Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly...Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly increased.This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F.taipaiensis P.Y.Li to the cultivation process of F.taipaiensis P.Y.Li.The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F.taipaiensis P.Y.Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis,physiological and biochemical properties,and gene expression related to the protective enzyme system in F.taipaiensis P.Y.Li.The experiment,conducted in pots at room temperature,included a control group(CK)and groups inoculated with inorganic phosphorussolubilizing bacteria:W1(Bacillus cereus),W2(Serratia plymuthica),W12(Bacillus cereus and Serratia plymuthica),and groups inoculated with organophosphorus-solubilizing bacteria:Y1(Bacillus cereus),Y2(Bacillus cereus),Y12(Bacillus cereus and Bacillus cereus),totaling seven groups.Compared to CK,most growth indices in the bacterial addition groups showed significant differences,with W12 achieving the highest values in all indices except the leaf area index.The content of photosynthetic pigments,photosynthetic parameters,and osmoregulatory substances increased variably in each bacterial treatment group.W12 exhibited the highest content of chlorophyll a and soluble protein,while W1 had the highest free proline content.The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT)in all inoculated groups were higher than in CK,with significant changes in SOD and CAT activities.The malondialdehyde(MDA)content in all inoculated groups was lower than in CK,with Y12 being the lowest,at approximately 30%of CK.Gene expression corresponding to these three enzymes also increased variably,with POD expression in Y2 being the highest at 2.73 times that of CK.SOD and CAT expression in Y12 were the highest,at 1.84 and 4.39 times that of CK,respectively.These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F.taipaiensis P.Y.Li,with the mixed inoculation groups W12 and Y12 demonstrating superior effects.This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F.taipaiensis P.Y.Li.展开更多
[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and h...[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.展开更多
By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechan...By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.展开更多
AIM: To evaluate the effects of frying oil and Houttuynia cordata Thunb (H. cordata), a vegetable traditionally consumed in Taiwan, on the xenobiotic-metabolizing enzyme system of rodents. METHODS: Forty-eight Sprague...AIM: To evaluate the effects of frying oil and Houttuynia cordata Thunb (H. cordata), a vegetable traditionally consumed in Taiwan, on the xenobiotic-metabolizing enzyme system of rodents. METHODS: Forty-eight Sprague-Dawley rats were fed with a diet containing 0%, 2% or 5% H. cordata powder and 15% fresh soybean oil or 24-h oxidized frying oil (OFO) for 28 d respectively. The level of microsomal protein, total cytochrome 450 content (CYP450) and enzyme activities including NADPH reductase, ethoxyresorufin 0-deethylase (EROD), pentoxyresorufin 0-dealkylase (PROD), aniline hydroxylase (ANH), aminopyrine demethylase (AMD), and quinone reductase (QR) were determined. QR represented phase Ⅱ enzymes, the rest of the enzymes tested represented phase Ⅰ enzymes. RESULTS: The oxidized frying oil feeding produced a significant increase in phase Ⅰ and Ⅱ enzyme systems, including the content of CYP450 and microsomal protein, and the activities of NADPH reductase, EROD, PROD, ANH, AMD and QR in rats (P<0.05). In addition, the activities of EROD, ANH and AMD decreased and QR increased after feeding with H. cordata in OFO-fed group (P<0.05). The feeding with 2% H. cordata diet showed the most significant effect. CONCLUSION: The OFO diet induces phases I and II enzyme activity, and the 2% H. cordata diet resulted in a better regulation of the xenobiotic-metabolizing enzyme system.展开更多
Pb,Cu,Cd,Zn content of soil in mining areas and abandoned land,flats of the Pijiang River and farmlands were inves-tigated.On this basis of soil heavy metal pollution,the changes of antioxidant enzyme system in maize(...Pb,Cu,Cd,Zn content of soil in mining areas and abandoned land,flats of the Pijiang River and farmlands were inves-tigated.On this basis of soil heavy metal pollution,the changes of antioxidant enzyme system in maize(Qiandan 88)under different Pb concentrations(0,20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)stress were studied.The results show that the content of Pb,Cu,Cd,and Zn in soil is the highest in mining areas and abandoned land,followed by flats of the Pijiang River>farmlands,and that the variation range of Pb,Cu,Cd in mining areas and abandoned land are 106.40-2564.72,14.83-490.88,22.57-712.77 mg/kg,respectively,which are higher than that of the other land use types.When maize is under stress of 20-500 mg/L Pb concentration,T-SOD activity of maize leaves increase with the increase of Pb concentration and the highest value is 50.21 U/mg prot,but under Pb concentration>1000 mg/L stress,T-SOD activity of maize leaves decrease gradually.The activity of POD decreases with the increases of Pb concentra-tion,and the lowest POD activity of leaves in maize with the value of 93.24 U/mg prot is appeared in Pb 1000 mg/L concentration treatment group.MDA content in leaves of maize increases with the increase of the Pb concentration and the highest value is 101.98 nmol/mg prot,then the content of MDA decreases gradually when the Pb concentration is more than 500 mg/L,which indicates that the membrane lipid peroxidation of maize leaves under high concentration of Pb stress is serious and leads to the cell damage.展开更多
