JA-mediated MYC2/LOX/AOS feedback loop regulates osmotic stress response in tea plant

Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.

Spatial and temporal variation of energy carbon emissions in Yantai from 2001 to 2011

In order to understand the characteristics of spatial and temporal variation,as well as provide effective ideas on carbon emissions and regulatory policy in Yantai,this article analyzed spatial and temporal variation of carbon emissions in Yantai based on energy consumption statistics for a variety of energy sorts together with industrial sectors from 2001 to 2011.The results were as following:First of all,Yantai's carbon emissions grew by an average of 5.5%per year during the last 10 years,and there was a peak of 10.48 million carbon in the year of 2011.Second,compared with the gross domestic product(GDP) growth rate,the figures for energy carbon emissions growth rate were smaller;however the problem of carbon emissions were still more obvious.Furthermore,carbon emissions in Yantai increased rapidly before 2008;while after 2008,it increased more slowly and gradually become stable.Third,the energy consumption was different among regions in Yantai.For instance,the energy consumption in Longkou city was the largest,which occupied 50%of the total carbon emissions in Yantai;and the energy consumption in Chang Island was generally less than 1%of the Longkou consumption.Finally,there were relative close relationships among the spatial difference of carbon emissions,regional resources endowment,economic development,industrial structure,and energy efficiency.

Moderate heat treatment of CoFe Prussian blue analogues for enhanced oxygen evolution reaction performance

Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a range of characterization techniques including Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS),this work discloses the process of replacement of K^(+)by NH4^(+)in the interstitial spaces of the CoFe PBA by a hot aqueous urea solution,which influences the transformation of PBAs under further heat treatment and the OER performance of the deriva tives.After heat treatment at 400℃ under Ar flow,high-resolution transmission electron microscopy(HRTEM) images reveal that CoFe alloy nanoparticles grew on the crystalline cubes of CoFe PBA with K^(+),while CoFe PBA cubes with NH4^(+)become amorphous.Besides,the derivative of CoFe PBA with NH4^(+)(Ar-U-CoFe PBA) performs better than the derivative of CoFe PBA with K^(+)(Ar-CoFe PBA) in OER,registering a lower overpotential of 305 mV at 10 mA cm^(-2),a smaller Tafel slope of 36.1 mV dec^(-1),and better stability over a testing course of 20 h in 1.0 M KOH.A single-cell alkaline electrolyzer,using Ar-U-CoFe PBA and Pt/C for the anodic and cathodic catalyst,respectively,requires an initial cell voltage of 1.66 V to achieve 100 mA cm^(-2)at 80℃,with negligible degradation after100 h.

CsGDH2.1 negatively regulates theanine accumulation in late-spring tea plants (Camellia sinensis var. sinensis)

Theanine,a unique and the most abundant non-proteinogenic amino acid in tea plants,endows tea infusion with the umami taste and anti-stress effects.Its content in tea correlates highly with green tea quality.Theanine content in new shoots of tea plants is high in mid-spring and greatly decreases in late spring.However,how the decrease is regulated is largely unknown.In a genetic screening,we observed that a yeast mutant,glutamate dehydrolase 2(gdh2),was hypersensitive to 40 mM theanine and accumulated more theanine.This result implied a role of CsGDH2s in theanine accumulation in tea plants.Therefore,we identified the two homologs of GDH2,CsGDH2.1 and CsGDH2.2,in tea plants.Yeast complementation assay showed that the expression of CsGDH2.1 in yeast gdh2 mutant rescued the theanine hypersensitivity and hyperaccumulation of this mutant.Subcellular localization and tissue-specific expression showed CsGDH2.1 localized in the mitochondria and highly expressed in young tissues.Importantly,CsGDH2.1 expression was low in early spring,and increased significantly in late spring,in the new shoots of tea plants.These results all support the idea that CsGDH2.1 regulates theanine accumulation in the new shoots.Moreover,the in vitro enzyme assay showed that CsGDH2.1 had glutamate catabolic activity,and knockdown of CsGDH2.1 expression increased glutamate and theanine accumulation in the new shoots of tea plants.These findings suggested that CsGDH2.1-mediated glutamate catabolism negatively regulates theanine accumulation in the new shoots in late spring,and provides a functional gene for improving late-spring green tea quality.

