The removal of ciprofloxacin(CIP)in sulfur-mediated bio processes,e.g.,sulfate-reducing bacteria(SRB)-mediated process and sulfur-oxidizing bacteria(SOB)-mediated process,was examined for the first time.The results sh...The removal of ciprofloxacin(CIP)in sulfur-mediated bio processes,e.g.,sulfate-reducing bacteria(SRB)-mediated process and sulfur-oxidizing bacteria(SOB)-mediated process,was examined for the first time.The results showed that the SRB-mediated process had more efficient CIP removal than that in SOB-mediated process.Adsorption was the primary removal pathway of CIP in SRB-mediated process and SOB-mediated process with the specific adsorption removal rate of 131.4±1.1μg/g-SS/d and30.1±1.4μg/g-SS/d,respectively,at influent CIP concentration of 500μg/L.In addition,extracellular polymeric substances(EPS)also played an important role on CIP migration and removal in both types of sludge.Further study was conducted to specify the different adsorption of CIP in these two sludge systems from the perspective of sludge properties.The results indicated that there are more potential adsorption sites exist on the SRB-mediated sludge for CIP adsorption than SOB-mediated sludge since the higher protein(PN)content and more kinds of aromatic amino acid substances in EPS,more negative zeta-potential and stronger and more numbers of functional groups in SRB-mediated sludge compared to SOB-mediated sludge.The findings of this study provide insights into the sludge properties affecting CIP removal in sulfur-mediated bioprocesses,and are of guiding significance to employ sulfur-mediated biological systems for treating CIP-containing wastewaters.展开更多
Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve ...Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.展开更多
Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on...Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci （QTLs）. However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.展开更多
The dorsal lingual epithelium,which is composed of taste buds and keratinocytes differentiated from K14^(+)basal cells,discriminates taste compounds and maintains the epithelial barrier.N6-methyladenosine(m^(6)A)is th...The dorsal lingual epithelium,which is composed of taste buds and keratinocytes differentiated from K14^(+)basal cells,discriminates taste compounds and maintains the epithelial barrier.N6-methyladenosine(m^(6)A)is the most abundant mRNA modification in eukaryotic cells.How METTL3-mediated m^(6)A modification regulates K14^(+)basal cell fate during dorsal lingual epithelium formation and regeneration remains unclear.Here we show knockout of Mettl3 in K14^(+)cells reduced the taste buds and enhanced keratinocytes.Deletion of Mettl3 led to increased basal cell proliferation and decreased cell division in taste buds.Conditional Mettl3 knock-in mice showed little impact on taste buds or keratinization,but displayed increased proliferation of cells around taste buds in a protective manner during post-irradiation recovery.Mechanically,we revealed that the most frequent m^(6)A modifications were enriched in Hippo and Wnt signaling,and specific peaks were observed near the stop codons of Lats1 and FZD7.Our study elucidates that METTL3 is essential for taste bud formation and could promote the quantity recovery of taste bud after radiation.展开更多
Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylate...Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylates, and styrene). However, the complexity of the reaction mechanism and multi-component system nature make it challenging to choose the appropriate conditions and consider the factors of achieving controllable polymerization when switching from one monomer to others with different reactivities. Herein, by polymerizing two examplary monomers: methyl methacrylate(MMA) and styrene via Cu(0)-mediated RDRP under different conditions,we have found that the reaction parameters(e.g., initiator, ligand, solvent, and deactivator) play a crucial role in regulating two equilibriums:(i) mutual conversion of different copper species which determines the relative concentration of Cu(Ⅰ) and Cu(Ⅱ), and(ii)polymerization equilibrium which is the combination of activation/deactivation, propagation and termination processes. We have demonstrated that by taking both the mutual conversion of different copper species and the polymerization equilibrium into account, the optimal reaction conditions could be selected, and the well-controlled Cu(0)-mediated RDRPs of methyl methacrylate and styrene were achieved with narrow molecular weight distributions and predicted molecular weight.展开更多
Receptor kinases play a pivotal role in detecting environmental signals,and consequently,gene pleiotropy is frequently observed within this family.However,the trade-off in trait expression resulting from gene pleiotro...Receptor kinases play a pivotal role in detecting environmental signals,and consequently,gene pleiotropy is frequently observed within this family.However,the trade-off in trait expression resulting from gene pleiotropy poses a constraint on the utilization of such genes in agricultural breeding.In this study,we identified the receptor kinase gene FERONIA-Like Receptor 13(FLR13)as a pleiotropic gene influencing plant height,tillering,grain yield,and disease resistance.Using promoter editing,we generated novel alleles(FLR13T5T6-1,FLR13T5T6-2)that confer resistance to rice blast and increase per-plant yield.The knockout of the T5T6 segment alleviates the inhibitory effects of two transcription factors,OsGBP1 and OsWRKY53,on FLR13 expression.In summary,our study presents a promising avenue for enhancing the pivotal attributes of receptor-like kinases through a promoter-editing strategy.展开更多
