Ascorbate(Asc),commonly known as vitamin C,is a vital molecule for plant growth,development,and stress resilience.It is also known to play a crucial role in various physiological processes,including photosynthesis,cel...Ascorbate(Asc),commonly known as vitamin C,is a vital molecule for plant growth,development,and stress resilience.It is also known to play a crucial role in various physiological processes,including photosynthesis,cell division,and differentiation.This article thoroughly explores the processes governing the metabolism of Asc in plants and its roles in physiological functions.It lays down a robust theoretical groundwork for delving into Asc production,transportation,functions,and its potential applications in stress alleviation and horticulture.Furthermore,recent studies indicate that Asc plays a role in regulating fruit development and affecting postharvest storage characteristics,thereby influencing fruit ripening and resilience to stress.Hence,there is a growing importance in studying the synthesis and utilization of Asc in plants.Although the critical role of Asc in controlling plant redox signals has been extensively studied,the precise mechanisms by which it manages cellular redox homeostasis to maintain the equilibrium between reactive oxygen scavenging and cell redox signaling remain elusive.This gap in knowledge presents fresh opportunities to explore how the production of Asc in plants is regulated and how plants react to environmental stressors.Furthermore,this article delves into the potential for a comprehensive investigation into the essential function of Asc in fruits,the development of Asc-rich fruits,and the enhancement of postharvest storage properties.展开更多
Banana(Musa spp.)is one of the most important fruit crop worldwide,and plays a critical role in human diet and agricultural economies across tropical and subtropical regions,including China(Jiang et al.,2025;Wu et al....Banana(Musa spp.)is one of the most important fruit crop worldwide,and plays a critical role in human diet and agricultural economies across tropical and subtropical regions,including China(Jiang et al.,2025;Wu et al.,2025).However,its rapid softening severely limits shelf life,causing substantial economic losses during transport and storage.Recently,the enhanced shelf-life can be generated by compromising the key ripening regulators,such as RIN,but other fruit quality traits including flavor and color also can be impaired concurrently(Kitagawa et al.,2005).展开更多
Fig fruit firmness decreases rapidly during ripening and after harvest,resulting in poor storability and transportation loss,which severely restricts development of the fresh fig industry.APETALA2/ethylene-responsive ...Fig fruit firmness decreases rapidly during ripening and after harvest,resulting in poor storability and transportation loss,which severely restricts development of the fresh fig industry.APETALA2/ethylene-responsive factor(AP2/ERF)transcription factors are downstream components of the ethylene-signaling pathway that play crucial roles in quality formation during fruit ripening.In this study,Ficus carica(Fc)ERF12 was clustered in repressor subfamily VIII of ERFs through phylogenetic analysis,and further recruited by its two EAR motifs and expression pattern during fig ripening.DNA affinity purification sequencing analysis indicated that FcERF12 binds to the promoter or gene body regions of multiple ripening-related genes,including cell wall-modification genes FcPG,FcXTH and FcPME,and ethylene-biosynthesis genes FcACS and FcACO.Yeast two-hybrid assay demonstrated that FcERF12 interacts with TOPLESS(TPL)co-repressors FcTPL1,FcTPL4 and FcTPL5,and histone deacetylases FcHDA6 and FcHDA19;interaction with FcTPL4 and FcTPL5 relied on the C-terminal EAR motif.Overexpressing FcERF12 in tomato did not change fruit size or yield,but resulted in an 18.37%increment in fruit firmness and a 49.62%reduction in ethylene-release rate at fruit ripening,accompanied by a significant decrease in seed number per fruit.Transcriptomic analysis revealed downregulation of tomato cell wallmodification genes SlPL,SlEXP and SlPG,and ethylene-synthesis genes SlACO and SlACS.Metabolomic profiling identified 82 differentially accumulated flavonoid metabolites,61 of them showing significantly decreased contents.Taken together,our results exhibit the negative regulatory role of FcERF12 in fig ethylene-signal transduction,providing new information on precise control of fruit firmness and other quality traits at ripening.展开更多
Fruit ripening,which is modulated by the up-and downregulation of numerous genes,is a sophisticated physiological event determining consumer acceptability.While many positive regulators have been known to regulate fru...Fruit ripening,which is modulated by the up-and downregulation of numerous genes,is a sophisticated physiological event determining consumer acceptability.While many positive regulators have been known to regulate fruit ripening,relatively less information is associated with the negative regulators in the process.Here,a negative regulator,MaMADS31,was characterized according to the banana fruit ripening transcriptome,which displayed nuclear localization and inhibitory transactivation activity.MaMADS31 suppresses the transcription of the cell wall modification gene MaPL15 and the ethylene biosynthesis-related gene MaACO13 by directly recognizing the CArG-box element in their promoters.Transient expression of MaMADS31 in banana fruit brought about downregulation of MaPL15 and MaACO13,thereby delaying fruit ripening.Importantly,MaMADS31 interacts with MaBZR2 to synergistically strengthen the transcriptional inhibition of MaPL15 and MaACO13.Overall,MaMADS31-MaBZR2 plays a negative role in fruit ripening by downregulating the MaPL15 and MaACO13 transcription,which provides new insights for innovating approaches for prolonging the postharvest life of horticultural plants.展开更多
Banana fruit ripening is a highly regulatory process involving various layers consisting of transcriptional regulation,epigenetic factor,and post-translational modification.Previously,we reported that MaERF11 cooperat...Banana fruit ripening is a highly regulatory process involving various layers consisting of transcriptional regulation,epigenetic factor,and post-translational modification.Previously,we reported that MaERF11 cooperated with MaHDA1 to precisely regulate the transcription of ripening-associated genes via histone deacetylation.However,whether MaERF11 is subjected to post-translational modification during banana ripening is largely unknown.In this study,we found that MaERF11 targeted a subset of starch degradation-related genes using the DNA affinity purification sequence(DAP-Seq)approach.Electrophoretic mobility shift assay(EMSA)and dual-luciferase reporter assay(DLR)demonstrated that MaERF11 could specifically bind and repress the expression of the starch degradation-related genes MaAMY3,MaBAM2 and MaGWD1.Further analyses of yeast two-hybrid(Y2H),bimolecular fluorescence complementation(BiFC)and Luciferase complementation imaging(LCI)assays indicated that MaERF11 interacted with the ubiquitin E3 ligase MaRFA1,and this interaction weakened the MaERF11-mediated transcriptional repression capacity.Collectively,our results suggest an additional regulatory layer in which MaERF11 regulates banana fruit ripening and expands the regulatory network in fruit ripening at the post-translational modification level.展开更多
