Overexpression of PbrGA2ox1 enhances pear drought tolerance through the regulation of GA_(3)-inhibited reactive oxygen species detoxification and abscisic acid signaling

Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.

OsbZIP53 Negatively Regulates Immunity Response by Involving in Reactive Oxygen Species and Salicylic Acid Metabolism in Rice

The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.

Behaviour of Tributylamine as Entrainer for the Separation of Water and Acetic Acid with Reactive Extractive Distillation

A new separation method, reactive extractive distillation, was put forward for separating water and acetic acid. The separation mechanism was analyzed through infrared spectra technique. Isobaric vapor-liquid equilibrium (VLE) data at 101.33 kPa for the binary or ternary systems consisting of water, acetic acid and tributylamine were measured. The activity coefficients were correlated by using Wilson, NRTL, and UNIQUAC Equations.The VLE experiment showed that tributylamine could enhance the relative volatility of water to acetic acid. An extractive distillation experiment was carried out and proved that tributylamine was a good extractive solvent.

Reactive Crystallization of Calcium Sulfate Dihydrate from Acidic Wastewater and Lime

The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from plateletlike and nee dlelike shape to rodlike shape when the temperature was increased from 25 to 70 ℃. An increase in the agglom.

All-trans retinoic acid increases ARPE-19 cell apoptosis via activation of reactive oxygen species and endoplasmic reticulum stress pathways

AIM:To explore the apoptosis of ARPE-19 cells after the treatment with different doses of all-trans-retinoic acid(ATRA).METHODS:ARPE-19 cells were used in the in-vitro experiment.Flow cytometry assay was employed to evaluate the level of reactive oxygen species(ROS)and apoptosis.The effects of ATRA(concentrations from 2.5 to 20μmol/L)on the expression of endoplasmic reticulum stress(ERS)markers in vitro were evaluated by Western blot and realtime quantitative polymerase chain reaction(qRT-PCR)assays.The contribution of ROS and ERS-induced apoptosis in vitro was determined by using N-acetyl-L-cysteine(NAC)and Salubrinal,an antagonist of NAC and ERS,respectively.RESULTS:Flow cytometry showed that ATRA significantly increased ARPE-19 cell apoptosis and ROS levels in each group(F=86.39,P<0.001;F=116.839.P<0.001).Western blot and qRT-PCR revealed that levels of CHOP and BIP were elevated in a concentration-dependent pattern after the cells were incubated with ATRA(2.5-20μmol/L).The upregulation of VEGF-A and CHOP induced by ATRA could be inhibited by NAC(antioxidant)and Salubrinal(ERS inhibitor)in vitro.CONCLUSION:ATRA induces the apoptosis of ARPE-19 cells via activated ROS and ERS signaling pathways.

Reactive Extraction of Nicotinic Acid with Trialkylamine in n-Octanol

The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.

Application of Bronsted acid ionic liquids as green catalyst in the synthesis of 2-propanol with reactive distillation

Five Br?nsted acidic ionic liquids(ILs) were prepared and characterized by FT-IR,~1H NMR and ^(13)C NMR. Their catalytic activities for the synthesis of 2-propanol(IPOH) via transesterification of isopropyl acetate(IPAc) with methanol(Me OH) were investigated. Among all the tested ILs, [Ps-mim]HSO_4 performed best and was used as catalyst for further studies. The reaction kinetics were carried out to correlate the parameters in a homogeneous second order kinetic model. It has been found that there is close agreement between the calculated and experimental values. The high-pressure batch reactive distillation experimental apparatus was set up in order to enhance the conversion of IPAc. A high conversion of IPAc of 99.4% was obtained under the optimal reaction conditions. The catalyst [Ps-mim]HSO_4 can be recycled easily by a rotary evaporator and reused without any further treatment. The catalyst had been repeatedly used for four times and no obvious changes in the structure of catalyst could be observed.

