To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,lig...To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.展开更多
Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate cl...Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.展开更多
Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various dis...Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various disturbances,ranging from natural storms or wildfires to anthropogenic events like logging and slashing-andburning,and sprouts of most tree species with non-structural carbohydrates(NSCs)storage can regenerate from stumps after gap formation.However,how the stump sprouts with diverse NSCs storages and stump sizes(i.e.,diameters)adapt to various micro-environments of within-gap positions remains unclear.Therefore in this study,we monitored the stump sprout regeneration(density,survival,and growth)and NSCs concentrations of three dominant tree species with different shade tolerances and varying stump diameters at five within-gap positions for the first two consecutive years after gap formation.Results:Stump diameter was positively correlated with sprout density,growth,and survival of all three tree species,but insignificantly related with sprout NSCs concentrations at the early stage after gap formation.The effect of within-gap position on sprout NSCs concentrations was different among species.After an environmental adaptation of two growing seasons,the north of gap(higher light availability and lower soil moisture habitat)was the least conducive for shade-intolerant Quercus mongolica to accumulate leaf NSCs,and the east of gap(shadier and drier habitat)was conducive to increasing the leaf NSCs concentrations of shade-tolerant Tilia mandshurica.Conclusions:Within-gap position significantly affected leaf NSCs concentrations of all three tree species,but most of the sprout growth,survival,and stem NSCs concentrations were independent of the various within-gap positions.Besides stump diameter,the NSCs stored in stump and root systems and the interspecific differences in shade tolerance also contributed more in sprout regeneration at the early stage(2 years)of gap formation.A prolonged monitoring(>10 years)is needed to further examine the long-term effects of stump diameter and within-gap position on sprout regeneration.All of these findings could be applied to gap-based silviculture by promoting sprout regeneration of dominant tree species with different shade tolerances,which would help accelerate the restoration of temperate secondary forests.展开更多
Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink char...Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink characteristics in short-growth duration rice,a field experiment was conducted at three sites(Yueyang,Liuyang,and Hengyang)in 2021 and 2022.This study compared yield,yield components,source–sink characteristics,and their stability between two stable-yielding short-growth duration rice cultivars,Zhongzao 39(Z-39)and Lingliangyou 268(L-268),and two unstable-yielding short-growth duration rice cultivars,Zhongjiazao 17(Z-17)and Zhuliangyou 819(Z-819).The stability of agronomic parameters was represented by the coefficient of variation(CV).The respective CVs of yield in Z-17,Z-819,Z-39,and L-268 were 10.2%,10.1%,4.5%,and 5.7%in 2021 and 19.7%,15.0%,5.4%,and 6.5%in 2022.The respective CVs of grain weight were 6.3%,5.7%,3.4%,and 4.5%in Z-17,Z-819,Z-39,and L-268 in 2021,and 8.1%,6.3%,1.5%,and 0.8%in 2022.The mean source capacity per spikelet and pre-heading non-structural carbohydrate reserves per spikelet(NSC_(pre))were 7%–43%and7%–72%lower in Z-819 and Z-17than in L-268 and Z-39 in 2021 and 2022.The mean quantum yield of photosystem II photochemistry of leaf,leaf area index,and specific leaf weight of L-268 and Z-39 were higher than those of Z-819 and Z-17 at the heading stage.This study suggests that high NSC_(pre),caused by great leaf traits before heading,increases source capacity per spikelet and its stability,thereby increasing the stability of grain weight and yield.Increasing NSC_(pre)is critical for achieving grain weight and yield stability in short-growth duration rice.展开更多
The more frequent occurrence and severer drought events resulting from climate change are increasingly affecting the physiological performance of trees and ecosystem carbon sequestration in many regions of the world.H...The more frequent occurrence and severer drought events resulting from climate change are increasingly affecting the physiological performance of trees and ecosystem carbon sequestration in many regions of the world.However,our understanding of the mechanisms underlying the responses and adaption of forest trees to prolonged and multi-year drought is still limited.To address this problem,we conducted a long-term manipulative throughfall reduction(TFR,reduction of natural throughfall by 50%–70%during growing seasons)experiment in a natural oriental white oak(Quercus aliena var.acuteserrata Maxim.)forest under warm-temperate climate.After seven years of continuous TFR treatment,the aboveground growth in Q.aliena var.acuteserrata started to decline.Compared with the control plots,trees in the TFR treatment significantly reduced growth increments of stems(14.2%)and leaf area index(6.8%).The rate of net photosynthesis appeared to be more susceptible to changes in soil water in trees subjected to the TFR than in the control.The TFR-treated trees allocated significantly more photosynthates to belowground,leading to enhanced growth and nonstructural carbohydrates(NSC)storage in roots.The 7-year continuous TFR treatment increased the biomass,the production and the NSC concentration in the fine roots by 53.6%,153.6%and 9.6%,respectively.There were clear trade-offs between the aboveground growth and the fine root biomass and NSC storage in Q.aliena var.acuteserrata trees in response to the multi-year TFR treatment.A negative correlation between the fine root NSC concentration and soil water suggested a strategy of preferential C storage over growth when soil water became deficient;the stored NSC during water limitation would then help promote root growth when drought stress is released.Our findings demonstrate the warm-temperate oak forest adopted a more conservative NSC use strategy in response to long-term drought stress,with enhanced root growth and NSC storage at the expenses of above-ground growth to mitigate climate changeinduced drought.展开更多