Fluorinated polymers are receiving more and more attention worldwide due to their unique chemical properties,and modified fluorinated polymers with different topologies are persued for enriching and enhancing their pe...Fluorinated polymers are receiving more and more attention worldwide due to their unique chemical properties,and modified fluorinated polymers with different topologies are persued for enriching and enhancing their performance in a variety of application fields.In this work,main-chain-type semifluorinated graft copolymers are produced steadily in continuous tube reactors via photocontrolled step transferaddition and radical-termination(START)polymerization and Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-RDRP)at room temperature for the first time.Specifically,semifluorinated alternating copolymer(AB)n B is prepared by START polymerization of 1,6-diiodoperfluorohexane(A)and 1,7-octadiene(B)in the first quartz pipeline under irradiation with purple LED light at 20℃.The(AB)nB with periodic C―I bonds is then flowed into the second copper pipeline directly and acts as the macroinitiators for Cu(0)-RDRP of methyl acrylate(MA)to obtain corresponding graft copolymer(AB)n B-g-PMA.This work provides a new strategy for continuous synthesis of fluorinated graft copolymer materials.展开更多
Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control o...Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control over the molecular weights(MWs) or complex or multi reaction steps, etc. In this work, we report the well-controlled polymerization of NIPAM in water via a facile one-pot and one-step Cu(0)-mediated RDRP. The results of this approach show that the key for kicking off the Cu(0)-mediated NIPAM RDRPs is to ensure sufficient Cu~I at the very beginning, and the key to achieve a well-controlled chain growth is to provide adequate deactivation strength during the polymerization process. For NIPAM, which has a high propagation rate constant, the deactivation control can be effectively enhanced by extra adding deactivator(i.e., Cu~II) to the system. Moreover, a low reaction temperature(4 ℃) is necessary in the controlled synthesis of higher MW poly(Nisopropylacrylamide)(PNIPAM) to avoid the compromise in control caused by the phase transition from its lower critical solution temperature(LCST). Through this new kinetically controlled strategy, PNIPAMs with well-defined structure, narrow molecular weight distributions(MWDs) and varied MWs were successfully achieved.展开更多
An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dime...An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary.The commercially available(R)-α-met hylbenzy la mine was identified as the best amine ligand for Cu(Ⅱ) in the reactions.A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined,affording the corresponding axially chiral diphenols with satis factory to excellent diastereomeric ratios,and a representative scalable preparation was also attempted.A formal synthesis of natural product(+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.展开更多
The ＂living＇/controlled radical polymerization （LRP） of styrene （St） at room temperature is rarely reported. In this work, copper（0） （Cu（0））-mediated radical polymerization of St at room temperature was in...The ＂living＇/controlled radical polymerization （LRP） of styrene （St） at room temperature is rarely reported. In this work, copper（0） （Cu（0））-mediated radical polymerization of St at room temperature was investigated in detail. Dimethyl sulfoxide （DMSO）, N,N-dimethylformamide （DMF） as well as a binary solvent, tetrahydrofuravdl,l,l,3,3,3-hexafluoro-2- propanol were used as the solvents, respectively. Methyl-2-bromopropionate and ethyl 2-bromoisobutyrate were used as the initiators, respectively. The polymerization proceeded smoothly with moderate conversions at room temperature. It was found that DMF was a good solvent with the essential features of LRP, while DMSO was a poor solvent with uncontrollable molecular weights. Besides, the match among the initiator, solvent and molar ratios of reactants can modulate the livingness of the polymerization, and the proper selection of ligand was also crucial to a controlled process. This work provided a first example of Cu（0）-mediated radical polymerization of St at room temperature, which would enrich and strength the LRP technique.展开更多
