Effects of nitrogen deposition on the carbon budget and water stress in Central Asia under climate change

Atmospheric deposition of nitrogen(N)plays a significant role in shaping the structure and functioning of various terrestrial ecosystems worldwide.However,the magnitude of N deposition on grassland ecosystems in Central Asia still remains highly uncertain.In this study,a multi-data approach was adopted to analyze the distribution and amplitude of N deposition effects in Central Asia from 1979 to 2014 using a process-based denitrification decomposition(DNDC)model.Results showed that total vegetation carbon(C)in Central Asia was 0.35(±0.09)Pg C/a and the averaged water stress index(WSI)was 0.20(±0.02)for the whole area.Increasing N deposition led to an increase in the vegetation C of 65.56(±83.03)Tg C and slightly decreased water stress in Central Asia.Findings of this study will expand both our understanding and predictive capacity of C characteristics under future increases in N deposition,and also serve as a valuable reference for decision-making regarding water resources management and climate change mitigation in arid and semi-arid areas globally.

The influences of canopy temperature measuring on the derived crop water stress index

Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.

Enhancing Canola Yield and Photosynthesis under Water Stress with Hydrogel Polymers

While Egypt’s canola production per unit area has recently grown,productivity remains low,necessitating increased productivity.Hydrogels are water-absorbent polymer compounds that can optimize irrigation schedules by increasing the soil’s ability to retain water.Accordingly,twofield experiments were conducted to examine hydrogel application to sandy soil on canola growth,biochemical aspects,yield,yield traits,and nutritional quality of yielded seeds grown under water deficit stress conditions.The experiments were conducted by arranging a split-plot layout in a randomized complete block design(RCBD)with three times replications of each treatment.While water stress at 75%or 50%of crop evapotranspiration(ETc)lowered chlorophyll a,chlorophyll b,caro-tenoids,and total pigments content,indole-3-acetic acid,plant development,seed yield,and oil and total carbo-hydrates of seed yield,hydrogel treatment enhanced all of the traits mentioned above.Furthermore,hydrogel enhanced to gather compatible solutes(proline,amino acids,total soluble sugars),phenolics content in leaves,seed protein,and crop water productivity,which increased while the plants were under water stress.The results revealed that the full irrigation(100%ETc)along with hydrogel compared to water-stressed(50%ETc)led to enhanced seed yield(kg ha^(-1)),Oil(%),and Total carbohydrates(%)of rapeseed by 57.1%,11.1%and 15.7%,respectively.Likewise,under water-stressed plots with hydrogel exhibited enhancement by 10.0%,3.2%and 5.1%in seed yield(kg ha^(-1)),oil(%),and total carbohydrates(%)of rapeseed by 57.1%,11.1%and 15.7%,respec-tively compared to control.As a result,the use of hydrogel polymer will be a viable and practical solution for increasing agricultural output under water deficit stress situations.

Research Progress on Economic Forest Water Stress Based on Bibliometrics and Knowledge Graph

This study employed the bibliometric software CiteSpace 6.1.R6 to analyze the correlation between thermal infrared,spectral remote sensing technology,and the estimation of economic forest water stress.It aimed to review the development and current status of this field,as well as to identify future research trends.A search was conducted on the China National Knowledge Infrastructure(CNKI)database using the keyword“water stress”for relevant studies from 2003 to 2023.The visual analysis function of CNKI was used to generate the distribution of annual publication volume,and CiteSpace 6.1.R6 was utilized to create network maps illustrating collaboration among authors and institutions.The study also analyzed the hotspots and frontiers of economic forest water stress.As a result,a total of 6664 academic journal articles related to water stress were retrieved.Considerable collaboration networks were observed among scholars and institutions,with a focus on using crown temperature monitoring to diagnose crop water stress.Based on the research findings,it was evident that the primary research trend involved the use of thermal infrared and spectral remote sensing technology for estimating water stress,making it a future research hotspot.

