucrose concentration of 40 g/L. The optimum culture medium for developing areca pollen comprises 5 g/L agar, 0.4 g/L to 0.6 g/L boric acid, 40 g/L sucrose, and water. Furthermore, areca pollen grows most rapidly approximately 1.5 h after in vitro cultivation at normal temperature, and growth stabilizes at approximately 3 h. The principle that governs the development of areca pollen is also discussed.展开更多
In the present paper, multi-walled carbon nanotubes(MWCNTs) are successfully assembled on graphite felt(GF) using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the b...In the present paper, multi-walled carbon nanotubes(MWCNTs) are successfully assembled on graphite felt(GF) using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.展开更多
A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymatically prepared monomer, 1'-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl ...A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymatically prepared monomer, 1'-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate in anhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60degreesC for 7 days gave VAS (yield 55%) without any blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiator to give poly(1'-O-vinyladipoyl-sucrose) with M-n = 33,000 and M-w = 53,200, M-w/M-n = 1.61. The polymer was biodegradable. After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1'-O-vinyladipoyl-sucrose) to M. of ca. 1080, M-w/M-n = 3.30 (37degreesC), and M-n of ca. 5200, M-w/M-n = 2.44 (4degreesC). The polymer containing the sucrose branch would be a functional material in various application fields.展开更多
The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of car...The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy(CLSM)-based analyses of the microbial vitality, respiratory activity(5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides(EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of xylitol.Under xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three.Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32172520)the earmarked fund for China Agriculture Research System(Grant No.CARS-26)。
文摘Pre-harvest water deficit(PHWD)plays an important role in sugar accumulation of citrus fruit.However,the mechanism is not known well.Here,it was confirmed that PHWD promoted sucrose accumulation of citrus fruit,but had limited effect on fructose,glucose and total acid.A sucrose transporter,Cs SUT1,which localizes to the plasma membrane,was demonstrated to function in sucrose transport induced by PHWD.Compared to wild-type,Cs SUT1 overexpression in citrus calli stimulated sucrose,fructose and glucose accumulation,while its silencing in juice sacs reduced sucrose accumulation.Increased sugar accumulation in transgenic lines enhanced plant drought tolerance,and resulted in decreased electrolyte leakage,malondialdehyde and hydrogen peroxide contents,as well as increased superoxide dismutase activity and proline contents.An abscisic acid(ABA)-responsive transcription factor,Cs ABF3,was found with a same expression pattern with Cs SUT1 under PHWD.Yeast one-hybrid,electrophoretic mobility shift assay and dual-luciferase assays all revealed that Cs ABF3 directly bound with the Cs SUT1 promoter by ABA responsive elements.When Cs ABF3 was overexpressed in citrus calli,the sucrose,fructose and glucose concentration increased correspondingly.Further,transgenic studies demonstrated that Cs ABF3 could affect sucrose accumulation by regulating Cs SUT1.Overall,this study revealed a regulation of Cs ABF3 promoting Cs SUT1 expression and sucrose accumulation in response to PHWD.Our results provide a detail insight into the quality formation of citrus fruit.
基金supported by the National Natural Science Foundation of China (32172521)the Excellent Youth Science Foundation of Heilongjiang Province,China (YQ2023C006)+1 种基金the Talent Introduction Program of Northeast Agricultural University of Chinathe Collaborative Innovation System of the Agricultural Bio-economy in Heilongjiang Province,China
文摘Sucrose phosphate synthase(SPS)is a rate-limiting enzyme that works in conjunction with sucrose-6-phosphate phosphatase(SPP)for sucrose synthesis,and it plays an essential role in energy provisioning during growth and development in plants as well as improving fruit quality.However,studies on the systematic analysis and evolutionary pattern of the SPS gene family in apple are still lacking.In the present study,a total of seven MdSPS and four MdSPP genes were identified from the Malus domestica genome GDDH13 v1.1.The gene structures and their promoter cis-elements,protein conserved motifs,subcellular localizations,physiological functions and biochemical properties were analyzed.A chromosomal location and gene-duplication analysis demonstrated that whole-genome duplication(WGD)and segmental duplication played vital roles in MdSPS gene family expansion.The Ka/Ks ratio of pairwise MdSPS genes indicated that the members of this family have undergone strong purifying selection during domestication.Furthermore,three SPS gene subfamilies were classified based on phylogenetic relationships,and old gene duplications and significantly divergent evolutionary rates were observed among the SPS gene subfamilies.In addition,a major gene related to sucrose accumulation(MdSPSA2.3)was identified according to the highly consistent trends in the changes of its expression in four apple varieties(‘Golden Delicious’,‘Fuji’,‘Qinguan’and‘Honeycrisp’)and the correlation between gene expression and soluble sugar content during fruit development.Furthermore,the virus-induced silencing of MdSPSA2.3 confirmed its function in sucrose accumulation in apple fruit.The present study lays a theoretical foundation for better clarifying the biological functions of the MdSPS genes during apple fruit development.