NLRP3 inflammasome-mediated cell pyroptosis aggravates the development of cerebral ischemia/reperfusion(I/R)injury,and the aim of this study is to investigate the potential utilization of the Chinese medicine,Puerarin...NLRP3 inflammasome-mediated cell pyroptosis aggravates the development of cerebral ischemia/reperfusion(I/R)injury,and the aim of this study is to investigate the potential utilization of the Chinese medicine,Puerarin,in treating this disease.Through conducting in vitro and in vivo experiments,the present study illustrated that Puerarin regulated LncRNA double homeobox A pseudogene 8(DUXAP8)/miR-223-3p axis to inactivate NLRP3-mediated pyroptotic cell death,resulting in the attenuation of I/R injury.Specifically,the cerebral I/R injury in rat models and hypoxia/reoxygenation(H/R)in primary hippocampus neuron(PHN)cells were inducted,which were subsequently exposed to Puerarin treatment.As expected,we validated that Puerarin suppressed cell pyroptosis and rescued cell viability in I/R rat hippocampus tissues and H/R PHN cells.Next,through bioinformatics analysis,we noticed that miR-223-3p targeted both LncRNA DUXAP8 and NLRP3 mRNA,and both LncRNA DUXAP8 ablation and miR-223-3p overexpression inactivate NLRP3-mediated cell pyroptosis to rescue cell viability in H/R PHN cells.Interestingly,we evidenced that Puerarin restrained LncRNA DUXAP8 expressions,but upregulated miR-223-3p in I/R rat tissues and H/R PHN cells,and the protective effects of Puerarin on H/R PHN cells were abrogated by overexpressing LncRNA DUXAP8 and silencing miR-223-3p.Collectively,we concluded that Puerarin regulated LncRNA DUXAP8/miR-223-3p/NLRP3 signaling cascade to attenuate I/R injury.展开更多
In order to investigate the reaction mechanism of intramolecular C-H insertion by Rh(II)-mediated carbenoids with trans-(2-phenylcyclopropyl) carbinal radical as the mechanistic probe, diazo compounds 2-(2-phenylcyclo...In order to investigate the reaction mechanism of intramolecular C-H insertion by Rh(II)-mediated carbenoids with trans-(2-phenylcyclopropyl) carbinal radical as the mechanistic probe, diazo compounds 2-(2-phenylcyclopropyl)ethyl diazoacetoacetate 8a and methyl 2-diazo-3oxo-6-(2-phenylcyclopropyl) hexanoate 8b have been synthesized. Preliminary investigation of the intramolecular C-H insertion with Rh2(OAc)4 as catalyst supports a concerted insertion process.展开更多
The three-dimensional organization of the genome plays a crucial role in regulating gene expression patterns in metazoans（Ong and Corces,2014）.The nuclear architectural proteins are known to facilitate the formation...The three-dimensional organization of the genome plays a crucial role in regulating gene expression patterns in metazoans（Ong and Corces,2014）.The nuclear architectural proteins are known to facilitate the formation of topological domains within the genome through mediating inter-and intra-chromosomal interactions.In vertebrate,CCCTC-binding factor（CTCF）is the main architectural protein that mediates long-range chromosomal interactions among its DNA binding sites through a process that is stabilized by cohesin （Parelho et al., 2008; Wendt et al., 2008）.展开更多
Direct C—H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnOas the sole and efficient oxidative system.This method provides an efficient protocol to construct regioselectively 2-ar...Direct C—H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnOas the sole and efficient oxidative system.This method provides an efficient protocol to construct regioselectively 2-arylquinoline N-oxides via radical cross-coupling reaction in moderated to good yields under mild conditions.展开更多
The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms re...The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms remain poorly characterized.Huanglongbing(HLB),a devastating citrus disease,is primarily caused by the bacterium"Candidatus Liberibacter asiaticus"(CLas)and transmitted by psyllid vectors.In this study,we demonstrate that the effector protein SDE5,secreted by CLas,suppresses the biosyn-thesis of volatile terpenoids in host citrus plants,thereby enhancing psyllid attraction.Biochemically,SDE5 functions as an inhibitor of bacterial C-type lysozyme,facilitating both CLas infection and psyllid vec-tor attraction.Two plant U-box(PUB)E3 ligases,PUB10 and PUB21,are recruited by SDE5 to promote ubiq-uitination and proteasomal degradation of MYC2,a key transcription factor in jasmonate signaling and terpene-based anti-herbivore defenses.Furthermore,SDE5 interferes with MYC2 dimerization,diminishing its ability to activate terpene biosynthesis genes.This dual suppression markedly reduces volatile terpe-noid emissions in SDE5-transgenic citrus lines,resulting in increased psyllid attraction and enhanced psyl-lid fitness.Conversely,the anti-proteolysis peptide 3-14(APP 3-14),which stabilizes the MYC2 protein and inhibits the HLB pathogen,enhances volatile terpenoid emission and repels psyllids.These findings pro-vide a novel strategy for disrupting mutualistic interactions between plant bacterial pathogens and insect vectors by modulation of olfactory defense.展开更多
Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been sug...Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been suggested as a mediator between Al stress and gene expression, but the underlying mechanisms remain largely unknown. Here,we investigated ABA-mediated Al-stress responses, using integrated physiological and molecular biology approaches.We demonstrate that Al stress caused ABA accumulation in the root apex of rice bean(Vigna umbellata [Thunb.] Ohwi &Ohashi), which positively regulated Al tolerance. However,this was not associated with known Al-tolerance mechanisms. Transcriptomic analysis revealed that nearly one-third of the responsive genes were shared between the Al-stress and ABA treatments. We further identified a transcription factor, ABI5, as being positively involved in Al tolerance. Arabidopsis abi5 mutants displayed increased sensitivity to Al, which was not related to the regulation of AtALMT1 and AtMATE expression. Functional categorization of ABI5-mediated genes revealed the importance of cell wall modification and osmoregulation in Al tolerance, a finding supported by osmotic stress treatment on Al tolerance. Our results suggest that ABA signal transduction pathways provide an additional layer of regulatory control over Al tolerance in plants.展开更多
Summary Vacuolar trafficking routes and their regu- lators have recently drawn lots of attention in plant cell biology. A recent study reported the discovery of a plant-specific vacuolar trafficking route, i.e., a dir...Summary Vacuolar trafficking routes and their regu- lators have recently drawn lots of attention in plant cell biology. A recent study reported the discovery of a plant-specific vacuolar trafficking route, i.e., a direct ER- to-vacuole route, through analysis of VHA-a3 subcellular targeting, a key component for the tonoplast V- ATPases. Our recent findings showed that VHA-a3 targets to the tonoplast through a Rab5-mediated but Rab7-independent pathway, shedding new lights on the unconventional vacuolar trafficking route in plant cells.展开更多
Great progress has been made in recent years in studies on the mechanism of Agrobacterium-mediated transformation and its application. Many details of the key molecular events within the bacterial cells involved in T-...Great progress has been made in recent years in studies on the mechanism of Agrobacterium-mediated transformation and its application. Many details of the key molecular events within the bacterial cells involved in T-DNA transfer have been elucidated, and it is notable that some plant factors which were elusive before are purified and characterized. Vast kinds of species, which were either recalcitrant to or not included in the host range of Agrobacterium, can' now be transformed by this bacterium, and they include the very important cereal species, gymnosperms, yeast and many filamentous fungi. The simple in vivo transformation of tissue in intact plants and the 'agrolistic' methods to transform recalcitrant plants are the two novel technical achievements. Combined with other powerful techniques such as bacterial artificial chromosome, very large DNA fragment can be transformed into the plant genome by Agrobacterium. Further studies will elucidate more plant-encoded factors involved in T-DNA展开更多
A unified strategy toward the construction of the [5.7.6]tricyclic skeleton of liphagal is reported,featuring InCl3-mediated intramolecular Friedel-Crafts-type cyclization.
Due to the chemoselective dehalogenation by SmI2, the addition of α-halomethylsulfones to carbonyl compounds afforded β-hy-droxysulfones. Those reactions with α-bromomethylsulfones gave the products in moderate to ...Due to the chemoselective dehalogenation by SmI2, the addition of α-halomethylsulfones to carbonyl compounds afforded β-hy-droxysulfones. Those reactions with α-bromomethylsulfones gave the products in moderate to good yields. The SmI2-mediat-ed addition of gem-dihalomethylsulfones to ketones also afforded α-halo-β-hydroxysulfones in moderate yields.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51922110 and 51778643)。
文摘The removal of ciprofloxacin(CIP)in sulfur-mediated bio processes,e.g.,sulfate-reducing bacteria(SRB)-mediated process and sulfur-oxidizing bacteria(SOB)-mediated process,was examined for the first time.The results showed that the SRB-mediated process had more efficient CIP removal than that in SOB-mediated process.Adsorption was the primary removal pathway of CIP in SRB-mediated process and SOB-mediated process with the specific adsorption removal rate of 131.4±1.1μg/g-SS/d and30.1±1.4μg/g-SS/d,respectively,at influent CIP concentration of 500μg/L.In addition,extracellular polymeric substances(EPS)also played an important role on CIP migration and removal in both types of sludge.Further study was conducted to specify the different adsorption of CIP in these two sludge systems from the perspective of sludge properties.The results indicated that there are more potential adsorption sites exist on the SRB-mediated sludge for CIP adsorption than SOB-mediated sludge since the higher protein(PN)content and more kinds of aromatic amino acid substances in EPS,more negative zeta-potential and stronger and more numbers of functional groups in SRB-mediated sludge compared to SOB-mediated sludge.The findings of this study provide insights into the sludge properties affecting CIP removal in sulfur-mediated bioprocesses,and are of guiding significance to employ sulfur-mediated biological systems for treating CIP-containing wastewaters.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA08040101)the Hundred Talents Program of Chinese Academy of Sciences to Q.Y. Bu+1 种基金the Natural Science Foundation of Heilongjiang (No.ZD2015005)Excellent Academic Leaders of Harbin (No.RC2014XK002003)
文摘Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.