Hydrogen-rich water alleviates constipation by attenuating oxidative stress through the sirtuin1/nuclear factor-erythroid-2-related factor 2/heme oxygenase-1 signaling pathway

BACKGROUND Constipation,a highly prevalent functional gastrointestinal disorder,induces a significant burden on the quality of patients'life and is associated with substantial healthcare expenditures.Therefore,identifying efficient therapeutic modalities for constipation is of paramount importance.Oxidative stress is a pivotal contributor to colonic dysmotility and is the underlying pathology responsible for constipation symptoms.Consequently,we postulate that hydrogen therapy,an emerging and promising intervention,can serve as a safe and efficacious treatment for constipation.AIM To determine whether hydrogen-rich water(HRW)alleviates constipation and its potential mechanism.METHODS Constipation models were established by orally loperamide to Sprague-Dawley rats.Rats freely consumed HRW,and were recorded their 24 h total stool weight,fecal water content,and charcoal propulsion rate.Fecal samples were subjected to 16S rDNA gene sequencing.Serum non-targeted metabolomic analysis,malondialdehyde,and superoxide dismutase levels were determined.Colonic tissues were stained with hematoxylin and eosin,Alcian blue-periodic acid-Schiff,reactive oxygen species(ROS)immunofluorescence,and immunohistochemistry for cell growth factor receptor kit(c-kit),PGP 9.5,sirtuin1(SIRT1),nuclear factor-erythroid-2-related factor 2(Nrf2),and heme oxygenase-1(HO-1).Quantitative real-time PCR and western blot analysis were conducted to determine the expression level of SIRT1,Nrf2 and HO-1.A rescue experiment was conducted by intraperitoneally injecting the SIRT1 inhibitor,EX527,into constipated rats.NCM460 cells were induced with H2O2 and treated with the metabolites to evaluate ROS and SIRT1 expression.RESULTS HRW alleviated constipation symptoms by improving the total amount of stool over 24 h,fecal water content,charcoal propulsion rate,thickness of the intestinal mucus layer,c-kit expression,and the number of intestinal neurons.HRW modulated intestinal microbiota imbalance and abnormalities in serum metabolism.HRW could also reduce intestinal oxidative stress through the SIRT1/Nrf2/HO-1 signaling pathway.This regulatory effect on oxidative stress was confirmed via an intraperitoneal injection of a SIRT1 inhibitor to constipated rats.The serum metabolites,β-leucine(β-Leu)and traumatic acid,were also found to attenuate H2O2-induced oxidative stress in NCM460 cells by up-regulating SIRT1.CONCLUSION HRW attenuates constipation-associated intestinal oxidative stress via SIRT1/Nrf2/HO-1 signaling pathway,modulating gut microbiota and serum metabolites.β-Leu and traumatic acid are potential metabolites that upregulate SIRT1 expression and reduce oxidative stress.

Ameliorative Effects of Paclobutrazol via Physio-Biochemical and Molecular Manifestation in Rice under Water Deficit Stress

To comprehensively explore the physio-biochemical and molecular changes of paclobutrazol(PBZ) at the ideal dose under water deficit stress(WDS) conditions, we investigated the effects of 100 mg/kg PBZ applied via drenching on various physio-biochemical and molecular parameters in three rice varieties(N22, IR64, and IR64 DTY1.1) under both mild [75%-80% relative water content(RWC)] and severe(60%-65% RWC) WDS conditions. The results showed that PBZ treatment positively influenced the physio-biochemical parameters, significantly increasing dry matter(16.27%-61.91%), RWC(6.48%-16.34%), membrane stability index(4.37%-10.35%), and total chlorophyll content(8.97%-29.09%) in the rice varieties under both mild and severe WDS. Moreover, PBZ treatment reduced drought susceptibility(0.83-0.95) and enhanced drought tolerance efficiency(60.92%-86.78%), indicating its potential as a stress-mitigating agent. Global methylation analysis revealed changes in DNA methylation patterns, indicating the regulatory influence of PBZ on gene expression. The expression analysis of genes involved in the diversification of geranylgeranyl pyrophosphate towards the biosynthesis of abscisic acid, gibberellin acid, and chlorophyll showed alterations in their expression levels, suggesting the involvement of PBZ in the isoprenoid pathway. Overall, this study provides valuable insights into the potential mechanisms by which PBZ modulates physiological and molecular responses in rice plants under WDS. The findings highlight the importance of PBZ as a promising agent for enhancing drought tolerance in rice and offer valuable information for future research in crop stress management.

