Fluorescent probes for imaging and detection of plant hormones and their receptors

Exploring plant behavior at the cellular scale in a minimally invasive manner is critical to understanding plant adaptation to the environment.Phytohormones play vital regulatory roles in multiple aspects of plant growth and development and acclimation to environmental changes.Since the biosynthesis,modification,transportation,and degradation of plant hormones in plants change with time and space,their content level and distribution are highly dynamic.To monitor the production,transport,perception,and distribution of phytohormones within undamaged tissues,we require qualitative and quantitative tools endowed with remarkably high temporal and spatial resolution.Fluorescent probes are regarded as excellent tools for widespread plant imaging because of their high sensitivity and selectivity,reproducibility,real-time in situ detection,and uncomplicated mechanism elucidation.In this review,we provide a systematical overview of the progress in the sensing and imaging of phytohormone fluorescent probes and fluorescently labeled phytohormones to their receptors in plants.Moreover,forthcoming viewpoints and possible applications of these fluorescent probes within the realm of plants are also presented.We hold the conviction that the new perspective brought by this paper can promote the development of fluorescent probes,enabling them to have better detection performance in plant hormone imaging.

Mechanistic studies on peroxymonosulfate activation by g-C3N4 under visible light for enhanced oxidation of light-inert dimethyl phthalate

Excitation of metal-free graphitic carbon nitride(g-C3N4) under visible light can successfully achieve efficient activation of peroxymonosulfate(PMS). Synergistic effects and involved mechanism were systematically investigated using a light-inert endocrine disrupting compound, dimethyl phthalate(DMP), as the target pollutant. Under visible light irradiation, DMP could not be degraded by direct g-C3 N4-mediated photocatalysis, while in the presence of PMS, the dominant radicals were converted from ·O2 to SO4·– and ·OH, resulting in effective DMP degradation and mineralization. Results showed that higher dosage of PMS or g-C3 N4 could increase the activation amount of PMS and corresponding DMP degradation efficiency, but the latter approach was more productive in terms of making the most of PMS. High DMP concentration hindered effective contact between PMS and g-C3 N4, but could provide efficient use of PMS. Higher DMP degradation efficiency was achieved at p H lower than the point of zero charge(5.4). Based on intermediates identification, the DMP degradation was found mainly through radical attack(·OH and SO4·–) of the benzene ring and oxidation of the aliphatic chains.

Optimizing progress variable definition in flamelet-based dimension reduction in combustion

An automated method to optimize the definition of the progress variables in the flamelet-based dimension reduction is proposed. The performance of these optimized progress variables in coupling the flamelets and flow solver is presented. In the proposed method, the progress variables are defined according to the first two principal components （PCs） from the principal component analysis （PCA） or kernel-density-weighted PCA （KEDPCA） of a set of flamelets. These flamelets can then be mapped to these new progress variables instead of the mixture fraction/conventional progress variables. Thus, a new chemistry look-up table is constructed. A priori validation of these optimized progress variables and the new chemistry table is implemented in a CH4/N2/air lift-off flame. The reconstruction of the lift-off flame shows that the optimized progress variables perform better than the conventional ones, especially in the high temperature area. The coefficient determinations （R2 statistics） show that the KEDPCA performs slightly better than the PCA except for some minor species. The main advantage of the KEDPCA is that it is less sensitive to the database. Meanwhile, the criteria for the optimization are proposed and discussed. The constraint that the progress variables should monotonically evolve from fresh gas to burnt gas is analyzed in detail.

Synthesis, Characterization, and Antifungal Evaluation of Thiolactomycin Derivatives

5-Substituted benzylidene 3-acylthiotetronic acids are antifungal.A series of 3-acylthiotetronic acid derivatives with varying substitutions at the 5-position were designed,synthesized,and characterized,based on the binding pose of 3-acyl thiolactone with the protein C171Q KasA.Fungicidal activities of these compounds were screened against Valsa Mali,Curvularia lunata,Fusarium graminearum,and Fusarium oxysporum f.sp.lycopersici.Most target compounds exhibited excellent fungicidal activities against target fungi at the concentration of 50μg·mL-1.Compounds 11c and 11i displayed the highest activity with a broad spectrum.The median effective concentration(EC50)values of 11c and 11i were 1.9–10.7 and 3.1–7.8μg·mL-1,respectively,against the tested fungi,while the EC50 values of the fungicides azoxystrobin,carbendazim,and fluopyram were respectively 0.30,4.22,and>50μg·mL-1 against V.Mali;6.7,41.7,and 0.18μg·mL-1 against C.lunata;22.4,0.42,and 0.43μg·mL-1 against F.graminearum;and 4.3,0.12,and>50μg·mL-1 against F.oxysporum f.sp.lycopersici.The structures and activities of the target compounds against C.lunata were analyzed to obtain a statistically significant comparative molecular field analysis(CoMFA)model with high prediction abilities(q2=0.9816,r2=0.8060),and its reliability was verified.The different substituents on the benzylidene at the 5-position had significant effects on the activity,while the introduction of a halogen atom at the benzene ring of benzylidene was able to improve the activity against the tested fungi.