基金supported by Genetically Modified Breeding Major Projects(No.2016ZX08010-002-008)the National Natural Science Foundation of China(Nos.31501239 and 31401454)
文摘Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci （QTLs）. However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.
基金supported by the National Natural Science Foundation of China(81970913 and 82125006)。
文摘The dorsal lingual epithelium,which is composed of taste buds and keratinocytes differentiated from K14^(+)basal cells,discriminates taste compounds and maintains the epithelial barrier.N6-methyladenosine(m^(6)A)is the most abundant mRNA modification in eukaryotic cells.How METTL3-mediated m^(6)A modification regulates K14^(+)basal cell fate during dorsal lingual epithelium formation and regeneration remains unclear.Here we show knockout of Mettl3 in K14^(+)cells reduced the taste buds and enhanced keratinocytes.Deletion of Mettl3 led to increased basal cell proliferation and decreased cell division in taste buds.Conditional Mettl3 knock-in mice showed little impact on taste buds or keratinization,but displayed increased proliferation of cells around taste buds in a protective manner during post-irradiation recovery.Mechanically,we revealed that the most frequent m^(6)A modifications were enriched in Hippo and Wnt signaling,and specific peaks were observed near the stop codons of Lats1 and FZD7.Our study elucidates that METTL3 is essential for taste bud formation and could promote the quantity recovery of taste bud after radiation.
基金financially supported by the National Natural Science Foundation of China (No. 51573129)Science Foundation Ireland (SFI) Principal Investigator Award (No. 13/IA/1962)+1 种基金Investigator Award (No. 12/IP/1688)Health Research Board (No. HRA-POR-2013-412)
文摘Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylates, and styrene). However, the complexity of the reaction mechanism and multi-component system nature make it challenging to choose the appropriate conditions and consider the factors of achieving controllable polymerization when switching from one monomer to others with different reactivities. Herein, by polymerizing two examplary monomers: methyl methacrylate(MMA) and styrene via Cu(0)-mediated RDRP under different conditions,we have found that the reaction parameters(e.g., initiator, ligand, solvent, and deactivator) play a crucial role in regulating two equilibriums:(i) mutual conversion of different copper species which determines the relative concentration of Cu(Ⅰ) and Cu(Ⅱ), and(ii)polymerization equilibrium which is the combination of activation/deactivation, propagation and termination processes. We have demonstrated that by taking both the mutual conversion of different copper species and the polymerization equilibrium into account, the optimal reaction conditions could be selected, and the well-controlled Cu(0)-mediated RDRPs of methyl methacrylate and styrene were achieved with narrow molecular weight distributions and predicted molecular weight.
基金supported by the National Natural Science Foundation of China (NSFC-32201712,32470328)the Science and Technology Innovation Program of Hunan Province (2021JJ10015,2023JJ10025)the National Key Research and Development Program of China (2023YFD1401100).
文摘Receptor kinases play a pivotal role in detecting environmental signals,and consequently,gene pleiotropy is frequently observed within this family.However,the trade-off in trait expression resulting from gene pleiotropy poses a constraint on the utilization of such genes in agricultural breeding.In this study,we identified the receptor kinase gene FERONIA-Like Receptor 13(FLR13)as a pleiotropic gene influencing plant height,tillering,grain yield,and disease resistance.Using promoter editing,we generated novel alleles(FLR13T5T6-1,FLR13T5T6-2)that confer resistance to rice blast and increase per-plant yield.The knockout of the T5T6 segment alleviates the inhibitory effects of two transcription factors,OsGBP1 and OsWRKY53,on FLR13 expression.In summary,our study presents a promising avenue for enhancing the pivotal attributes of receptor-like kinases through a promoter-editing strategy.