Effect of vitamin C supplementation in restoring lead induced alterations in hematopoietic system and drug metabolizing enzymes were investigated in male rats. Intraperitoneal administration of 20 mg/kg lead produced ...Effect of vitamin C supplementation in restoring lead induced alterations in hematopoietic system and drug metabolizing enzymes were investigated in male rats. Intraperitoneal administration of 20 mg/kg lead produced a significant inhibition of heme synthesis in blood and liver and drug metabolism in liver. Toxic insult by lead also resulted into a marked decline in tissue thiols and vitamin C levels. Oral supplementation of vitamin C (100 mg/kg for 3 days) completely restored blood delta aminolevulinic acid dehydratase, uroporphyrinogen I synthetase and a few drug metabolizing enzymes. Level of vitamin C and sulfhydryl contents too recovered to a great extent. A marked reduction in blood and liver lead concentration occurred on vitamin C supplementation although renal lead contents were marginally reduced in lead exposed animals. The results, thus, indicate a significant protective action of vitamin C against toxic effects of lead on heme synthesis and drug metabolism.展开更多
Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitos...Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitosan depend on its physical and chemical characteristics, which result from the treatments used for its production. In this study, we report the preparation and characterization ofchitosan oligosaccharides by a green synthesis from crystalline shrimp chitin, using a sequential enzyme treatment by chitinase and chitin deacetylase. Chitinases were purified from grapes and used to rupture the crystalline shrimp chitin structure, modifying the crystallinity index from 57.6% to 15.9%. The resultant polymers were deacetylated using a recombinant chitin deacetylase from Saccharomyces cerevisiae, which was cloned and expressed in Pichia pastoris. The chitosans produced showed an estimated DA （degree of acetylation） of approximately 20%, and the molecular weights ranged from -7,600 to -3,700 after treatment in pH 3.0 and pH 6.0 for 10 min and 40 min, respectively. Physical and chemical characterization of the products indicated that enzyme fragmentation of chitin probably makes the acetamide groups more accessible to deacetylation, forming homogeneous polymers that are free of hazardous sub-products, have defined low molecular weights, and are highly deacetylated.展开更多
AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar ...AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.展开更多
Paeonia ostii is an economically important oil crop,which has been widely cultivated in the middle and lower reaches of the Yangtze River in China in recent years.Although P.ostii is highly adaptable to the environmen...Paeonia ostii is an economically important oil crop,which has been widely cultivated in the middle and lower reaches of the Yangtze River in China in recent years.Although P.ostii is highly adaptable to the environment,the prolonged high summer temperature in this region severely inhibits its growth,which adversely affects seed yield and quality.In this study,P.ostii plants were subjected to 20℃/15℃(day/night)and 40℃/35℃(day/night)temperatures for 15 days.The changes in physiological and biochemical indicators of P.ostii under high-temperature stress were initially investigated.The results showed that with the deepening of leaf etiolation,chlorophyll a and chlorophyll b concentration,carotenoid concentration,Soil Plant Analysis Development(SPAD)values and leaf relative water content decreased significantly,while both relative electrical conductivity(REC)and free proline concentration showed an upward trend.Meanwhile,the continuous accumulation of reactive oxygen species(ROS)in P.ostii plants,led to an increased activity of antioxidant enzymes including superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and ascorbate peroxidase(APX).Moreover,with the extension of the high-temperature treatment,the anatomical structures of P.ostii were destroyed,resulting in a decreased photochemical efficiency of the photosystem II(PSII)reaction center and photosynthesis was inhibited.Taken together,these results provide reference values for understanding the physiological response of P.ostii to hightemperature stress and establish a foundation for further research on the relevant underlying molecular mechanisms.展开更多
Chinese peony(Paeonia lactiflora Pall.)is both medicinally and aesthetically beneficial.Powdery mildew is a common fungal disease that seriously jeopardizes the value of numerous species,including peonies as a crop.In...Chinese peony(Paeonia lactiflora Pall.)is both medicinally and aesthetically beneficial.Powdery mildew is a common fungal disease that seriously jeopardizes the value of numerous species,including peonies as a crop.In order to provide a basis for the prevention and treatment of peony powdery mildew,we examined the microbial diversity,the malondialdehyde(MDA)concentrations and antioxidant enzyme activities of peony leaves infected with three levels of powdery mildew to determine any modifications to the leaf's antioxidant enzyme systems and microbial community structure following the onset of disease.The results show that the MDA content rose as the degree of infection became worse.Antioxidant enzyme activity rose and then declined.Following the initiation of powdery mildew,fungal community diversity decreased,whereas there was not any appreciable change in bacterial communities according to microbial diversity sequencing.The relative abundance of more than half of fungal species decreased,with the bacterial genera displaying both abundant and diminished communities with less pronounced alterations in their community structure after the disease spread.Significant different taxa that were critical to the organization of each microbiome were found.Correlation analysis showed that the relative abundance of powdery mildew pathogenic fungal genus Erysiphe was correlated with those of 11 fungal genera and one bacterial genus.Among them,Aureobasidium,Neosetophoma and Sclerostagonospora showed significant positive correlations with Erysiphe and MDA.展开更多
Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsol...Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsola imbricata was characterized by HPLC.Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200μL,7.5%acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays.The levels of malondialdehyde,glutathione peroxidase 1,superoxide dismutase,and catalase were determined in colon tissues.Proinflammatory cytokines including interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were quantified by ELISA.The extent of tissue damage was assessed by histological analysis.Results:Phytochemical analysis confirmed the presence of phytochemicals including quercetin,gallic acid,syringic acid,benzoic acid and chlorogenic acid in the crude extract.The crude extract of Salsola imbricata(300 and 500 mg/kg)markedly decreased malondialdehyde and nitric oxide(P<0.01)and increased antioxidant activities of glutathione peroxidase 1(P<0.001)and superoxide dismutase(P<0.001).Moreover,it decreased the levels of IL-1β,IL-6 and TNF-αsignificantly(P<0.001)and reduced the damage to the colon mucosa,promoting tissue healing and regeneration.Conclusions:Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.展开更多
Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, ...Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, glutathione peroxidase （GPx）, as well as a non-enzymatic antioxidant malondialdehyde （MDA）, in the liver were measured 3, 7, 14 and 21 d post exposure （dpe） to 0.02 （1/100 of acute toxicity）, 0.036 （monitored concentration）, 0.08 （1/20 of acute toxicity）, 0.16 （1/10 of acute toxicity） and 0.32 mg/L （1/5 of acute toxicity） boscalid using a semi-static method. [Result] SOD, CAT, POD, GPx and MDA activity in the liver of zebrafish varied with boscalid concentration and exposure time. Boscalid significantly enhanced MDA content at 21 dpe. A significant upregulation of the activity of SOD, CAT, POD and GPx at 7 dpe was observed, suggesting that boscalid resulted in oxidative stress and lipid peroxidation. [Conclusion] These results show that these biomarkers are all appropriate for monitoring oxidative stress and the lipid peroxidation status of fish after exposure to boscalid. Key words Boscalid; Zebrafish; Antioxidant enzyme展开更多
In this paper, an approximate analytical method to solve the non-linear differential equations in an immobilized enzyme film is presented. Analytical expressions for concentrations of substrate and product have been d...In this paper, an approximate analytical method to solve the non-linear differential equations in an immobilized enzyme film is presented. Analytical expressions for concentrations of substrate and product have been derived for all values of dimensionless parameter. Dimensionless numbers that can be used to study the effects of enzyme loading, enzymatic gel thickness, and oxidation/ reduction kinetics at the electrode in biosensor/biofuel cell performance were identified. Using the dimensionless numbers identified in this paper, and the plots representing the effects of these dimensionless numbers on concentrations and current in biosensor/biofuel cell are discussed. Analytical results are compared with simulation results and satisfactory agreement is noted.展开更多
In order to investigate the effects of cadmium on the immune defense function of spiders infected with bacteria,Pirata subpiraticus was taken as research object,and the cadmium-treated group and the control group were...In order to investigate the effects of cadmium on the immune defense function of spiders infected with bacteria,Pirata subpiraticus was taken as research object,and the cadmium-treated group and the control group were all infected with bacteria(S.aureus and E.coli).After 6 and 24 h of infection,the energy substances contents and the activity of immune detoxification enzyme system in Pirata subpiraticus were determined.The results showed that after 6 and 24 h of infection with S.aureus and 6 h of infection with E.coli,the amount of soluble sugars and soluble proteins of Pirata subpiraticus in the cadmium-treated group increased significantly.Compared with the control,after 6 h of infection with S.aureus and 24 h of infection with E.coli,the activity of acetylcholinesterase(AChE)of Pirata subpiraticus in the cadmium-treated group decreased significantly.This indicated that cadmium inhibited the activity of AChE in infected Pirata subpiraticus.After 24 h of infection with S.aureus and 6 h of infection with E.coli,the activity of polyphenol oxidase(PPO)was signicantly higher than that of the control,indicating that cadmium induced the activity of PPO in infected Pirata subpiraticus.These results suggested that cadmium can affect the content of energy substance and immune detoxification enzyme activity in infected Pirata subpiraticus.展开更多
Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme syner...Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme synergy.However,the proteinaceous characteristics of lignin-degrading enzymes restrict their accessibility to certain regions of intricate lignin,resulting in the multienzyme systems being unable to fully demonstrate their effectiveness.Herein,a de novo biomimetic enzyme-nanozyme hybrid system was constructed by combiningλ-MnO_(2) nanozyme with laccase CotA from Bacillus subtilis,aimed at facilitating lignin degradation under mild conditions.The lignin degradation rate of the CotA+λ-MnO_(2) hybrid system was determined to be 25.15%,which was much higher than those of the lignin degradation systems with only laccase CotA(15.32%)orλ-MnO_(2) nanozyme(14.90%).Notably,the proportion of aromatic chemicals in the products derived from the hybrid system reached as much as 48%,which was 41.2%and 118.2%higher than those of the CotA-andλ-MnO_(2)-catalyzed systems,respectively.Analysis of products mapping and lignin structure changes suggested that the higher proportion of aromatic compounds in the CotA+λ-MnO_(2)hybrid system was more likely to benefit from the laccase-mediated methoxylation.Moreover,electron paramagnetic resonance analysis indicated that the intensity and kind of free radicals such as·OH and·O_(2)^(-)are closely linked to the degradation rate and reaction type.This work is the inaugural application of an enzyme-nanozyme hybrid system for lignin degradation,demonstrating the potential of the synergistic interaction between enzyme and nanozyme in the directed degradation of lignin.展开更多
Rice seed germination marks the start of cultivation and influences subsequent seedling growth,and is affected by hormones and environmental factors.Ubiquitination plays a critical role in this process by regulating h...Rice seed germination marks the start of cultivation and influences subsequent seedling growth,and is affected by hormones and environmental factors.Ubiquitination plays a critical role in this process by regulating hormonal homeostasis.In the ubiquitination cascade,ubiquitin-conjugating enzymes(UBCs)function as ubiquitin carriers to determine linkage specificity of ubiquitin chains.In rice(Oryza sativa),39 UBC genes are identified,but only one gene OsUBC12 has been functionally studied to promote seed germination under low-temperatures in japonica rice.To elucidate the role of UBCs in seed germination,we generated CRISPR-Cas9 mutants for 23 UBC genes and overexpressed 20 members in rice.Among them,seven UBC genes(OsUBC4/6/7/12/25/27/48)were found to regulate seed germination,with OsUBC27 and OsUBC48 acting through the ABA pathway.Exogenous ABA inhibitors restored the germination rate of osubc27^(CR).RT-qPCR analysis revealed that the ABA synthesis genes OsNCED1-5 were significantly upregulated in the mutants.Further differential ubiquitination proteomics in knockout mutants and wild-type plants showed that OsUBC27 regulates ABA homeostasis by modulating ubiquitination of the ABA-degrading protein OsABA8ox1,thereby balancing seed dormancy and germination.Sequence analysis identified distinct haplotypes of the seven OsUBCs that showed differential distribution between japonica and indica subspecies.Our study provides valuable molecular targets for developing rice varieties resistant to seed vivipary.展开更多
DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide ...DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.展开更多
The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can ...The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.展开更多
Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs...Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.展开更多
Coronavirus disease 2019(COVID-19)is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus.It has affected over 768 million people worldwide,result...Coronavirus disease 2019(COVID-19)is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus.It has affected over 768 million people worldwide,resulting in approx-imately 6900000 deaths.High-risk groups,identified by the Centers for Disease Control and Prevention,include individuals with conditions like type 2 diabetes mellitus(T2DM),obesity,chronic lung disease,serious heart conditions,and chronic kidney disease.Research indicates that those with T2DM face a hei-ghtened susceptibility to COVID-19 and increased mortality compared to non-diabetic individuals.Examining the renin-angiotensin system(RAS),a vital regulator of blood pressure and pulmonary stability,reveals the significance of the angiotensin-converting enzyme(ACE)and ACE2 enzymes.ACE converts angiotensin-I to the vasoconstrictor angiotensin-II,while ACE2 counters this by converting angiotensin-II to angiotensin 1-7,a vasodilator.Reduced ACE2 exp-ression,common in diabetes,intensifies RAS activity,contributing to conditions like inflammation and fibrosis.Although ACE inhibitors and angiotensin receptor blockers can be therapeutically beneficial by increasing ACE2 levels,concerns arise regarding the potential elevation of ACE2 receptors on cell membranes,potentially facilitating COVID-19 entry.This review explored the role of the RAS/ACE2 mechanism in amplifying severe acute respiratory syndrome cor-onavirus 2 infection and associated complications in T2DM.Potential treatment strategies,including recombinant human ACE2 therapy,broad-spectrum antiviral drugs,and epigenetic signature detection,are discussed as promising avenues in the battle against this pandemic.展开更多
基金This work was funded by Chongqing Municipal Technology Innovation and Application Development Program(cstc2020jscx-gksb0001)Yunnan Academician(Expert)Workstation Project(202105AF150073).
