摘要：
Hydrochar serves not only as a fuel source but also as a versatile carbon material that has found extensive application across various domains. The application performance of hydrochar, e.g., energy recovery and carbon stability, is substantially influenced by its mass yield, higher heating value (HHV), and compositions (C, H, O, N, S, and ash), so the prediction and engineering of these properties is promising. In this study, two machine learning algorithms, namely gradient boosting regression (GBR) and random forest (RF), were used to predict the hydrochar properties mentioned above. The GBR models (with test regression coefficient (R2) values of 0.87-0.98 for single-target prediction and average test R2 of 0.93 for multi-target prediction) exhibited superior predictive capabilities to the RF models (with test R2 of 0.78-0.97 for single-target and average test R2 of 0.90 for multi-target prediction). The interpretation of ML models revealed the importance ranking of features for all targets. Then, engineering hydrochar was carried out through three different optimizations to the as-built multi target prediction model: i) optimizations of HTC conditions for given biomass samples; ii) optimization of biomass mixture recipes; iii) simultaneous optimization of both biomass mixing recipes and HTC conditions.
摘要：
Dissolved organic matter (DOM) is a pivotal component of the biogeochemical cycles and can combine with metal ions through chelation or complexation. Understanding this process is crucial for tracing metal solubility, mobility, and bioavailability. Fluorescence excitation emission matrix (EEM) and parallel factor analysis (PARAFAC) has emerged as a popular tool in deciphering DOM-metal interactions. In this review, we primarily discuss the advantages of EEM-PARAFAC compared with other algorithms and its main limitations in studying DOM-metal binding, including restrictions in spectral considerations, mathematical assumptions, and experimental procedures, as well as how to overcome these constraints and shortcomings. We summarize the principles of EEM to uncover DOM-metal association, including why fluorescence gets quenched and some potential mechanisms that affect the accuracy of fluorescence quenching. Lastly, we review some significant and innovative research, including the application of 2D-COS in DOM-metal binding analysis, hoping to provide a fresh perspective for possible future hotspots of study. We argue the expansion of EEM applications to a broader range of areas related to natural organic matter. This extension would facilitate our exploration of the mobility and fate of metals in the environment.
摘要：
<bold>Background:</bold> Chlamydia is a Gram-negative obligate intracellular bacterium that is pathogenic for humans and a large variety of veterinary animal species. However, there is no continuous monitoring of chlamydia infection data in pigs in Hunan province, southern China. Therefore, in order to evaluate the seroprevalence and identify risk factors associated with Chlamydia infection in pigs within this region, a comprehensive study was conducted. <bold>Methods:</bold> A total of 3848 serum samples were collected from pigs (from farmers and companies) between May 2017 and August 2018. The presence of specific antibodies against Chlamydia was determined through the employment of the indirect hemagglutination assay (IHA). <bold>Results:</bold> The overall seroprevalence of Chlamydia was determined to be 26.90% (1038/3848, 95% confidence interval: 25.60-28.40). By employing statistical analysis using SPSS software (p < 0.05), factors such as altitude, sampling regions, and rearing systems of pigs were identified as potential risk factors for Chlamydia infection. <bold>Conclusion:</bold> These findings elucidate a substantial prevalence of Chlamydia in pigs within the mountainous region of Hunan province, southern China, thereby highlighting a potential risk to human health. These results underscore the need for proactive measures and targeted interventions to mitigate the transmission of Chlamydia in porcine populations, safeguarding both animal welfare and public health.
