OsPPG encodes a pseudouridine-5'-phosphate glycosidase and regulates rice spikelet development

Florets are the basic structural units of spikelets,and their morphogenesis determines the yield and quality of rice grains.However,whether and how pseudouridine-5’-phosphate glycosidase participates in rice spikelet development remains an open question.In this study,we identified a novel gene,OsPPG,which encodes a peroxisome-localized pseudouridine-5’-phosphate glycosidase and regulates the development of rice spikelets.osppg mutants exhibited abnormal sterile lemma,lemma,palea,lodicule,stamens,and pistils;male sterility;shorter panicles;and reduced plant height.OsPPG was found to regulate several OsMADS genes,thereby affecting the morphogenesis of rice spikelets.Furthermore,metabolomics revealed that the OsPPG gene was involved in the decomposition of pseudouridine via the pyrimidine metabolism pathway and may affect the jasmonic acid signaling pathway.These results suggest that OsPPG is a key regulator of rice spikelet development.

A novel histone methyltransferase gene Cg SDG40 positively regulates carotenoid biosynthesis during citrus fruit ripening

The flesh color of pummelo(Citrus maxima)fruits is highly diverse and largely depends on the level of carotenoids,which are beneficial to human health.It is vital to investigate the regulatory network of carotenoid biosynthesis to improve the carotenoid content in pummelo.However,the molecular mechanism underlying carotenoid accumulation in pummelo is not fully understood.In this study,we identified a novel histone methyltransferase gene,CgSDG40,involved in carotenoid regulation by analyzing the flesh transcriptome of typical white-fleshed pummelo,red-fleshed pummelo and extreme-colored F1 hybrids from a segregated pummelo population.Expression of CgSDG40 corresponded to flesh color change and was highly coexpressed with CgPSY1.Interestingly,CgSDG40 and CgPSY1 are located physically adjacent to each other on the chromosome in opposite directions,sharing a partially overlapping promoter region.Subcellular localization analysis indicated that CgSDG40 localizes to the nucleus.Overexpression of CgSDG40 significantly increased the total carotenoid content in citrus calli relative to that in wild type.In addition,expression of CgPSY1 was significantly activated in overexpression lines relative to wild type.Taken together,our findings reveal a novel histone methyltransferase regulator,CgSDG40,involved in the regulation of carotenoid biosynthesis in citrus and provide new strategies for molecular design breeding and genetic improvement of fruit color and nutritional quality.

Selection of Negative Charged Acidic Polar Additives to Regulate Electric Double Layer for Stable Zinc Ion Battery

Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic Zn electrodeposition.Although the regulation of electric double layer(EDL)has been verified for interfacial issues,the principle to select the additive as the regulator is still misted.Here,several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode.Negative charged acidic polarity(NCAP)has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H_(2)O-poor layer and to replace H_(2)O molecules of hydrated Zn^(2+)with NCAP glutamate.Taking the synergistic effects of EDL regulation,the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition.Consequently,by adding NCAP glutamate,a high average Coulombic efficiency of 99.83%of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles,and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1%after 3000 cycles at 2 A g^(-1).Recapitulating,the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.

Ultrathin Zincophilic Interphase Regulated Electric Double Layer Enabling Highly Stable Aqueous Zinc‑Ion Batteries

The practical application of aqueous zinc-ion batteries for large-grid scale systems is still hindered by uncontrolled zinc dendrite and side reactions.Regulating the elec-trical double layer via the electrode/electrolyte interface layer is an effective strategy to improve the stability of Zn anodes.Herein,we report an ultrathin zincophilic ZnS layer as a model regu-lator.At a given cycling current,the cell with Zn@ZnS electrode displays a lower potential drop over the Helmholtz layer(stern layer)and a suppressed diffuse layer,indicating the regulated charge distribution and decreased electric double layer repulsion force.Boosted zinc adsorption sites are also expected as proved by the enhanced electric double-layer capacitance.Consequently,the symmetric cell with the ZnS protection layer can stably cycle for around 3,000 h at 1 mA cm^(-2) with a lower overpotential of 25 mV.When coupled with an I2/AC cathode,the cell demonstrates a high rate performance of 160 mAh g^(-1) at 0.1 A g^(-1) and long cycling stability of over 10,000 cycles at 10 A g^(-1).The Zn||MnO_(2) also sustains both high capacity and long cycling stability of 130 mAh g^(-1) after 1,200 cycles at 0.5 A g^(-1).