文摘Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly increased.This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F.taipaiensis P.Y.Li to the cultivation process of F.taipaiensis P.Y.Li.The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F.taipaiensis P.Y.Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis,physiological and biochemical properties,and gene expression related to the protective enzyme system in F.taipaiensis P.Y.Li.The experiment,conducted in pots at room temperature,included a control group(CK)and groups inoculated with inorganic phosphorussolubilizing bacteria:W1(Bacillus cereus),W2(Serratia plymuthica),W12(Bacillus cereus and Serratia plymuthica),and groups inoculated with organophosphorus-solubilizing bacteria:Y1(Bacillus cereus),Y2(Bacillus cereus),Y12(Bacillus cereus and Bacillus cereus),totaling seven groups.Compared to CK,most growth indices in the bacterial addition groups showed significant differences,with W12 achieving the highest values in all indices except the leaf area index.The content of photosynthetic pigments,photosynthetic parameters,and osmoregulatory substances increased variably in each bacterial treatment group.W12 exhibited the highest content of chlorophyll a and soluble protein,while W1 had the highest free proline content.The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT)in all inoculated groups were higher than in CK,with significant changes in SOD and CAT activities.The malondialdehyde(MDA)content in all inoculated groups was lower than in CK,with Y12 being the lowest,at approximately 30%of CK.Gene expression corresponding to these three enzymes also increased variably,with POD expression in Y2 being the highest at 2.73 times that of CK.SOD and CAT expression in Y12 were the highest,at 1.84 and 4.39 times that of CK,respectively.These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F.taipaiensis P.Y.Li,with the mixed inoculation groups W12 and Y12 demonstrating superior effects.This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F.taipaiensis P.Y.Li.
基金Supported by the National 863 Program:Gene Polymerization Tech-nology Study and New Variety Breeding of High-qualityMulti-resist-ance and High-yield Tomato(2007AA10Z178)+1 种基金Shanghai Agricul-ture Committee Key ProjectGermplasm Innovation of Tomato Re-sistance to Yellow Leaf Curl Virus(2007)~~
文摘[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.
基金Supported by Science and Technology Innovation Project of Ji'nan City "Identification of Stress-resistant Malus sieversii Germplasm Resources and Screening of Stressresistance Functional Genes"(201401125)~~
文摘By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.
基金Supported by Grant From the National Science Council of Taiwan, No. NSC 90-2320-13-038-038
文摘AIM: To evaluate the effects of frying oil and Houttuynia cordata Thunb (H. cordata), a vegetable traditionally consumed in Taiwan, on the xenobiotic-metabolizing enzyme system of rodents. METHODS: Forty-eight Sprague-Dawley rats were fed with a diet containing 0%, 2% or 5% H. cordata powder and 15% fresh soybean oil or 24-h oxidized frying oil (OFO) for 28 d respectively. The level of microsomal protein, total cytochrome 450 content (CYP450) and enzyme activities including NADPH reductase, ethoxyresorufin 0-deethylase (EROD), pentoxyresorufin 0-dealkylase (PROD), aniline hydroxylase (ANH), aminopyrine demethylase (AMD), and quinone reductase (QR) were determined. QR represented phase Ⅱ enzymes, the rest of the enzymes tested represented phase Ⅰ enzymes. RESULTS: The oxidized frying oil feeding produced a significant increase in phase Ⅰ and Ⅱ enzyme systems, including the content of CYP450 and microsomal protein, and the activities of NADPH reductase, EROD, PROD, ANH, AMD and QR in rats (P<0.05). In addition, the activities of EROD, ANH and AMD decreased and QR increased after feeding with H. cordata in OFO-fed group (P<0.05). The feeding with 2% H. cordata diet showed the most significant effect. CONCLUSION: The OFO diet induces phases I and II enzyme activity, and the 2% H. cordata diet resulted in a better regulation of the xenobiotic-metabolizing enzyme system.
基金supported by special project of Basic Research in Yunnan Local Colleges and Universities(2017FH001-026,2018FH001-004)the National Natural Science Foundation of China(31300349)Scientific and Technological Innovation team Project of Agricultural Resources Utilization of Kunming University,Scientific Research Fund Project of Yunnan Provincial Department of Education(2021Y730,2021Y716).
