The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiatio...The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers:(Ⅰ) differentiation of male or female primordia to produce staminate flowers(SFs) or transient hermaphrodite flowers(HFs),and(Ⅱ) complete abortion of stamens in transient HFs to generate pistillate flowers(PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptomebased analysis revealed that the differentially expressed genes(DEGs) between PFs and SFs in phase Ⅰ involved in abscisic acid(ABA), auxin(AUX), cytokinin(CK), ethylene(ET), and gibberellin(GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid(JA) and salicylic acid(SA) pathways displayed opposite expression patterns. Moreover,differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MSbased analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase Ⅱ indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.展开更多
Gingko biloba accumulates high levels of secondary metabolites of pharmaceutical value.Ginkgo calli develop a typical browning that reduces its regenerative capacity and thus its usefulness.To elucidate the browning m...Gingko biloba accumulates high levels of secondary metabolites of pharmaceutical value.Ginkgo calli develop a typical browning that reduces its regenerative capacity and thus its usefulness.To elucidate the browning mechanism,histological,transcriptomic,and metabolic alterations were compared between green and browning calli derived from immature ginkgo embryos.Histological observations revealed that browning calli had a more loosely arranged cell structure and accumulated more tannins than in green calli.Integrated metabolic and transcriptomic analyses showed that phenylpropanoid metabolism was specifi-cally activated in the browning calli,and 428 diff erentially expressed genes and 63 diff erentially abundant metabolites,including 12 fl avonoid compounds,were identifi ed in the browning calli compared to the green calli.Moreover,the expression of fl avonol synthase(FLS)and UDP-glucuronosyl-transferase(UGT)genes involved in the fl avonoid pathway was more than tenfold higher in browning calli than in green calli,thus promoting biosynthesis of fl avonol,which serves as a substrate to form glycosylated fl avonoids.Flavonoid glycosides constituted the major coloring component of the browning calli and may act in response to multiple stress conditions to delay cell death caused by browning.Our results revealed the cellular and biochemical changes in browning callus cells that accompanied changes in expression of browning-related genes,providing a scientifi c basis for improving ginkgo tissue culturability.展开更多
The aluminum(Al)cation Al^(3+)in acidic soil shows severe rhizotoxicity that inhibits plant growth and development.Most woody plants adapted to acidic soils have evolved specific strategies against Al^(3+)toxicity,but...The aluminum(Al)cation Al^(3+)in acidic soil shows severe rhizotoxicity that inhibits plant growth and development.Most woody plants adapted to acidic soils have evolved specific strategies against Al^(3+)toxicity,but the underlying mechanism remains elusive.The four-carbon amino acid gamma-aminobutyric acid(GABA)has been well studied in mammals as an inhibitory neurotransmitter;GABA also controls many physiological responses during environmental or biotic stress.The woody plant hybrid Liriodendron(L.chinense×tulipifera)is widely cultivated in China as a horticultural tree and provides high-quality timber;studying its adaptation to high Al stress is important for harnessing its ecological and economic potential.Here,we performed quantitative iTRAQ(isobaric tags for relative and absolute quantification)to study how protein expression is altered in hybrid Liriodendron leaves subjected to Al stress.Hybrid Liriodendron shows differential accumulation of several proteins related to cell wall biosynthesis,sugar and proline metabolism,antioxidant activity,cell autophagy,protein ubiquitination degradation,and anion transport in response to Al damage.We observed that Al stress upregulated glutamate decarboxylase(GAD)and its activity,leading to increased GABA biosynthesis.Additional GABA synergistically increased Al-induced antioxidant enzyme activity to efficiently scavenge ROS,enhanced proline biosynthesis,and upregulated the expression of MATE1/2,which subsequently promoted the efflux of citrate for chelation of Al^(3+).We also showed similar effects of GABA on enhanced Al^(3+)tolerance in Arabidopsis.Thus,our findings suggest a function of GABA signaling in enhancing hybrid Liriodendron tolerance to Al stress through promoting organic acid transport and sustaining the cellular redox and osmotic balance.展开更多
Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 1...Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 156,990 bp long and predicted to encode 134 genes including 85 protein-coding genes,41 tRNA genes and 8 rRNA genes.The chloroplast genome has a typical quadripartite structure with a pair of inverted repeat regions(IRa and IRb,17,732 bp),a large(LSC,99,259 bp)and small single(SSC,22,267 bp)copy region.After an extensive comparison to previously published gymnosperm plastomes,the gene content and organisation of G.biloba showed high divergence,although part was relatively conserved.The two typical IR regions in the G.biloba chloroplast genome were relatively shorter because it the ycf2 gene.In addition,it was obvious that the IR regions and gene loss were responsible for changes in chloroplast genome size and structure stability,which influenced plastome evolution in different gymnosperms.Phylogenetic analysis revealed that G.biloba is sister to cycads rather than to gnetophytes,cupressophytes,and Pinaceae.Overall,the study showed that the genomic characteristics of G.biloba would be of great help in the further research on the taxonomy,species identification and evolutionary history of gymnosperms,especially for their position in plant systematics and evolution.展开更多
Expert opinions have been used in a variety of fields to identify relevant issues and courses of action. This study surveys experts in forestry and climate change from the Asia–Pacific region to gauge their perspecti...Expert opinions have been used in a variety of fields to identify relevant issues and courses of action. This study surveys experts in forestry and climate change from the Asia–Pacific region to gauge their perspectives on the impacts of climate change and on the challenges faced by forest adaptation in the region, and explores recommendations and initiatives for adapting forests to climate change. There was consensus regarding the impacts of climate change on forest ecosystems and on economic sectors such as agriculture and forestry. Respondents also indicated a lack of public awareness and policy and legislation as challenges to addressing climate change. However, the results indicate differences in opinion between regions on the negative impacts of climate change and in satisfaction with actions taken to address climate change,highlighting the need for locally specific policies and research. The study presents specific recommendations to address issues of most concern, based on subregion and professional affiliation throughout the Asia–Pacific region.The results can be used to improve policy and forest management throughout the region. This research will also provide valuable suggestions on how to apply research findings and management recommendations outside of the AP region. The conclusions should be communicated relative to the level of the research and the target audience,ensuring that scientific findings and management recommendations are effectively communicated to ensure successful implementation of forest adaptation strategies.展开更多
The response of soil fauna to the litter decomposition process has received considerable attention,but this effect has not been fully examined in agroforestry systems.A 1-year in situ decomposition experiment was carr...The response of soil fauna to the litter decomposition process has received considerable attention,but this effect has not been fully examined in agroforestry systems.A 1-year in situ decomposition experiment was carried out in a pure ginkgo plantation and two ginkgo agroforestry systems using a litterbag method(11 different treatments were tested in three systems).We found that the application of different organic materials(crop residues)produced positive effects on the number of soil fauna in the ginkgo planting systems;the mixture of ginkgo leaves and corn leaves was the best performing treatment.Collembola and Acarina were the predominant groups in the litter bags and were mainly responsible for the differences among the treatments.Litter mixing promoted the abundance,richness,and diversity of soil fauna,and significant differences regarding the Shannon–Wiener index of the soil fauna were observed among the 11 treatments in July.Significantly higher soil MBC(microbial biomass carbon)and MBN(microbial biomass nitrogen)were observed in agroforestry systems than in pure ginkgo plantations.These results suggest that the practice of intercrop residue application plays an important role in enhancing soil ecosystem function in ginkgo agroforestry systems and may ultimately contribute to sustainable intercrop production,soil fertility,and local economic diversity.展开更多
This paper describes the importance of plant quarantine to the food safety in China through cases where plant quarantine helps to effectively intercept harmful organisms for food safety and promote export and import t...This paper describes the importance of plant quarantine to the food safety in China through cases where plant quarantine helps to effectively intercept harmful organisms for food safety and promote export and import trading.It also presents the existing problems in plant quarantine work and appropriate measures.展开更多