Charge-transfer-regulated bimetal ferrocene-based organic frameworks for promoting electrocatalytic oxygen evolution

The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity and flexible electronic structure.Herein,density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping,which demonstrated that the well-proposed CoNiFc-MOFs delivered a small energy barrier,promoted conductivity,and well-regulated d-band center.Inspired by these,a series of sea-urchin-like CoNiFc-MOFs were successfully synthesized via a facile solvothermal method.Moreover,the synchrotron X-ray and X-ray photoelectron spectroscopy measurements manifested that the introduction of nickel could tailor the electronic structure of the catalyst and induce the directional transfer of electrons,thus optimizing the rate-determining step of^(*)O→^(*)OOH during the OER process and yielding decent overpotentials of 209 and 252 mV at 10 and 200 mA cm^(−2),respectively,with a small Tafel slope of 39 mV dec^(−1).This work presents a new paradigm for developing highly efficient and durable MOF-based electrocatalysts for OER.

Role of CAST-Drp1 Pathway in Retinal Neuron-Regulated Necrosis in Experimental Glaucoma

Objective Numerous studies have indicated that excitatory amino acid toxicity,such as glutamate toxicity,is involved in glaucoma.In addition,excessive glutamate can lead to an intracellular calcium overload,resulting in regulated necrosis.Our previous studies have found that the calpastatin(CAST)-calpain pathway plays an important role in retinal neuron-regulated necrosis after glutamate injury.Although inhibition of the calpain pathway can decrease regulated necrosis,necrotic cells remain.It has been suggested that there are other molecules that participate in retinal neuron-regulated necrosis.CAST is an important regulator of dynamin-related protein 1(Drp1)-mediated mitochondrial defects.Thus,the aim of this study was to determine whether the CAST-Drp1 pathway may be an underlying signaling axis in neuron-regulated necrosis.Methods Using cultured retinal neurons and in an in-vivo glaucoma model induced by glutamate overload,members of the CAST-Drp1 pathway were assessed by immunofluorescence,Western blotting,Phos-tagTM SDS-PAGE,and co-immunoprecipitation assays.Moreover,the black and white box test was performed on the rats.Results We found that more retinal neuron-regulated necrosis and Drp1 activation as well as lower CAST levels were present in the glutamate-induced glaucoma model.Rats with glutamate-induced glaucoma exhibited impaired visual function.We also observed retinal neuron-regulated necrosis and Drp1 activity decreased,and impaired vision recovered after CAST active peptide application,indicating that the CAST-Drp1 pathway plays a critical role in retinal neuron-regulated necrosis and visual function.Conclusion The results of this study indicate that the CAST-Drp1 pathway protects against retinal neuron-regulated necrosis,which may expand the therapeutic targets for the treatment of neurodegenerative disorders involving dysfunction of glutamate metabolism,such as glaucoma.

Mesenchymal stem cell-derived exosomes regulate microglia phenotypes:a promising treatment for acute central nervous system injury

There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progression.In acute CNS injury,brain microglia are among the first cells to respond and play a critical role in neural repair and regeneration.However,microglial activation can also impede CNS repair and amplify tissue damage,and phenotypic transformation may be responsible for this dual role.Mesenchymal stem cell(MSC)-derived exosomes(Exos)are promising therapeutic agents for the treatment of acute CNS injuries due to their immunomodulatory and regenerative properties.MSC-Exos are nanoscale membrane vesicles that are actively released by cells and are used clinically as circulating biomarkers for disease diagnosis and prognosis.MSC-Exos can be neuroprotective in several acute CNS models,including for stroke and traumatic brain injury,showing great clinical potential.This review summarized the classification of acute CNS injury disorders and discussed the prominent role of microglial activation in acute CNS inflammation and the specific role of MSC-Exos in regulating pro-inflammatory microglia in neuroinflammatory repair following acute CNS injury.Finally,this review explored the potential mechanisms and factors associated with MSCExos in modulating the phenotypic balance of microglia,focusing on the interplay between CNS inflammation,the brain,and injury aspects,with an emphasis on potential strategies and therapeutic interventions for improving functional recovery from early CNS inflammation caused by acute CNS injury.

Phase separation and transcriptional regulation in cancer development

Liquid-liquid phase separation,a novel biochemical phenomenon,has been increasingly studied for its medical applications.It underlies the formation of membrane-less organelles and is involved in many cellular and biological processes.During transcriptional regulation,dynamic condensates are formed through interactions between transcriptional elements,such as transcription factors,coactivators,and mediators.Cancer is a disease characterized by uncontrolled cell proliferation,but the precise mechanisms underlying tumorigenesis often remain to be elucidated.Emerging evidence has linked abnormal transcriptional condensates to several diseases,especially cancer,implying that phase separation plays an important role in tumorigenesis.Condensates formed by phase separation may have an effect on gene transcription in tumors.In the present review,we focus on the correlation between phase separation and transcriptional regulation,as well as how this phenomenon contributes to cancer development.

