Camellia sinensis CsMYB4a participates in regulation of stamen growth by interaction with auxin signaling transduction repressor CsAUX/IAA4

Subgroup 4(Sg4)members of the R2R3-MYB are generally known as negative regulators of the phenylpropanoid pathway in plants.Our previous research showed that a R2R3-MYB Sg4 member from Camellia sinensis(CsMYB4a)inhibits expression of some genes in the phenylpropanoid pathway,but its physiological function in the tea plant remained unknown.Here,CsMYB4a was found to be highly expressed in anther and filaments,and participated in regulating filament growth.Transcriptome analysis and exogenous auxin treatment showed that the target of CsMYB4a might be the auxin signal pathway.Auxin/indole-3-acetic acid 4(AUX/IAA4),a repressor in auxin signal transduction,was detected from a yeast two-hybrid screen using CsMYB4a as bait.Gene silencing assays showed that both CsIAA4 and CsMYB4a regulate filament growth.Tobacco plants overexpressing CsIAA4 were insensitive to exogenous a-NAA,consistent with overexpression of CsMYB4a.Protein-protein interaction experiments revealed that CsMYB4a interacts with N-terminal of CsIAA4 to prevent CsIAA4 degradation.Knock out of the endogenous NtIAA4 gene,a CsIAA4 homolog,in tobacco alleviated filament growth inhibition and a-NAA insensitivity in plants overexpressing CsMYB4a.All results strongly suggest that CsMYB4a works synergistically with CsIAA4 and participates in regulation of the auxin pathway in stamen.

Phosphate deficiency induced by infection promotes synthesis of anthracnose-resistant anthocyanin-3-O-galactoside phytoalexins in the Camellia sinensis plant

Tea(Camellia sinensis)is a well-known beverage crop rich in polyphenols with health benefits for humans.Understanding how tea polyphenols participate in plant resistance is beneficial to breeding resistant varieties and uncovering the resistance mechanisms.Here,we report that a Colletotrichum infection-induced‘pink ring’symptom appeared outside the lesion,which is highly likely to occur in resistant cultivars.By identifying morphological feature-specific metabolites in the pink ring and their association with disease resistance,and analysis of the association between metabolite and gene expression,the study revealed that the accumulation of anthocyanin-3-O-galactosides,red phytotoxin compounds resistant to anthracnose,plays a pivotal role in the hypersensitive response surrounding infection sites in tea plants.The results of genetic manipulation showed that the expression of CsF3Ha,CsANSa,CsUGT78A15,CsUGT75L43,and CsMYB113,which are involved in anthocyanin biosynthesis,is positively correlated with anthracnose-resistance and the formation of the pink ring.Further phosphorus quantification and fertilization experiments confirmed that phosphate deficiency caused by anthracnose is involved in the occurrence of the pink ring.Genetic manipulation studies indicated that altering the expression levels of Pi transporter proteins(CsPHT2-1,CsPHT4;4)and phosphate deprivation response transcription factors(CsWRKY75-1,CsWRKY75-2,CsMYB62-1)enhances resistance to anthracnose and the formation of the pink ring symptom in tea plants.This article provides the first evidence that anthocyanin-3-O-galactosides are the anthracnose-resistant phytoalexins among various polyphenols in tea plants,and this presents an approach for identifying resistance genes in tea plants,where genetic transformation is challenging.