文摘Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.
基金supported in part by the National Natural Science Foundation of China (31372038)the Natural Basic Research Plan in Shaanxi Province of China (2015JQ3082)
文摘Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs), and phylogenetic analysis revealed that the Md SUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively. The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs. SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. After assessing four different tissues, Md SUS1 s and Md SUS2.1 showed the highest expression in fruit, whereas Md SUS2.2/2.3 and Md SUS3 s exhibit the highest expression in shoot tips. Most Md SUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both Md SUS2.1 and Md SUS1.4 displayed opposite expression profiles. These results suggest that different Md SUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.
基金supported by the National Natural Science Fundation of China(30170640)Natural Science Fund of Liaoning Provice,China(20022080).
文摘Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.
文摘Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg.mL^-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg.mL^-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.
基金supported by FAR, Fondo Ateneoper la Ricerca Universitá di Pavia,Italy
文摘A robust voltammetric method has been developed and validated for the determination of Fe(Ⅱ) and Fe(Ⅲ) in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe(Ⅱ) and Fe(Ⅲ) composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.
基金supported by the National Key Technologies R&D Program of China(2012BAD12B02)the Program of International S&T Cooperation of China(2010DFB34230)the Scientific&Technological Innovation Project of Shaanxi,China(2011KTCQ02-02)
文摘We evaluated the effects of neutral detergent soluble fiber (NDSF) and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC). The experiment had a 2x2 factorial design with two dosages of sucrose, low (ca. 0.26 g d-1, low-sucrose) and high (ca. 1.01 g d-1, high-sucrose), and two dosages of supplied NDSF, low (1.95 g d-1, Iow-NDSF) and high (2.70 g d-1, high-NDSF). Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber (NDF) and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.
文摘The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the understanding of sucrose metabolism in microspores and the supporting tissues. The aims of the present work were to 1) follow the changes in total and relative concentrations of sucrose, glucose, fructose and starch in the stamen parts and microspores up until anthesis, 2) follow the activities of sucrose-metabolism-related enzymes, in the anther walls fraction and microspores of the crop plant tomato. Sucrose was found to be partially cleaved in the filament, decreasing by more than twofold in the anther wall layers and the locular fluid, and to accumulate in the mature pollen grains, constituting 80% of total soluble sugars. Thus, sucrose was both the starting sugar, supporting microspore development, and the main carbohydrate accumulated at the end of the pollen-development program. The major invertase found to be active in both the anther wall layers and in maturing microspores was cell-wall-bound invertase. High fructokinase 2 and sucrose phosphate synthase activities during pollen maturation coincided with sucrose accumulation. The potential importance of sucrose accumulation during pollen dehydration phase and germination is discussed.
基金supported by the Joint Sino-GermanResearch Project (GZ984 to X. Lu)the Excellent Youth Award of the Shandong Natural Science Foundation (JQ201306 to X. Lu)the Shandong Taishan Scholarship (X. Lu)
文摘The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps(encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and csc B(encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing csc B only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China(20070759002)the Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD21B02)
文摘Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.
基金supported by the China Postdoctoral Science Foundation(2014M560809)the Shaanxi Province Postdoctoral Science Foundation,China+1 种基金the Fundamental Research Funds for the Central Universities,China(NWSUAF,2452015145)the National Basic Research Program of China(2014CB943100)
文摘Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this work was to study the effect of sucrose during pSSC cryopreservation and to find the most effective concentration in freezing medium, pSSCs were cryopreserved with freezing media containing different concentrations of sucrose (70, 140, 210, and 280 mmol L^-1) and a control group without sucrose. The survival rates, plasma membrane integrity, and mitochondrial membrane potential of thawed cells were detected by trypan blue (TB) staining, SYBR-14/propidium iodide (PI) dual staining, and JC-1 staining, respectively. All the staining results showed an obvious increase in cell survival in the sucrose-treated groups as compared to that in the control group, with the exception of 280 mmol L^-1 sucrose. Moreover, the 210 mmol L^-1 sucrose group yielded the highest survival rate among all the groups (P〈0.05). The results of SYBR-14/PI dual staining and JC-1 staining were consistent with those of TB staining as above described. Quantitative real-time PCR (qRT-PCR) indicated that the mRNA levels of three apoptosis-promoting genes (BAX, APAF1 and CASPASE9) were significantly higher in thawed cells than in cells before freezing (P〈0.05). Moreover, the mRNA level of one anti-apoptotic gene (XIAP) was significantly lower in thawed cells than in cells before freezing (P〈0.05). When comparing the mRNA expression of apoptosis-related genes in thawed cells, the mRNA level of the anti-apoptotic genes in the control group was significantly lower than that in the sucrose-treated groups (P〈0.05). Western blot analyses showed that the expression levels of cleaved CASPASE9, CASPASE3 and PARP-1 in the sucrose-treated groups were lower than those in the control group and were the lowest in the 210 mmol L-1 sucrose group. Both qRT-PCR and Western blot analyses suggested that sucrose inhibited cell apoptosis during freezing and thawing. Briefly, sucrose promoted pSSCs survival after freezing and thawing, especially at a concentration of 210 mmol L^-1, which possibly assisted pSSC dehydration and inhibited cell apoptosis. These findings hold great promise for further studies of the regulatory mechanism of proliferation and differentiation of pSSCs.