Effect of degree of saturation on stresses and pore water pressure in the subgrade layer caused by railway track loading

Purpose-The experiments of this study investigated the effect of the subgrade degree of saturation on the value of the stresses generated on the surface and the middle(vertical and lateral stresses).The objectives of this study can be identified by studying the effect of subgrade layer degree of saturation variation,load amplitude and load frequency on the transmitted stresses through the ballast layer to the subgrade layer and the stress distribution inside it and investigating the excess pore water pressure development in the clay layer in the case of a fully saturated subgrade layer and the change in matric suction in the case of an unsaturated subgrade layer.Design/methodology/approach-Thirty-six laboratory experiments were conducted using approximately half-scale replicas of real railways,with an iron box measuring 1.5×1.031.0 m.Inside the box,a 0.5 m thick layer of clay soil representing the base layer was built.Above it is a 0.2 m thick ballast layer made of crushed stone,and on top of that is a 0.8 m long rail line supported by three 0.9 m(0.1×0.1 m)slipper beams.The subgrade layer has been built at the following various saturation levels:100,80,70 and 60%.Experiments were conducted with various frequencies of 1,2 and 4 Hz with load amplitudes of 15,25 and 35 kN.Findings-The results of the study demonstrated that as the subgrade degree of saturation decreased from 100 to 60%,the ratio of stress in the lateral direction to stress in the vertical direction generated in the middle of the subgrade layer decreased as well.On average,this ratio changed from approximately 0.75 to approximately 0.65.Originality/value-The study discovered that as the test proceeded and the number of cycles increased,the value of negative water pressure(matric suction)in the case of unsaturated subgrade soils declined.The frequency of loads had no bearing on the ratio of decline in matric suction values,which was greater under a larger load amplitude than a lower one.As the test progressed(as the number of cycles increased),the matric suction dropped.For larger load amplitudes,there is a greater shift in matric suction.The change in matric suction is greater at higher saturation levels than it is at lower saturation levels.Furthermore,it is seen that the load frequency value has no bearing on how the matric suction changes.For all load frequencies and subgrade layer saturation levels,the track panel settlement rises with the load amplitude.Higher load frequency and saturation levels have a greater impact.

Performance of water-coupled charge blasting under different in-situ stresses

Water-coupled charge blasting is a promising technique to efficiently break rock masses.In this study,numerical models of double boreholes with water-coupled charge are established using LS-DYNA and are calibrated by the tests of rock masses subjected to explosion loads to examine its performance.The crack levels of rock mass induced by water-coupled charge blasting and air-coupled charge blasting are first compared.It is found that water-coupled charge blasting is more appropriate to fracture deep rock mass than air-coupled charge blasting.In addition,the effects of rock properties,water-coupled charge coefficients,and borehole connection angles on the performance of water-coupled charge blasting are investigated.The results show that rock properties and water-coupled charge coefficients can greatly influence the crack and fragmentation levels of rock mass induced by water-coupled charge blasting under uniform and non-uniform in-situ stresses.However,changing borehole-connection angles can only affect crack and fragmentation levels of rock mass under non-uniform in-situ stresses but barely affect those under uniform in-situ stresses.A formula is finally proposed by considering the above-mentioned factors to provide the design suggestion of water-coupled charge blasting to fracture rock mass with different in-situ stresses.