Al-induced CsUGT84J2 enhances flavonol and auxin accumulation to promote root growth in tea plants

Although Al is not necessary or even toxic to most plants,it is beneficial for the growth of tea plants.However,the mechanism through which Al promotes root growth in tea plants remains unclear.In the present study,we found that flavonol glycoside levels in tea roots increased following Al treatment,and the Al-induced UDP glycosyltransferase CsUGT84J2 was involved in this mechanism.Enzyme activity assays revealed that rCsUGT84J2 exhibited catalytic activity on multiple types of substrates,including phenolic acids,flavonols,and auxins in vitro.Furthermore,metabolic analysis with UPLC-QqQ-MS/MS revealed significantly increased flavonol and auxin glycoside accumulation in CsUGT84J2-overexpressing Arabidopsis thaliana.In addition,the expression of genes involved in the flavonol pathway as well as in the auxin metabolism,transport,and signaling pathways was remarkably enhanced.Additionally,lateral root growth and exogenous Al stress tolerance were significantly improved in transgenic A.thaliana.Moreover,gene expression and metabolic accumulation related to phenolic acids,flavonols,and auxin were upregulated in CsUGT84J2-overexpressing tea plants but downregulated in CsUGT84J2-silenced tea plants.In conclusion,Al treatment induced CsUGT84J2 expression,mediated flavonol and auxin glycosylation,and regulated endogenous auxin homeostasis in tea roots,thereby promoting the growth of tea plants.Our findings lay the foundation for studying the precise mechanisms through which Al promotes the growth of tea plants.

Functional diversity of subgroup 5 R2R3-MYBs promoting proanthocyanidin biosynthesis and their key residues and motifs in tea plant

The tea plant(Camellia sinensis)is rich in polyphenolic compounds.Particularly,flavan-3-ols and proanthocyanidins(PAs)are essential for the flavor and disease-resistance property of tea leaves.The fifth subgroup of R2R3-MYB transcription factors comprises the primary activators of PA biosynthesis.This study showed that subgroup 5 R2R3-MYBs in tea plants contained at least nine genes belonging to the TT2,MYB5,and MYBPA types.Tannin-rich plants showed an expansion in the number of subgroup 5 R2R3-MYB genes compared with other dicotyledonous and monocot plants.The MYBPA-type genes of tea plant were slightly expanded.qRT–PCR analysis and GUS staining analysis of promoter activity under a series of treatments revealed the differential responses of CsMYB5s to biotic and abiotic stresses.In particular,CsMYB5a,CsMYB5b,and CsMYB5e responded to high-intensity light,high temperature,MeJA,and mechanical wounding,whereas CsMYB5f and CsMYB5g were only induced by wounding.Three genetic transformation systems(C.sinensis,Nicotiana tabacum,and Arabidopsis thaliana)were used to verify the biological function of CsMYB5s.The results show that CsMYB5a,CsMYB5b,and CsMYB5e could promote the gene expression of CsLAR and CsANR.However,CsMYB5f and CsMYB5g could only upregulate the gene expression of CsLAR but not CsANR.A series of site-directed mutation and domain-swapping experiments were used to verify functional domains and key amino acids of CsMYB5s responsible for the regulation of PA biosynthesis.This study aimed to provide insight into the induced expression and functional diversity model of PA biosynthesis regulation in tea plants.

Effects of Sweet Potato Rotation and Intercropping on the Microbial Community of Rhizosphere Soil

To reveal the response mechanism of soil microbial community in different planting systems of sweet potato,the effects of rotation and intercropping on microbial community structure and carbon source utilization capacities of sweet potato rhizosphere soil were studied by using phospholipid fatty acid(PLFA)and ecological board(BIOLOG ECO)through field positioning experiments.In this study,three treatments were sweet potato continuous cropping,sweet potato-wheat rotation,and sweet potato-corn intercropping.The main results showed that compared with the sweet potato continuous cropping treatment,sweet potato rotation and intercropping changed the PLFA biomass of soil microorganisms;the contents of bacteria increased by 21.82%and 38.77%,respectively(P<0.05);the contents of actinomycetes increased by 6.98%and 12.77%,and the biomass of Gram-positive bacteria increased by 28.60%and 63.44%,respectively;and the biomass of Gram-negative bacteria increased by 18.21%and 22.29%,and the fungal contents decreased by 16.60%and 13.03%,respectively.With the extension of culture time,the average well color development(AWCD value)of sweet potato-corn intercropping was significantly higher than other two treatments.The utilization capacities of carboxylic acid compounds,polymers,carbohydrates,amino acids,and amines in the sweet potato-corn intercropping treatment were significantly increased by 17.28%,14.67%,54.17%,36.62%,and 20.00%,respectively,compared with the sweet potato continuous cropping treatment.The results of the multivariate analysis(RDA)showed that the changes of soil microbial community structure and functional diversity were controlled by many factors,and the soil available potassium and total nitrogen were the main driving factors.However,sweet potato-wheat rotation and sweet potato-corn intercropping could optimize the soil microbial community structure and enhance the microbial functional diversity,and the effect of sweet potato-corn intercropping treatment was better.