摘要：
center dot Sugar transporter proteins (STPs) play critical roles in regulating plant stress tolerance, growth, and development. However, the role of STPs in regulating crop yield is poorly understood.center dot This study elucidates the mechanism by which knockout of the sugar transporter OsSTP15 enhances grain yield via increasing the tiller number in rice.center dot We found that OsSTP15 is specifically expressed in the shoot base and vascular bundle sheath of seedlings and encodes a plasma membrane-localized high-affinity glucose efflux transporter. OsSTP15 knockout enhanced sucrose and trehalose-6-phosphate (Tre6P) synthesis in leaves and improved sucrose transport to the shoot base by inducing the expression of sucrose transporters. Higher glucose, sucrose, and Tre6P contents were observed at the shoot base of stp15 plants. Transcriptome and metabolome analyses of the shoot base demonstrated that OsSTP15 knockout upregulated the expression of cytokinin (CK) synthesis-and signaling pathway-related genes and increased CK levels.center dot These findings suggest that OsSTP15 knockout represses glucose export from the cytoplasm and simultaneously enhances sugar transport from source leaves to the shoot base by promoting the synthesis of sucrose and Tre6P in leaves. Subsequent accumulation of glucose, sucrose, and Tre6P in the shoot base promotes tillering by stimulating the CK signaling pathway.
作者：
Su, Zhaohong;Hu, Shiyu;Xu, Yanqun;Liu, Ju;Liang, Pengcheng;...
期刊：
NEW JOURNAL OF CHEMISTRY,2024年 ISSN：1144-0546
通讯作者：
Zhang, Wei;Fan, DQ
作者机构：
[Su, Zhaohong; Zhang, Wei; Fan, Duoqing; Xu, Yanqun] R&D Ctr China Tobacco Yunnan Ind Co Ltd, Yunnan Key Lab Tobacco Chem, Kunming 650231, Peoples R China.;[Su, Zhaohong; Hu, Shiyu; Peng, Yi; Liu, Ju; Liang, Pengcheng; Cao, Qinyi; Wang, Jiaqi] Hunan Agr Univ, Coll Chem & Mat Sci, Changsha 410128, Peoples R China.
通讯机构：
[Zhang, W; Fan, DQ ] R;R&D Ctr China Tobacco Yunnan Ind Co Ltd, Yunnan Key Lab Tobacco Chem, Kunming 650231, Peoples R China.
摘要：
"One stone-three birds": we developed a smart portable electrochemical sensor based on electrodeposited ferrocene-functionalized multiwalled carbon nanotubes (FC-MWCNTs) for the in vitro and in vivo detection of nicotine (NIC) in tobacco samples. The "one stone" was the establishment of the standard curve for the concentrationof NIC based on the oxidation of NIC itself as a single signal on the FC-MWCNT modified electrode or to use the FC-MWCNTs as a ratiometric probe to establish the standard curve for the NIC concentration on the modified electrode. The "three birds" were: (1) to broaden the application of the Nernst equation (the correlation between the potential and the concentration); (2) to use the function of materials modified by electrodeposition from multiple perspectives; and (3) to use a portable electrochemical workstation with a smartphone as an intelligent electrochemical sensing platform for NIC detection. The Tyndall effect, scanning electron microscopy, X-ray diffraction, UV-vis spectrophotometry, Fourier transform infrared spectrophotometry, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectrometry were used to characterize the properties of the sensor materials. The effects of the electrochemical properties, such as the electrochemical active area, the charge transfer resistance and the adsorbed charge were investigated. The sensor was then studied by differential pulse voltammetry. Under the optimized conditions, the detection range of NIC was 60-1000 mu mol L-1 and the detection limit was 4.25 mu mol L-1 in the single-signal mode and 0.44 mu mol L-1 in the ratiometric signal mode. The sensor can be used for the rapid and accurate detection of NIC in tobacco samples, both in vitro and in vivo.