Cullin-RING E3 ubiquitin ligases(CRLs),the largest family of multi-subunit E3 ubiquitin ligases in eukaryotic cells,represent core cellular machinery for executing protein degradation and maintaining proteostasis.Here...Cullin-RING E3 ubiquitin ligases(CRLs),the largest family of multi-subunit E3 ubiquitin ligases in eukaryotic cells,represent core cellular machinery for executing protein degradation and maintaining proteostasis.Here,we asked what roles Cullin proteins play in human mesenchymal stem cell(hMSC)homeostasis and senescence.To this end,we conducted a comparative aging phenotype analysis by individually knocking down Cullin members in three senescence models:replicative senescent hMSCs,Hutchinson-Gilford Progeria Syndrome hMSCs,and Werner syndrome hMSCs.Among all family members,we found that CUL2 deficiency rendered hMSCs the most susceptible to senescence.To investigate CUL2-specific underlying mechanisms,we then applied CRISPR/Cas9-mediated gene editing technology to generate CUL2-deficient human embryonic stem cells(hESCs).When we differentiated these into h MSCs,we found that CUL2 deletion markedly accelerates hMSC senescence.Importantly,we identified that CUL2 targets and promotes ubiquitin proteasome-mediated degradation of TSPYL2(a known negative regulator of proliferation)through the substrate receptor protein APPBP2,which in turn downregulates one of the canonical aging marker-P21^(waf1/cip1),and thereby delays senescence.Our work provides important insights into how CRL2^(APPBP2)-mediated TSPYL2 degradation counteracts hMSC senescence,providing a molecular basis for directing intervention strategies against aging and aging-related diseases.展开更多
Redwood trees(Sequoioideae),including Metasequoia glyptostroboides(dawn redwood),Sequoiadendron giganteum(giant sequoia),and Sequoia sempervirens(coast redwood),are threatened and widely recognized iconic tree species...Redwood trees(Sequoioideae),including Metasequoia glyptostroboides(dawn redwood),Sequoiadendron giganteum(giant sequoia),and Sequoia sempervirens(coast redwood),are threatened and widely recognized iconic tree species.Genomic resources for redwood trees could provide clues to their evolutionary relationships.Here,we report the 8-Gb reference genome of M.glyptostroboides and a comparative analysis with two related species.More than 62%of the M.glyptostroboides genome is composed of repetitive sequences.Clade-specific bursts of long terminal repeat retrotransposons may have contributed to genomic differentiation in the three species.The chromosomal synteny between M.glyptostroboides and S.giganteum is extremely high,whereas there has been significant chromosome reorganization in S.sempervirens.Phylogenetic analysis of marker genes indicates that S.sempervirens is an autopolyploid,and more than 48%of the gene trees are incongruent with the species tree.Results of multiple analyses suggest that incomplete lineage sorting(ILS)rather than hybridization explains the inconsistent phylogeny,indicating that genetic variation among redwoods may be due to random retention of polymorphisms in ancestral populations.Functional analysis of ortholog groups indicates that gene families of ion channels,tannin biosynthesis enzymes,and transcription factors for meristem maintenance have expanded in S.giganteum and S.sempervirens,which is consistent with their extreme height.As a wetland-tolerant species,M.glyptostroboides shows a transcriptional response to flooding stress that is conserved with that of analyzed angiosperm species.Our study offers insights into redwood evolution and adaptation and provides genomic resources to aid in their conservation and management.展开更多
The direct blending of polyether ether ketone(PEEK)with a solid lubricant such as polytetrafluoroethylene(PTFE)improves its tribological performance,but compromises its outstanding mechanical properties and processabi...The direct blending of polyether ether ketone(PEEK)with a solid lubricant such as polytetrafluoroethylene(PTFE)improves its tribological performance,but compromises its outstanding mechanical properties and processability.While these negative effects might be circumvented via the hybrid wear method,the influence of the contact temperature between multiple sliding components acting together is not fully understood.Herein,an analytical temperature model considering the influence of both micro-and macro-thermal behavior is extended to predict the contact temperature of a dual-pin-on-disk hybrid wear system.The interactions between several heat sources are investigated and experimentally verified.The analytical results show that the nominal temperature rise of the shared wear track is determined by the combined effect of the heat generated by both pin components,while the rise in flash temperature at the region in contact with each pin component is dependent upon its individual characteristics and working conditions.Hence,while different temperature peaks can coexist in the shared wear track,the maximum value dominates the performance of the system.For the experimentally investigated PEEK–PTFE–steel hybrid wear system,the formation of tribofilms is blocked,and the hybrid wear system fails,when the peak temperature exceeds the glass transition temperature of both pins due to an increase in applied load.展开更多