基金supported by the National Key Tech-nologies R&D Program of China (2008BADA6B05)
文摘Changes in sucrose metabolism in response to salt (NaC1) and water (polyethylene glycol, PEG6000) iso-osmotic stresses were measured in tomato cultivar Liaoyuan Duoli (Solanum lycopersicum L.) and the objective was to provide a new evidence for the relationship between salt and osmotic stresses. The carbohydrate contents, as well as sucrose metabolizing enzymes activities and transcript levels were determined. The results indicated that soluble sugar and hexoses accumulated to higher levels and the contents of sucrose and starch were lower in mature fruit under the two stress treatments. Salt and water stresses can enhance the invertase and sucrose synthase activities of tomato fruit in a long period of time (45-60 days after anthesis), and elevate the expression of soluble acid invertase mRNA. It showed that two different stresses could also regulate the soluble acid invertase activity by controlling its gene expression. The activity of sucrose synthase was linked to the changes in soluble sugar levels but not with transcript levels. The effects of salt and water stress treatments on sucrose phosphate synthase activities were weak.
基金supported by Major Program of National Natural Science Foundation of China (31590820,31590823)
文摘In higher plants, sugars(mainly sucrose) are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and development. Sucrose transporters, or sucrose carriers(SUCs), play an important role in the long-distance transportation of sucrose from source organs to sink organs, thereby affecting crop yield and quality.The identification, characterization, and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants. However, no relevant study has been reported on sucrose transporter genes in Brassica rapa var. rapa, a cruciferous root crop used mainly as vegetables and fodder.We identified and cloned 12 sucrose transporter genes from turnips, named BrrSUC1.1 to BrrSUC6.2according to the SUC gene sequences of B. rapa pekinensis. We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified. Real-time quantitative polymerase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip. These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.
文摘This study investigates the effect of boric acid and sucrose on the germination and growth of Areca catechu L (areca palm). Using areca pollen from Hainan, China, this study determines the influence of culture media with different concentrations of boric acid and sucrose on the germination and growth of areca pollen. Results show that the germination and growth of the pollen tube growth are highest under a boric acid concentration of 0.4 g/L to 0.6 g/L. The germination rate of areca pollen is highest in solid medium with a sucrose concentration of 40 g/L. The optimum culture medium for developing areca pollen comprises 5 g/L agar, 0.4 g/L to 0.6 g/L boric acid, 40 g/L sucrose, and water. Furthermore, areca pollen grows most rapidly approximately 1.5 h after in vitro cultivation at normal temperature, and growth stabilizes at approximately 3 h. The principle that governs the development of areca pollen is also discussed.
基金financial support of the National Natural Science Foundation of China (project no. 51504231, 51504232, 51774262 and 21325628)Open Project of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (project no. CNMRCUKF1704)
文摘In the present paper, multi-walled carbon nanotubes(MWCNTs) are successfully assembled on graphite felt(GF) using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.
文摘A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymatically prepared monomer, 1'-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate in anhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60degreesC for 7 days gave VAS (yield 55%) without any blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiator to give poly(1'-O-vinyladipoyl-sucrose) with M-n = 33,000 and M-w = 53,200, M-w/M-n = 1.61. The polymer was biodegradable. After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1'-O-vinyladipoyl-sucrose) to M. of ca. 1080, M-w/M-n = 3.30 (37degreesC), and M-n of ca. 5200, M-w/M-n = 2.44 (4degreesC). The polymer containing the sucrose branch would be a functional material in various application fields.
基金supported by the National Deutsche Gesellschaft fr Zahnerhaltung-GABA Scientific Fund, Germany
文摘The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy(CLSM)-based analyses of the microbial vitality, respiratory activity(5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides(EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of xylitol.Under xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three.Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.