摘要：
In this study, the speciation, leachability, phytoaccessibility, and environmental risks of heavy metals (Cd, Zn, and Cu) during liquefaction of contaminated peanut straw in ethanol at different temperatures (220, 260, 300, 340, and 380 degrees C) were comprehensively investigated. The results showed that elevated temperatures facilitated heavy metal accumulation in the biochar. The acid-soluble/exchangeable and reducible fraction percentages of heavy metals were substantially reduced in the biochar after liquefaction as the temperature increased, and the oxidizable fraction became the dominant heavy metal fraction, accounting for 44.14-78.67%. Furthermore, although an excessively high liquefaction temperature (380 degrees C) increased the residual fraction percentages of Zn and Cu, it was detrimental to Cd immobilization. The acid-soluble/exchangeable Cd in the contaminated peanut straw readily migrates to the bio-oil during liquefaction, with the highest concentration of 1.60 mg/kg at 260 degrees C liquefaction temperature, whereas Zn and Cu are predominantly bound to the unexchangeable fraction in the bio-oil. Liquefaction inhibited heavy metal leachability and phytoaccessibility in biochar, the lowest extraction rates of Cd, Zn, and Cu were 0.71%, 1.66% and 0.95% by diethylenetriamine pentaacetic acid, respectively. However, the leaching and extraction concentrations increased when the temperature was raised to 380 degrees C. Additionally, heavy metal risk was reduced from medium and high risk to no and low risk. In summary, liquefaction reduces heavy metal toxicity and the risks associated with contaminated peanut straw, and a temperature range of 300-340 degrees C for ethanol liquefaction can be considered optimal for stabilizing heavy metals.
关键词：
lipid metabolism;machine learning;melatonin;meta-analysis;obesity mice;obesity rat
摘要：
Melatonin appears to be a promising supplement for obesity treatment. The antiobesity effects of melatonin on obese rodents are influenced by various factors, including the species, sex, the dosage of melatonin, treatment duration, administration via, daily treatment time, and initial body weight (IBW). Therefore, we conducted a meta-analysis and machine learning study to evaluate the antiobesity effect of melatonin on obese mice or rats from 31 publications. The results showed that melatonin significantly reduced body weight, serum glucose (GLU), triglycerides (TGs), low-density lipoprotein (LDL), and cholesterol (TC) levels in obese mice or rats but increased high-density lipoprotein (HDL) levels. Melatonin showed a slight positive effect on clock-related genes, although the number of studies was limited. Meta-regression analysis and machine learning indicated that the dosage of melatonin was the primary factor influencing body weight, with higher melatonin dosages leading to a stronger weight reduction effect. Together, male obese C57BL/6 mice and Sprague-Dawley rats with an IBW of 100-200 g showed better body weight reduction when supplemented with a dose of 10-30 mg/kg melatonin administered at night via injection for 5-8weeks.
摘要：
Biological nitrogen fixation and nitrification inhibitor applications contribute to improving soil nitrogen (N) availability, however, free-living N fixation affected by nitrification inhibitors has not been effectively evaluated in soils under different weed management methods. In this study, the effects of the nitrification inhibitors dicyandiamide (DCD) and 3, 4-dimethylpyrazole phosphate (DMPP) on the nitrogenase, nifH gene，and diazotrophic communities in soils under different weed management methods (AMB, weeds growth without mowing or glyphosate spraying; GS, glyphosate spraying; MSG, mowing and removing weeds and glyphosate spraying; and WM, mowing aboveground weeds) were investigated. Compared to the control counterparts, the DCD application decreased soil nitrogenase activity and nifH gene abundance by 4.5% and 37.9%, respectively, under the GS management method, and the DMPP application reduced soil nitrogenase activity by 20.4% and reduced the nifH gene abundance by 83.4% under the MSG management method. The application of nitrification inhibitors significantly elevated soil NH(4)(+)-N contents but decreased NO(3)(-)-N contents, which had adverse impacts on soil nifH gene abundance and nitrogenase activity. The nifH gene abundances were also negatively impacted by dissolved organic N and Geobacter but were positively affected by available phosphorus and diazotrophic community structures. Nitrification inhibitors significantly inhibited Methylocella but stimulated Rhizobiales and affected soil diazotrophic communities. The nitrification inhibitors DCD and DMPP significantly altered soil diazotrophic community structures, but weed management outweighed nitrification inhibitors in reshaping soil diazotrophic community structures. The non-targeted effects of the nitrification inhibitors DMPP and DCD on soil free-living N fixation were substantially influenced by the weed management methods.