Effects of water stress on quality and sugar metabolism in'Gala'apple fruit

Sugar plays an important role in apple fruit development,appearance and quality as well as contributing to a plant’s water stress response.Trehalose and the trehalose biosynthetic metabolic pathways are part of the sugar signaling system in plants,which are important regulator of water stress response in apple.The effect of water stress treatments applied to apple trees and the corresponding effects of ABA on developmental fruit quality were examined for indicators of fruit quality during fruit development.The results indicated that the severe water stress treatment(W2)occurring after the last stage of fruit cell division caused a decrease in the color and size of fruit.The moderate water stress(W1)occurring after the last stage of fruit cell enlargement(S2)caused an increase in the content of fructose and sorbitol while the apple fruit shape was not affected.These changes in sugar are related to the activity of sugar metabolic enzymes.While the enzymatic activity of vacuolar acid invertase(vAINV)was higher,that of sucrose-phosphate synthase(SPS)was lower in water stress treated fruit throughout the developmental period.This indicates that enhanced sucrose degradation and reduced sucrose synthesis leads to an overall reduced sucrose content during times of drought.Thus,water stress reduced sucrose content.Whereas the content of endogenous trehalose and ABA were the highest in water stress treated fruit.A moderate water stress(W1)imposed on apple trees via water restriction(60%–65%of field capacity)after the fruit cell enlargement phase of fruit development yielded sweeter fruit of higher economic value.

Rapid testing and prediction of soil–water characteristic curve of subgrade soils considering stress state and degree of compaction

The subgrade soil is generally in saturated or unsaturated condition. To analyze complex thermo-hydro-mechanical-chemical (THMC) behaviors of subgrade, it is essential to determine the soil–water characteristic curve (SWCC) that represents the relationship between matric suction and moisture content. In this study, a full-automatic rapid stress-dependent SWCC pressure-plate extractor was developed. Then, the influences of overburden stress and degree of compaction on the SWCC of subgrade soil such as high liquid limit silt (MH) and low liquid limit clay (CL) were analyzed. Accordingly, a new model taking into account the influences of overburden stress and degree of compaction based on the well-known Van Genuchten (VG) SWCC fitting model was presented and validated. The results show that with the increase of the degree of compaction and overburden stress, the saturated moisture content of subgrade soil decreases, while the air-entry value increases and the transition section curve becomes flat. The influences of the degree of compaction and overburden stress on the SWCC of MH is greater than that of CL. Meanwhile, there was a satisfactory agreement between the prediction and measurement, indicating a good performance of the new model for predicting the SWCC.

Stress release mechanism of deep bottom hole rock by ultra-high-pressure water jet slotting

To solve the problems of rock strength increase caused by high in-situ stress,the stress release method with rock slot in the bottom hole by an ultra-high-pressure water jet is proposed.The stress conditions of bottom hole rock,before and after slotting are analyzed and the stress release mechanism of slotting is clarified.The results show that the stress release by slotting is due to the coupling of three factors:the relief of horizontal stress,the stress concentration zone distancing away from the cutting face,and the increase of pore pressure caused by rock mass expansion;The stress concentration increases the effective stress of rock along the radial distance from O.6R to 1R(R is the radius of the well),and the presence of groove completely releases the stress,it also allows the stress concentration zone to be pushed away from the cutting face,while significantly lowering the value of stresses in the area the drilling bit acting,the maximum stress release efficiency can reach 80%.The effect of slotting characteristics on release efficiency is obvious when the groove location is near the borehole wall.With the increase of groove depth,the stress release efficiency is significantly increased,and the release range of effective stress is enlarged along the axial direction.Therefore,the stress release method and results of simulations in this paper have a guiding significance for best-improving rock-breaking efficiency and further understanding the technique.

An Automatic Classification Grading of Spinach Seedlings Water Stress Based on N-MobileNetXt

To solve inefficient water stress classification of spinach seedlings under complex background,this study proposed an automatic classification method for the water stress level of spinach seedlings based on the N-MobileNetXt(NCAM+MobileNetXt)network.Firstly,this study recon-structed the Sandglass Block to effectively increase the model accuracy;secondly,this study introduced the group convolution module and a two-dimensional adaptive average pool,which can significantly compress the model parameters and enhance the model robustness separately;finally,this study innovatively proposed the Normalization-based Channel Attention Module(NCAM)to enhance the image features obviously.The experimental results showed that the classification accuracy of N-MobileNetXt model for spinach seedlings under the natural environment reached 90.35%,and the number of parameters was decreased by 66%compared with the original MobileNetXt model.The N-MobileNetXt model was superior to other net-work models such as ShuffleNet and GhostNet in terms of parameters and accuracy of identification.It can provide a theoretical basis and technical support for automatic irrigation.