Crop yield and quality are often limited by the amount of phosphate fertilizer added to infertile soils,a key limiting factor for sustainable development in modern agriculture.The polyphosphate kinase(ppk)gene-express...Crop yield and quality are often limited by the amount of phosphate fertilizer added to infertile soils,a key limiting factor for sustainable development in modern agriculture.The polyphosphate kinase(ppk)gene-expressing transgenic rice with a single-copy line(ETRS)is constructed to improve phosphate fertilizer utilization efficiency for phosphorus resource conservation.To investigate the potential mechanisms of the increased biomass in ETRS in low phosphate culture,ETRS was cultivated in a low inorganic phosphate(Pi)culture medium(15μmol/L Pi,LP)and a normal Pi culture medium(300μmol/L Pi,CP),respectively.After 89 d of cultivation in different concentrations of phosphate culture media,the total phosphorus,polyphosphate(polyP),biomass,photosynthetic rate,nonstructural carbohydrate(NSC)contents,related enzyme activities,and related gene expression levels were analyzed.The results showed that ETRS had a high polyP amount to promote the photosynthetic rate in LP,and its biomass was almost the same as the wild type(WT)in CP.The NSC content of ETRS in LP was higher than that of WT in LP,but slightly lower than that of WT in CP.PolyP notably promoted the sucrose phosphate synthase activities of ETRS and significantly down-regulated the expression levels of sucrose transporter genes(OsSUT3 and OsSUT4),resulting in inhibiting the transport of sucrose from shoot to root in ETRS.It was concluded that polyP can stimulate the synthesis of NSCs in LP,which improved the growth of ETRS and triggered the biological activities of ETRS to save phosphate fertilizer.Our study provides a new way to improve the utilization rate of phosphate fertilizer in rice production.展开更多
17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body wei...17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.展开更多
Hypoxia is a common environmental stress factor in aquatic organisms,which varies among fish species.However,the mechanisms underlying the ability of fish species to tolerate hypoxia are not well known.Here,we showed ...Hypoxia is a common environmental stress factor in aquatic organisms,which varies among fish species.However,the mechanisms underlying the ability of fish species to tolerate hypoxia are not well known.Here,we showed that hypoxia response in different fish species was affected by lipid catabolism and preference for lipid or carbohydrate energy sources.Activation of biochemical lipid catabolism through peroxisome proliferator-activated receptor alpha(Pparα)or increasing mitochondrial fat oxidation in tilapia decreased tolerance to acute hypoxia by increasing oxygen consumption and oxidative damage and reducing carbohydrate catabolism as an energy source.Conversely,lipid catabolism inhibition by suppressing entry of lipids into mitochondria in tilapia or individually knocking out three key genes of lipid catabolism in zebrafish increased tolerance to acute hypoxia by decreasing oxygen consumption and oxidative damage and promoting carbohydrate catabolism.However,anaerobic glycolysis suppression eliminated lipid catabolism inhibition-promoted hypoxia tolerance in adipose triglyceride lipase(atgl)mutant zebrafish.Using 14 fish species with different trophic levels and taxonomic status,the fish preferentially using lipids for energy were more intolerant to acute hypoxia than those preferentially using carbohydrates.Our study shows that hypoxia tolerance in fish depends on catabolic preference for lipids or carbohydrates,which can be modified by regulating lipid catabolism.展开更多
Interactions between water and carbon dynamics underlie drought-related tree mortality.While whole-tree water relations have been shown to play a key role in the response to and recovery from drought,the role of nonst...Interactions between water and carbon dynamics underlie drought-related tree mortality.While whole-tree water relations have been shown to play a key role in the response to and recovery from drought,the role of nonstructural carbohydrates(NSC) and how their storage and allocation changes surrounding drought events deserves further attention and is critical for understanding tree survival.Here,we quantified in situ NSC responses of temperate forest trees to the 2016 drought in the northeastern United States.Sugar and starch concentrations were measured in the stemwood of five tree species from 2014 to 2019,which allowed us to monitor NSCs in relation to climatic conditions before,during,and after the natural drought.We found that immediately following the drought,measured stemwood NSC concentrations decreased.However,NSC concentrations rebounded quickly within three years.Notably,trees allocated proportionally more to starch than to sugars following the 2016 drought.In winter 2017,starch comprised 45% of total stemwood stores,whereas starch made up only 1-2% in other years.Further,we modeled and assessed the climatic drivers of total NSC concentrations in the stem.Variation in total NSC concentrations was significantly predicted by the previous year’s temperature,precipitation,and standardized precipitation-evapotranspiration index(SPEI),with stemwood concentrations decreasing following hotter,drier periods and increasing following cooler,wetter periods.Overall,our work provides insight into the climatic drivers of NSC storage and highlights the important role that a tree’s carbon economy may play in its response and recovery to environmental stress.展开更多
Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oats...Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oatsβ-glucan oligosaccharides(OGOS),Astragalus polysaccharides(APS),Astragalus oligosaccharides(AOS),xanthan gum oligosaccharides(XGOS),gellan gum oligosaccharides(GGOS),curdlan oligosaccharides(COS),and pullulan oligosaccharides(POS)were used to investigate NDC specifi city in modulating butyrate-producing bacteria and butyrate production in 48 h in vitro fermentation studies in combination with fecal inocula from 7 healthy donors and 11 patients with type 2 diabetes(T2D).We observed that the amount of these ten NDCs utilized depended on NDC structure and inter-individual gut microbial differences.XGOS and GGOS fermentations signifi cantly increased butyrate-producing bacteria(especially f_Lachnospiraceae)and butyric acid production.Furthermore,XGOS and GGOS fermentations showed a better ability to consistently modulate gut microbiota composition and metabolic properties between individuals of healthy donors or T2D patients when compared to inulin,FOS,APS,AOS,OGS,OGOS,COS and POS fermentation.This research indicated that xanthan gum and gellan gum oligosaccharides have strong specifi city to enhance butyrate-producing bacteria and butyrate production.展开更多
For years,non-structural masonry walls have received little attention by code developers and professional engineers.Recently,significant efforts have been made to shed more light on out-of-plane(OOP)behavior of non-st...For years,non-structural masonry walls have received little attention by code developers and professional engineers.Recently,significant efforts have been made to shed more light on out-of-plane(OOP)behavior of non-structural masonry walls.In updated provisions of the Iranian seismic code,bed joint reinforcements(BJRs)and steel wallposts have been suggested for use.BJRs are horizontal reinforcements;steel wallposts are vertical truss-like elements intended to provide additional OOP restraints for a wall.The contribution of BJRs has previously been investigated by the authors.This study is devoted to investigating the contribution of steel wallposts to the OOP behavior of non-structural masonry walls.Using pre-validated 3D finite element(FE)models,the OOP behavior of 180 non-structural masonry walls with varying configurations and details are investigated.The OOP pressure-displacement curve,ultimate strength,the response modification factor,and the cracking pattern are among the results presented in this study.It is found that steel wallposts,especially those with higher rigidity,can improve the OOP strength of the walls.The contribution of wallposts in the case of shorter length walls and walls with an opening are more pronounced.Results also indicate that masonry walls with wallpost generally have smaller modification factors compared to similar walls without wallpost.展开更多