Origin and formation of the Ryukyu Current revealed by HYCOM reanalysis

The origin of the Ryukyu Current(RC)and the formation of its subsurface velocity core were investigated using a 23-year(1993–2015)global Hybrid Coordinate Ocean Model(HYCOM)dataset.The volume transport of the RC comes from the Kuroshio eastward branch(KEB)east of Taiwan and part of the North Pacific Subtropical Gyre(p-NPSG).From the surface to 2000m depth,the KEB(p-NPSG)transport contributes 41.5%(58.5%)to the mean total RC transport.The KEB originally forms the subsurface velocity core of the RC east of Taiwan due to blockage of the subsurface Kuroshio by the Ilan Ridge(sill depth:700 m).Above 700m,the Kuroshio can enter the East China Sea(ECS)over the Ilan Ridge,meanwhile,the blocked Kuroshio below 700m turns to the right and flows along the Ryukyu Islands.With the RC flowing northeastward,the p-NPSG contribution strengthens the subsurface maximum structure of the RC owing to the blockage of the Ryukyu Ridge.In the surface layer,the p-NPSG cannot form a stable northeastward current due to frequent disturbance by mesoscale eddies and water exchange through the gaps(with net volume transport into ECS)between the Ryukyu Islands.

Duplication and transcriptional divergence of three Kunitz protease inhibitor genes that modulate insect and pathogen defenses in tea plant(Camellia sinensis)

Kunitz protease inhibitors(KPIs)are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection.However,the influence of gene duplication on the postdivergence of the CsKPI genes involved in biotic stresses in tea plant is not well known.Here,we identified three CsKPI genes from tea plant(Camellia sinensis)and characterized their expression and evolutionary patterns among plant species.We found that CsKPI1,CsKPI2,and CsKPI3 diverged from their common ancestor 72.94 million years ago(MYA),and the tandem duplication of CsKPI2 and CsKPI3 occurred 26.78 MYA.An in vitro protein assay showed that the three CsKPI proteins were functional and inhibited the production of p-nitroanilide(PNA)from an artificial substrate.The three CsKPI-GFP fusion proteins localized to the cytoplasm.We showed that salicylic acid(SA)and transcripts of CsKPI2 and CsKPI3 significantly accumulated after infection with Glomerella cingulata.The application of exogenous SA stimulated the high expression of both CsKPI2 and CsKPI3 by activating cis-elements within their promoters.Under Ectropis oblique attack,CsKPI1 expression and jasmonic acid(JA)levels were more abundant in both insect-damaged leaf tissues and undamaged neighboring leaves.The application of jasmonic acid methyl ester elicited high expression levels of CsKPI1,suggesting that CsKPI1 accumulation requires JA production in tea plant.The overall findings suggest that the transcriptional divergence of KPI genes after duplication led to the specialized role of CsKPI1 in the physiological response to insect stress;the functional conservation between CsKPI2 and CsKPI3 confers resistance to pathogen infection in tea plant.

The near-inertial waves observed east of the Philippines

Based on mooring observations from Aug.1,2016 to Dec.14,2017,the characteristics and underlying mechanisms of near-inertial waves(NIWs)observed east of the Philippines were studied.Three strong NIW events were investigated in detail.The NIWs in EventⅠwere induced by typhoon Lan and had the strongest magnitudes of 0.35 m/s.The maximum near-inertial kinetic energy(NIKE)was shown at the ocean surface.The NIW in EventⅡwas stimulated by a moderate cyclonic wind with the extreme NIKE located at about 110-m depth.The existence of a cyclonic eddy during EventsⅠandⅡled to a blue shift of near-inertial frequencies.For EventⅢ,the surface near-inertial signals were also induced by local weak wind,whereas the real generation mechanisms for the subsurface NIWs remain unclear.In particular,during EventⅢ,there was a nonlinear wave-wave interaction between NIWs and semidiurnal(D)tides,which further induced strong D±f waves.Overall,the NIWs in the three events exhibited distinct vertical structures.The NIWs in EventsⅠandⅡwere dominated by lower mode s with elevated NIKE well confined to the upper 250 m and 270 m,respectively.In contrast,the NIW EventⅢwas dominated by higher modes and the NIWs penetrated downward beyond 360 m.Such deep penetration of NIWs could be attributed to the weak wind stress curl and positive sea level anomalies associated with an anticyclonic eddy.In addition,the three NIW events had e-folding timescales of less than 7 days.