Fruit ripening is a complex developmental process tightly regulated by hormonal crosstalk,transcriptional networks,and epigenetic modifications,with striking divergence between climacteric and non-climacteric species....Fruit ripening is a complex developmental process tightly regulated by hormonal crosstalk,transcriptional networks,and epigenetic modifications,with striking divergence between climacteric and non-climacteric species.In climacteric fruits,such as tomatoes,apples,and bananas,ethylene acts as the master regulator,driving autocatalytic biosynthesis through ACS/ACO genes and activating hierarchical transcriptional cascades mediated by MADS-box(RIN),NAC(NOR),and ERF-family transcription factors.These pathways are amplified by epigenetic reprogramming,including DNA demethylation at ripening-related promoters and histone acetylation,which enhance chromatin accessibility to facilitate gene expression.Conversely,non-climacteric fruits like strawberries and grapes predominantly rely on abscisic acid(ABA)to coordinate ripening.Hormonal interplay,such as ethylene-ABA synergy in climacteric fruit systems,further fine-tunes ripening dynamics.Advances in CRISPR-based gene editing and epigenome engineering now enable precise manipulation of these pathways,offering transformative solutions to reduce postharvest losses,enhance nutritional quality,and improve climate resilience.This review integrates mechanistic insights across species,emphasizing opportunities to translate fundamental discoveries into sustainable agricultural innovations,from breeding nutrient-rich cultivars to optimizing postharvest technologies for global food security.展开更多
Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most ...Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.展开更多
In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only ...In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only advanced in recent years,largely because these fruits produce much less ethylene than climacteric fruits.Consequently,reports on its molecular regulatory involvement are still limited.Grape(Vitis vinifera L.),one of the most economically valuable fruits,is regarded as a classical non-climacteric fruit.In this study,an enzyme participating in the last step of ethylene biosynthesis,VvACO1,has been identified as a key enzyme controlling ethylene release in grape fruits(Vitis vinifera‘Jingyan’and‘Red Balado’)using correlation analysis and enzymatic experiments.The transcriptional regulation of VvACO1 was investigated by integrating multiple methods such as DNA pull-down assays,co-expression analysis,dual luciferase reporting system,yeast one-hybrid assays,and transgenic experiments.Our findings revealed that the upregulation of VvACO1 in grape fruits was primarily caused by the removal of transcriptional inhibition.Remarkably,seven transcription factors(TFs)were identified as inhibitors of VvACO1,including VvHY5 from bZIP family,VvWIP2 from C2H2 family,VvBLH1 from Homeobox family,VvAG1 and VvCMB1 from MADS-box family,VvASIL1 and VvASIL2 from Trihelix family.These seven TFs were located in nuclei and exhibited transcriptional inhibition activity.Notably,VvAG1 and VvASIL2 could inhibit VvACO1 expression when overexpressed in grape leaves.Our findings provided theoretical clues for differences of ethylene release regulation between climacteric and non-climacteric fruits,also the identified seven TFs could be potential targets for grape molecular breeding.展开更多
Melon(Cucumis melo)is an economically important horticultural crop cultivated worldwide.NAC(NAM/ATAC/CUC)transcription factors play crucial roles in the transcriptional regulation of various developmental stages in pl...Melon(Cucumis melo)is an economically important horticultural crop cultivated worldwide.NAC(NAM/ATAC/CUC)transcription factors play crucial roles in the transcriptional regulation of various developmental stages in plant growth and fruit development,but their gene functions in melon remain largely unknown.Here,we identified 78 CmNAC family genes with an integrated and conserved no apical meristem(NAM)domain in the melon genome by performing genome-wide identification and bioinformatics analysis.Transcriptome data analysis and qRTPCR results showed that most CmNACs are specifically enriched in either the vegetative or reproductive organs of melon.Through genetic transformation,we found that overexpression of CmNAC34 in melons led to early ripening fruits,suggesting its positive role in promoting fruit maturation.Using yeast two-hybrid and bimolecular fluorescence complementation assays,we verified the direct protein interaction between CmNAC34 and CmNACNOR.The expression patterns of CmNAC34 and CmNAC-NOR were similar in melon tissues,and subcellular localization revealed their nuclear protein characteristics.We transformed CmNAC-NOR in melon and found that its overexpression resulted in early ripening fruits.Then,the yeast one-hybrid and dual luciferase reporter gene assays showed that the CmNAC34 protein can bind to the promoters of two glyoxalase(GLY)genes,which are involved in the abscisic acid signal pathway and associated with fruit regulation.These findings revealed the molecular characteristics,expression profiles,and functional patterns of the NAC family genes and provide new insights into the molecular mechanism by which CmNAC34 regulates climacteric fruit ripening.展开更多
Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent therma...Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent thermal stability and high-voltage short-pulse initiation performance. However, the solid phase ripening of ultrafine HNS leads to a degradation in its impact detonation performance. Previous studies have indicated that residual dimethyl formamide(DMF), which is present in ultrafine HNS prepared using the recrystallization method, affects ultrafine HNS ripening. The mechanism of residual solvent effects on solid phase ripening of ultrafine HNS is unclear. In this work, the specific surface area(SSA) derived from small angle X-ray scattering(SAXS) was utilized for kinetic fitting analysis to explore the mechanism by which residual solvents enhance the solid phase ripening of ultrafine HNS. The results of the SSA measured by insitu SAXS under conditions of 150℃ for 40 h revealed that the sample with 0.2% residual DMF exhibited a 21.51% decrease in SSA, whereas the sample with only 0.04% residual DMF showed a decrease of 15.66%.Furthermore, the higher amounts of residual DMF accelerated the reduction in SSA with time. Kinetic fitting analysis demonstrated that reducing residual DMF would lower both the activation energy and the pre-exponential factor, consequently decreasing the rate constant of solid phase ripening. The mechanism was speculated that it primarily facilitated the Ostwald ripening(OR). Additionally, contrast variation small angle X-ray scattering(CV-SAXS) confirmed that coating of ultrafine HNS particles is an effective method for inhibiting ripening, significantly reducing both the rate and extent of ripening of ultrafine HNS. This study predicts how residual solvents impact the solid phase ripening process of ultrafine HNS and proposes strategies for enhancing the long-term stability of ultrafine explosives.展开更多