Union Dyeing Behavior on the Blends of Tencel and Shrink-proofing Wool with the Same Reactive Dyestuffs in One Bath

In order to obtain union colour on the blends of Tencel and shrink-proofing wool and improve the efficiency of dyeing process, the dyeing behavior on the blends of Tencel and shrink-proofing wool in the same bath was studied. The Argazol TW reactive dyestuffs were involved in the dyeing process. The parameters under different conditions such as exhaustion, fixation,compatibility as well as soaping fastness were investigated in detail. It is shown that the Argazol TW reactive dyestuffs are suitable for dyeing of blends of Tencel and shrink-proofing wool and good dyeing behavior can be expected.

Performance of Metal and Acid Ions Remediation in Contaminated Soils by Electrokinetics with Chitosan Permeable Reactive Barrier

Metal and acid ions contamination of soil in China is serious. To find an efficient solution for remediating the combined pollution,electrokinetics( EK) coupled with chitosan( CTS)permeable reactive barrier( EK/CPRB) was used to investigate the performances of metal and acid ions remediation. Adsorption characteristics of Zn^(2+),Fe^(3+),Ca^(2+),SO_4^(2-) and NO_3^- onto CTS were also conducted. The results showed the sorption of Zn^(2+),Fe^(3+),Ca^(2+),SO_4^(2-) and NO_3^- on CTS could be well described by Freundlich model. When the CTS dosage is 8 g,the total removal efficiency for Zn^(2+),Fe^(3+),Ca^(2+),SO_4^(2-) and NO_3^- is 86. 8%,90. 2%,92. 4%,90. 0% and 82. 5%,respectively. CTS enhanced ions remediation efficiencies significantly compared with the single EK system,especially for SO_4^(2-) and NO_3^-. The results indicate EK/CPRB system is suitable for the remediation of soil contaminated by both metal ions and acid ions.

Assessment of the Total Organic Carbon and Conductivity in Consecutive Dyeings with Reactive Dyestuffs Using Treated Effluent by UV/H202 Photocatalysis

The paper was monitored the conductivity （g.L＂l of NaCI）, the absorbances values （Abs） and the amount of TOC （total organic carbon）, before and after five consecutive dyeings made with reuse water, obtained from treated effluent by UV/H202 photocatalysis. All rates of decolorization were above 92%, the removal of total organic carbon was above 89% in all treatments and the economy of NaCI was from 3.10 in the first recipe, 3.17 in the second, 3.49 in the third, 3.79 in the fourth and 4.05 in the fifth recipe. The five dyeings compared with same dyeings made with deionized water presented a color deviation （AE＊） below 1. The conventional dyeings would consume 80 L/kg against 40 L/kg used in the dyeing process proposed in this study, representing a great economy of water, with no discharge of effluents.

Reactive Compatibilization of Short-Fiber Reinforced Poly(lactic acid)Biocomposites

Poor interfacial adhesion between biobased thermoplastics and natural fibers is recognized as a major drawback for biocomposites.To be applicable for the large-scale production,a simple method to handle is of importance.This work presented poly(lactic acid)(PLA)reinforced with short-fiber and three reactive agents including anhydride and epoxide groups were selected as compatibilizers.Biocomposites were prepared by one-step meltmixing methods.The influence of reactive agents on mechanical,dynamic mechanical properties and morphology of PLA biocomposites were investigated.Tensile strength and storage modulus of PLA biocomposites incorporated with epoxide-based reactive agent was increased 13.9%and 37.4%compared to non-compatibilized PLA biocomposite,which was higher than adding anhydride-based reactive agent.SEM micrographs and Molau test exhibited an improvement of interfacial fiber-matrix adhesion in the PLA biocomposites incorporated with epoxide-based reactive agent.FTIR revealed the chemical reaction between the fiber and PLA with the presence of epoxide-based reactive agents.