It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ form...It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ formed carboxylic acid-functionalized poly(aryl ether sulfone)(PAES-COOH)/polyvinylpyrrolidone(PVPON)complex nanoparticles can significantly enhance the mechanical strength of PAES-COOH by mixing PAES-COOH with a small fraction of PVPON.The PAES-COOH/PVPON10%composite,which contained∼10 wt%PVPON,exhibited a tensile strength of∼104.8 MPa and Young’s modulus of∼932.2 MPa,which were∼2.0 and∼1.7 times higher than those of the PAES-COOH,respectively.The PAES-COOH/PVPON nanoparticles which were uniformly dispersed in PAES-COOH matrices and had strong hydrogen-bonding interactions with PAES-COOH,served as nanofillers to reinforce the mechanical strength of the PAES-COOH.The PAES-COOH/PVPON_(10%)composites possessed excellent solvent-assisted healability,and the fractured composites could be healed to restore their original mechanical strength.Meanwhile,the PAES-COOH/PVPON_(10%)composites could be recycled multiple times,and yet retained their shape integration and their original mechanical strength.展开更多
The synergies between electricity and other energy resources could promote energy utilization efficiency in electricity market.Within this context,this paper proposes a bi-level stochastic optimization model for the j...The synergies between electricity and other energy resources could promote energy utilization efficiency in electricity market.Within this context,this paper proposes a bi-level stochastic optimization model for the joint operation of a coordinated wind power plant(WPP)and natural gas generating(NGG)-power to gas(P2G)suppliers participating in the day-ahead(DA)market and real-time(RT)market as well as providing real-time auxiliary services.The coordinated supplier’s payoff is maximized in the upper level with consideration of the uncertainties of WPP output capacity and RT electricity price,while the social welfare of the grid is maximized in the lower level.Simulation results demonstrate the effectiveness of the proposed bidding model of the coordinated WPPs and NGG-P2G suppliers by examining its bidding behaviors and benefits with comparisons of four other bidding models.展开更多
Ginkgolic acids are unwanted constituents in standard Ginkgo biloba leaves extracts. Thus, for the quality control of ginkgo extracts, it is important to establish an effective degradation method, with high catalytic ...Ginkgolic acids are unwanted constituents in standard Ginkgo biloba leaves extracts. Thus, for the quality control of ginkgo extracts, it is important to establish an effective degradation method, with high catalytic efficiency and safety, to remove ginkgolic acids.Laccases are oxidases with potential for application in elimination of hazardous phenolic compounds. In this study, single-factor and orthogonal experiments were used to optimize extraction of ginkgolic acid from G. biloba sarcotestae. The results showed that ethanol was the best solvent, with the highest extraction rate for ginkgolic acid at 85% ethanol. On this basis, we measured ethanol volume fraction, extraction time, temperature and solidliquid ratio using an orthogonal experiment. By using absorbance of 310 nm as standard, the optimal extraction conditions were 85% ethanol with, solid-liquid ratio of1:14 at 40°C for 12 h. These conditions gave a ginkgolic acid yield of 73.1 mg·g^(–1). Subsequently, recombinant laccase was used to degrade the ginkgolic acid in several laccase/mediator systems, of which Lac C was the best. At50°C, p H 4.5, enzyme concentration of 0.01 U·m L^(–1),0.5 mmol·L^(–1) mediator ABTS and reaction time of 3 h, the degradation rate of ginkgolic acid reached 100%. These results lay the foundation for research on and application of biological enzymes for detoxification of G. biloba extracts.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.32171843)the Postgraduate Scientific Research Innovation Project of Hunan Province (Grant No.CX20200696)the Scientific Innovation Fund for Graduate of Central South University of Forestry and Technology (Grant No.CX20201003)。
文摘The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers:(Ⅰ) differentiation of male or female primordia to produce staminate flowers(SFs) or transient hermaphrodite flowers(HFs),and(Ⅱ) complete abortion of stamens in transient HFs to generate pistillate flowers(PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptomebased analysis revealed that the differentially expressed genes(DEGs) between PFs and SFs in phase Ⅰ involved in abscisic acid(ABA), auxin(AUX), cytokinin(CK), ethylene(ET), and gibberellin(GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid(JA) and salicylic acid(SA) pathways displayed opposite expression patterns. Moreover,differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MSbased analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase Ⅱ indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20210611)the China Postdoctoral Science Foundation(2018M642261)+2 种基金the Postdoctoral Science Foundation of Jiangsu Province(2018K197C)the Jiangsu Science and Technology Plan Project(BE2021367)the National Natural Science Foundation of China(31971689).