While developing nuclear materials,predicting their behavior under long-term irradiation regimes span-ning decades poses a significant challenge.We developed a novel Kinetic Monte Carlo(KMC)model to explore the precip...While developing nuclear materials,predicting their behavior under long-term irradiation regimes span-ning decades poses a significant challenge.We developed a novel Kinetic Monte Carlo(KMC)model to explore the precipitation behavior of Y-Ti-O oxides along grain boundaries within nanostructured ferritic alloys(NFA).This model also assessed the response of the oxides to neutron irradiation,even up sim-ulated radiation damage levels in the desired long dpa range for reactor components.Our simulations investigated how temperature and grain boundary sinks influenced the oxide characteristics of a 12YWT-like alloy during heat treatments at 1023,1123,and 1223 K.The oxide characteristics observed in our simulations were in good agreement with existing literature.Furthermore,the impact of grain bound-aries on precipitation was found to be minimal.The resulting oxide configurations and positions were used in subsequent simulations that exposed them to simulated neutron irradiation to a total accumu-lated dose of 8 dpa at three temperatures:673,773,and 873 K,and at dose rates of 10-3,10-4,and 10-5 dpa/s.This demonstrated the expected inverse relationship between oxide size and dose rate.In a long-term irradiation simulation at 873 K and 10-3 dpa/s was taken out to 66 dpa and found the oxides in the vicinity of the grain boundary were more susceptible to dissolution.Additionally,we conducted irradia-tion simulations of a 14YWT-like alloy to reproduce findings from neutron irradiation experiments.The larger oxides in the 14YWT-like alloy did not dissolve and displayed stability similar to the experimental results.展开更多
The modified precipitation theory was employed to directly predict the multi-variantε-carbide precipitation from thermodynamics and growing and ripening kinetics.Three distinct variants were identified:Variants 1 and...The modified precipitation theory was employed to directly predict the multi-variantε-carbide precipitation from thermodynamics and growing and ripening kinetics.Three distinct variants were identified:Variants 1 and 2 were the perpendicular plate-likeε-carbides,while the granularε-carbides were Variant 3.The particle sizes of Variants 1 and 2 were usually larger than those of Variant 3.The mean aspect ratios of Variants 1 and 2 were 4.96,4.62 and 4.35 larger than those(1.72,1.63 and 1.56)for the granularε-carbides when coiled at 140,200 and 250℃,respectively.Thermodynamic analysis indicated that Variants 1 and 2 are easier to nucleate than Variant 3.The growing kinetic analysis implied that the relative nucleation time and precipitation time for Variants 1 and 2 were about 8 and 5 orders of magnitude less than those for Variant 3,respectively.The ripening kinetics further displayed that the ripening rate was similar for Variants 1,2 and 3.In addition,the dislocation density has weak influence onε-carbide nucleation.These findings suggest that the precipitation thermodynamic and kinetic models could be extended to second phase precipitation in other materials systems.Besides,nano-scaleε-carbides,fine block size and nano-twins,as well as medium-density dislocations,jointly caused the optimal match between strength and total elongation when coiled at 140℃.展开更多
BACKGROUND The full implementation of the national two-child policy has presented significant challenges in ensuring the safety of pregnant women.AIM To investigate the effect of cervical balloon fluid volume on mater...BACKGROUND The full implementation of the national two-child policy has presented significant challenges in ensuring the safety of pregnant women.AIM To investigate the effect of cervical balloon fluid volume on maternal processes,maternal and infant outcomes,and anxiety during pregnancy.METHODS A total of 100 singleton term pregnancies with cervical maturity induction and anxiety were selected using a lottery method;50 women were included.Cervical balloons were used for all participants.In the control group,80 mL of fluid was injected into both balloons;in the observation group,80 and 100 mL were injected into the vaginal and cervical balloons,respectively.The two groups were compared for cervical maturity,labor duration,anxiety,maternal and infant outcomes,and effects on cervical ripening.RESULTS After treatment,the cervical maturity test(Bishop)score was significantly higher in the observation group(9.76±1.19)than in the control group(7.62±0.83),and the Hamilton Anxiety Scale score was lower in the observation group(7.32±0.85)than in the control group(13.05±1.12).The observation group showed higher rates of natural delivery and lower rates of cesarean section than the control group.The first and total stages of labor were shorter in the observation than in the control group;no significant differences were found in the second and third stages.The incidence of complications was lower in the observation group[1(2.00%)vs 9(18.00%)for complications;49(98.00%)vs 41(82.00%)for non-complications].CONCLUSION The selected fluid volumes to promote cervical maturity and induce labor stabilize maternal mood,increase the natural delivery rate,shorten labor,and improve maternal and infant outcomes.展开更多
The postharvest senescence phase of table grapes comprises a series of biological processes.MicroRNAs(miRNAs)regulate downstream genes at the post-transcriptional level;however,whether miRNAs are involved in postharve...The postharvest senescence phase of table grapes comprises a series of biological processes.MicroRNAs(miRNAs)regulate downstream genes at the post-transcriptional level;however,whether miRNAs are involved in postharvest grape senescence remains unclear.We used small RNA sequencing to identify postharvest-related miRNAs in‘Red Globe'(Vitis vinifera)grapes harvested after 0,30,and 60 d of storage at 4℃(RG0,RG30,RG60).In total,42 known and 219 novel miRNA candidates were obtained.During fruit senescence,the expression of PC-3p-3343_1921,mi R2950,miR395k,miR2111,miR159c,miR169q,PC-5p-1112_4500,and miR167b changed signifcantly(P<0.05).Degradation sequencing identifed 218 targets associated with cell wall organization,tricarboxylic acid(TCA)cycling,pathogen defense,carbon metabolism,hormone signaling,the anthocyanin metabolism pathway,and energy regulation,of which ARF6,GRF3,TCP2,CP1,MYBA2,and WRKY72 were closely related to fruit senescence.We also verified that VIT_00s2146g00010,VIT_02s0012g01750,and VIT_03s0038g00160 with unknown functions are cleaved by senescence-related PC-5p-1112_4500 via the dual luciferase assay,and the transient transformation of grape berries showed that they regulate berry senescence.These results deepen our understanding of the role of mi RNAs in regulating grape berry senescence and prolonging the shelf life of horticultural products.Based on these results,we propose a new theoretical strategy for delaying the postharvest senescence of horticultural products by regulating the expression of key miRNAs(e.g.,PC-5p-1112_4500),thereby extending their shelf life.展开更多
Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient cata...Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient catalysts due to their complementary elemental and structural properties.We developed a deposition in-situ reduction(D-ISR)approach for the rapid synthesis of single-phase medium/high-entropy oxides(M/HEOs)at room temperature,along with establishing general criteria for M/HEOs synthesis based on component properties.Deposition facilitates the incorporation of active elements(Ti/Zr/V/Cr/Nb),which significantly enhance the enthalpy-driven force of the dynamic oxidation(DO)process via an“active element coordination”strategy,thereby overcoming low-temperature solid solubility limitations.Nine-component HEOs and large-scale experiments confirm the universality and mass-production potential of the D-ISR approach.CoCuNiTi-O/AC synthesized via this strategy exhibits pronounced crystal distortion and disorder(Co–O coordination number=10.2),enhancing the Co–O coordination environment and mitigating Ostwald ripening.This leads to high activity and significantly enhanced structural stability,achieving a turnover frequency of 236.6 min^(-1)for ammonia borane hydrolysis,15 times higher than Co-O/AC and surpassing the most non-noble catalysts.These observations highlight an efficient M/HEOs synthesis methodology that advances M/HEMs applications in nanoenergy.展开更多
Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Bat...Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Batsch cv. Feicheng) is described. The pMT18 clone is 1188 bp in length, with an open reading frame of 393 amino acids. The homology and phylogenetic analyses indicate a remarkable similarity between peach PG and other ripening related PG. And seven consensus sequences have revealed in peach PG compared to the PG from other plants. However, the profound divergence with other PG and the unique structure features suggest that peach PG probably belongs to a new evolutionary class. In RT PCR analysis, pMT18 related RNA was undetectable in leaves, and was much abundant in ripe fruits. The ripening specific expression pattern of this cDNA will be useful in investigating the roles of PG in fruit ripening and developing a transgenic peach with the improved post harvesting quality in the future.展开更多
Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at...Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.展开更多
Glyphosate is the most widely used herbicide in the world. In sugarcane, it is used as a herbicide when applied at its field rate, but it is also used as ripener when applied as low doses. However, the effects of glyp...Glyphosate is the most widely used herbicide in the world. In sugarcane, it is used as a herbicide when applied at its field rate, but it is also used as ripener when applied as low doses. However, the effects of glyphosate on plant metabolism and sugarcane growth are not fully understood. This study aimed to evaluate the metabolic changes and the effects on sugarcane plant growth caused by the application of different doses of glyphosate. Sugarcane plants were grown in a greenhouse and subjected to glyphosate applications at doses of 7.2;18;36;72;180;360 and 720 g a.e. ha-1. Plants grown without an herbicide application were used as a control. Plants from each treatment were collected at 2, 7, 14, and 21 days after treatment (DAT) application to quantify the levels of shikimic acid, quinic acid, shikimate-3-phosphate, glyphosate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), phenylalanine, tyrosine, and tryptophan. Visual evaluations of plant intoxication were performed at the same time as the collection of plants, and the quantification of their shoot dry biomass was performed at 21 DAT. At doses of glyphosate greater than 72 g a.e. ha-1, increases in the levels of shikimic acid, quinic acid, and shikimate-3-phosphate occurred and AMPA was detected in the plants. Initially, glyphosate caused increases in the plant levels of phenylalanine and tyrosine at doses of 72 and 180 g a.e. ha-1, although a decrease in the levels of aromatic amino acids subsequently occurred at and above the doses of 72 or 180 g a.e. ha-1. The doses ranging from 7.2 to 36 g a.e. ha-1 promoted an increase in plant shoot biomass, and doses greater than 72 g a.e. ha-1 caused significant reductions in dry mass.展开更多
基金supported by the Lendület/Momentum Programme of the Hungarian Academy of Sciencesthe National Research, Development, and Innovation Office, Hungary (Grant Nos. LP2024/21 and K146791)+2 种基金Bayers fellowship program MEDHA and Department of Botany, University of Calicutthe financial assistance provided in the form of Junior Research Fellowship from the University Grants Commission (UGC), Indiathe financial assistance provided by the Council for Scientific and Industrial Research(CSIR), India
文摘Ascorbate(Asc),commonly known as vitamin C,is a vital molecule for plant growth,development,and stress resilience.It is also known to play a crucial role in various physiological processes,including photosynthesis,cell division,and differentiation.This article thoroughly explores the processes governing the metabolism of Asc in plants and its roles in physiological functions.It lays down a robust theoretical groundwork for delving into Asc production,transportation,functions,and its potential applications in stress alleviation and horticulture.Furthermore,recent studies indicate that Asc plays a role in regulating fruit development and affecting postharvest storage characteristics,thereby influencing fruit ripening and resilience to stress.Hence,there is a growing importance in studying the synthesis and utilization of Asc in plants.Although the critical role of Asc in controlling plant redox signals has been extensively studied,the precise mechanisms by which it manages cellular redox homeostasis to maintain the equilibrium between reactive oxygen scavenging and cell redox signaling remain elusive.This gap in knowledge presents fresh opportunities to explore how the production of Asc in plants is regulated and how plants react to environmental stressors.Furthermore,this article delves into the potential for a comprehensive investigation into the essential function of Asc in fruits,the development of Asc-rich fruits,and the enhancement of postharvest storage properties.