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

Dichloroacetic Acid (DCA)-Induced Cytotoxicity in Human Breast Cancer Cells Accompanies Changes in Mitochondrial Membrane Permeability and Production of Reactive Oxygen Species

Cancer cells utilize cytosolic glycolysis for their energy production even in the presence of adequate levels of oxygen (Warbug effect) due to mitochondrial defects. Dichloroacetic acid (DCA) shifts cytosolic glucose metabolism to aerobic oxidation by inhibiting mitochondrial pyruvate dehydrogenase kinase (PDK) and increasing pyruvate uptake. Therefore, DCA has potential in reversing the glycolytic metabolism defect in cancerous cells. DCA is also known to induce apoptosis in a number of cancer cell lines, the mechanism of which is not well understood. In this study, an attempt has been made to investigate the effects of DCA on aggressive human breast cancer (MCF-7) cells as compared with less aggressive mouse osteoblastic (MC3T3) cells. Cell cytotoxicity was determined by MTT, crystal violet and Trypan blue exclusion assays. Western blot was used to detect any changes in the expression of apoptotic markers. Flow cytometry was used to measure apoptotic and necrotic effects of DCA. Mitochondrial integrity was determined by change in mitochondrial membrane potential (Δψm), whereas oxidative damage was determined by production of reactive oxygen species (ROS). DCA caused a concentration-dependent cytotoxicity both in MCF-7 and MC3T3 cell lines. MCF-7 cells were most affected. Flow cytometry results showed a significantly higher apoptosis in MCF-7 even at lower concentrations of DCA. However, higher concentrations of DCA were necrotic. Western blotting showed an increased expression of Mn-SOD-1 upon DCA treatment. Further, DCA decreased Δψm and increased ROS production. The effects of DCA were more pronounced on MCF-7 cells as compared to MC3T3 cells. Our results suggest that DCA-induced cytotoxicity in cancerous cells is mediated via changes in Δψm and production of ROS.

Equilibrium Study for Reactive Extraction of Caproic Acid in Mibk and Xylene

The recovery of caproic acid from the aqueous stream is of practical relevance due to its market value and the stringent environmental standards. The profound success of reactive extraction has been noted in the recovery of carboxylic acids from dilute solutions. In present paper, equilibrium of caproic acid with aliquat-336, a quaternary amine compound, in xylene and Methyl Isobutyl Ketone (MIBK) has been studied. Equilibrium parameters such as distribution coefficients, loading ratio, degree of extraction and equilibrium complexation constants have been presented. The data obtained is useful in understanding the equilibrium characteristics and efficient design of the recovery process of caproic acid by reactive extraction.

Separation of Lactic Acid from Diluted Solution by Hybrid Short Path Evaporation and Reactive Distillation

This work describes the separation and purification of lactic acid from diluted solution by HSPE （hybrid short path evaporation） and RD （reactive distillation） as coupled process. The results showed that it is possible to increase lactic acid concentration up to 4.7 times higher than the raw material concentration.

Quantitative structure-activity relationship study on the biodegradation of acid dyestuffs

Quantitative structure-biodegradability relationships （QSBRs） were established to develop predictive models and mechanistic explanations for acid dyestuffs as well as biological activities. With a total of four descriptors, molecular weight （MW）, energies of the highest occupied molecular orbital （EHOMO）, the lowest unoccupied molecular orbital （ELUMO）, and the excited state （EES）, calculated using quantum chemical semi-empirical methodology, a series of models were analyzed between the dye biodegradability and each descriptor. Results showed that EHOMO and Mw were the dominant parameters controlling the biodegradability of acid dyes. A statistically robust QSBR model was developed for all studied dyes, with the combined application of EHOMO and Mw. The calculated biodegradations fitted well with the experimental data monitored in a facultative-aerobic process, indicative of the reliable prediction and mechanistic character of the developed model.