文摘Pb,Cu,Cd,Zn content of soil in mining areas and abandoned land,flats of the Pijiang River and farmlands were inves-tigated.On this basis of soil heavy metal pollution,the changes of antioxidant enzyme system in maize(Qiandan 88)under different Pb concentrations(0,20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)stress were studied.The results show that the content of Pb,Cu,Cd,and Zn in soil is the highest in mining areas and abandoned land,followed by flats of the Pijiang River>farmlands,and that the variation range of Pb,Cu,Cd in mining areas and abandoned land are 106.40-2564.72,14.83-490.88,22.57-712.77 mg/kg,respectively,which are higher than that of the other land use types.When maize is under stress of 20-500 mg/L Pb concentration,T-SOD activity of maize leaves increase with the increase of Pb concentration and the highest value is 50.21 U/mg prot,but under Pb concentration>1000 mg/L stress,T-SOD activity of maize leaves decrease gradually.The activity of POD decreases with the increases of Pb concentra-tion,and the lowest POD activity of leaves in maize with the value of 93.24 U/mg prot is appeared in Pb 1000 mg/L concentration treatment group.MDA content in leaves of maize increases with the increase of the Pb concentration and the highest value is 101.98 nmol/mg prot,then the content of MDA decreases gradually when the Pb concentration is more than 500 mg/L,which indicates that the membrane lipid peroxidation of maize leaves under high concentration of Pb stress is serious and leads to the cell damage.
文摘Effect of vitamin C supplementation in restoring lead induced alterations in hematopoietic system and drug metabolizing enzymes were investigated in male rats. Intraperitoneal administration of 20 mg/kg lead produced a significant inhibition of heme synthesis in blood and liver and drug metabolism in liver. Toxic insult by lead also resulted into a marked decline in tissue thiols and vitamin C levels. Oral supplementation of vitamin C (100 mg/kg for 3 days) completely restored blood delta aminolevulinic acid dehydratase, uroporphyrinogen I synthetase and a few drug metabolizing enzymes. Level of vitamin C and sulfhydryl contents too recovered to a great extent. A marked reduction in blood and liver lead concentration occurred on vitamin C supplementation although renal lead contents were marginally reduced in lead exposed animals. The results, thus, indicate a significant protective action of vitamin C against toxic effects of lead on heme synthesis and drug metabolism.
文摘Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitosan depend on its physical and chemical characteristics, which result from the treatments used for its production. In this study, we report the preparation and characterization ofchitosan oligosaccharides by a green synthesis from crystalline shrimp chitin, using a sequential enzyme treatment by chitinase and chitin deacetylase. Chitinases were purified from grapes and used to rupture the crystalline shrimp chitin structure, modifying the crystallinity index from 57.6% to 15.9%. The resultant polymers were deacetylated using a recombinant chitin deacetylase from Saccharomyces cerevisiae, which was cloned and expressed in Pichia pastoris. The chitosans produced showed an estimated DA （degree of acetylation） of approximately 20%, and the molecular weights ranged from -7,600 to -3,700 after treatment in pH 3.0 and pH 6.0 for 10 min and 40 min, respectively. Physical and chemical characterization of the products indicated that enzyme fragmentation of chitin probably makes the acetamide groups more accessible to deacetylation, forming homogeneous polymers that are free of hazardous sub-products, have defined low molecular weights, and are highly deacetylated.
文摘AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.
基金This work was supported by the National Key Research and Development Project of China[2019YFD1001502]Forestry Science and Technology Prossmotion Project of Jiangsu Province[LYKJ[2018]26],Qing Lan Project of Jiangsu Province and High-Level Talent Support Program of Yangzhou University.
文摘Paeonia ostii is an economically important oil crop,which has been widely cultivated in the middle and lower reaches of the Yangtze River in China in recent years.Although P.ostii is highly adaptable to the environment,the prolonged high summer temperature in this region severely inhibits its growth,which adversely affects seed yield and quality.In this study,P.ostii plants were subjected to 20℃/15℃(day/night)and 40℃/35℃(day/night)temperatures for 15 days.The changes in physiological and biochemical indicators of P.ostii under high-temperature stress were initially investigated.The results showed that with the deepening of leaf etiolation,chlorophyll a and chlorophyll b concentration,carotenoid concentration,Soil Plant Analysis Development(SPAD)values and leaf relative water content decreased significantly,while both relative electrical conductivity(REC)and free proline concentration showed an upward trend.Meanwhile,the continuous accumulation of reactive oxygen species(ROS)in P.ostii plants,led to an increased activity of antioxidant enzymes including superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and ascorbate peroxidase(APX).Moreover,with the extension of the high-temperature treatment,the anatomical structures of P.ostii were destroyed,resulting in a decreased photochemical efficiency of the photosystem II(PSII)reaction center and photosynthesis was inhibited.Taken together,these results provide reference values for understanding the physiological response of P.ostii to hightemperature stress and establish a foundation for further research on the relevant underlying molecular mechanisms.