Stored nonstructural carbohydrates(NSC)indicate a balance between photosynthetic carbon(C)assimilation and growth investment or loss through respiration and root exudation.They play an important role in plant function...Stored nonstructural carbohydrates(NSC)indicate a balance between photosynthetic carbon(C)assimilation and growth investment or loss through respiration and root exudation.They play an important role in plant function and whole-plant level C cycling.CO_(2)elevation and nitrogen(N)deposition,which are two major environmental issues worldwide,aff ect plant photosynthetic C assimilation and C release in forest ecosystems.However,information regarding the eff ect of CO_(2)elevation and N deposition on NSC storage in diff erent organs remains limited,especially regarding the trade-off between growth and NSC reserves.Therefore,here we analyzed the variations in the NSC storage in diff erent organs of Chinese fi r(Cunninghamia lanceolata)under CO_(2)elevation and N addition and found that NSC concentrations and contents in all organs of Chinese fi r saplings increased remarkably under CO_(2)elevation.However,N addition induced diff erential accumulation of NSC among various organs.Specifi cally,N addition decreased the NSC concentrations of needles,branches,stems,and fi ne roots,but increased the NSC contents of branches and coarse roots.The increase in the NSC contents of roots was more pronounced than that in the NSC content of aboveground organs under CO_(2)elevation.The role of N addition in the increase in the structural biomass of aboveground organs was greater than that in the increase in the structural biomass of roots.This result indicated that a diff erent tradeoff between growth and NSC storage occurred to alleviate resource limitations under CO_(2)elevation and N addition and highlights the importance of separating biomass into structural biomass and NSC reserves when investigating the eff ects of environmental change on biomass allocation.展开更多
Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocati...Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocation for growth and consequently,wood production may be reduced.Non-structural carbohydrates comprising starch and sugars stored in plant organs,may serve as intermediate pools between assimilation and utilisation.However,the effect of resin tapping between tree growth and non-structural carbo-hydrates is not well understood.This study investigated(1)the effects of resin tapping on radial growth,(2)the effects of resin tapping on non-structural carbohydrate pools in different compartments,and(3)the feasibility of resin pro-duction without disruption of tree growth.Twenty one-year-old slash pines were subjected to resin tapping over two suc-cessive years.Non-structural carbohydrate concentrations in needles,branches,stem phloem,and roots of tapped and untapped trees in summer and winter were determined after the second year of resin harvest.The results showed that tapping had no significant effects on annual increments.Starch was the dominant non-structural carbohydrate frac-tion,regardless of tissues and season,and constituted up to 99%of the total non-structural carbohydrates in the phloem and roots.Glucose and fructose were the dominant sugars;sucrose was negligible.Compared with the controls,tapped trees showed 26%lower non-structural carbohydrate concen-tration in the phloem above the tapping wound in summer,which was attributable to the decreased abundance of starch,glucose,fructose,and sucrose.In winter,the altered non-structural carbohydrate profiles in the phloem above the tap-ping wounding were minimised as a result of recovery of the sugar concentrations.In contrast to free sugars,which accu-mulated substantially in needles and branches during winter,starch was enriched in the phloem,roots,and current-year needles.The results provide evidence for a localised effect of resin tapping,and highlight the observation that resin extrac-tion does not always cause a sacrifice in wood growth under a moderate resin-tapping intensity in slash pine plantations.展开更多
BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a common cancer with increasing morbidity and mortality due to changes of social environment.AIM To evaluate the significance of serum carbohydrate antigen 19-9(CA19...BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a common cancer with increasing morbidity and mortality due to changes of social environment.AIM To evaluate the significance of serum carbohydrate antigen 19-9(CA19-9)and tumor size changes pre-and post-neoadjuvant therapy(NAT).METHODS This retrospective study was conducted at the Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment,Chongqing University Cancer Hospital.This study specifically assessed CA19-9 levels and tumor size before and after NAT.RESULTS A total of 156 patients who completed NAT and subsequently underwent tumor resection were included in this study.The average age was 65.4±10.6 years and 72(46.2%)patients were female.Before survival analysis,we defined the post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level as the CA19-9 ratio(CR).The patients were divided into three groups:CR<0.5,CR>0.5 and<1 and CR>1.With regard to tumor size measured by both computed tomography and magnetic resonance imaging,we defined the post-NAT tumor size/pre-NAT tumor size as the tumor size ratio(TR).The patients were then divided into three groups:TR<0.5,TR>0.5 and<1 and TR>1.Based on these groups divided according to CR and TR,we performed both overall survival(OS)and disease-free survival(DFS)analyses.Log-rank tests showed that both OS and DFS were significantly different among the groups according to CR and TR(P<0.05).CR and TR after NAT were associated with increased odds of achieving a complete or near-complete pathologic response.Moreover,CR(hazard ratio:1.721,95%CI:1.373-3.762;P=0.006),and TR(hazard ratio:1.435,95%CI:1.275-4.363;P=0.014)were identified as independent factors associated with OS.CONCLUSION This study demonstrated that post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level and post-NAT tumor size/pre-NAT tumor size were independent factors associated with OS in patients with PDAC who received NAT and subsequent surgical resection.展开更多
Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen (N) fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms of ...Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen (N) fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms of N effect. Two rice cultivars with high lodging resistance were grown in the field and pot. Four panicle N fertilization treatments were conducted in 2006 and repeated in 2007. The result showed that medium level of panicle N fertilization treatment (NM) enhanced the accumulation and translocation of non-structural carbohydrate (NSC) in the stem and sheath. Compared with non-nitrogen treatment (N0), NM promoted the translocation of labeled 13C from stem and sheath to grain. But, low level of panicle N fertilization treatment (NL) and high level of panicle N fertilization treatment (NH) showed the negative effect. The endosperm cell, grain length, and grain width of NM increased more quickly than that of N0 from 4 to 10 d after anthesis. During the early period of grain filling, sucrose-phosphate synthase (EC 2.4.1.14, SPS) activity were significantly higher for the NM treatment than those of the NL and NH treatments. Sucrose synthase (EC 2.4.1.13, SuSase) activity in the grains was substantially enhanced by NM, with the duration of higher activity being longer than those of the other treatments. At maturing stage, NM significantly increased the filled grain number, the seed-setting rate, and the grain weight compared with NL and NH. The results suggest that NM have a positive effect on the activities of enzymes of physiological importance, thereby increasing the grain size and promoting grain filling.展开更多
We investigated non-structural carbohydrates(NSC) levels and components(starch,glucose,fructose and sucrose) in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri(ES),fern Parathely...We investigated non-structural carbohydrates(NSC) levels and components(starch,glucose,fructose and sucrose) in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri(ES),fern Parathelypteris nipponica(PN) and forb Aruncus sylvester(AS) in a 30-year-old Chinese pine(Pinus tabulaeformis)plantation forest on the eastern Tibetan Plateau.We also explored their responses to three gap creation treatments(control and two gap creations of 80 and 110 m2) based on NSC levels.PN had the highest leaf NSC level of the three plants,with AS second and ES lowest.Starch was the predominant component of NSC and the contents of glucose were higher than those of fructose or sucrose for all three species.The NSC level of ES in intermediate gaps was significantly higher than at control sites.PN also had higher NSC levels in both small and intermediate gaps than in control sites.But the differences between treatments were not obvious for AS.Our results suggest that ES and PN benefit from gap formation while the two species have different NSC response sensitivities to gap size,but the leaf NSC level of AS is less sensitive to the disturbance.展开更多
Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to st...Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to starch metabolism in rice stems and grains, and the microstructures related to carbohydrate accumulation and transportation to investigate the effects of different water regimes on grain filling. Two ‘super’ rice cultivars were grown under two irrigation regimes of well-watered(WW) and alternate wetting and moderate soil drying(AWMD). Compared with the WW treatment,the activities of ADP glucose pyrophosphorylase(AGPase), starch synthase(StSase) and starch branching enzyme(SBE), and the accumulation of non-structural carbohydrates(NSCs) in the stems before heading were significantly improved, and more starch granules were stored in the stems in the AWMD treatment. After heading, the activities of α-amylase, β-amylase, sucrose phosphate synthase(SPS) and sucrose synthase in the synthetic direction(SSs)were increased in the stems to promote the remobilization of NSCs for grain filling under AWMD. During grain filling, the enzymatic activities of sucrose synthase in the cleavage direction(SSc), AGPase, StSase and SBE in the inferior spikelets were increased, which promoted grain filling, especially for the inferior spikelets under AWMD.However, there were no significant differences in vascular microstructures. The grain yield and grain weight could be improved by 13.1 and 7.5%, respectively, by optimizing of the irrigation regime. We concluded that the low activities of key enzymes in carbon metabolism is the key limitation for the poor grain filling, as opposed to the vascular microstructures, and AWMD can increase the amount of NSC accumulation in the stems before heading, improve the utilization rate of NSCs after heading, and increase the grain filling, especially in the inferior spikelets, by altering the activities of key enzymes in carbon metabolism.展开更多
Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catal...Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe_2(SO_4)_3 was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe_2(SO_4)_3, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe_2(SO_4)_3 was studied by characterizing them using powder X-ray diffraction(XRD), scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS). A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.展开更多
p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both o...p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.展开更多
The current paper reviews the content and variation of fiber fractions in feed ingredients commonly used in swine diets.Carbohydrates serve as the main source of energy in diets fed to pigs.Carbohydrates may be classi...The current paper reviews the content and variation of fiber fractions in feed ingredients commonly used in swine diets.Carbohydrates serve as the main source of energy in diets fed to pigs.Carbohydrates may be classified according to their degree of polymerization: monosaccharides,disaccharides,oligosaccharides,and polysaccharides.Digestible carbohydrates include sugars,digestible starch,and glycogen that may be digested by enzymes secreted in the gastrointestinal tract of the pig.Non-digestible carbohydrates,also known as fiber,may be fermented by microbial populations along the gastrointestinal tract to synthesize short-chain fatty acids that may be absorbed and metabolized by the pig.These non-digestible carbohydrates include two disaccharides,oligosaccharides,resistant starch,and non-starch polysaccharides.The concentration and structure of non-digestible carbohydrates in diets fed to pigs depend on the type of feed ingredients that are included in the mixed diet.Cellulose,arabinoxylans,and mixed linked β-(1,3)(1,4)-D-glucans are the main cell wall polysaccharides in cereal grains,but vary in proportion and structure depending on the grain and tissue within the grain.Cell walls of oilseeds,oilseed meals,and pulse crops contain cellulose,pectic polysaccharides,lignin,and xyloglucans.Pulse crops and legumes also contain significant quantities of galacto-oligosaccharides including raffinose,stachyose,and verbascose.Overall,understanding the structure,characteristics and measurable chemical properties of fiber in feed ingredients may result in more accurate diet formulations,resulting in an improvement in the utilization of energy from less expensive high-fiber ingredients and a reduction in reliance on energy from more costly cereal grains.展开更多
基金This study was supported by the National Natural Science Foundation of China(31960306).
文摘To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.
基金the National Natural Science Foundation of China(32260379&32371852)the Jiangxi Provincial Natural Science Foundation(20224ACB215005)
文摘Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.
基金supported by grants from the Strategic Leading Science&Technology Programme,CAS(XDA23070100)National Natural Science Foundation of China(U1808201,31330016)Liaoning Revitalization Talents Program(XLYC1807102).