Light-absorbing impurities on Keqikaer Glacier in western Tien Shan: concentrations and potential impact on albedo reduction

Light-absorbing impurities on glaciers are important factors that influence glacial surface albedo and accelerate glacier melt. In this study, the quantity of light-absorbing impurities on Keqikaer Glacier in western Tien Shan, Central Asia, was measured. We found that the average concentrations of black carbon was 2,180 ng/g, with a range from 250 ng/g to more than 10,000 ng/g. The average concentrations of organic carbon and mineral dust were 1,738 ng/g and 194 μg/g, respectively. Based on simulations performed with the Snow Ice Aerosol Radiative model simulations, black carbon and dust are responsible for approximately 64% and 9%, respectively, of the albedo reduction, and are associated with instantaneous radiative forcing of 323.18 W/m2(ranging from 142.16 to 619.25 W/m2) and 24.05 W/m2(ranging from 0.15 to69.77 W/m2), respectively. For different scenarios, the albedo and radiative forcing effect of black carbon is considerably greater than that of dust. The estimated radiative forcing at Keqikaer Glacier is higher than most similar values estimated by previous studies on the Tibetan Plateau, perhaps as a result of black carbon enrichment by melt scavenging. Light-absorbing impurities deposited on Keqikaer Glacier appear to mainly originate from central Asia, Siberia, western China(including the Taklimakan Desert) and parts of South Asia in summer, and from the Middle East and Central Asia in winter.A footprint analysis indicates that a large fraction(>60%) of the black carbon contributions on Keqikaer Glacier comes from anthropogenic sources. These results provide a scientific basis for regional mitigation efforts to reduce black carbon.

Effects of curcumin on hippocampal Bax and Bcl-2 expression and cognitive function of a rat model of Alzheimer's disease

We tested the effects of curcumin treatment on a rat model of Alzheimer＇s disease induced by beta-amlyoid （Aβ1-40） expression. We investigated alterations in the expression of the apoptosis-related genes Bax and Bcl-2 in the hippocampus, as well as changes in the spatial memory and cognitive function of the rats. Reverse transcription-polymerase chain reaction and immunohistochemistry results showed that Bax expression was remarkably decreased and Bcl-2 expression was increased in the rat Alzheimer＇s disease model after curcumin treatment. Morris water maze results showed that the average time of escape latency was shortened in the curcumin treated model rats. Our study shows that curcumin can significantly improve spatial learning and memory functions in rats with Aβ1-40-induced Alzheimer＇s disease by modulating Bax and Bcl-2 expression.