基金supported by the Natural Science Foundation of China(Grant Nos.32172544,32441071)the special fund for scientific innovation strategy-construction of high level Academy of Agriculture Science(Grant No.R2023PY-JG003)+4 种基金the earmarked fund for CARS(Grant No.CARS-31-01)Guangdong Special Support Program(Grant No.NYLJ2024010)Guangdong S&T Program(Grant No.2025B0202070005)IAEA CRP D23033the Project from Guangzhou Municipal Science and Technology Bureau(2023B03J0991).
文摘Banana(Musa spp.)is one of the most important fruit crop worldwide,and plays a critical role in human diet and agricultural economies across tropical and subtropical regions,including China(Jiang et al.,2025;Wu et al.,2025).However,its rapid softening severely limits shelf life,causing substantial economic losses during transport and storage.Recently,the enhanced shelf-life can be generated by compromising the key ripening regulators,such as RIN,but other fruit quality traits including flavor and color also can be impaired concurrently(Kitagawa et al.,2005).
基金supported by the key research project for fig development of Weiyuan County(Grant No.1002-69199007),China.
文摘Fig fruit firmness decreases rapidly during ripening and after harvest,resulting in poor storability and transportation loss,which severely restricts development of the fresh fig industry.APETALA2/ethylene-responsive factor(AP2/ERF)transcription factors are downstream components of the ethylene-signaling pathway that play crucial roles in quality formation during fruit ripening.In this study,Ficus carica(Fc)ERF12 was clustered in repressor subfamily VIII of ERFs through phylogenetic analysis,and further recruited by its two EAR motifs and expression pattern during fig ripening.DNA affinity purification sequencing analysis indicated that FcERF12 binds to the promoter or gene body regions of multiple ripening-related genes,including cell wall-modification genes FcPG,FcXTH and FcPME,and ethylene-biosynthesis genes FcACS and FcACO.Yeast two-hybrid assay demonstrated that FcERF12 interacts with TOPLESS(TPL)co-repressors FcTPL1,FcTPL4 and FcTPL5,and histone deacetylases FcHDA6 and FcHDA19;interaction with FcTPL4 and FcTPL5 relied on the C-terminal EAR motif.Overexpressing FcERF12 in tomato did not change fruit size or yield,but resulted in an 18.37%increment in fruit firmness and a 49.62%reduction in ethylene-release rate at fruit ripening,accompanied by a significant decrease in seed number per fruit.Transcriptomic analysis revealed downregulation of tomato cell wallmodification genes SlPL,SlEXP and SlPG,and ethylene-synthesis genes SlACO and SlACS.Metabolomic profiling identified 82 differentially accumulated flavonoid metabolites,61 of them showing significantly decreased contents.Taken together,our results exhibit the negative regulatory role of FcERF12 in fig ethylene-signal transduction,providing new information on precise control of fruit firmness and other quality traits at ripening.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFD2100102)China Agriculture Research System of Ministry of Finance(MOF)and Ministry of Agriculture and Rural Affairs(MARA)(Grant No.CARS-31)。
文摘Fruit ripening,which is modulated by the up-and downregulation of numerous genes,is a sophisticated physiological event determining consumer acceptability.While many positive regulators have been known to regulate fruit ripening,relatively less information is associated with the negative regulators in the process.Here,a negative regulator,MaMADS31,was characterized according to the banana fruit ripening transcriptome,which displayed nuclear localization and inhibitory transactivation activity.MaMADS31 suppresses the transcription of the cell wall modification gene MaPL15 and the ethylene biosynthesis-related gene MaACO13 by directly recognizing the CArG-box element in their promoters.Transient expression of MaMADS31 in banana fruit brought about downregulation of MaPL15 and MaACO13,thereby delaying fruit ripening.Importantly,MaMADS31 interacts with MaBZR2 to synergistically strengthen the transcriptional inhibition of MaPL15 and MaACO13.Overall,MaMADS31-MaBZR2 plays a negative role in fruit ripening by downregulating the MaPL15 and MaACO13 transcription,which provides new insights for innovating approaches for prolonging the postharvest life of horticultural plants.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31830071,32202561)the earmarked fund for CARS(Grant No.CARS-31)。
文摘Banana fruit ripening is a highly regulatory process involving various layers consisting of transcriptional regulation,epigenetic factor,and post-translational modification.Previously,we reported that MaERF11 cooperated with MaHDA1 to precisely regulate the transcription of ripening-associated genes via histone deacetylation.However,whether MaERF11 is subjected to post-translational modification during banana ripening is largely unknown.In this study,we found that MaERF11 targeted a subset of starch degradation-related genes using the DNA affinity purification sequence(DAP-Seq)approach.Electrophoretic mobility shift assay(EMSA)and dual-luciferase reporter assay(DLR)demonstrated that MaERF11 could specifically bind and repress the expression of the starch degradation-related genes MaAMY3,MaBAM2 and MaGWD1.Further analyses of yeast two-hybrid(Y2H),bimolecular fluorescence complementation(BiFC)and Luciferase complementation imaging(LCI)assays indicated that MaERF11 interacted with the ubiquitin E3 ligase MaRFA1,and this interaction weakened the MaERF11-mediated transcriptional repression capacity.Collectively,our results suggest an additional regulatory layer in which MaERF11 regulates banana fruit ripening and expands the regulatory network in fruit ripening at the post-translational modification level.