文摘Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various disturbances,ranging from natural storms or wildfires to anthropogenic events like logging and slashing-andburning,and sprouts of most tree species with non-structural carbohydrates(NSCs)storage can regenerate from stumps after gap formation.However,how the stump sprouts with diverse NSCs storages and stump sizes(i.e.,diameters)adapt to various micro-environments of within-gap positions remains unclear.Therefore in this study,we monitored the stump sprout regeneration(density,survival,and growth)and NSCs concentrations of three dominant tree species with different shade tolerances and varying stump diameters at five within-gap positions for the first two consecutive years after gap formation.Results:Stump diameter was positively correlated with sprout density,growth,and survival of all three tree species,but insignificantly related with sprout NSCs concentrations at the early stage after gap formation.The effect of within-gap position on sprout NSCs concentrations was different among species.After an environmental adaptation of two growing seasons,the north of gap(higher light availability and lower soil moisture habitat)was the least conducive for shade-intolerant Quercus mongolica to accumulate leaf NSCs,and the east of gap(shadier and drier habitat)was conducive to increasing the leaf NSCs concentrations of shade-tolerant Tilia mandshurica.Conclusions:Within-gap position significantly affected leaf NSCs concentrations of all three tree species,but most of the sprout growth,survival,and stem NSCs concentrations were independent of the various within-gap positions.Besides stump diameter,the NSCs stored in stump and root systems and the interspecific differences in shade tolerance also contributed more in sprout regeneration at the early stage(2 years)of gap formation.A prolonged monitoring(>10 years)is needed to further examine the long-term effects of stump diameter and within-gap position on sprout regeneration.All of these findings could be applied to gap-based silviculture by promoting sprout regeneration of dominant tree species with different shade tolerances,which would help accelerate the restoration of temperate secondary forests.
基金the National Natural Science Foundation of China(32001470)the Scientific Research Fund of Hunan Provincial Education Department(21B0184)The Science and Technology Innovation Program of Hunan province(2021RC3088).
文摘Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink characteristics in short-growth duration rice,a field experiment was conducted at three sites(Yueyang,Liuyang,and Hengyang)in 2021 and 2022.This study compared yield,yield components,source–sink characteristics,and their stability between two stable-yielding short-growth duration rice cultivars,Zhongzao 39(Z-39)and Lingliangyou 268(L-268),and two unstable-yielding short-growth duration rice cultivars,Zhongjiazao 17(Z-17)and Zhuliangyou 819(Z-819).The stability of agronomic parameters was represented by the coefficient of variation(CV).The respective CVs of yield in Z-17,Z-819,Z-39,and L-268 were 10.2%,10.1%,4.5%,and 5.7%in 2021 and 19.7%,15.0%,5.4%,and 6.5%in 2022.The respective CVs of grain weight were 6.3%,5.7%,3.4%,and 4.5%in Z-17,Z-819,Z-39,and L-268 in 2021,and 8.1%,6.3%,1.5%,and 0.8%in 2022.The mean source capacity per spikelet and pre-heading non-structural carbohydrate reserves per spikelet(NSC_(pre))were 7%–43%and7%–72%lower in Z-819 and Z-17than in L-268 and Z-39 in 2021 and 2022.The mean quantum yield of photosystem II photochemistry of leaf,leaf area index,and specific leaf weight of L-268 and Z-39 were higher than those of Z-819 and Z-17 at the heading stage.This study suggests that high NSC_(pre),caused by great leaf traits before heading,increases source capacity per spikelet and its stability,thereby increasing the stability of grain weight and yield.Increasing NSC_(pre)is critical for achieving grain weight and yield stability in short-growth duration rice.
基金supported by the National Key Research and Development Program of China,China(No.2021YFD2200405)National Natural Science Foundation of China,China(No.31930078)+1 种基金the Fundamental Research Funds of Chinese Academy of Forestry(CAFYBB2020QB009)the special funding for long term forest ecosystem research from National Forestry and Grassland Administration and Ecology and Nature Conservation Institute,Chinese Academy of Forestry.
文摘The more frequent occurrence and severer drought events resulting from climate change are increasingly affecting the physiological performance of trees and ecosystem carbon sequestration in many regions of the world.However,our understanding of the mechanisms underlying the responses and adaption of forest trees to prolonged and multi-year drought is still limited.To address this problem,we conducted a long-term manipulative throughfall reduction(TFR,reduction of natural throughfall by 50%–70%during growing seasons)experiment in a natural oriental white oak(Quercus aliena var.acuteserrata Maxim.)forest under warm-temperate climate.After seven years of continuous TFR treatment,the aboveground growth in Q.aliena var.acuteserrata started to decline.Compared with the control plots,trees in the TFR treatment significantly reduced growth increments of stems(14.2%)and leaf area index(6.8%).The rate of net photosynthesis appeared to be more susceptible to changes in soil water in trees subjected to the TFR than in the control.The TFR-treated trees allocated significantly more photosynthates to belowground,leading to enhanced growth and nonstructural carbohydrates(NSC)storage in roots.The 7-year continuous TFR treatment increased the biomass,the production and the NSC concentration in the fine roots by 53.6%,153.6%and 9.6%,respectively.There were clear trade-offs between the aboveground growth and the fine root biomass and NSC storage in Q.aliena var.acuteserrata trees in response to the multi-year TFR treatment.A negative correlation between the fine root NSC concentration and soil water suggested a strategy of preferential C storage over growth when soil water became deficient;the stored NSC during water limitation would then help promote root growth when drought stress is released.Our findings demonstrate the warm-temperate oak forest adopted a more conservative NSC use strategy in response to long-term drought stress,with enhanced root growth and NSC storage at the expenses of above-ground growth to mitigate climate changeinduced drought.
基金supported by the National Natural Science Foundation of China(Grant No.41871082)the Scientific Research Project of Ecological Environment Department of Jiangsu Province,China(Grant Nos.2020019 and 2021005)the National Special Program of Water Environment,China(Grant No.2017ZX07204002).