基金financially supported by the National Natural Science Foundation of China(Nos.22071168,21971178 and 21674071)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Fluorinated polymers are receiving more and more attention worldwide due to their unique chemical properties,and modified fluorinated polymers with different topologies are persued for enriching and enhancing their performance in a variety of application fields.In this work,main-chain-type semifluorinated graft copolymers are produced steadily in continuous tube reactors via photocontrolled step transferaddition and radical-termination(START)polymerization and Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-RDRP)at room temperature for the first time.Specifically,semifluorinated alternating copolymer(AB)n B is prepared by START polymerization of 1,6-diiodoperfluorohexane(A)and 1,7-octadiene(B)in the first quartz pipeline under irradiation with purple LED light at 20℃.The(AB)nB with periodic C―I bonds is then flowed into the second copper pipeline directly and acts as the macroinitiators for Cu(0)-RDRP of methyl acrylate(MA)to obtain corresponding graft copolymer(AB)n B-g-PMA.This work provides a new strategy for continuous synthesis of fluorinated graft copolymer materials.
基金financially supported by the Science Foundation Ireland (SFI) Frontiers for the Future 2019 call (No.19/FFP/6522)the National Natural Science Foundation of China (NSFC)(No.51873179)Irish Research Council (IRC) Government of Ireland Postdoctoral Fellowship (No.GOIPD/2022/209)。
文摘Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control over the molecular weights(MWs) or complex or multi reaction steps, etc. In this work, we report the well-controlled polymerization of NIPAM in water via a facile one-pot and one-step Cu(0)-mediated RDRP. The results of this approach show that the key for kicking off the Cu(0)-mediated NIPAM RDRPs is to ensure sufficient Cu~I at the very beginning, and the key to achieve a well-controlled chain growth is to provide adequate deactivation strength during the polymerization process. For NIPAM, which has a high propagation rate constant, the deactivation control can be effectively enhanced by extra adding deactivator(i.e., Cu~II) to the system. Moreover, a low reaction temperature(4 ℃) is necessary in the controlled synthesis of higher MW poly(Nisopropylacrylamide)(PNIPAM) to avoid the compromise in control caused by the phase transition from its lower critical solution temperature(LCST). Through this new kinetically controlled strategy, PNIPAMs with well-defined structure, narrow molecular weight distributions(MWDs) and varied MWs were successfully achieved.
基金Financial support by National Key Research and Development Program of China(No.2018YFC0310900)the National Natural Science Foundation of China(Nos.21472087,21532002,21901112,21778031,21761142001)Jiangsu Provincial Department of Science and Technology(No.BK20190277)is greatly appreciated。
文摘An intramolecular dehydrogenative homo-and hetero-coupling of phenols has been successfully developed for quick preparation of enantiopure axial diphenols under mild Cu(Ⅱ)-mediated conditions,using((4 S,5 S)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)dimethanol as the chiral auxiliary.The commercially available(R)-α-met hylbenzy la mine was identified as the best amine ligand for Cu(Ⅱ) in the reactions.A variety of homo/hetero bis-dihydroxylbenzoate substrates were examined,affording the corresponding axially chiral diphenols with satis factory to excellent diastereomeric ratios,and a representative scalable preparation was also attempted.A formal synthesis of natural product(+)-deoxyschizandrin has been achieved in this work using one axially chiral diphenol as the synthetic intermediate.
基金supported by the National Natural Science Foundation of China (Nos. 20904036 and 21174094)the Nature Science Key Basic Research of Jiangsu Province for High Education (No. 12KJA150007)Creative Experiment Plan of Soochow University Undergraduates (57315977)
文摘The ＂living＇/controlled radical polymerization （LRP） of styrene （St） at room temperature is rarely reported. In this work, copper（0） （Cu（0））-mediated radical polymerization of St at room temperature was investigated in detail. Dimethyl sulfoxide （DMSO）, N,N-dimethylformamide （DMF） as well as a binary solvent, tetrahydrofuravdl,l,l,3,3,3-hexafluoro-2- propanol were used as the solvents, respectively. Methyl-2-bromopropionate and ethyl 2-bromoisobutyrate were used as the initiators, respectively. The polymerization proceeded smoothly with moderate conversions at room temperature. It was found that DMF was a good solvent with the essential features of LRP, while DMSO was a poor solvent with uncontrollable molecular weights. Besides, the match among the initiator, solvent and molar ratios of reactants can modulate the livingness of the polymerization, and the proper selection of ligand was also crucial to a controlled process. This work provided a first example of Cu（0）-mediated radical polymerization of St at room temperature, which would enrich and strength the LRP technique.
基金supported by the Project of Scientific Research Fund of Traditional Chinese Medicine of Zhejiang Province(No.2020ZB230).