摘要：
Previous epidemiological and animal studies have showed the lipid metabolic disruption of antimicrobial tri-clocarban (TCC) and triclosan (TCS). However, the present in vivo researches were mainly devoted to the hepatic lipid metabolism, while the evidence about the impacts of TCC/TCS on the adipose tissue is very limited and the potential mechanism is unclear, especially the molecular initiation events. Moreover, little is known about the toxic difference between TCC and TCS. This study aimed to demonstrate the differential adipogenic activity of TCC/TCS as well as the potential molecular mechanism via peroxisome proliferator-activated receptors (PPAR alpha/ beta/gamma). The in vitro experiment based on 3T3-L1 cells showed that TCC/TCS promoted the differentiation of preadipocytes into mature adipocytes at nanomolar to micromolar concentrations, which was approach to their human exposure levels. We revealed for the first time by reporter gene assay that TCC could activate three PPARs signaling pathways in a concentration-dependent manner, while TCS only activate PPAR beta. The molecular docking strategy was applied to simulate the interactions of TCC/TCS with PPARs, which explained well the different PPARs activities between TCC and TCS. TCC up-regulated the mRNA expression of three PPARs, but TCS only up-regulated PPAR beta and PPAR gamma significantly. Meanwhile, TCC/TCS also promoted the expression of adi-pogenic genes targeted by PPARs to different extent. The cellular and simulating studies demonstrated that TCC exerted higher adipogenic effects and PPARs activities than TCS. Our mice in vivo experiment showed that TCC could lead to adipocyte size increase, adipocyte lipid accumulation growing, fat weight and body weight gain at human-related exposure levels, and high fat diet exacerbated these effects. Moreover, male mice tended to be more susceptible to TCC induced obesogenic effect than female mice. This work highlights the potential obe-sogenic risks of TCC/TCS via PPARs signaling pathways, and TCC deserves more concerns for its higher activity.
摘要：
Maize (Zea mays) cultivation is strongly affected by both abiotic and biotic stress, leading to reduced growth and productivity. It has recently become clear that regulators of plant stress responses, including the phytohormones abscisic acid (ABA), ethylene (ET), and jasmonic acid (JA), together with reactive oxygen species (ROS), shape plant growth and development. Beyond their well established functions in stress responses, these molecules play crucial roles in balancing growth and defense, which must be finely tuned to achieve high yields in crops while maintaining some level of defense. In this review, we provide an in-depth analysis of recent research on the developmental functions of stress regulators, focusing specifically on maize. By unraveling the contributions of these regulators to maize development, we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.
关键词：
Dongting Lake area;Ecological environment;Zoning control;Influencing factors;ecological restoration
摘要：
IntroductionProtecting the ecosystem of the Dongting Lake area is of utmost importance for maintaining ecological balance and achieving human well-being.MethodsThis study identifies the key factors influencing the remote sensing based ecological index (RESI) in the Dongting Lake area based on the spatial and temporal evolution characteristics of the RESI and environmental changes and anthropogenic disturbance factors. The priority zoning for ecological restoration was delineated in combination with the anthropogenic composite index (ACI). By exploring the influence of anthropogenic disturbances on RESI, the zoning locations were determined using spatial statistics and linear regression methods.ResultsThe overall RESI of the Dongting Lake area showed a decline from 2001 to 2020, with the mean value decreasing from 0.52 to 0.48. High-quality zones were mainly located in mountainous and forested areas, while low-quality zones were mainly distributed in more developed cities in the east urban area. Anthropogenic factors were the main reasons for the decline in the ecological environment, while natural factors showed a positive correlation with RESI. Based on the RESI and ACI, four ecological control zones (H-H, H-L, L-H, and L-L) were delineated, which accounted for a total of 45.66% of the Dongting Lake area. Among them, 3.91% required immediate control and management, while 17.80% required artificial maintenance. This study explores the influencing factors and mechanisms of the ecological environment quality in the Dongting Lake area, and explores the effective spatial paths for the implementation of ecological restoration zoning control and differentiated restoration strategies in the Dongting Lake area.DiscussionThis study provides a scientific basis for mitigating ecological and environmental problems in the Dongting Lake area, and provides a reference for ecological restoration and regulation and the realization of sustainable development goals in China and global regions with complex environmental problems.