低浓度胰蛋白酶原代培养大鼠血管内皮细胞实验方法研究

目的:探索改进一种简单、经济和高纯度的大鼠血管内皮细胞分离培养方法。方法:采用2%戊巴比妥钠麻醉Wistar大鼠,在无菌条件下截取主动脉约3~4 cm,再将主动脉血管外翻使内膜暴露,用丝线结扎动脉两端,以0.125%胰蛋白酶消化18~20 min,在倒置相差显微镜下直接观察细胞生长和细胞形态特征,分别应用免疫组化和免疫荧光方法检测第VIII因子相关抗原抗体结合情况,对培养传代的血管内皮细胞进行鉴定。结果:采用0.125%胰蛋白酶直接消化可获得高纯度的大鼠主动脉血管内皮细胞。经过3~4天培养,细胞呈集落样散在分布于六孔培养板底,到10~12天时,细胞贴壁增长至覆盖大部分培养板底,约85%的细胞汇合成单层,呈现典型的“鹅卵石”样内皮细胞特征;此外,免疫组化和免疫荧光方法检测第VIII因子相关抗原抗体结合情况,发现大多数细胞胞浆呈现棕黄色和绿色荧光的阳性反应,显示分离培养的细胞主要是血管内皮细胞。结论:本改良的细胞培养方法操作简便,只需浓度低至0.125%胰蛋白酶即可获取较高纯度的血管内皮细胞,不需要较昂贵的胶原酶及内皮细胞生长因子,与现有的其他培养方法相比更为经济实用。

Protective effects of Dioscin on TNF-α-induced collagen-induced arthritis rat fibroblast-like synoviocytes involves in regulating the LTB4/BLT pathway

Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring whether Dioscin’s effects on TNF-αinduced collagen-induced arthritis(CIA)rat fibroblast-like synoviocytes(FLS)connected with the LTB4 and its receptor pathway.Materials&Methods:In this experiment,control group,TNF-αgroup,and different concentrations of Dioscin groups were established.Cell viability was evaluated using MTT assay.The levels of LTB4 in the samples of above groups were measured using ELISA.The mRNA expression levels of LTA4H,BLT1,and BLT2 were detected by quantitative real time PCR,while the expression level of LTA4H proteins were detected using western blot.The distribution of LTA4H was assessed by immunofluorescence assay.Results:the LTB4 level of TNF-αgroup in sample supernatant was higher than both control group and Dioscin groups with decreased LTB4 levels(p<0.05).Compared with the control group,the expression of LTA4H was significantly increased in TNF-αgroup(p<0.05),whereas LTA4H expressions were significantly decreased in all Dioscin groups when compared to TNF-αgroup(p<0.05).The mRNA expressions of BLT1 and BLT2 were markedly higher in TNF-αgroup than those in control group while Dioscin treatment significantly inhibited the increased expressions of BLT1 and BLT2 induced by TNF-α(p<0.05).Conclusions:These results firstly demonstrate that the protective effect of Dioscin on TNF-αinduced FLS may involve in its reducing LTB4 production by down-regulating LTA4H expression,and may inhibit its downstream pathway by decreasing LTB4 receptors levels.This findings suggest that dioscin produces a potential therapeutic effects for RA via its influencing LTA4H/LTB4/BLT pathway.

Roles of YABBY tanscription factors in the regulation of leaf development and abiotic stress responses in Camellia sinensis

The formation of leaf polarity directly determines the development of leaf spreading and type,and affects the physiological functions of photosynthesis,transpiration and stress resistance of plants.Many famous Chinese teas are highly dependent on the morphological characteristics and size of the tea leaves.To date,there have been few reports on the establishment of tea leaf polarity and leaf type development.The plant-specific transcription factor YABBY family gene has been reported to be involved in the formation of leaf polarity and growth.Herein we describe the isolation and functional characterization of transcription factor YABBY genes of the tea plant(Camellia sinensis).Six YABBY transcription factors were isolated from tea plants and classified into five clusters in the protein phylogenetic tree.Among them,CsFILa and CsFILb were highly expressed in buds and mature petals,and their expression decreased with the stage of leaf development.The Arabidopsis transgenic lines of CsFILa and CsFILb showed abaxial curled and long-narrow leaves.The above results indicated that CsFILa and CsFILb regulated the leaf growth of tea plants.The growth and expansion rate of leaf on the picked shoots decreased significantly after being plucked from tea plants,especially those suffering from drought stress.In this process,CsFILa expression levels decreased 60%−80%compared to the control.These data indicated YABBY genes play important roles in the leaf development of Camellia sinensis.