文摘NLRP3 inflammasome-mediated cell pyroptosis aggravates the development of cerebral ischemia/reperfusion(I/R)injury,and the aim of this study is to investigate the potential utilization of the Chinese medicine,Puerarin,in treating this disease.Through conducting in vitro and in vivo experiments,the present study illustrated that Puerarin regulated LncRNA double homeobox A pseudogene 8(DUXAP8)/miR-223-3p axis to inactivate NLRP3-mediated pyroptotic cell death,resulting in the attenuation of I/R injury.Specifically,the cerebral I/R injury in rat models and hypoxia/reoxygenation(H/R)in primary hippocampus neuron(PHN)cells were inducted,which were subsequently exposed to Puerarin treatment.As expected,we validated that Puerarin suppressed cell pyroptosis and rescued cell viability in I/R rat hippocampus tissues and H/R PHN cells.Next,through bioinformatics analysis,we noticed that miR-223-3p targeted both LncRNA DUXAP8 and NLRP3 mRNA,and both LncRNA DUXAP8 ablation and miR-223-3p overexpression inactivate NLRP3-mediated cell pyroptosis to rescue cell viability in H/R PHN cells.Interestingly,we evidenced that Puerarin restrained LncRNA DUXAP8 expressions,but upregulated miR-223-3p in I/R rat tissues and H/R PHN cells,and the protective effects of Puerarin on H/R PHN cells were abrogated by overexpressing LncRNA DUXAP8 and silencing miR-223-3p.Collectively,we concluded that Puerarin regulated LncRNA DUXAP8/miR-223-3p/NLRP3 signaling cascade to attenuate I/R injury.
文摘In order to investigate the reaction mechanism of intramolecular C-H insertion by Rh(II)-mediated carbenoids with trans-(2-phenylcyclopropyl) carbinal radical as the mechanistic probe, diazo compounds 2-(2-phenylcyclopropyl)ethyl diazoacetoacetate 8a and methyl 2-diazo-3oxo-6-(2-phenylcyclopropyl) hexanoate 8b have been synthesized. Preliminary investigation of the intramolecular C-H insertion with Rh2(OAc)4 as catalyst supports a concerted insertion process.
基金Additional support for EIPC was provided by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR000454supported by the core funding from Temasek Life Sciences Laboratory,Singapore
文摘The three-dimensional organization of the genome plays a crucial role in regulating gene expression patterns in metazoans（Ong and Corces,2014）.The nuclear architectural proteins are known to facilitate the formation of topological domains within the genome through mediating inter-and intra-chromosomal interactions.In vertebrate,CCCTC-binding factor（CTCF）is the main architectural protein that mediates long-range chromosomal interactions among its DNA binding sites through a process that is stabilized by cohesin （Parelho et al., 2008; Wendt et al., 2008）.
基金supported by the Department of Henan Province Natural Science and Technology Foundation(No.142102210410)Natural Science Foundation in Henan Province Department of Education(No.17A150005)+1 种基金the Program for Innovative Research Team from Zhengzhou(No.131PCXTD605)Project of Youth Backbone Teachers of Henan University of Technology
文摘Direct C—H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnOas the sole and efficient oxidative system.This method provides an efficient protocol to construct regioselectively 2-arylquinoline N-oxides via radical cross-coupling reaction in moderated to good yields under mild conditions.
基金supported by the China National Key Research and Development Program(2023YFC2606800,2021YFD1400800,and 2024YFC3406000)the National Natural Science Foundation of China(32125032)+2 种基金the Inner Mongolia Science and Technology Program(2023KJHZ0018)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0810000 and XDA0450000)Project of the State Key Laboratory of Discovery and Utilization of Functional Components in Traditional Chinese Medicine.
文摘The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms remain poorly characterized.Huanglongbing(HLB),a devastating citrus disease,is primarily caused by the bacterium"Candidatus Liberibacter asiaticus"(CLas)and transmitted by psyllid vectors.In this study,we demonstrate that the effector protein SDE5,secreted by CLas,suppresses the biosyn-thesis of volatile terpenoids in host citrus plants,thereby enhancing psyllid attraction.Biochemically,SDE5 functions as an inhibitor of bacterial C-type lysozyme,facilitating both CLas infection and psyllid vec-tor attraction.Two plant U-box(PUB)E3 ligases,PUB10 and PUB21,are recruited by SDE5 to promote ubiq-uitination and proteasomal degradation of MYC2,a key transcription factor in jasmonate signaling and terpene-based anti-herbivore defenses.Furthermore,SDE5 interferes with MYC2 dimerization,diminishing its ability to activate terpene biosynthesis genes.This dual suppression markedly reduces volatile terpe-noid emissions in SDE5-transgenic citrus lines,resulting in increased psyllid attraction and enhanced psyl-lid fitness.Conversely,the anti-proteolysis peptide 3-14(APP 3-14),which stabilizes the MYC2 protein and inhibits the HLB pathogen,enhances volatile terpenoid emission and repels psyllids.These findings pro-vide a novel strategy for disrupting mutualistic interactions between plant bacterial pathogens and insect vectors by modulation of olfactory defense.