A fluorescent probe based on BODIPY for hydrogen sulfide imaging in living cells and zebrafish

A novel fluorescent probe based on 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene(BODIPY)structure as fluorophore with 7-nitro-1,2,3-benzoxadiazole(NBD)served as detection unit was designed for specific and sensitive detection of H2S in living cells and zebrafish.In this work,we prepared a novel fluorescent probe for detection of hydrogen sulfide with strong fluorescent enhancement,good biocompatible and excellent specifically detection.The probe 1 displayed emission at 580 nm with excited wavelength at 530 nm in aqueous solution which organic proportion was only 10%.This probe exhibits highly selectively and specifically to detect H2S compared with other related interferences including sulphur-amino acids,sulfite ion and cations.In the addition of H2S into the detection system,the fluorescent intensity was sharply increased about 170-fold with the limitation detection as low as 16.8 nM.The sensing mechanism was through the cleave reaction between analyte and NBD unit which was characterized by high resolution mass spectrum(HRMS).This platform also permits low biotoxicity which can successfully be utilized to evaluate the concentration level of H2S and imaging in living cells and zebrafish.

Novel reusable sulfate-type zirconium alginate ion-exchanger for fluoride removal

It is still a challenge to eliminate efficiently fluoride ion from groundwater,especially to design and synthesis an adsorbent possessing high adsorption capacity,recyclability and wide pH application conditions.Herein we present millimeter-sized sulfate-type zirconium alginate hydrogel beads with 3D network structure(AHB@Zr-SO^(2−)_(4))that exhibited a maximum adsorption capacity of 101.3 mg/g with wide pH applicability(pH 3−9).This material have~2.5 times higher adsorption capacity than that of pure zirconium alginate hydrogel beads(AHB@Zr)and it was ascribed to ion exchange between SO^(2−)_(4)and F−on the surface of AHB@Zr-SO^(2−)_(4),which was verified via ion chromatography measurement coupled with X-ray photoelectron spectroscopy(XPS)and Fourier Transform Infrared Spectrometer(FTIR Spectrometer)analysis.Density functional theory(DFT)calculations indicated that the ion exchange process between SO^(2−)_(4)and F−in AHB@Zr-SO^(2−)_(4)was energetically favorable than OH^(−)and F^(−)in AHB@Zr.In addition,310 bed volumes(BV)of effluent was realized via column adsorption of groundwater containing fluoride on AHB@Zr-SO^(2−)_(4)and indicated that it is a promising candidate for mitigating the problem of fluoride-containing groundwater.

N-acyl homoserine lactonase attenuates the virulence of Salmonella typhimurium and its induction of intestinal damages in broilers

This study aimed to investigate the potential mitigating effects of N-acyl homoserine lactonase(AHLase)on the virulence of Salmonella typhimurium and its induction of intestinal damages in broilers.In vitro study was firstly conducted to examine if AHLase treatment could attenuate the virulence of S.typhimurium.Then,an in vivo experiment was performed by allocating 240 broiler chicks at 1 d old into 3 groups(8 replicates per group):negative control(NC),positive control(PC),and PC supplemented with 10,000 U/kg AHLase.All chicks except those in NC were orally challenged by S.typhimurium from 8to 10 d of age.Parameters were measured on d 11 and 21.The results showed that treatment with 1 U/mL AHLase suppressed the biofilm-forming ability(including biofilm biomass,extracellular DNA secretion and biofilm formation-related gene expression),together with swarming motility and adhesive capacity of S.typhimurium.Supplemental 10,000 U/kg AHLase counteracted S.typhimurium-induced impairments(P<0.05)in broiler growth performance(including final body weight,average daily gain and average daily feed intake)during either 1-11 d or 12-21 d,and increases(P<0.05)in the indexes of liver,spleen and bursa of Fabricius on d 11,together with reductions(P<0.05)in ileal villus height and its ratio to crypt depth on both d 11 and 21.AHLase addition also normalized the increased(P<0.05)m RNA expression of ileal occludin on both d 11 and 21 in S.typhimurium-challenged broilers.However,neither S.typhimurium challenge nor AHLase addition altered(P>0.05)serum diamine oxidase activity of broilers.Noticeably,S.typhimurium challenge caused little change in the mRNA expression of ileal inflammatory cytokines except for an increase(P<0.05)in interleukin-8 expression on d 11,whereas AHLase addition normalized(P<0.05)this change.In conclusion,AHLase treatment could attenuate the virulence and pathogenicity of S.typhimurium,thus contributing to alleviate S.typhimurium-induced growth retardation and intestinal damages in broilers.