Inhibiting ATP/P2X7R signaling protects intestinal barrier in dextran sulfate sodium-induced colitis and Crohn’s disease through inactivating NF-κB pathway in macrophages

To the Editor:The enhanced activation of immune cells is a decisive factor for the pathological progress of inflammatory bowel disease(IBD),which can release generous inflammatory cytokines and bioactive molecules suggesting their roles as potential therapeutic targets for IBD.Purinergic receptors are a family of membranous proteins found extensively in many mammalian tissues and organs.As a subtype of purinergic receptors,the expressions of P2X7 receptor(P2X7R)can be detected abundantly in epithelial cells and most immune cells.During inflammation,adenosine triphosphate(ATP)is released extracellularly by various stimuli.In general,through the activation of P2X7R.

Self-assembly of porphyrins on perovskite film for blade-coating stable large-area methylammonium-free solar cells

Phase transition and phase separation of formamidinium-cesium(FA-Cs)perovskite during the fabrication and operation processes reduce the efficiency and stability of perovskite solar cells(PSCs).Here,we develop an in situ molecular self-assembly approach on perovskite surface using an amine nickel porphyrin(NiP).The NiP doped perovskite precursor solution was deposited on substrate by blade-coating under ambient condition.NiP molecules self-assemble into supramolecule bound on perovskite surface during the vacuum-assisted process.Such a modification controls the perovskite grain growth to generate the uniform perovskite film.The supramolecule can release the residual lattice strain to inhibit the phase transition of perovskite film,and promote the charge extraction and transport to suppress the phase separation of FA-Cs perovskite during long-term illumination condition.Consequently,the best efficiency of large-area NiP-based FA-Cs-PSCs with the active area of 1.0 cm2 is up to 20.3%(certified as 19.2%),which is close to the record efficiency(20.37%)by blade-coating.Unencapsulated NiP-doped device reveals the remarkably improved overall stabilities.This work affords a novel way to address the phase transition and phase separation in FA-Cs perovskite.

Concentrations and light absorption properties of PM_(2.5) organic and black carbon based on online measurements in Lanzhou, China

To elucidate the variations in mass concentrations of organic carbon(OC)and black carbon(BC)in PM_(2.5) and their light absorption characteristics in Lanzhou,we conducted one-year online measurements by using a newly developed total carbon analyzer(TCA08)coupled with an aethalometer(AE33)from July 2018 to July 2019.The mean OC and BC concentrations were 6.4±4.4 and 2.0±1.3μg/m^(3),respectively.Clear seasonal variations were observed for both components,with winter having the highest concentrations,followed by autumn,spring,and summer.The diurnal variations of OC and BC concentrations were similar throughout the year,with daily two peaks occurring in the morning and evening,respectively.A relatively low OC/BC ratio(3.3±1.2,n=345)were observed,indicating that fossil fuel combustion was the primary source of the carbonaceous components.This is further substantiated by relatively low biomass burning contribution(f_(biomass):27.1%±11.3%)to BC using aethalometer based measurement though f_(biomass) value which increased significantly in winter(41.6%±5.7%).We estimated a considerable brown carbon(BrC)contribution to the total absorption coefficient(b_(abs))at 370 nm(yearly average of 30.8%±11.1%),with a winter maximum of 44.2%±4.1%and a summer minimum of 19.2%±4.2%.Calculation of the wavelength dependence of total b_(abs) revealed an annual mean AAE_(370-520) value of 4.2±0.5,with slightly higher values in spring and winter.The mass absorption cross-section of BrC also exhibited higher values in winter,with an annual mean of 5.4±1.9 m^(2)/g,reflecting the impact of emissions from increased biomass burning on BrC concentrations.