文摘Gingko biloba accumulates high levels of secondary metabolites of pharmaceutical value.Ginkgo calli develop a typical browning that reduces its regenerative capacity and thus its usefulness.To elucidate the browning mechanism,histological,transcriptomic,and metabolic alterations were compared between green and browning calli derived from immature ginkgo embryos.Histological observations revealed that browning calli had a more loosely arranged cell structure and accumulated more tannins than in green calli.Integrated metabolic and transcriptomic analyses showed that phenylpropanoid metabolism was specifi-cally activated in the browning calli,and 428 diff erentially expressed genes and 63 diff erentially abundant metabolites,including 12 fl avonoid compounds,were identifi ed in the browning calli compared to the green calli.Moreover,the expression of fl avonol synthase(FLS)and UDP-glucuronosyl-transferase(UGT)genes involved in the fl avonoid pathway was more than tenfold higher in browning calli than in green calli,thus promoting biosynthesis of fl avonol,which serves as a substrate to form glycosylated fl avonoids.Flavonoid glycosides constituted the major coloring component of the browning calli and may act in response to multiple stress conditions to delay cell death caused by browning.Our results revealed the cellular and biochemical changes in browning callus cells that accompanied changes in expression of browning-related genes,providing a scientifi c basis for improving ginkgo tissue culturability.
基金the National Natural Science Foundation of China(32071784 and 31770715)Natural Science Foundation of Jiangsu Province(BK20181176)Qinglan project of Jiangsu province,Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The aluminum(Al)cation Al^(3+)in acidic soil shows severe rhizotoxicity that inhibits plant growth and development.Most woody plants adapted to acidic soils have evolved specific strategies against Al^(3+)toxicity,but the underlying mechanism remains elusive.The four-carbon amino acid gamma-aminobutyric acid(GABA)has been well studied in mammals as an inhibitory neurotransmitter;GABA also controls many physiological responses during environmental or biotic stress.The woody plant hybrid Liriodendron(L.chinense×tulipifera)is widely cultivated in China as a horticultural tree and provides high-quality timber;studying its adaptation to high Al stress is important for harnessing its ecological and economic potential.Here,we performed quantitative iTRAQ(isobaric tags for relative and absolute quantification)to study how protein expression is altered in hybrid Liriodendron leaves subjected to Al stress.Hybrid Liriodendron shows differential accumulation of several proteins related to cell wall biosynthesis,sugar and proline metabolism,antioxidant activity,cell autophagy,protein ubiquitination degradation,and anion transport in response to Al damage.We observed that Al stress upregulated glutamate decarboxylase(GAD)and its activity,leading to increased GABA biosynthesis.Additional GABA synergistically increased Al-induced antioxidant enzyme activity to efficiently scavenge ROS,enhanced proline biosynthesis,and upregulated the expression of MATE1/2,which subsequently promoted the efflux of citrate for chelation of Al^(3+).We also showed similar effects of GABA on enhanced Al^(3+)tolerance in Arabidopsis.Thus,our findings suggest a function of GABA signaling in enhancing hybrid Liriodendron tolerance to Al stress through promoting organic acid transport and sustaining the cellular redox and osmotic balance.
基金supported by the Key Forestry Public Welfare Project of China(201504105)the National Key Research and Development Program of China(2017YFD0600700)the Agricultural Science and Technology Independent Innovation Funds of Jiangsu Province[CX(16)1005].
文摘Ginkgo biloba is a famous living“fossil”and has played an important role in the evolution of the Plant Kingdom.Here,the complete chloroplast genome of G.biloba was sequenced and analysed.The chloroplast genome was 156,990 bp long and predicted to encode 134 genes including 85 protein-coding genes,41 tRNA genes and 8 rRNA genes.The chloroplast genome has a typical quadripartite structure with a pair of inverted repeat regions(IRa and IRb,17,732 bp),a large(LSC,99,259 bp)and small single(SSC,22,267 bp)copy region.After an extensive comparison to previously published gymnosperm plastomes,the gene content and organisation of G.biloba showed high divergence,although part was relatively conserved.The two typical IR regions in the G.biloba chloroplast genome were relatively shorter because it the ycf2 gene.In addition,it was obvious that the IR regions and gene loss were responsible for changes in chloroplast genome size and structure stability,which influenced plastome evolution in different gymnosperms.Phylogenetic analysis revealed that G.biloba is sister to cycads rather than to gnetophytes,cupressophytes,and Pinaceae.Overall,the study showed that the genomic characteristics of G.biloba would be of great help in the further research on the taxonomy,species identification and evolutionary history of gymnosperms,especially for their position in plant systematics and evolution.