基金supported by grants from“Cataloguing,flora study and database establishment of mini-type fungi in Northeast Asia”from the Northeast Asia Biodiversity Research Center。
文摘Chinese peony(Paeonia lactiflora Pall.)is both medicinally and aesthetically beneficial.Powdery mildew is a common fungal disease that seriously jeopardizes the value of numerous species,including peonies as a crop.In order to provide a basis for the prevention and treatment of peony powdery mildew,we examined the microbial diversity,the malondialdehyde(MDA)concentrations and antioxidant enzyme activities of peony leaves infected with three levels of powdery mildew to determine any modifications to the leaf's antioxidant enzyme systems and microbial community structure following the onset of disease.The results show that the MDA content rose as the degree of infection became worse.Antioxidant enzyme activity rose and then declined.Following the initiation of powdery mildew,fungal community diversity decreased,whereas there was not any appreciable change in bacterial communities according to microbial diversity sequencing.The relative abundance of more than half of fungal species decreased,with the bacterial genera displaying both abundant and diminished communities with less pronounced alterations in their community structure after the disease spread.Significant different taxa that were critical to the organization of each microbiome were found.Correlation analysis showed that the relative abundance of powdery mildew pathogenic fungal genus Erysiphe was correlated with those of 11 fungal genera and one bacterial genus.Among them,Aureobasidium,Neosetophoma and Sclerostagonospora showed significant positive correlations with Erysiphe and MDA.
文摘Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsola imbricata was characterized by HPLC.Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200μL,7.5%acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays.The levels of malondialdehyde,glutathione peroxidase 1,superoxide dismutase,and catalase were determined in colon tissues.Proinflammatory cytokines including interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were quantified by ELISA.The extent of tissue damage was assessed by histological analysis.Results:Phytochemical analysis confirmed the presence of phytochemicals including quercetin,gallic acid,syringic acid,benzoic acid and chlorogenic acid in the crude extract.The crude extract of Salsola imbricata(300 and 500 mg/kg)markedly decreased malondialdehyde and nitric oxide(P<0.01)and increased antioxidant activities of glutathione peroxidase 1(P<0.001)and superoxide dismutase(P<0.001).Moreover,it decreased the levels of IL-1β,IL-6 and TNF-αsignificantly(P<0.001)and reduced the damage to the colon mucosa,promoting tissue healing and regeneration.Conclusions:Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.
文摘Abstract [Objective] This study was conducted to evaluate the ecotoxicity of boscalid to adult zebrafish （Danio rerio）. [Method] The activities of antioxidant enzymes superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, glutathione peroxidase （GPx）, as well as a non-enzymatic antioxidant malondialdehyde （MDA）, in the liver were measured 3, 7, 14 and 21 d post exposure （dpe） to 0.02 （1/100 of acute toxicity）, 0.036 （monitored concentration）, 0.08 （1/20 of acute toxicity）, 0.16 （1/10 of acute toxicity） and 0.32 mg/L （1/5 of acute toxicity） boscalid using a semi-static method. [Result] SOD, CAT, POD, GPx and MDA activity in the liver of zebrafish varied with boscalid concentration and exposure time. Boscalid significantly enhanced MDA content at 21 dpe. A significant upregulation of the activity of SOD, CAT, POD and GPx at 7 dpe was observed, suggesting that boscalid resulted in oxidative stress and lipid peroxidation. [Conclusion] These results show that these biomarkers are all appropriate for monitoring oxidative stress and the lipid peroxidation status of fish after exposure to boscalid. Key words Boscalid; Zebrafish; Antioxidant enzyme
文摘In this paper, an approximate analytical method to solve the non-linear differential equations in an immobilized enzyme film is presented. Analytical expressions for concentrations of substrate and product have been derived for all values of dimensionless parameter. Dimensionless numbers that can be used to study the effects of enzyme loading, enzymatic gel thickness, and oxidation/ reduction kinetics at the electrode in biosensor/biofuel cell performance were identified. Using the dimensionless numbers identified in this paper, and the plots representing the effects of these dimensionless numbers on concentrations and current in biosensor/biofuel cell are discussed. Analytical results are compared with simulation results and satisfactory agreement is noted.
文摘In order to investigate the effects of cadmium on the immune defense function of spiders infected with bacteria,Pirata subpiraticus was taken as research object,and the cadmium-treated group and the control group were all infected with bacteria(S.aureus and E.coli).After 6 and 24 h of infection,the energy substances contents and the activity of immune detoxification enzyme system in Pirata subpiraticus were determined.The results showed that after 6 and 24 h of infection with S.aureus and 6 h of infection with E.coli,the amount of soluble sugars and soluble proteins of Pirata subpiraticus in the cadmium-treated group increased significantly.Compared with the control,after 6 h of infection with S.aureus and 24 h of infection with E.coli,the activity of acetylcholinesterase(AChE)of Pirata subpiraticus in the cadmium-treated group decreased significantly.This indicated that cadmium inhibited the activity of AChE in infected Pirata subpiraticus.After 24 h of infection with S.aureus and 6 h of infection with E.coli,the activity of polyphenol oxidase(PPO)was signicantly higher than that of the control,indicating that cadmium induced the activity of PPO in infected Pirata subpiraticus.These results suggested that cadmium can affect the content of energy substance and immune detoxification enzyme activity in infected Pirata subpiraticus.