基金the National Natural Science Foundation of China(32372780 and 32172643)the Institutional Research Funding of Sichuan University(2022SCUNL105)+2 种基金the Natural Science Foundation of Sichuan Province(2024NSFSC1302)the China Postdoctoral Science Foundation(2023M732486)the Guangxi Science and Technology Program(2024AB08197).
文摘Fruit ripening is a complex developmental process tightly regulated by hormonal crosstalk,transcriptional networks,and epigenetic modifications,with striking divergence between climacteric and non-climacteric species.In climacteric fruits,such as tomatoes,apples,and bananas,ethylene acts as the master regulator,driving autocatalytic biosynthesis through ACS/ACO genes and activating hierarchical transcriptional cascades mediated by MADS-box(RIN),NAC(NOR),and ERF-family transcription factors.These pathways are amplified by epigenetic reprogramming,including DNA demethylation at ripening-related promoters and histone acetylation,which enhance chromatin accessibility to facilitate gene expression.Conversely,non-climacteric fruits like strawberries and grapes predominantly rely on abscisic acid(ABA)to coordinate ripening.Hormonal interplay,such as ethylene-ABA synergy in climacteric fruit systems,further fine-tunes ripening dynamics.Advances in CRISPR-based gene editing and epigenome engineering now enable precise manipulation of these pathways,offering transformative solutions to reduce postharvest losses,enhance nutritional quality,and improve climate resilience.This review integrates mechanistic insights across species,emphasizing opportunities to translate fundamental discoveries into sustainable agricultural innovations,from breeding nutrient-rich cultivars to optimizing postharvest technologies for global food security.
基金supported by the National Natural Science Foundation of China(Grant Nos.32302642,32272790)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(Grant No.SN-ZJU-SIAS-0011)+1 种基金Collaborative Promotion Program of Zhejiang Provincial Agricultural Technology of China(Grant No.2023ZDXT05)the Fundamental Research Funds for the Central Universities(Grant No.226-2022-00122).
文摘Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32025032 and 32202415)the Agricultural Breeding Project of Ningxia Hui Autonomous Region(Grant No.NXNYYZ20210104)the National Key Research and Development Program of China(Grant No.2022YFE0116400).
文摘In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only advanced in recent years,largely because these fruits produce much less ethylene than climacteric fruits.Consequently,reports on its molecular regulatory involvement are still limited.Grape(Vitis vinifera L.),one of the most economically valuable fruits,is regarded as a classical non-climacteric fruit.In this study,an enzyme participating in the last step of ethylene biosynthesis,VvACO1,has been identified as a key enzyme controlling ethylene release in grape fruits(Vitis vinifera‘Jingyan’and‘Red Balado’)using correlation analysis and enzymatic experiments.The transcriptional regulation of VvACO1 was investigated by integrating multiple methods such as DNA pull-down assays,co-expression analysis,dual luciferase reporting system,yeast one-hybrid assays,and transgenic experiments.Our findings revealed that the upregulation of VvACO1 in grape fruits was primarily caused by the removal of transcriptional inhibition.Remarkably,seven transcription factors(TFs)were identified as inhibitors of VvACO1,including VvHY5 from bZIP family,VvWIP2 from C2H2 family,VvBLH1 from Homeobox family,VvAG1 and VvCMB1 from MADS-box family,VvASIL1 and VvASIL2 from Trihelix family.These seven TFs were located in nuclei and exhibited transcriptional inhibition activity.Notably,VvAG1 and VvASIL2 could inhibit VvACO1 expression when overexpressed in grape leaves.Our findings provided theoretical clues for differences of ethylene release regulation between climacteric and non-climacteric fruits,also the identified seven TFs could be potential targets for grape molecular breeding.
基金funded by the National Natural Science Foundation of China(32202513)the Applied Technology Research and Development Foundation of Inner Mongolia Autonomous Region,China(2021PT0001)+3 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region,China(2021BS03002)the Inner Mongolia Autonomous Region Universities“Young Science and Technology Talent Support Project”,China(NJYT24067)the Inner Mongolia University High-Level Talent Research Program,China(10000-21311201/056)the Inner Mongolia Autonomous Region Department of Education First-class Scientific Research Project,China(YLXKZX-ND-030)。
文摘Melon(Cucumis melo)is an economically important horticultural crop cultivated worldwide.NAC(NAM/ATAC/CUC)transcription factors play crucial roles in the transcriptional regulation of various developmental stages in plant growth and fruit development,but their gene functions in melon remain largely unknown.Here,we identified 78 CmNAC family genes with an integrated and conserved no apical meristem(NAM)domain in the melon genome by performing genome-wide identification and bioinformatics analysis.Transcriptome data analysis and qRTPCR results showed that most CmNACs are specifically enriched in either the vegetative or reproductive organs of melon.Through genetic transformation,we found that overexpression of CmNAC34 in melons led to early ripening fruits,suggesting its positive role in promoting fruit maturation.Using yeast two-hybrid and bimolecular fluorescence complementation assays,we verified the direct protein interaction between CmNAC34 and CmNACNOR.The expression patterns of CmNAC34 and CmNAC-NOR were similar in melon tissues,and subcellular localization revealed their nuclear protein characteristics.We transformed CmNAC-NOR in melon and found that its overexpression resulted in early ripening fruits.Then,the yeast one-hybrid and dual luciferase reporter gene assays showed that the CmNAC34 protein can bind to the promoters of two glyoxalase(GLY)genes,which are involved in the abscisic acid signal pathway and associated with fruit regulation.These findings revealed the molecular characteristics,expression profiles,and functional patterns of the NAC family genes and provide new insights into the molecular mechanism by which CmNAC34 regulates climacteric fruit ripening.