Water Stress Early Detection of Eggplant Plants by Hyperspectral Fluorescence Spectroscopy

Water stress early detection is essential for precision farming to improve crop productivity and product quality. The methods usually used are destructive, long and expensive. In this work, we used hyperspectral chlorophyll fluorescence technology as a rapid, non-destructive approach to detect the water deficiency of eggplant plants using their spectral footprint. So, an experiment was made on 54 eggplant plants subjected to three water treatments: normal irrigation (T100), intermediate irrigation (T50) and no irrigation (T0). The fluorescence spectra were acquired in vivo and in situ using a USB4000 spectrometer from Ocean optics. For the classification of the plants subjected to three water treatments, we used three pretreatments of the raw hyperspectral data in order to suppress the non-informative variability present in these spectra and to obtain robust models. These are the Savitzky-Golay smoothing (SG), the standard normal variable (SNV) and the first derivative of Savitzky-Golay (SG-D1). The preprocessed data were then subjected to two partial least squares discriminant analyses (PLS-DA): Hard PLS-DA and Soft PLS-DA. These statistical approaches are suitable for large samples as it reduces the dimensionality of the data but improves the accuracy of the prediction. The SG-D1 combined with the Soft PLS-DA gave the best discrimination of plants with scores of sensitivity, specificity and total efficiency respectively of 97.33%, 94% and 95% for calibration, 6 days after hydric stress induction. For the plants used for the prediction, the scores are 86%, 91% and 90% respectively. This study shows that hyperspectral chlorophyll fluorescence spectroscopy is a fast and non-destructive technology allowing early detection of water stress in eggplant plants.

Effects of Flooding Stress on Growth and Root Physiology and Biochemistry of Grafted Red-seed Watermelon Seedlings

[Objectives]This study was conducted to explore how to improve the waterlogging tolerance of red-seed watermelon through grafting,to provide a theoretical basis for its cultivation in rainy season.[Methods]The effects of flooding stress on the growth and root physiological and biochemical characteristics of grafted and own-rooted red-seed watermelon seedlings were studied using Luffa as rootstocks and"Zhongxin 1"red-seed watermelon as scions.[Results]After flooding stress,the biomass and root activity of grafted seedlings of red-seed watermelon were significantly higher than those of own-rooted seedlings.With the prolongation of flooding stress time,the soluble sugar and proline content showed a trend of first increasing and then decreasing,and the grafted seedlings had a larger increase and a smaller decrease,and were always significantly higher than own-rooted seedlings in the same period.The content of malondialdehyde in the root system of grafted seedlings increased first and then decreased,while it continued to increase in own-rooted seedlings,and the increase in own-rooted seedlings was significantly greater than that in grafted seedlings during the same period.[Conclusions]Grafting on Luffa rootstocks could improve waterlogging tolerance of red-seed watermelon.

Effects of water stress on growth phenology photosynthesis and leaf water potential in Stipagrostis ciliata(Desf.)De Winter in North Africa

Stipagrostis ciliata(Desf.)De Winter is a pastoral C4 grass grown in arid regions.This research work focused on assessing the growth of S.ciliata accessions derived from two different climate regions(a wet arid region in the Bou Hedma National Park in the central and southern part of Tunisia(coded as WA),and a dry arid region from the Matmata Mountain in the south of Tunisia(coded as DA))under water stress conditions.Specifically,the study aimed to investigate the phenological and physiological responses of potted S.ciliata seedlings under different water treatments:T_(1)(200 mm/a),T_(2)(150 mm/a),T_(3)(100 mm/a)and T_(4)(50 mm/a).Growth phenology,net photosynthesis(Pn),stomatal conductance(gs),midday leaf water potential(Ψmd),predawn leaf water potential(Ψpd),soil water content(SWC)and soil water potential(Ψs)were observed during the water stress cycle(from December 2016 to November 2017).The obtained results showed that the highest growth potential of the two accessions(WA and DA)was recorded under treatment T_(1).The two accessions responded differently and significantly to water stress.Photosynthetic parameters,such as Pn and gs,decreased sharply under treatments T_(2),T_(3)and T_(4)compared to treatment T_(1).The higher water stress increased the R/S ratio(the ratio of root dry biomass to shoot dry biomass),with values of 1.29 and 2.74 under treatment T_(4)for accessions WA and DA,respectively.Principal component analysis(PCA)was applied,and the separation of S.ciliata accessions on the first two axes of PCA(PC1 and PC2)suggested that accession DA was detected in the negative extremity of PC1 and PC2 under treatments T_(1)and T_(2).This accession was characterized by a high number of spikes.For treatments T_(3)and T_(4),both accessions were detected in the negative extremity of PC1 and PC2.They were characterized by a high root dry biomass.Therefore,S.ciliata accessions responded to water stress by displaying significant changes in their behaviours.Accession WA from the Bou Hedma National Park(wet arid region)showed higher drought tolerance than accession DA from the Matmata Mountain(dry arid region).S.ciliata exhibits a significant adaptation capacity for water limitation and may be an important species for ecosystem restoration.