文摘Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme synergy.However,the proteinaceous characteristics of lignin-degrading enzymes restrict their accessibility to certain regions of intricate lignin,resulting in the multienzyme systems being unable to fully demonstrate their effectiveness.Herein,a de novo biomimetic enzyme-nanozyme hybrid system was constructed by combiningλ-MnO_(2) nanozyme with laccase CotA from Bacillus subtilis,aimed at facilitating lignin degradation under mild conditions.The lignin degradation rate of the CotA+λ-MnO_(2) hybrid system was determined to be 25.15%,which was much higher than those of the lignin degradation systems with only laccase CotA(15.32%)orλ-MnO_(2) nanozyme(14.90%).Notably,the proportion of aromatic chemicals in the products derived from the hybrid system reached as much as 48%,which was 41.2%and 118.2%higher than those of the CotA-andλ-MnO_(2)-catalyzed systems,respectively.Analysis of products mapping and lignin structure changes suggested that the higher proportion of aromatic compounds in the CotA+λ-MnO_(2)hybrid system was more likely to benefit from the laccase-mediated methoxylation.Moreover,electron paramagnetic resonance analysis indicated that the intensity and kind of free radicals such as·OH and·O_(2)^(-)are closely linked to the degradation rate and reaction type.This work is the inaugural application of an enzyme-nanozyme hybrid system for lignin degradation,demonstrating the potential of the synergistic interaction between enzyme and nanozyme in the directed degradation of lignin.
基金supported by the Zhejiang Provincial Natural Science Foundation,China(ZCLMS25C1302)the Central Public-interest Scientific Institution Basal Research Fund(CPSIBRF-CNRRI-202408)the Agricultural Science and Technology Innovation Program(ASTIP)
文摘Rice seed germination marks the start of cultivation and influences subsequent seedling growth,and is affected by hormones and environmental factors.Ubiquitination plays a critical role in this process by regulating hormonal homeostasis.In the ubiquitination cascade,ubiquitin-conjugating enzymes(UBCs)function as ubiquitin carriers to determine linkage specificity of ubiquitin chains.In rice(Oryza sativa),39 UBC genes are identified,but only one gene OsUBC12 has been functionally studied to promote seed germination under low-temperatures in japonica rice.To elucidate the role of UBCs in seed germination,we generated CRISPR-Cas9 mutants for 23 UBC genes and overexpressed 20 members in rice.Among them,seven UBC genes(OsUBC4/6/7/12/25/27/48)were found to regulate seed germination,with OsUBC27 and OsUBC48 acting through the ABA pathway.Exogenous ABA inhibitors restored the germination rate of osubc27^(CR).RT-qPCR analysis revealed that the ABA synthesis genes OsNCED1-5 were significantly upregulated in the mutants.Further differential ubiquitination proteomics in knockout mutants and wild-type plants showed that OsUBC27 regulates ABA homeostasis by modulating ubiquitination of the ABA-degrading protein OsABA8ox1,thereby balancing seed dormancy and germination.Sequence analysis identified distinct haplotypes of the seven OsUBCs that showed differential distribution between japonica and indica subspecies.Our study provides valuable molecular targets for developing rice varieties resistant to seed vivipary.
基金supported by the National Natural Science Foundation of China(Nos.21874060 and 22174058,U21A20282)the Science and Technology program of Gansu Province(No.22JR5RA476)。
文摘DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.
文摘The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.
文摘Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.
文摘Coronavirus disease 2019(COVID-19)is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus.It has affected over 768 million people worldwide,resulting in approx-imately 6900000 deaths.High-risk groups,identified by the Centers for Disease Control and Prevention,include individuals with conditions like type 2 diabetes mellitus(T2DM),obesity,chronic lung disease,serious heart conditions,and chronic kidney disease.Research indicates that those with T2DM face a hei-ghtened susceptibility to COVID-19 and increased mortality compared to non-diabetic individuals.Examining the renin-angiotensin system(RAS),a vital regulator of blood pressure and pulmonary stability,reveals the significance of the angiotensin-converting enzyme(ACE)and ACE2 enzymes.ACE converts angiotensin-I to the vasoconstrictor angiotensin-II,while ACE2 counters this by converting angiotensin-II to angiotensin 1-7,a vasodilator.Reduced ACE2 exp-ression,common in diabetes,intensifies RAS activity,contributing to conditions like inflammation and fibrosis.Although ACE inhibitors and angiotensin receptor blockers can be therapeutically beneficial by increasing ACE2 levels,concerns arise regarding the potential elevation of ACE2 receptors on cell membranes,potentially facilitating COVID-19 entry.This review explored the role of the RAS/ACE2 mechanism in amplifying severe acute respiratory syndrome cor-onavirus 2 infection and associated complications in T2DM.Potential treatment strategies,including recombinant human ACE2 therapy,broad-spectrum antiviral drugs,and epigenetic signature detection,are discussed as promising avenues in the battle against this pandemic.