基金the Presidential Foundation of CAEP(Grant No.YZJJZQ2023005)the National Natural Science Foundation of China(Grant No.22375191).
文摘Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent thermal stability and high-voltage short-pulse initiation performance. However, the solid phase ripening of ultrafine HNS leads to a degradation in its impact detonation performance. Previous studies have indicated that residual dimethyl formamide(DMF), which is present in ultrafine HNS prepared using the recrystallization method, affects ultrafine HNS ripening. The mechanism of residual solvent effects on solid phase ripening of ultrafine HNS is unclear. In this work, the specific surface area(SSA) derived from small angle X-ray scattering(SAXS) was utilized for kinetic fitting analysis to explore the mechanism by which residual solvents enhance the solid phase ripening of ultrafine HNS. The results of the SSA measured by insitu SAXS under conditions of 150℃ for 40 h revealed that the sample with 0.2% residual DMF exhibited a 21.51% decrease in SSA, whereas the sample with only 0.04% residual DMF showed a decrease of 15.66%.Furthermore, the higher amounts of residual DMF accelerated the reduction in SSA with time. Kinetic fitting analysis demonstrated that reducing residual DMF would lower both the activation energy and the pre-exponential factor, consequently decreasing the rate constant of solid phase ripening. The mechanism was speculated that it primarily facilitated the Ostwald ripening(OR). Additionally, contrast variation small angle X-ray scattering(CV-SAXS) confirmed that coating of ultrafine HNS particles is an effective method for inhibiting ripening, significantly reducing both the rate and extent of ripening of ultrafine HNS. This study predicts how residual solvents impact the solid phase ripening process of ultrafine HNS and proposes strategies for enhancing the long-term stability of ultrafine explosives.
基金supported by the Nuclear Regulatory Commission Fellowship Grant No.NRC-HQ-84-14-G-0035.
文摘While developing nuclear materials,predicting their behavior under long-term irradiation regimes span-ning decades poses a significant challenge.We developed a novel Kinetic Monte Carlo(KMC)model to explore the precipitation behavior of Y-Ti-O oxides along grain boundaries within nanostructured ferritic alloys(NFA).This model also assessed the response of the oxides to neutron irradiation,even up sim-ulated radiation damage levels in the desired long dpa range for reactor components.Our simulations investigated how temperature and grain boundary sinks influenced the oxide characteristics of a 12YWT-like alloy during heat treatments at 1023,1123,and 1223 K.The oxide characteristics observed in our simulations were in good agreement with existing literature.Furthermore,the impact of grain bound-aries on precipitation was found to be minimal.The resulting oxide configurations and positions were used in subsequent simulations that exposed them to simulated neutron irradiation to a total accumu-lated dose of 8 dpa at three temperatures:673,773,and 873 K,and at dose rates of 10-3,10-4,and 10-5 dpa/s.This demonstrated the expected inverse relationship between oxide size and dose rate.In a long-term irradiation simulation at 873 K and 10-3 dpa/s was taken out to 66 dpa and found the oxides in the vicinity of the grain boundary were more susceptible to dissolution.Additionally,we conducted irradia-tion simulations of a 14YWT-like alloy to reproduce findings from neutron irradiation experiments.The larger oxides in the 14YWT-like alloy did not dissolve and displayed stability similar to the experimental results.
基金supported by the National Natural Science Foundation of China(No.52293395)National Key R&D Program of China(No.2021YFB3702403).
文摘The modified precipitation theory was employed to directly predict the multi-variantε-carbide precipitation from thermodynamics and growing and ripening kinetics.Three distinct variants were identified:Variants 1 and 2 were the perpendicular plate-likeε-carbides,while the granularε-carbides were Variant 3.The particle sizes of Variants 1 and 2 were usually larger than those of Variant 3.The mean aspect ratios of Variants 1 and 2 were 4.96,4.62 and 4.35 larger than those(1.72,1.63 and 1.56)for the granularε-carbides when coiled at 140,200 and 250℃,respectively.Thermodynamic analysis indicated that Variants 1 and 2 are easier to nucleate than Variant 3.The growing kinetic analysis implied that the relative nucleation time and precipitation time for Variants 1 and 2 were about 8 and 5 orders of magnitude less than those for Variant 3,respectively.The ripening kinetics further displayed that the ripening rate was similar for Variants 1,2 and 3.In addition,the dislocation density has weak influence onε-carbide nucleation.These findings suggest that the precipitation thermodynamic and kinetic models could be extended to second phase precipitation in other materials systems.Besides,nano-scaleε-carbides,fine block size and nano-twins,as well as medium-density dislocations,jointly caused the optimal match between strength and total elongation when coiled at 140℃.
基金Supported by the Wuxi Municipal Health Commission Maternal and Child Health Research Project,No.FYKY202202.
文摘BACKGROUND The full implementation of the national two-child policy has presented significant challenges in ensuring the safety of pregnant women.AIM To investigate the effect of cervical balloon fluid volume on maternal processes,maternal and infant outcomes,and anxiety during pregnancy.METHODS A total of 100 singleton term pregnancies with cervical maturity induction and anxiety were selected using a lottery method;50 women were included.Cervical balloons were used for all participants.In the control group,80 mL of fluid was injected into both balloons;in the observation group,80 and 100 mL were injected into the vaginal and cervical balloons,respectively.The two groups were compared for cervical maturity,labor duration,anxiety,maternal and infant outcomes,and effects on cervical ripening.RESULTS After treatment,the cervical maturity test(Bishop)score was significantly higher in the observation group(9.76±1.19)than in the control group(7.62±0.83),and the Hamilton Anxiety Scale score was lower in the observation group(7.32±0.85)than in the control group(13.05±1.12).The observation group showed higher rates of natural delivery and lower rates of cesarean section than the control group.The first and total stages of labor were shorter in the observation than in the control group;no significant differences were found in the second and third stages.The incidence of complications was lower in the observation group[1(2.00%)vs 9(18.00%)for complications;49(98.00%)vs 41(82.00%)for non-complications].CONCLUSION The selected fluid volumes to promote cervical maturity and induce labor stabilize maternal mood,increase the natural delivery rate,shorten labor,and improve maternal and infant outcomes.