基金supported by the Asia Pacific Network for Sustainable Forest Management and Rehabilitation(APFNet)under the project ‘‘Adaption of Asia Pacific Forests to Climate Change’’
文摘Expert opinions have been used in a variety of fields to identify relevant issues and courses of action. This study surveys experts in forestry and climate change from the Asia–Pacific region to gauge their perspectives on the impacts of climate change and on the challenges faced by forest adaptation in the region, and explores recommendations and initiatives for adapting forests to climate change. There was consensus regarding the impacts of climate change on forest ecosystems and on economic sectors such as agriculture and forestry. Respondents also indicated a lack of public awareness and policy and legislation as challenges to addressing climate change. However, the results indicate differences in opinion between regions on the negative impacts of climate change and in satisfaction with actions taken to address climate change,highlighting the need for locally specific policies and research. The study presents specific recommendations to address issues of most concern, based on subregion and professional affiliation throughout the Asia–Pacific region.The results can be used to improve policy and forest management throughout the region. This research will also provide valuable suggestions on how to apply research findings and management recommendations outside of the AP region. The conclusions should be communicated relative to the level of the research and the target audience,ensuring that scientific findings and management recommendations are effectively communicated to ensure successful implementation of forest adaptation strategies.
基金supported by the Agricultural Science and Technology Independent Innovation Funds of Jiangsu Province(CX(16)1005)the National Key Research and Development Program of China(2017YFD0600700)
文摘The response of soil fauna to the litter decomposition process has received considerable attention,but this effect has not been fully examined in agroforestry systems.A 1-year in situ decomposition experiment was carried out in a pure ginkgo plantation and two ginkgo agroforestry systems using a litterbag method(11 different treatments were tested in three systems).We found that the application of different organic materials(crop residues)produced positive effects on the number of soil fauna in the ginkgo planting systems;the mixture of ginkgo leaves and corn leaves was the best performing treatment.Collembola and Acarina were the predominant groups in the litter bags and were mainly responsible for the differences among the treatments.Litter mixing promoted the abundance,richness,and diversity of soil fauna,and significant differences regarding the Shannon–Wiener index of the soil fauna were observed among the 11 treatments in July.Significantly higher soil MBC(microbial biomass carbon)and MBN(microbial biomass nitrogen)were observed in agroforestry systems than in pure ginkgo plantations.These results suggest that the practice of intercrop residue application plays an important role in enhancing soil ecosystem function in ginkgo agroforestry systems and may ultimately contribute to sustainable intercrop production,soil fertility,and local economic diversity.
文摘This paper describes the importance of plant quarantine to the food safety in China through cases where plant quarantine helps to effectively intercept harmful organisms for food safety and promote export and import trading.It also presents the existing problems in plant quarantine work and appropriate measures.