Mobilization of monocytic myeloid-derived suppressor cells is regulated by PTH1R activation in bone marrow stromal cells

Myeloid-derived suppressor cells(MDSCs)are bone marrow(BM)-derived immunosuppressive cells in the tumor microenvironment,but the mechanism of MDSC mobilization from the BM remains unclear.We investigated how BM stromal cell activation by PTH1R contributes to MDSC mobilization.PTH1R activation by parathyroid hormone(PTH)or PTH-related peptide(PTHrP),a tumor-derived counterpart,mobilized monocytic(M-)MDSCs from murine BM without increasing immunosuppressive activity.In vitro cell-binding assays demonstrated thatα4β1 integrin and vascular cell adhesion molecule(VCAM)-1,expressed on M-MDSCs and osteoblasts,respectively,are key to M-MDSC binding to osteoblasts.Upon PTH1R activation,osteoblasts express VEGF-A and IL6,leading to Src family kinase phosphorylation in M-MDSCs.Src inhibitors suppressed PTHrP-induced MDSC mobilization,and Src activation in M-MDSCs upregulated two proteases,ADAM-17 and MMP7,leading to VCAM1 shedding and subsequent disruption of M-MDSC tethering to osteoblasts.Collectively,our data provide the molecular mechanism of M-MDSC mobilization in the bones of tumor hosts.

A novel candidate gene CLN8 regulates fat deposition in avian

Background The fat deposition has a crucial role in animal meat flavor,and fat deposition-related traits are vital for breeding in the commercial duck industry.Avian fat-related traits are typical complex phenotypes,which need a large amount of data to analyze the genetic loci.Results In this study,we performed a new phenotypic analysis of fat traits and genotyped whole-genome varia-tions for 1,246 ducks,and combed with previous GWAS data to reach 1,880 ducks for following analysis.The carcass composition traits,subcutaneous fat weight(SFW),subcutaneous fat percentage(SFP),abdominal fat weight(AFW),abdominal fat percentage(AFP)and the body weight of day 42(BW42)for each duck were collected.We identified a set of new loci that affect the traits related to fat deposition in avian.Among these loci,ceroid-lipofuscinosis,neuronal 8(CLN8)is a novel candidate gene controlling fat deposition.We investigated its novel function and regulation in avian adipogenesis.Five significant SNPs(the most significant SNP,P-value=21.37E-12)and a single haplotype were detected in the upstream of CLN8 for subcutaneous fat percentage.Subsequently,luciferase assay demonstrated that 5 linked SNPs in the upstream of the CLN8 gene significantly decreased the transcriptional activity of CLN8.Further,ATAC-seq analysis showed that transcription factor binding sites were identified in a region close to the haplotype.A set of luciferase reporter gene vectors that contained different deletion fragments of the CLN8 promoter were con-structed,and the core promoter area of CLN8 was finally identified in the-1,884/-1,207 bp region of the 5′flanking sequences,which contains adipogenesis-related transcription factors binding sites.Moreover,the over-expression of CLN8 can remarkably facilitate adipocyte differentiation in ICPs.Consistent with these,the global transcriptome profiling and functional analysis of the over-expressed CLN8 in the cell line further revealed that the lipid biosynthetic process during the adipogenesis was significantly enriched.Conclusions Our results demonstrated that CLN8 is a positive regulator of avian adipocyte differentiation.These findings identify a novel function of CLN8 in adipocyte differentiation,which provides important clues for the further study of the mechanism of avian fat deposition.

An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power consumption.An event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional structures.The presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump structure.This breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient recovery.Moreover,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS technology.The measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change.

A novel short transcript isoform of chicken IRF7 negatively regulates interferon-βproduction

Type I interferon(IFN-I)provides an important first line to protect avian species against pathogens invasion.IFN regulatory factor 7(IRF7)has been identified as the most important regulator for both DNA and RNA virus-induced IFN-I production in chickens.Although four splicing variants of IRF7 have been identified in mammals,it is still unclear whether alternative splicing patterns and the function of IRF7 isoform(s)exist in chickens.In this study,we reported a novel short transcript isoform of chicken IRF7(chIRF7),termed chIRF7-iso,which contained an intact N-terminal DNA-binding domain(DBD)and 14 amino acids different from chIRF7 in the C-terminal.Overexpression of chIRF7 in chicken leghorn male hepatocellular(LMH)cells activated the IFN-βpromoter and significantly inhibited Newcastle disease virus(NDV)and fowl adenovirus serotype 4(FAdV-4)replication.Conversely,overexpression of chIRF7-iso blocked the IFN-βpromoter activity and was favorable for NDV and FAdV-4 replication in vitro.Collectively,our results confirm that a novel chIRF7 isoform-mediated negative regulates IFN-βproduction,which will contribute to understanding the role of chIRF7 in innate antiviral response in chicken.