文摘Crop yield and quality are often limited by the amount of phosphate fertilizer added to infertile soils,a key limiting factor for sustainable development in modern agriculture.The polyphosphate kinase(ppk)gene-expressing transgenic rice with a single-copy line(ETRS)is constructed to improve phosphate fertilizer utilization efficiency for phosphorus resource conservation.To investigate the potential mechanisms of the increased biomass in ETRS in low phosphate culture,ETRS was cultivated in a low inorganic phosphate(Pi)culture medium(15μmol/L Pi,LP)and a normal Pi culture medium(300μmol/L Pi,CP),respectively.After 89 d of cultivation in different concentrations of phosphate culture media,the total phosphorus,polyphosphate(polyP),biomass,photosynthetic rate,nonstructural carbohydrate(NSC)contents,related enzyme activities,and related gene expression levels were analyzed.The results showed that ETRS had a high polyP amount to promote the photosynthetic rate in LP,and its biomass was almost the same as the wild type(WT)in CP.The NSC content of ETRS in LP was higher than that of WT in LP,but slightly lower than that of WT in CP.PolyP notably promoted the sucrose phosphate synthase activities of ETRS and significantly down-regulated the expression levels of sucrose transporter genes(OsSUT3 and OsSUT4),resulting in inhibiting the transport of sucrose from shoot to root in ETRS.It was concluded that polyP can stimulate the synthesis of NSCs in LP,which improved the growth of ETRS and triggered the biological activities of ETRS to save phosphate fertilizer.Our study provides a new way to improve the utilization rate of phosphate fertilizer in rice production.
文摘17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.
基金supported by the National Natural Science Foundation of China (31830102,32202950)。
文摘Hypoxia is a common environmental stress factor in aquatic organisms,which varies among fish species.However,the mechanisms underlying the ability of fish species to tolerate hypoxia are not well known.Here,we showed that hypoxia response in different fish species was affected by lipid catabolism and preference for lipid or carbohydrate energy sources.Activation of biochemical lipid catabolism through peroxisome proliferator-activated receptor alpha(Pparα)or increasing mitochondrial fat oxidation in tilapia decreased tolerance to acute hypoxia by increasing oxygen consumption and oxidative damage and reducing carbohydrate catabolism as an energy source.Conversely,lipid catabolism inhibition by suppressing entry of lipids into mitochondria in tilapia or individually knocking out three key genes of lipid catabolism in zebrafish increased tolerance to acute hypoxia by decreasing oxygen consumption and oxidative damage and promoting carbohydrate catabolism.However,anaerobic glycolysis suppression eliminated lipid catabolism inhibition-promoted hypoxia tolerance in adipose triglyceride lipase(atgl)mutant zebrafish.Using 14 fish species with different trophic levels and taxonomic status,the fish preferentially using lipids for energy were more intolerant to acute hypoxia than those preferentially using carbohydrates.Our study shows that hypoxia tolerance in fish depends on catabolic preference for lipids or carbohydrates,which can be modified by regulating lipid catabolism.
基金the National Science Foundation’s Graduate Research Fellowship (Grant Nos.DGE-1144152 and DGE-1745303)the Garden Club of New Jersey。
文摘Interactions between water and carbon dynamics underlie drought-related tree mortality.While whole-tree water relations have been shown to play a key role in the response to and recovery from drought,the role of nonstructural carbohydrates(NSC) and how their storage and allocation changes surrounding drought events deserves further attention and is critical for understanding tree survival.Here,we quantified in situ NSC responses of temperate forest trees to the 2016 drought in the northeastern United States.Sugar and starch concentrations were measured in the stemwood of five tree species from 2014 to 2019,which allowed us to monitor NSCs in relation to climatic conditions before,during,and after the natural drought.We found that immediately following the drought,measured stemwood NSC concentrations decreased.However,NSC concentrations rebounded quickly within three years.Notably,trees allocated proportionally more to starch than to sugars following the 2016 drought.In winter 2017,starch comprised 45% of total stemwood stores,whereas starch made up only 1-2% in other years.Further,we modeled and assessed the climatic drivers of total NSC concentrations in the stem.Variation in total NSC concentrations was significantly predicted by the previous year’s temperature,precipitation,and standardized precipitation-evapotranspiration index(SPEI),with stemwood concentrations decreasing following hotter,drier periods and increasing following cooler,wetter periods.Overall,our work provides insight into the climatic drivers of NSC storage and highlights the important role that a tree’s carbon economy may play in its response and recovery to environmental stress.
基金supported by the National Key R&D Program of China(2021YFC2101100)Project funded by China Postdoctoral Science Foundation(2021M701463)+2 种基金the National Key R&D Program of China(2017YFD0400302)the National first-class discipline program of light industry technology and engineering(LITE2018-17)the Program of Introducing Talents of Discipline to Universities(111-2-06).
文摘Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oatsβ-glucan oligosaccharides(OGOS),Astragalus polysaccharides(APS),Astragalus oligosaccharides(AOS),xanthan gum oligosaccharides(XGOS),gellan gum oligosaccharides(GGOS),curdlan oligosaccharides(COS),and pullulan oligosaccharides(POS)were used to investigate NDC specifi city in modulating butyrate-producing bacteria and butyrate production in 48 h in vitro fermentation studies in combination with fecal inocula from 7 healthy donors and 11 patients with type 2 diabetes(T2D).We observed that the amount of these ten NDCs utilized depended on NDC structure and inter-individual gut microbial differences.XGOS and GGOS fermentations signifi cantly increased butyrate-producing bacteria(especially f_Lachnospiraceae)and butyric acid production.Furthermore,XGOS and GGOS fermentations showed a better ability to consistently modulate gut microbiota composition and metabolic properties between individuals of healthy donors or T2D patients when compared to inulin,FOS,APS,AOS,OGS,OGOS,COS and POS fermentation.This research indicated that xanthan gum and gellan gum oligosaccharides have strong specifi city to enhance butyrate-producing bacteria and butyrate production.
文摘For years,non-structural masonry walls have received little attention by code developers and professional engineers.Recently,significant efforts have been made to shed more light on out-of-plane(OOP)behavior of non-structural masonry walls.In updated provisions of the Iranian seismic code,bed joint reinforcements(BJRs)and steel wallposts have been suggested for use.BJRs are horizontal reinforcements;steel wallposts are vertical truss-like elements intended to provide additional OOP restraints for a wall.The contribution of BJRs has previously been investigated by the authors.This study is devoted to investigating the contribution of steel wallposts to the OOP behavior of non-structural masonry walls.Using pre-validated 3D finite element(FE)models,the OOP behavior of 180 non-structural masonry walls with varying configurations and details are investigated.The OOP pressure-displacement curve,ultimate strength,the response modification factor,and the cracking pattern are among the results presented in this study.It is found that steel wallposts,especially those with higher rigidity,can improve the OOP strength of the walls.The contribution of wallposts in the case of shorter length walls and walls with an opening are more pronounced.Results also indicate that masonry walls with wallpost generally have smaller modification factors compared to similar walls without wallpost.
