Salt-induced hydrogen peroxide is involved in modulation of antioxidant enzymes in cotton

Salt severely restricts cotton(Gossypium hirsutum) growth and production.The present study was undertaken to study the effect of salt-induced hydrogen peroxide(H_2O_2) on antioxidant enzymes in cotton.Na Cl treatment or exogenous H_2O_2 was used to investigate the relationship between H_2O_2 content and levels of antioxidant enzymes including superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),and catalase(CAT),as well as the transcriptional levels of corresponding genes.H_2O_2 content increased within 24 h following 200 mmol L^(–1)Na Cl treatment.Both Na Cl-induced and exogenous H_2O_2 increased the activity of antioxidant enzymes including APX and SOD and upregulated the transcriptional levels of Ghc APX1,Gh Fe SOD,and Ghchl CSD.These increased activities and upregulated transcriptional levels were inhibited when the salt-induced H_2O_2 was scavenged by NAC.These results indicate that salt-induced H_2O_2 as a second signaling messenger modulates APX and SOD activities by regulating the transcription levels of corresponding genes,alleviating oxidative stress,and increasing salt tolerance in cotton.

基于电子给体-受体复合物的脂肪烃碳氢键多样性转化

The ability to selectively introduce diverse functionality onto hydrocarbons is of substantial value in the synthesis of both small molecules and pharmaceuticals.In this endeavour,as a photocatalyst-and metalfree process,the electron donor–acceptor(EDA)strategy has not been well explored.Here we report an approach to aliphatic carbon-hydrogen bond diversification through an EDA complex constituted by HCl and S^(IV)=O groups.As an efficient hydrogen atom transfer(HAT)reagent,chlorine radical can be produced via a proton-coupled electron transfer process in this system.Based on this unusual path,a photopromoted versatile aliphatic C–H functionalization is developed without photo-and metal-catalysts,including thiolation,arylation,alkynylation,and allylation.This conversion has concise and ambient reaction conditions,good functional group tolerance,and substrate diversity,and provides an alternative solution for the high value-added utilization of bulk light alkanes.

Establishment of a new molecular model for mercury determination verified by single crystal X-ray diffraction,spectroscopic analysis and biological potentials

A wide variety of molecular probes have been developed for real-time analysis,but most of organic fluorophores possess small Stokes shifts and self-absorption or inner filter effect that could not be avoided.In this study,a new dicyanoisophorone-based derivative(E)-0-(4-(2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl)diphenylphosphinothioate(λ_(ex)=405 nm,X_(em)=551 nm,denoted as ICM-S) with strong push-pull electron effect has been afforded and it exhibits red shift for absorption from 407 nm to 426 nm with distinct color change from pale yellow to deep yellow upon exposure to Hg~(2+).Moreover,an easily distinguishable fluorescence color change follows the route from green,yellow to red in the presence of Hg~(2+) over the range of 0-90 μmol/L(detection limit=137 nmol/L)can be observed by the naked eye under a UV lamp irradiation.Chlorodiphenylphosphine and sublimedsulfur are incorpo rated as re s ponsive sites and P-O bond has been cleaved upon the addition of mercu ry ions.During the recognition process,such dicyanoisophorone dye(ICM-S) has been evolved to 2-(3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene) malononitrile(ICM-OH).Clear evidences in the chemical processes can be identified via single crystal X-ray diffraction,spectroscopic analysis,photophysical studies and titration experiments.With the aim of exploring its potential in biological systems,its in vitro responses to Hg~(2+) have been evaluated in 293 T cells and the effectiveness in zebrafish model has also been verified.