Duplicated chalcone synthase(CHS)genes modulate flavonoid production in tea plants in response to light stress

In tea plants,the abundant flavonoid compounds are responsible for the health benefits for the human body and define the astringent flavor profile.While the downstream mechanisms of flavonoid biosynthesis have been extensively studied,the role of chalcone synthase(CHS)in this secondary metabolic process in tea plants remains less clear.In this study,we compared the evolutionary profile of the flavonoid metabolism pathway and discovered that gene duplication of CHS occurred in tea plants.We identified three CsCHS genes,along with a CsCHS-like gene,as potential candidates for further functional investigation.Unlike the CsCHS-like gene,the CsCHS genes effectively restored flavonoid production in Arabidopsis chs-mutants.Additionally,CsCHS transgenic tobacco plants exhibited higher flavonoid compound accumulation compared to their wild-type counterparts.Most notably,our examination of promoter and gene expression levels for the selected CHS genes revealed distinct responses to UV-B stress in tea plants.Our findings suggest that environmental factors such as UV-B exposure could have been the key drivers behind the gene duplication events in CHS.

Radial extracorporeal shock wave promotes the enhanced permeability and retention effect to reinforce cancer nanothermotherapeutics

Since most cancer nanomedicine relies on the enhanced permeability and retention (EPR) effect to eradicate tumors, strategies that are able to promote nanoparticle (NP) delivery and extravasation are presupposed to elevate the EPR effect for more effective cancer therapeutics. However, nanothermotherapeutics still suffers from limited drug delivery into tumor sites, for even though numerous efforts have been made to enhance the selective tumor targeting of NPs. In this study, we uncovered that radial extracorporeal shock wave therapy (rESWT), an important approach in physical therapy that has been overlooked in cancer treatment in the past, can largely improve the EPR-dependent tumor uptake of NPs. We here defined the optimal low dosage and desirable combinatory manner for rESWT in driving NP accumulation towards tumors. Two underlying biophysical mechanisms responsible for the rESWT-enhanced EPR effect were proposed. On one hand, rESWT-conducted compressive and tensile forces could relieve high intra-tumoral pressure;on the other hand, rESWT-induced cavitation bubbles could directly distend and disrupt tumor blood vessels. All these together synergistically promoted vessel vasodilation, tumor perfusion and NP extravasation. Further experiments revealed that the combinatory therapeutics between rESWT and nanothermotherapeutics greatly improved the tumor-killing efficacy. Thus, our findings open a new path to improve EPR-mediated drug delivery w让h the assistance of rESWT.

L^p(p > 1) Solutions of BSDEs with Generators Satisfying Some Non-uniform Conditions in t and ω

This paper is devoted to the L^p(p > 1) solutions of one-dimensional backward stochastic differential equations(BSDEs for short) with general time intervals and generators satisfying some non-uniform conditions in t and ω. An existence and uniqueness result,a comparison theorem and an existence result for the minimal solutions are respectively obtained, which considerably improve some known works. Some classical techniques used to deal with the existence and uniqueness of L^p(p > 1) solutions of BSDEs with Lipschitz or linear-growth generators are also developed in this paper.

Guidelines for navigation-assisted spine surgery

Spinal surgery is a technically demanding and challenging procedure because of the complicated anatomical structures of the spine and its proximity to several important tissues.Surgical landmarks and fluoroscopy have been used for pedicle screw insertion but are found to produce inaccuracies in placement.Improving the safety and accuracy of spinal surgery has increasingly become a clinical concern.Computerassisted navigation is an extension and application of precision medicine in orthopaedic surgery and has significantly improved the accuracy of spinal surgery.However,no clinical guidelines have been published for this relatively new and fast-growing technique,thus potentially limiting its adoption.In accordance with the consensus of consultant specialists,literature reviews,and our local experience,these guidelines include the basic concepts of the navigation system,workflow of navigation-assisted spinal surgery,some common pitfalls,and recommended solutions.This work helps to standardize navigation-assisted spinal surgery,improve its clinical efficiency and precision,and shorten the clinical learning curve.