基金the National Natural Science Foundation of China(Grant Nos.32192434,42007102)Natural Science Foundation of Fujian Province(Grant No.2020J01376)+1 种基金the Start-up Foundation for Advanced Talents in Sanming University(Grant No.19YG13)Educational Research Project for Young and Middle-aged Teachers of Fujian Provincial Department of Education(Grant No.JAT190704).
文摘Stored nonstructural carbohydrates(NSC)indicate a balance between photosynthetic carbon(C)assimilation and growth investment or loss through respiration and root exudation.They play an important role in plant function and whole-plant level C cycling.CO_(2)elevation and nitrogen(N)deposition,which are two major environmental issues worldwide,aff ect plant photosynthetic C assimilation and C release in forest ecosystems.However,information regarding the eff ect of CO_(2)elevation and N deposition on NSC storage in diff erent organs remains limited,especially regarding the trade-off between growth and NSC reserves.Therefore,here we analyzed the variations in the NSC storage in diff erent organs of Chinese fi r(Cunninghamia lanceolata)under CO_(2)elevation and N addition and found that NSC concentrations and contents in all organs of Chinese fi r saplings increased remarkably under CO_(2)elevation.However,N addition induced diff erential accumulation of NSC among various organs.Specifi cally,N addition decreased the NSC concentrations of needles,branches,stems,and fi ne roots,but increased the NSC contents of branches and coarse roots.The increase in the NSC contents of roots was more pronounced than that in the NSC content of aboveground organs under CO_(2)elevation.The role of N addition in the increase in the structural biomass of aboveground organs was greater than that in the increase in the structural biomass of roots.This result indicated that a diff erent tradeoff between growth and NSC storage occurred to alleviate resource limitations under CO_(2)elevation and N addition and highlights the importance of separating biomass into structural biomass and NSC reserves when investigating the eff ects of environmental change on biomass allocation.
基金The work was supported by the General Program of the National Natural Science Foundation of China(31,470,635)the Fundamental Research Funds of the Chinese Academy of Forestry(No.CAFYBB2017ZX001-3).
文摘Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocation for growth and consequently,wood production may be reduced.Non-structural carbohydrates comprising starch and sugars stored in plant organs,may serve as intermediate pools between assimilation and utilisation.However,the effect of resin tapping between tree growth and non-structural carbo-hydrates is not well understood.This study investigated(1)the effects of resin tapping on radial growth,(2)the effects of resin tapping on non-structural carbohydrate pools in different compartments,and(3)the feasibility of resin pro-duction without disruption of tree growth.Twenty one-year-old slash pines were subjected to resin tapping over two suc-cessive years.Non-structural carbohydrate concentrations in needles,branches,stem phloem,and roots of tapped and untapped trees in summer and winter were determined after the second year of resin harvest.The results showed that tapping had no significant effects on annual increments.Starch was the dominant non-structural carbohydrate frac-tion,regardless of tissues and season,and constituted up to 99%of the total non-structural carbohydrates in the phloem and roots.Glucose and fructose were the dominant sugars;sucrose was negligible.Compared with the controls,tapped trees showed 26%lower non-structural carbohydrate concen-tration in the phloem above the tapping wound in summer,which was attributable to the decreased abundance of starch,glucose,fructose,and sucrose.In winter,the altered non-structural carbohydrate profiles in the phloem above the tap-ping wounding were minimised as a result of recovery of the sugar concentrations.In contrast to free sugars,which accu-mulated substantially in needles and branches during winter,starch was enriched in the phloem,roots,and current-year needles.The results provide evidence for a localised effect of resin tapping,and highlight the observation that resin extrac-tion does not always cause a sacrifice in wood growth under a moderate resin-tapping intensity in slash pine plantations.
基金Natural Science Foundation of Chongqing,China,No.cstc2021jcyj-msxmX0501Chongqing Medical Scientific Research Project(Joint Project of Chongqing Health Commission and Science and Technology Bureau),No.2022QNXM074.
文摘BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a common cancer with increasing morbidity and mortality due to changes of social environment.AIM To evaluate the significance of serum carbohydrate antigen 19-9(CA19-9)and tumor size changes pre-and post-neoadjuvant therapy(NAT).METHODS This retrospective study was conducted at the Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment,Chongqing University Cancer Hospital.This study specifically assessed CA19-9 levels and tumor size before and after NAT.RESULTS A total of 156 patients who completed NAT and subsequently underwent tumor resection were included in this study.The average age was 65.4±10.6 years and 72(46.2%)patients were female.Before survival analysis,we defined the post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level as the CA19-9 ratio(CR).The patients were divided into three groups:CR<0.5,CR>0.5 and<1 and CR>1.With regard to tumor size measured by both computed tomography and magnetic resonance imaging,we defined the post-NAT tumor size/pre-NAT tumor size as the tumor size ratio(TR).The patients were then divided into three groups:TR<0.5,TR>0.5 and<1 and TR>1.Based on these groups divided according to CR and TR,we performed both overall survival(OS)and disease-free survival(DFS)analyses.Log-rank tests showed that both OS and DFS were significantly different among the groups according to CR and TR(P<0.05).CR and TR after NAT were associated with increased odds of achieving a complete or near-complete pathologic response.Moreover,CR(hazard ratio:1.721,95%CI:1.373-3.762;P=0.006),and TR(hazard ratio:1.435,95%CI:1.275-4.363;P=0.014)were identified as independent factors associated with OS.CONCLUSION This study demonstrated that post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level and post-NAT tumor size/pre-NAT tumor size were independent factors associated with OS in patients with PDAC who received NAT and subsequent surgical resection.