基金supported by the National Key Research and Development Program of China(2020YFA0804000,2022YFA1103700,2020YFA0112200,2021YFF1201000,the STI2030-Major Projects-2021ZD0202400,2022YFA1103800)the National Natural Science Foundation of China(82201714,81921006,82125011,92149301,92168201,91949209,92049304,92049116,32121001,82192863,82122024,82071588,32000500,82271600,82001477,82201727)+12 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16000000)CAS Project for Young Scientists in Basic Research(YSBR-076,YSBR-012)the Program of the Beijing Natural Science Foundation(Z190019)the Fellowship of China Postdoctoral Science Foundation(2022M712216)the Project for Technology Development of Beijing-affiliated Medical Research Institutes(11000023T000002036310)the Pilot Project for Public Welfare Development and Reform of Beijing-affiliated Medical Research Institutes(11000022T000000461062)Youth Innovation Promotion Association of CAS(E1CAZW0401,2022083,2023092)Young Elite Scientists Sponsorship Program by CAST(YESS20200012,YESS20210002)the Informatization Plan of Chinese Academy of Sciences(CAS-WX2021SF-0301,CAS-WX2022SDC-XK14,CASWX2021SF-0101)New Cornerstone Science Foundation through the XPLORER PRIZE(2021-1045)Excellent Young Talents Program of Capital Medical University(12300927)Excellent Young Talents Training Program for the Construction of Beijing Municipal University Teacher Team(BPHR202203105)Beijing Hospitals Authority Youth Programme(QML20230806)。
文摘Cullin-RING E3 ubiquitin ligases(CRLs),the largest family of multi-subunit E3 ubiquitin ligases in eukaryotic cells,represent core cellular machinery for executing protein degradation and maintaining proteostasis.Here,we asked what roles Cullin proteins play in human mesenchymal stem cell(hMSC)homeostasis and senescence.To this end,we conducted a comparative aging phenotype analysis by individually knocking down Cullin members in three senescence models:replicative senescent hMSCs,Hutchinson-Gilford Progeria Syndrome hMSCs,and Werner syndrome hMSCs.Among all family members,we found that CUL2 deficiency rendered hMSCs the most susceptible to senescence.To investigate CUL2-specific underlying mechanisms,we then applied CRISPR/Cas9-mediated gene editing technology to generate CUL2-deficient human embryonic stem cells(hESCs).When we differentiated these into h MSCs,we found that CUL2 deletion markedly accelerates hMSC senescence.Importantly,we identified that CUL2 targets and promotes ubiquitin proteasome-mediated degradation of TSPYL2(a known negative regulator of proliferation)through the substrate receptor protein APPBP2,which in turn downregulates one of the canonical aging marker-P21^(waf1/cip1),and thereby delays senescence.Our work provides important insights into how CRL2^(APPBP2)-mediated TSPYL2 degradation counteracts hMSC senescence,providing a molecular basis for directing intervention strategies against aging and aging-related diseases.
基金supported by the National Key Research and Development Program of China(2017YFD0600701).
文摘Redwood trees(Sequoioideae),including Metasequoia glyptostroboides(dawn redwood),Sequoiadendron giganteum(giant sequoia),and Sequoia sempervirens(coast redwood),are threatened and widely recognized iconic tree species.Genomic resources for redwood trees could provide clues to their evolutionary relationships.Here,we report the 8-Gb reference genome of M.glyptostroboides and a comparative analysis with two related species.More than 62%of the M.glyptostroboides genome is composed of repetitive sequences.Clade-specific bursts of long terminal repeat retrotransposons may have contributed to genomic differentiation in the three species.The chromosomal synteny between M.glyptostroboides and S.giganteum is extremely high,whereas there has been significant chromosome reorganization in S.sempervirens.Phylogenetic analysis of marker genes indicates that S.sempervirens is an autopolyploid,and more than 48%of the gene trees are incongruent with the species tree.Results of multiple analyses suggest that incomplete lineage sorting(ILS)rather than hybridization explains the inconsistent phylogeny,indicating that genetic variation among redwoods may be due to random retention of polymorphisms in ancestral populations.Functional analysis of ortholog groups indicates that gene families of ion channels,tannin biosynthesis enzymes,and transcription factors for meristem maintenance have expanded in S.giganteum and S.sempervirens,which is consistent with their extreme height.As a wetland-tolerant species,M.glyptostroboides shows a transcriptional response to flooding stress that is conserved with that of analyzed angiosperm species.Our study offers insights into redwood evolution and adaptation and provides genomic resources to aid in their conservation and management.
基金supported by the National Natural Science Foundation of China(No.62073151)the Jilin Provincial Science&Technology Department(Nos.20200301011RQ and 20210101177JC)the Fundamental Research Funds for the Central Universities(No.22120210160).
文摘The direct blending of polyether ether ketone(PEEK)with a solid lubricant such as polytetrafluoroethylene(PTFE)improves its tribological performance,but compromises its outstanding mechanical properties and processability.While these negative effects might be circumvented via the hybrid wear method,the influence of the contact temperature between multiple sliding components acting together is not fully understood.Herein,an analytical temperature model considering the influence of both micro-and macro-thermal behavior is extended to predict the contact temperature of a dual-pin-on-disk hybrid wear system.The interactions between several heat sources are investigated and experimentally verified.The analytical results show that the nominal temperature rise of the shared wear track is determined by the combined effect of the heat generated by both pin components,while the rise in flash temperature at the region in contact with each pin component is dependent upon its individual characteristics and working conditions.Hence,while different temperature peaks can coexist in the shared wear track,the maximum value dominates the performance of the system.For the experimentally investigated PEEK–PTFE–steel hybrid wear system,the formation of tribofilms is blocked,and the hybrid wear system fails,when the peak temperature exceeds the glass transition temperature of both pins due to an increase in applied load.