Corrigendum to‘Characterization of lipid-based nanomedicines at the single-particle level’[Fundamental Research 3(2023)488-504]

The authors regret that the original version of this article unfortunately contained a mistake[1].It is stated that:“Based on TIRF,another strategy for resolution increase…However,this technique requires the chemical modification to immobilize an individual particle,which may in turn alter their physical and biochemical properties.”on page 494-495.This is incorrect and should be replaced by:“Another strategy for resolution increase…This technique doesn’t require the chemical modification to immobilize an individual particle,which avoids altering their physical and biochemical properties.”

Antibacterial evaporator based on reduced graphene oxide/polypyrrole aerogel for solar-driven desalination

Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.

A new aggregation-induced emission-based fluorescent probe for effective detection of Hg^(2+)and its multiple applications

Detection of mercury ions(Hg^(2+))in actual samples is of significant importance due to the toxicity of Hg^(2+)to human health.In this work,a simple tetraphenylethene(TPE)derived fluorescent probe TPE-Hg based on aggregation-induced emission(AIE)mechanism was synthesized.TPE-Hg can visually recognize Hg^(2+)in THF/HEPES(1:9,v/v,HEPES 20 mmol/L,pH 7.3)system with rapid response,strong anti-interference ability,large Stokes shift(203 nm),and low detection limit(7.548×10^(-7)mol/L).The results show that Hg^(2+)triggered elimination of TPE-Hg lead to releasing of an AIE-active compound 2 is responsible to the sensing mechanism.TPE-Hg is applicable to detect Hg^(2+)in actual water samples and image Hg^(2+)in living MCF-7 cells.In addition,TPE-Hg is suitable to assay the Hg^(2+)level in seafood and tea samples,and it is alsoapplicable intest strips.

Characterization of lipid-based nanomedicines at the single-particle level

Lipid-based nanomedicines(LBNMs),including liposomes,lipid nanoparticles(LNPs)and extracellular vesicles(EVs),are recognized as one of the most clinically acceptable nano-formulations.However,the bench-to-bedside translation efficiency is far from satisfactory,mainly due to the lack of in-depth understanding of their physical and biochemical attributes at the single-particle level.In this review,we first give a brief introduction of LBNMs,highlighting some milestones and related scientific and clinical achievements in the past several decades,as well as the grand challenges in the characterization of LBNMs.Next,we present an overview of each category of LB-NMs as well as the core properties that largely dictate their biological characteristics and clinical performance,such as size distribution,particle concentration,morphology,drug encapsulation and surface properties.Then,the recent applications of several analytical techniques including electron microscopy,atomic force microscopy,fluorescence microscopy,Raman microscopy,nanoparticle tracking analysis,tunable resistive pulse sensing and flow cytometry on the single-particle characterization of LBNMs are thoroughly discussed.Particularly,the com-parative advantages of the newly developed nano-flow cytometry that enables quantitative analysis of both the physical and biochemical characteristics of LBNMs smaller than 40 nm with high throughput and statistical ro-bustness are emphasized.The overall aim of this review article is to illustrate the importance,challenges and achievements associated with single-particle characterization of LBNMs.

Designing polyoxometalate-based metal-organic framework for oxidation of styrene and cycloaddition of CO_(2) with epoxides

A photoactive polyoxometalate-based metal-organic framework (POMOF),NiW-DPNDI,was synthesized by combination of Ni(Ⅱ) ions,[ZnW_(12)O_(40)]^(6–)anions,and N,N’-bis(4-pyridylmethyl)naphthalene diimide(DPNDI) molecules into one single framework.Ni W-DPNDI displays a three-dimensional structure by the strong anion···π interactions between the trapped[ZnW_(12)O_(40)]^(6–)anions and the electron-deficient naphthalenic ring centroids and theπ-πstacking interactions between DPNDI moieties.Ni W-DPNDI displayed a highly efficient hole-electron separation and ordered electron transfer under irradiation,thus ensuing its excellent photocatalysis in oxidation of styrene to produce benzaldehyde.In addition,it gave a high efficiency for styrene oxide under thermocatalytic conditions.Because the carbonic anhydrase (CA)-mimicking Ni sites and the negative electron-enriched[ZnW_(12)O_(40)]^(6–)anions are well aligned in the pores,it can promote the cycloaddition of CO_(2) with epoxides under mild conditions.