Deformation and Stress Analysis of the Deepwater Steel Lazy Wave Riser Subjected to Internal Solitary Waves

The dynamic response of the steel lazy wave riser(SLWR)subjected to the internal solitary wave is a key to assessing its application feasibility.The innovation of this paper is to study the dynamic response properties of the SLWR with large deformation characteristics under internal wave excitation.A numerical scheme of the SLWR is constructed using the slender-rod theory,and the internal solitary wave(ISW)with a two-layer seawater model is simulated by the extended Korteweg-deVries equation.The finite element method combined with the Newmark-βmethod is applied to discretize the equations and update the time integration.The ISW excitation combined with vessel motion on the dynamic deformation and stress of the SLWR is investigated,and extensive simulations of the ISW parameters,including the interface depth ratio and density difference,are carried out.Case calculation reveals that the displacement of the riser in the lower interface layer increases significantly under the ISW excitation,and the stresses at a part of both ends grow evidently.Moreover,the mean value of riser responses under a combination of vessel motion and ISW coincides with the ISW-induced ones.Furthermore,the dynamic responses along the whole riser,including the displacement amplitudes,bending moment amplitudes,and stress amplitudes,almost increase with the increase in interface depth ratios and density differences.

Ferroptosis and endoplasmic reticulum stress in ischemic stroke

Ferroptosis is a form of non-apoptotic programmed cell death,and its mechanisms mainly involve the accumulation of lipid peroxides,imbalance in the amino acid antioxidant system,and disordered iron metabolism.The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum,and the progression of inflammatory diseases can trigger endoplasmic reticulum stress.Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival.Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke.However,there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke.This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke,aiming to provide a reference for developing treatments for ischemic stroke.

Grain Yield,Biomass Accumulation,and Leaf Photosynthetic Characteristics of Rice under Combined Salinity-Drought Stress

Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.

Piezo1 channel exaggerates ferroptosis of nucleus pulposus cells by mediating mechanical stress-induced iron influx

To date,several molecules have been found to facilitate iron influx,while the types of iron influx channels remain to be elucidated.Here,Piezo1 channel was identified as a key iron transporter in response to mechanical stress.Piezo1-mediated iron overload disturbed iron metabolism and exaggerated ferroptosis in nucleus pulposus cells(NPCs).Importantly,Piezo1-induced iron influx was independent of the transferrin receptor(TFRC),a well-recognized iron gatekeeper.Furthermore,pharmacological inactivation of Piezo1 profoundly reduced iron accumulation,alleviated mitochondrial ROS,and suppressed ferroptotic alterations in stimulation of mechanical stress.Moreover,conditional knockout of Piezo1(Col2a1-CreERT Piezo1^(flox/flox))attenuated the mechanical injury-induced intervertebral disc degeneration(IVDD).Notably,the protective effect of Piezo1 deficiency in IVDD was dampened in Piezo1/Gpx4 conditional double knockout(cDKO)mice(Col2a1-CreERT Piezo1^(flox/flox)/Gpx4^(flox/flox)).These findings suggest that Piezo1 is a potential determinant of iron influx,indicating that the Piezo1-iron-ferroptosis axis might shed light on the treatment of mechanical stress-induced diseases.

Insights on advanced substrates for controllable fabrication of photoanodes toward efficient and stable photoelectrochemical water splitting

Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.