基金Acknowledgements This work was partially supported by the National High-tech R＆D Program of China （863 Program） （2012AA01A301, 2013AA014301, 2013AA01A208）, and by the National Basic Research Program of China （973 Program） （2011CB309705）, and by the National Natural Science Foundation of China （Grant Nos. 61120106005, 61303063 and 61272482）.
基金This work was supported by the National Natural Science Foundation of China(NSFC grant 20935004 and 21774049).
文摘It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ formed carboxylic acid-functionalized poly(aryl ether sulfone)(PAES-COOH)/polyvinylpyrrolidone(PVPON)complex nanoparticles can significantly enhance the mechanical strength of PAES-COOH by mixing PAES-COOH with a small fraction of PVPON.The PAES-COOH/PVPON10%composite,which contained∼10 wt%PVPON,exhibited a tensile strength of∼104.8 MPa and Young’s modulus of∼932.2 MPa,which were∼2.0 and∼1.7 times higher than those of the PAES-COOH,respectively.The PAES-COOH/PVPON nanoparticles which were uniformly dispersed in PAES-COOH matrices and had strong hydrogen-bonding interactions with PAES-COOH,served as nanofillers to reinforce the mechanical strength of the PAES-COOH.The PAES-COOH/PVPON_(10%)composites possessed excellent solvent-assisted healability,and the fractured composites could be healed to restore their original mechanical strength.Meanwhile,the PAES-COOH/PVPON_(10%)composites could be recycled multiple times,and yet retained their shape integration and their original mechanical strength.
基金This work was jointly supported by The Hong Kong Polytechnic University,Shenzhen Polytechnic,the National Natural Science Foundation of China(52077075)the National Natural Science Foundation of China(Grant No.72001058)National Natural Science Foundation of China(Grant No.72171155)。
文摘The synergies between electricity and other energy resources could promote energy utilization efficiency in electricity market.Within this context,this paper proposes a bi-level stochastic optimization model for the joint operation of a coordinated wind power plant(WPP)and natural gas generating(NGG)-power to gas(P2G)suppliers participating in the day-ahead(DA)market and real-time(RT)market as well as providing real-time auxiliary services.The coordinated supplier’s payoff is maximized in the upper level with consideration of the uncertainties of WPP output capacity and RT electricity price,while the social welfare of the grid is maximized in the lower level.Simulation results demonstrate the effectiveness of the proposed bidding model of the coordinated WPPs and NGG-P2G suppliers by examining its bidding behaviors and benefits with comparisons of four other bidding models.
基金supported by the Forestry Achievements of Science and Technology to Promote Projects([2017]10)the Eleventh Six Talents Peak Project of Jiangsu Province(2014-JY-011)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Ginkgolic acids are unwanted constituents in standard Ginkgo biloba leaves extracts. Thus, for the quality control of ginkgo extracts, it is important to establish an effective degradation method, with high catalytic efficiency and safety, to remove ginkgolic acids.Laccases are oxidases with potential for application in elimination of hazardous phenolic compounds. In this study, single-factor and orthogonal experiments were used to optimize extraction of ginkgolic acid from G. biloba sarcotestae. The results showed that ethanol was the best solvent, with the highest extraction rate for ginkgolic acid at 85% ethanol. On this basis, we measured ethanol volume fraction, extraction time, temperature and solidliquid ratio using an orthogonal experiment. By using absorbance of 310 nm as standard, the optimal extraction conditions were 85% ethanol with, solid-liquid ratio of1:14 at 40°C for 12 h. These conditions gave a ginkgolic acid yield of 73.1 mg·g^(–1). Subsequently, recombinant laccase was used to degrade the ginkgolic acid in several laccase/mediator systems, of which Lac C was the best. At50°C, p H 4.5, enzyme concentration of 0.01 U·m L^(–1),0.5 mmol·L^(–1) mediator ABTS and reaction time of 3 h, the degradation rate of ginkgolic acid reached 100%. These results lay the foundation for research on and application of biological enzymes for detoxification of G. biloba extracts.