A novel gene-activated matrix composed of PEI/plasmid-BMP2 complexes and hydroxyapatite/chitosan-microspheres promotes bone regeneration

The incorporation of pro-osteogenic growth factors into bone graft materials to enhance bone regeneration is a key research area within the field of bone tissue engineering and regenerative medicine.However,growth factors directly incorporated in protein form are easily degraded,and have a limited active half-life,which cannot exert long-term and stable osteoinductive and oteoconductive effects.The combination of gene therapy and tissue engineering through gene-activated matrix(GAM)may provide a good alternative solution to overcome such limitations.Scaffold materials can be combined together with plasmid DNA and a chemical-based transfection agent to form GAM,through which transfected cells could secrete growth factors in a sustained manner over a longer time duration;thereby enabling bone graft materials to act as a repository of therapeutic genes,while providing structural support and a scaffold matrix for new bone tissue ingrowth.In this study,we prepared hydroxyapatite/chitosan-microspheres(HA/CS-MS)with microfabrication technology and emulsification method,and loaded the polyethylene imine/bone morphogenetic protein 2 plasmid(PEI/pBMP2)complexes with high transfection capacity(transfection efficiency up to 54.79%±4.95%),thus forming a novel GAM system with superior bone regeneration capacity—PEI/pBMP2-HA/CS-MS.The in vitro experiments in this study demonstrated that our GAM had excellent biocompatibility(with cell viability over 95%),and that the as-fabricated microsphere material possessed a nano-network fibrous structure similar to natural extracellular matrix(ECM),together with a higher surface area that can provide more cell adhesion sites.The sizes of the prepared microspheres were mainly distributed in the 160–180μm range,while the maximal loading rate of PEI-pBMP2 complexes was 59.79%±1.85%.As a loaded complexes system,the GAM can release plasmids in a slow controlled manner,effectively transfecting surrounding target cells(release effect for up to 21 days),while cells adherent to the material can also take up plasmids,resulting in sustained secretion of the target protein,thereby effectively promoting bone regeneration.In vivo data from micro-computed tomography(micro-CT)and histological staining showed that the use of the composite materials effectively enhanced bone regeneration in defect areas.These findings thus demonstrated that the novel GAM system had excellent osteoinductivity with significant clinical potential.

Augmentation of tribenuron methyl removal from polluted soil with Bacillus sp.strain BS2 and indigenous earthworms

Tribenuron methyl （TBM） is a member of the sulfonylurea herbicide family and is widely used worldwide. In this study, TBM- degrading bacteria were enriched with TBM as potential carbon, nitrogen or sulfur source, and 44 bacterial isolates were obtained. These isolates were phylogenetically diverse, and were grouped into 25 operational taxonomic units and 14 currently known genera. Three representatives, Bacillus sp. strain BS2, Microbacterium sp. strain BS3, and Cellulosimicrobium sp. strain BSI 1, were selected, and their growth and TBM removal from culture broth were investigated. In addition, indigenous earthworms were collected and applied to augment TBM degradation in lab-scale soil column experiments. Results demonstrated that Bacillus sp. strain BS2 and earthworms significantly increased TBM removal during soil column experiments.

In-situ generation of poly(quinolizine)s via catalyst-free polyannulations of activated diyne and pyridines

The development of new polymerization routes to afford N-heterocyclic polymers is of vital importance and highly desired for various practical applications. Herein, a facile and efficient polyannulation reaction of dual-activated alkyne and pyridines was developed to construct novel N-heterocyclic poly(quinolizine)s. This polymerization can proceed smoothly under catalystfree conditions with 100% atom utilization to furnish poly(quinolizine)s with high molecular weights(up to 34,100) and welldefined structures in acceptable yields. The resulting polymers show good solubility, high thermal stability and strong red emission. Moreover, the prepared poly(quinolizine)s exhibit low cytotoxicity and can selectively label lysosomes in live cells.Considering the remarkable advantages of readily available raw materials, mild polymerization conditions, atom economy, and excellent product performance, this new and efficient polymerization tool will open up enormous opportunities for preparing functional N-heterocyclic polymers.