基金supported by the Natural Science Foundation of Ningxia,China(2024AAC02039)the Scientific and Technological Innovation Leadership Talent Program of Ningxia,China(2022GKLRLX07)+1 种基金the National Natural Science Foundation of China(32260727 and 32371924)China Agriculture Research System(CARS-29-zp-6)。
文摘The postharvest senescence phase of table grapes comprises a series of biological processes.MicroRNAs(miRNAs)regulate downstream genes at the post-transcriptional level;however,whether miRNAs are involved in postharvest grape senescence remains unclear.We used small RNA sequencing to identify postharvest-related miRNAs in‘Red Globe'(Vitis vinifera)grapes harvested after 0,30,and 60 d of storage at 4℃(RG0,RG30,RG60).In total,42 known and 219 novel miRNA candidates were obtained.During fruit senescence,the expression of PC-3p-3343_1921,mi R2950,miR395k,miR2111,miR159c,miR169q,PC-5p-1112_4500,and miR167b changed signifcantly(P<0.05).Degradation sequencing identifed 218 targets associated with cell wall organization,tricarboxylic acid(TCA)cycling,pathogen defense,carbon metabolism,hormone signaling,the anthocyanin metabolism pathway,and energy regulation,of which ARF6,GRF3,TCP2,CP1,MYBA2,and WRKY72 were closely related to fruit senescence.We also verified that VIT_00s2146g00010,VIT_02s0012g01750,and VIT_03s0038g00160 with unknown functions are cleaved by senescence-related PC-5p-1112_4500 via the dual luciferase assay,and the transient transformation of grape berries showed that they regulate berry senescence.These results deepen our understanding of the role of mi RNAs in regulating grape berry senescence and prolonging the shelf life of horticultural products.Based on these results,we propose a new theoretical strategy for delaying the postharvest senescence of horticultural products by regulating the expression of key miRNAs(e.g.,PC-5p-1112_4500),thereby extending their shelf life.
基金the financial support from the National Natural Science Foundation of China(52171223)the Guangxi Science and Technology Major Project(No.AA24206007)。
文摘Ammonia borane(AB)is a promising hydrogen storage medium widely used for hydrogen generation,but its slow hydrolysis kinetics limits its applications.Medium/high-entropy materials(M/HEMs)have emerged as efficient catalysts due to their complementary elemental and structural properties.We developed a deposition in-situ reduction(D-ISR)approach for the rapid synthesis of single-phase medium/high-entropy oxides(M/HEOs)at room temperature,along with establishing general criteria for M/HEOs synthesis based on component properties.Deposition facilitates the incorporation of active elements(Ti/Zr/V/Cr/Nb),which significantly enhance the enthalpy-driven force of the dynamic oxidation(DO)process via an“active element coordination”strategy,thereby overcoming low-temperature solid solubility limitations.Nine-component HEOs and large-scale experiments confirm the universality and mass-production potential of the D-ISR approach.CoCuNiTi-O/AC synthesized via this strategy exhibits pronounced crystal distortion and disorder(Co–O coordination number=10.2),enhancing the Co–O coordination environment and mitigating Ostwald ripening.This leads to high activity and significantly enhanced structural stability,achieving a turnover frequency of 236.6 min^(-1)for ammonia borane hydrolysis,15 times higher than Co-O/AC and surpassing the most non-noble catalysts.These observations highlight an efficient M/HEOs synthesis methodology that advances M/HEMs applications in nanoenergy.
文摘Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Batsch cv. Feicheng) is described. The pMT18 clone is 1188 bp in length, with an open reading frame of 393 amino acids. The homology and phylogenetic analyses indicate a remarkable similarity between peach PG and other ripening related PG. And seven consensus sequences have revealed in peach PG compared to the PG from other plants. However, the profound divergence with other PG and the unique structure features suggest that peach PG probably belongs to a new evolutionary class. In RT PCR analysis, pMT18 related RNA was undetectable in leaves, and was much abundant in ripe fruits. The ripening specific expression pattern of this cDNA will be useful in investigating the roles of PG in fruit ripening and developing a transgenic peach with the improved post harvesting quality in the future.
文摘Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.
基金funded by the Sao Paulo Research Foundation(FAPESP).
文摘Glyphosate is the most widely used herbicide in the world. In sugarcane, it is used as a herbicide when applied at its field rate, but it is also used as ripener when applied as low doses. However, the effects of glyphosate on plant metabolism and sugarcane growth are not fully understood. This study aimed to evaluate the metabolic changes and the effects on sugarcane plant growth caused by the application of different doses of glyphosate. Sugarcane plants were grown in a greenhouse and subjected to glyphosate applications at doses of 7.2;18;36;72;180;360 and 720 g a.e. ha-1. Plants grown without an herbicide application were used as a control. Plants from each treatment were collected at 2, 7, 14, and 21 days after treatment (DAT) application to quantify the levels of shikimic acid, quinic acid, shikimate-3-phosphate, glyphosate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), phenylalanine, tyrosine, and tryptophan. Visual evaluations of plant intoxication were performed at the same time as the collection of plants, and the quantification of their shoot dry biomass was performed at 21 DAT. At doses of glyphosate greater than 72 g a.e. ha-1, increases in the levels of shikimic acid, quinic acid, and shikimate-3-phosphate occurred and AMPA was detected in the plants. Initially, glyphosate caused increases in the plant levels of phenylalanine and tyrosine at doses of 72 and 180 g a.e. ha-1, although a decrease in the levels of aromatic amino acids subsequently occurred at and above the doses of 72 or 180 g a.e. ha-1. The doses ranging from 7.2 to 36 g a.e. ha-1 promoted an increase in plant shoot biomass, and doses greater than 72 g a.e. ha-1 caused significant reductions in dry mass.