基金supported by the National Natural Science Foundation of China (30871482)the Scientific Research Innovation Project for Graduate Student of Jiangsu Province, China (CXO7B_184Z)
文摘Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen (N) fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms of N effect. Two rice cultivars with high lodging resistance were grown in the field and pot. Four panicle N fertilization treatments were conducted in 2006 and repeated in 2007. The result showed that medium level of panicle N fertilization treatment (NM) enhanced the accumulation and translocation of non-structural carbohydrate (NSC) in the stem and sheath. Compared with non-nitrogen treatment (N0), NM promoted the translocation of labeled 13C from stem and sheath to grain. But, low level of panicle N fertilization treatment (NL) and high level of panicle N fertilization treatment (NH) showed the negative effect. The endosperm cell, grain length, and grain width of NM increased more quickly than that of N0 from 4 to 10 d after anthesis. During the early period of grain filling, sucrose-phosphate synthase (EC 2.4.1.14, SPS) activity were significantly higher for the NM treatment than those of the NL and NH treatments. Sucrose synthase (EC 2.4.1.13, SuSase) activity in the grains was substantially enhanced by NM, with the duration of higher activity being longer than those of the other treatments. At maturing stage, NM significantly increased the filled grain number, the seed-setting rate, and the grain weight compared with NL and NH. The results suggest that NM have a positive effect on the activities of enzymes of physiological importance, thereby increasing the grain size and promoting grain filling.
基金supported by the Strategic Priority Research Program of the CAS(No.XDA05070306)the National Science&Technology Pillar Program in 12th 5-year Plan of China(No.2011BAC09B0402)
文摘We investigated non-structural carbohydrates(NSC) levels and components(starch,glucose,fructose and sucrose) in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri(ES),fern Parathelypteris nipponica(PN) and forb Aruncus sylvester(AS) in a 30-year-old Chinese pine(Pinus tabulaeformis)plantation forest on the eastern Tibetan Plateau.We also explored their responses to three gap creation treatments(control and two gap creations of 80 and 110 m2) based on NSC levels.PN had the highest leaf NSC level of the three plants,with AS second and ES lowest.Starch was the predominant component of NSC and the contents of glucose were higher than those of fructose or sucrose for all three species.The NSC level of ES in intermediate gaps was significantly higher than at control sites.PN also had higher NSC levels in both small and intermediate gaps than in control sites.But the differences between treatments were not obvious for AS.Our results suggest that ES and PN benefit from gap formation while the two species have different NSC response sensitivities to gap size,but the leaf NSC level of AS is less sensitive to the disturbance.
基金This project was finically supported by the R&D Foundation of Jiangsu Province,China(BE2022425)the National Key Research and Development Program of China(2022YFD2300304)the Priority Academic Program Development of Jiangsu Higher-Education Institutions,China(PAPD).
文摘Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to starch metabolism in rice stems and grains, and the microstructures related to carbohydrate accumulation and transportation to investigate the effects of different water regimes on grain filling. Two ‘super’ rice cultivars were grown under two irrigation regimes of well-watered(WW) and alternate wetting and moderate soil drying(AWMD). Compared with the WW treatment,the activities of ADP glucose pyrophosphorylase(AGPase), starch synthase(StSase) and starch branching enzyme(SBE), and the accumulation of non-structural carbohydrates(NSCs) in the stems before heading were significantly improved, and more starch granules were stored in the stems in the AWMD treatment. After heading, the activities of α-amylase, β-amylase, sucrose phosphate synthase(SPS) and sucrose synthase in the synthetic direction(SSs)were increased in the stems to promote the remobilization of NSCs for grain filling under AWMD. During grain filling, the enzymatic activities of sucrose synthase in the cleavage direction(SSc), AGPase, StSase and SBE in the inferior spikelets were increased, which promoted grain filling, especially for the inferior spikelets under AWMD.However, there were no significant differences in vascular microstructures. The grain yield and grain weight could be improved by 13.1 and 7.5%, respectively, by optimizing of the irrigation regime. We concluded that the low activities of key enzymes in carbon metabolism is the key limitation for the poor grain filling, as opposed to the vascular microstructures, and AWMD can increase the amount of NSC accumulation in the stems before heading, improve the utilization rate of NSCs after heading, and increase the grain filling, especially in the inferior spikelets, by altering the activities of key enzymes in carbon metabolism.
基金financially supported by the National Natural Science Foundation of China (nos.21176227 and U1404519)
文摘Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe_2(SO_4)_3 was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe_2(SO_4)_3, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe_2(SO_4)_3 was studied by characterizing them using powder X-ray diffraction(XRD), scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS). A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.
基金NSFA !(No.29825112)CAS !(No.KJ951-A1-507)Madam Xu Guiyun (Center for Molecular Science, Institute of Chemistry, Chinese
文摘p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.
文摘The current paper reviews the content and variation of fiber fractions in feed ingredients commonly used in swine diets.Carbohydrates serve as the main source of energy in diets fed to pigs.Carbohydrates may be classified according to their degree of polymerization: monosaccharides,disaccharides,oligosaccharides,and polysaccharides.Digestible carbohydrates include sugars,digestible starch,and glycogen that may be digested by enzymes secreted in the gastrointestinal tract of the pig.Non-digestible carbohydrates,also known as fiber,may be fermented by microbial populations along the gastrointestinal tract to synthesize short-chain fatty acids that may be absorbed and metabolized by the pig.These non-digestible carbohydrates include two disaccharides,oligosaccharides,resistant starch,and non-starch polysaccharides.The concentration and structure of non-digestible carbohydrates in diets fed to pigs depend on the type of feed ingredients that are included in the mixed diet.Cellulose,arabinoxylans,and mixed linked β-(1,3)(1,4)-D-glucans are the main cell wall polysaccharides in cereal grains,but vary in proportion and structure depending on the grain and tissue within the grain.Cell walls of oilseeds,oilseed meals,and pulse crops contain cellulose,pectic polysaccharides,lignin,and xyloglucans.Pulse crops and legumes also contain significant quantities of galacto-oligosaccharides including raffinose,stachyose,and verbascose.Overall,understanding the structure,characteristics and measurable chemical properties of fiber in feed ingredients may result in more accurate diet formulations,resulting in an improvement in the utilization of energy from less expensive high-fiber ingredients and a reduction in reliance on energy from more costly cereal grains.