Proliferation and differentiation of reactive nestin^+/GFAP^+ cells in an adult rat model of compression-induced spinal cord injury

BACKGROUND： Studies have demonstrated that astrocytes may possess similar properties to neural stem cells/neural precursor cells and have the potential to differentiate into neurons. OBJECTIVE： To observe neuroepithelial stem cell protein （nestin） and glial fibrillary acidic protein （GFAP） expression following spinal cord injury, and to explore whether nestin＋/GFAP＋ cells, which are detected at peak levels in gray and white matter around the ependymal region of the central canal in injured spinal cord, possess similar properties of neural stem cells. DESIGN, TIME AND SETTING： A randomized, controlled experiment. The study was performed at the Key Laboratory of Environment and Genes Related to Diseases （Xi＇an Jiaotong University）, Ministry of Education between January 2004 and December 2006. MATERIALS： Rabbit anti-rat nestin, β-tubulinⅢ, mouse anti-rat GFAP, galactocerebroside （GaLC） antibodies were utilized, as well as flow cytometry. METHODS： A total of 60 male, Sprague Dawley rats, aged 8 weeks, were randomly assigned to control （n = 12） and model （n = 48） groups. The spinal cord injury model was established in the model group by aneurysm clip compression, while the control animals were not treated. The gray and white matter around the ependymal region of the central canal exhibited peak expression of nestin＋/GFAP＋ cells. These cells were harvested and prepared into single cell suspension, followed by primary and passage cultures. The cells were incubated with serum-containing neural stem cell complete medium. MAINOUTCOME MEASURES： Nestin and GFAP expression in injured spinal cord was determined using immunohistochemistry and double-labeled immunofluorescence at 1, 3, 5, 7, 14, 28, and 56 days post-injury. In addition, cell proliferation and differentiation were detected using immunofluorescence cytochemistry and flow cytometry. RESULTS： Compared with the control group, the model group exhibited significantly increased nestin and GFAP expression （P 〈 0.05）, which reached peak levels between 3 and 7 days. The majority of cells in the ependymal region around the central canal were nestin＋/GFAP- cells, while the gray and white matter around the ependymal region were full of nestin＋/GFAP＋ cells, with an astrocytic-like appearance. A large number of nestin＋/GFAP＋cells were observed in the model group cell culture, and the cells formed clonal spheres and displayed strong nestin-positive immunofluorescence staining. Following induced differentiation, a large number of GaLC-nestin, β-tubulin Ⅲ-nestin, and GFAP-nestin positive cells were observed. However, no obvious changes were seen in the control group. Cells in S stage, as well as the percentage of proliferating cells, in the model group were significantly greater than in the control group （P 〈 0.01）, CONCLUSION： Spinal cord injury in the adult rat induced high expression of nestin＋/GFAP＋ in the gray and white matter around the ependymal region of the central canal. These nestin＋/GFAP＋ cells displayed the potential to self-renew and differentiate into various cells. The cells could be neural stem cells of the central nervous system.

Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

The compositions of copolymers of diethyldiallylammonium chloride （DEDAAC） with acrylamide （AM）, acrylic acid （AA） or sodium acrylic acid （NaAA） at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and roe and rNsAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.

Properties of Novel Reactive Transfer Printing of Silk

The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted hydroxypropyl cellulose （H-HPC） and printing thickener earboxymethyl cellulose （CMC）. The effects of each ingredient in the paste on color yield of the prints and dye penetration were investigated. The major results indicate that, color yield is chiefly governed by the adhesion extent imparted by H-HPC, the type of fixing alkaline agent, and the content of urea. Trichloroacetic acid （TCAA） as the fixing alkaline agent and adding 5% urea can enhance the color depth obviously. Dye penetration depends on the coating quantity on the transfer paper, the contents of urea and dicyandiamide. The printed silk possesses a higher color yield, color fastness of grade 3 or above, clear sharpness, and good handle when the paste contains 3 % H-HPC, 0. 7 % CMC, 3 % TCAA, 5 % urea, 3 % dicyandiamide, and 0. 5 % physical sorbent nano-silica.