我国智能教育装备发展现状及重点研发方向分析

智能教育装备是智能时代教学活动的基础条件,直接作用于教育教学过程,对深化课程改革、提高教育质量、培养学生核心素养和实践创新能力具有重要作用。教育装备内容陈旧、利用率低、适用性差、智能化程度低是现阶段制约我国教育信息化深入推进的重要瓶颈之一。在调研总结我国当前教育装备发展状况的基础上,界定了智能教育装备的概念并提出智能教育装备发展的必要性和新思路。从智能教育装备体系构建、研究重点和发展思路三个方面进行深入阐述,为我国智能教育装备的研究和发展提供有价值的参考。

Applications and challenges for single-bacteria analysis by flow cytometry

Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the single-cell level,FCM has gained an increased popularity in microbiological research,food safety monitoring,water quality control,and clinical diagnosis.Here we will review the recent applications of flow cytometry in areas such as(1)total bacterial cell count,(2)bacterial viability analysis,(3)specific bacterial detection and identification,(4)characterization of physiological changes under environmental perturbations,and(5)biological function studies.Nevertheless,despite these widespread applications,challenges still remain for the detection of small sizes of bacteria and biochemical features that cannot be brightly stained via fluorescence.Recent improvement in FCM instrumentation will be discussed,and particularly the development of high sensitivity flow cytometry for advanced analysis of single bacterial cells will be highlighted.

High-resolution crustal velocity structure in the Shanxi rift zone and its tectonic implications

The Shanxi rift zone,located in the Trans-North China Orogen(TNCO)of the North China Craton(NCC),is wellknown for hosting large intraplate earthquakes in continental China.The TNCO is a suture zone formed by the amalgamation of the eastern and the western blocks of the NCC.After its formation,it was reactived and deformed by later tectonic activities,which result in complex lithospheric heterogeneities.Thus,the detailed crustal structure of the Shanxi rift zone is critical for understanding the tectonics and seismogenic mechanism in this area,which will shed new lights on the formation and dynamic evolution of the NCC.In this study,we applied ambient noise tomography based on 18 months continuous records from 108 seismic stations located in Shanxi and its surroundings,in order to constrain its detailed crustal structure.We measured 4437 Rayleigh wave phase velocity dispersion curves in the period of 5–45 s from the cross-correlation functions.Next,a surface wave direct inversion algorithm based on surface-wave ray tracing was used to resolve a 3-D S-wave velocity model in the upper 60 km with lateral resolution of~50–80 km.The tomographic images show that the sedimentary thickness of the Taiyuan Basin is less than 5 km.At depth of 0–10 km,we observe a good correlation between the imaged structural variations with geological and topographic features at the surface.For example,the center of rift shows low-velocity anomalies and the uplifting areas on both sides are characterized by high velocity anomalies.The western and eastern boundaries of the slow materials coincide with the faults that control the basin.The slow material extends from the shallow surface to depth of about 15 km but it getting smaller in shape at deeper depth.For the Taiyuan Basin,Linfen Basin,and Yuncheng Basin in the central and southern parts,the structure is dominant by slow materials in the upper crust but changes to strong high-velocity anomalies in the lower crust and the uppermost mantle at depth deeper than 25 km.We interprete these high-velocity anomalies to be associated with the cold remnant of the underplated basalt in the lower crust that were formed in early Tertiary before the basin was stretched.We also observe the low-velocity anomaly beneath the Datong volcanic area,which extends from the uppermost mantle to a depth of 20 km vertically and migrates from west to east laterally.It may reflect the upwelling channel of the magmatic material in Datong.Moreover,the strong low-velocity anomalies presented north of 38°N could be related to the heated crustal materials with paritial melting as a result of the intensive magmatic activities of the Datong Volcano since the Cenozoic.In our study region,seismicity mainly concentrates in the depth range of 5–20 km and we find that most earthquakes appear to occur in places where velocity changes from high to low rapidly,with slight higher concentration in the faster material areas.In summary,our high-resolution 3-D crustal velocity model provides important seismological constraints to understand the tectonic evolution and seismicity across the Shanxi rift zone.