Transcriptional regulation in the development and dysfunction of neocortical projection neurons

Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal cord.Appropriate development of cortical projection neurons is regulated by certain essential events such as neural fate determination,proliferation,specification,differentiation,migration,survival,axonogenesis,and synaptogenesis.These processes are precisely regulated in a tempo-spatial manner by intrinsic factors,extrinsic signals,and neural activities.The generation of correct subtypes and precise connections of projection neurons is imperative not only to support the basic cortical functions(such as sensory information integration,motor coordination,and cognition)but also to prevent the onset and progression of neurodevelopmental disorders(such as intellectual disability,autism spectrum disorders,anxiety,and depression).This review mainly focuses on the recent progress of transcriptional regulations on the development and diversity of neocortical projection neurons and the clinical relevance of the failure of transcriptional modulations.

Serine protease inhibitors LmSPN2 and LmSPN3 co-regulate embryonic diapause in Locusta migratoria manilensis(Meyen)via the Toll pathway

Female adults of the migratory locust,Locusta migratoria manilensis(Meyen),can sense seasonal photoperiod changes,which induces embryonic diapause as a key strategy to overwinter.Serine protease inhibitor genes(SPNs)were thought to play key roles during diapause,while few SPNs were functionally characterized.LmSPN2 was one of those genes differentially expressed between diapause and non-diapause eggs;however,its biological function remained to be explored.So,we conducted RNAi knockdown of LmSPN2,resulting in a significant decrease of the egg diapause rate by 29.7%.Using yeast two-hybrid assays,co-immunoprecipitation,and pull-down methods,we found an interaction between LmSPN2 and LmSPN3,which was proved to be mediated by a glutamate(E331)binding site of LmSPN2.RNAi knockdown of LmSPN3 resulted in a significant increase in diapause rate by 14.6%,indicating an inverse function of LmSPN2 and LmSPN3 on diapause regulation.Double knockdown of two SPN genes resulted in a 26.4%reduction in diapause rate,indicating that LmSPN2 was the dominant regulatory signal.Moreover,we found four Toll pathway genes(easter,spätzle,pelle,and dorsal)upregulated significantly after the knockdown of LmSPN2 while downregulated after the knockdown of LmSPN3.Therefore,we speculate that two SPNs regulate diapause through the Toll pathway.Our results indicated that LmSPN2 positively regulates locust egg entry into diapause,while LmSPN3 is a negative regulator of embryonic commitment to diapause.Their interaction is mediated by the binding site of E331 and influences egg diapause through the Toll pathway.This mechanistic understanding of diapause regulation expands our understanding of insect developmental regulation and provides functional targets for developing locust management strategies.

Using Rn-222 to Study Human-Regulated River Water-Sediment Input Event in the Estuary

The implementation of the water sediment regulation scheme(WSRS)is a typical example of artificially controlling land-source input.During WSRS,the water discharge of the Yellow River will increase significantly,and so will the input of terri-genous materials.In this study,we used a natural geochemical tracer 222Rn to quantify terrestrial inputs under the influence of the 2014 WSRS in the Yellow River Estuary.The results indicated that during WSRS the concentration of 222Rn in the estuary increased by about four times than in the period before WSRS.The high-level 222Rn plume disappeared quickly after WSRS,indicating that 222Rn has a very short‘memory effect’in the estuary.Based on the investigation conducted from 2015 to 2016,the concentration of 222Rn tended to be stable in the lower reaches of the Yellow River.During WSRS,the concentrations of 222Rn in the river water in-creased sharply at about 3–5 times greater than in the non-WSRS period.Based on the 222Rn mass balance model,the fluxes of 222Rn caused by submarine groundwater discharge(SGD)were estimated to be(3.5±1.7)×10^(3),(11±3.9)×10^(3),and(5.2±1.9)×10^(3)dpm m^(-2)d^(-1)in the periods before,during,and after WSRS,respectively.This finding indicated that SGD was the major source of 222Rn in the Yellow River Estuary,which can be significantly increased during WSRS.Furthermore,the SGD-associated nutrient fluxes were estimated to be 9.8×10^(3),2.5×102,and 1.1×10^(4)μmolm^(-2)d^(-1)for dissolved inorganic nitrogen,phosphorus,and silicon,respectively,during WSRS or about 2–40 times greater than during the non-WSRS period.

Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis

BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.

Compartmentalized regulation of organelle integrity in neurodegenerative diseases:lessons from the Drosophila motor neuron

Neurons are highly polarized,morphologically asymmetric,and functionally compartmentalized cells that contain long axons extending from the cell body.For this reason,their maintenance relies on spatiotemporal regulation of organelle distribution between the somatodendritic and axonal domains.Although some organelles,such as mitochondria and smooth endoplasmic reticulum,are widely distributed throughout the neuron,others are segregated to either the somatodendritic or axonal compartment.For example,Golgi outposts and acidified lysosomes are predominantly present in the somatodendritic domain and rarely distributed along the axon,whereas newly formed autophagosomes and synaptic vesicles are mainly distributed in the distal axon(Britt et al.,2016).

New advances of adiponectin in regulating obesity and related metabolic syndromes

Obesity and related metabolic syndromes have been recognized as important disease risks,in which the role of adipokines cannot be ignored.Adiponectin(ADP)is one of the key adipokines with various beneficial effects,including improving glucose and lipid metabolism,enhancing insulin sensitivity,reducing oxidative stress and inflammation,promoting ceramides degradation,and stimulating adipose tissue vascularity.Based on those,it can serve as a positive regulator in many metabolic syndromes,such as type 2 diabetes(T2D),cardiovascular diseases,non-alcoholic fatty liver disease(NAFLD),sarcopenia,neurodegenerative diseases,and certain cancers.Therefore,a promising therapeutic approach for treating various metabolic diseases may involve elevating ADP levels or activating ADP receptors.The modulation of ADP genes,multimerization,and secretion covers the main processes of ADP generation,providing a comprehensive orientation for the development of more appropriate therapeutic strategies.In order to have a deeper understanding of ADP,this paper will provide an all-encompassing review of ADP.

Contract Mechanism of Water Environment Regulation for Small and Medium Sized Enterprises Based on Optimal Control Theory

The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.

Dynamic regulation of the irrigation-nitrogen-biochar nexus for the synergy of yield,quality,carbon emission and resource use efficiency in tomato

Integrated water and fertilizer management is important for promoting sustainable development of facility agriculture,and biochar plays an important role in guaranteeing food production,as well as alleviating water shortages and the overuse of fertilizers.The field experiment had twelve treatments and a control(CK)trial including two irrigation amounts(I1,100%ETm;I2,60%ETm;where ETm is the maximum evapotranspiration),two nitrogen applications(N1,360 kg ha^(−1);N2,120 kg ha^(−1))and three biochar application levels(B1,60 t ha^(−1);B_(2),30 t ha^(−1)and B3,0 t ha^(−1)).A multi-objective synergistic irrigation-nitrogen-biochar application system for improving tomato yield,quality,water and nitrogen use efficiency,and greenhouse emissions was developed by integrating the techniques of experimentation and optimization.First,a coupled irrigation-nitrogen-biochar plot experiment was arranged.Then,tomato yield and fruit quality parameters were determined experimentally to establish the response relationships between irrigation-nitrogen-biochar dosage and yield,comprehensive quality of tomatoes(TCQ),irrigation water use efficiency(IWUE),partial factor productivity of nitrogen(PFPN),and net greenhouse gas emissions(NGE).Finally,a multi-objective dynamic optimization regulation model of irrigation-nitrogen-biochar resource allocation at different growth stages of tomato was constructed which was solved by the fuzzy programming method.The results showed that the application of irrigation and nitrogen to biochar promoted increase in yield,IWUE and PFPN,while it had an inhibitory effect on NGE.In addition,the optimal allocation amounts of water and fertilizer were different under different scenarios.The yield of the S1 scenario increased by 8.31%compared to the B_(1)I_(1)N_(2) treatment;TCQ of the S2 scenario increased by 5.14%compared to the B_(2)I_(2)N_(1) treatment;IWUE of the S3 scenario increased by 10.01%compared to the B1I2N2 treatment;PFPN of the S4 scenario increased by 9.35%compared to the B_(1)I_(1)N_(2) treatment;and NGE of the S5 scenario decreased by 11.23%compared to the B_(2)I1N1 treatment.The optimization model showed that the coordination of multiple objectives considering yield,TCQ,IWUE,PFPN,and NGE increased on average from 4.44 to 69.02%compared to each treatment when the irrigation-nitrogen-biochar dosage was 205.18 mm,186 kg ha^(−1)and 43.31 t ha^(−1),respectively.This study provides a guiding basis for the sustainable management of water and fertilizer in greenhouse tomato production under drip irrigation fertilization conditions.