基金supported by the National Natural Science Foundation of China (31501827, 31222049, 31071849, and 31572193)National Basic Research Program of China (973 Program, 2014CB441002)+1 种基金the Open Foundation for State Key Laboratory of Plant Physiology and Biochemistrythe Innovation Team for Farmland Non-pollution Production of Yunnan Province (2017HC015)
文摘Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been suggested as a mediator between Al stress and gene expression, but the underlying mechanisms remain largely unknown. Here,we investigated ABA-mediated Al-stress responses, using integrated physiological and molecular biology approaches.We demonstrate that Al stress caused ABA accumulation in the root apex of rice bean(Vigna umbellata [Thunb.] Ohwi &Ohashi), which positively regulated Al tolerance. However,this was not associated with known Al-tolerance mechanisms. Transcriptomic analysis revealed that nearly one-third of the responsive genes were shared between the Al-stress and ABA treatments. We further identified a transcription factor, ABI5, as being positively involved in Al tolerance. Arabidopsis abi5 mutants displayed increased sensitivity to Al, which was not related to the regulation of AtALMT1 and AtMATE expression. Functional categorization of ABI5-mediated genes revealed the importance of cell wall modification and osmoregulation in Al tolerance, a finding supported by osmotic stress treatment on Al tolerance. Our results suggest that ABA signal transduction pathways provide an additional layer of regulatory control over Al tolerance in plants.
基金supported by Major Research Plan(2013CB945102) from the Ministry of Science,Technology of ChinaNational Natural Science Foundation of China(31261160490 to Y.Z.)Natural Science Foundation of Shandong Province(ZR2014CM027 to S.L.)
文摘Summary Vacuolar trafficking routes and their regu- lators have recently drawn lots of attention in plant cell biology. A recent study reported the discovery of a plant-specific vacuolar trafficking route, i.e., a direct ER- to-vacuole route, through analysis of VHA-a3 subcellular targeting, a key component for the tonoplast V- ATPases. Our recent findings showed that VHA-a3 targets to the tonoplast through a Rab5-mediated but Rab7-independent pathway, shedding new lights on the unconventional vacuolar trafficking route in plant cells.
文摘Great progress has been made in recent years in studies on the mechanism of Agrobacterium-mediated transformation and its application. Many details of the key molecular events within the bacterial cells involved in T-DNA transfer have been elucidated, and it is notable that some plant factors which were elusive before are purified and characterized. Vast kinds of species, which were either recalcitrant to or not included in the host range of Agrobacterium, can' now be transformed by this bacterium, and they include the very important cereal species, gymnosperms, yeast and many filamentous fungi. The simple in vivo transformation of tissue in intact plants and the 'agrolistic' methods to transform recalcitrant plants are the two novel technical achievements. Combined with other powerful techniques such as bacterial artificial chromosome, very large DNA fragment can be transformed into the plant genome by Agrobacterium. Further studies will elucidate more plant-encoded factors involved in T-DNA
基金supported by the grants of National Basic Research Program(973 Program,2010CB833201 & 2009CB940904)the National Science and Technology Major Project "Development of Key Technology for the Combinatorial Synthesis of Privileged Scaffolds" (2009ZX09501-012)the National Natural Science Foundation of China(20821062,20832003 and 20902007)
文摘A unified strategy toward the construction of the [5.7.6]tricyclic skeleton of liphagal is reported,featuring InCl3-mediated intramolecular Friedel-Crafts-type cyclization.
基金Project supported by the National Natural Science Foundation of China(No.20272050).
文摘Due to the chemoselective dehalogenation by SmI2, the addition of α-halomethylsulfones to carbonyl compounds afforded β-hy-droxysulfones. Those reactions with α-bromomethylsulfones gave the products in moderate to good yields. The SmI2-mediat-ed addition of gem-dihalomethylsulfones to ketones also afforded α-halo-β-hydroxysulfones in moderate yields.