摘要：
Neither chemical nor physical adsorption play well in heavy metals remediation in acid soil due to the competing behavior of abundant protons, where stable chelators that can be reused are of significant demand. Herein, biochar with abundant nitro and carboxyl groups is prepared, which can be assembled into self-supporting electrode. Under the catalyzation of electricity, the surface decorated -NO2 on the biochar can be in situ transformed into -NH2. Combined with the carboxyl group that attached on the same carbon atom, a special alpha-amino acid-like structure modified biochar (alpha-AC@BC) can be successfully constructed. Due to the strong affinity between the alpha-amino acid-like ligand and heavy metals, this alpha-AC@BC exhibits high removal efficiencies of 83.41%, 80.94%, 92.54% and 77.05% for available copper, cadmium, lead and zinc respectively, even in a strong acid soil with low pH of 4. After four adsorption-desorption cycles, the alpha-AC@BC could still eliminate 83.88% of copper. The high adsorption energy among -NH2, -COOH and heavy metals (-2.99 eV for copper, -1.90 eV for lead, -1.30 eV for zinc and -0.91 eV for cadmium) could form steady coordination structure to guarantee a highly practical application potential of alpha-AC@BC in strong acid soil. This study provides a novel concept for the decontamination of multiple heavy metal polluted acid soil.
摘要：
Decarbonizing innovation plays a significant role in curbing carbon emissions, allowing a firm to meet governmental environmental regulations and gain a competitive edge. However, innovation uncertainty and technology spillovers deter a firm from doing so. This paper studies the issue of firms' decarbonizing innovation investment in a competing market under carbon emission regulation. We construct game-theoretic models of two competing supply chains, each consisting of a manufacturer and a retailer. Either manufacturer has the opportunity to invest in decarbonizing innovation, but she may fail in the end. According to the manufacturers' innovation investment decisions, several subcases with no investment, unilateral decarbonizing investment, and bilateral decarbonizing investment are explored. The results show that when both manufacturers have a strong absorbing capacity, neither invests in decarbonizing innovation; when they are weak in absorbing external technology, bilateral decarbonizing investment exists. The findings also reveal that unilateral decarboning investment dominates when the probability of innovation success is moderate. There is a case in which both manufacturers do not conduct decarbonizing investment, although the probability of innovation success is high. In addition, we also find that a retailer can make more profit if his upstream manufacturer invests in decarbonizing innovation than in the no-investment scenario. However, he is harmed by bilateral decarbonizing investment if his upstream manufacturer is weak in absorbing external knowledge relative to the case of unilateral decarbonizing investment. Our results elucidated how technology spillovers and the stochastic nature of innovation affect a manufacturer's decarbonizing innovation investment strategy in a competitive environment.
期刊：
Colloids and Surfaces A: Physicochemical and Engineering Aspects,2024年682:132863 ISSN：0927-7757
通讯作者：
Huang, W;Zhu, KM
作者机构：
[Huang, Wei; Yu, Peng; Tan, Juan; Wang, Zhiguo; Zhang, Chun; Wang, Qiongchao] Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Hunan, Peoples R China.;[Zhu, Keming] Xian Univ Technol, Sch Mech & Precis Instrument Engn, Xian 710048, Peoples R China.;[Peng, Chao] Chinese Acad Sci, Multiscale Crystal Mat Res Ctr, Shenzhen Inst Adv Technol, Shenzhen 518055, Guangdong, Peoples R China.;[Xiao, Xinxin] Aalborg Univ, Dept Chem & Biosci, Fredrik Bajers Vej 7H, DK-9220 Aalborg, Denmark.
通讯机构：
[Huang, W ] H;[Zhu, KM ] X;Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Hunan, Peoples R China.;Xian Univ Technol, Sch Mech & Precis Instrument Engn, Xian 710048, Peoples R China.
关键词：
Zero -valent iron;Coconut shell derived carbon;Long-life Cr(VI) removal;DFT computation;Enhanced electron transfer pathway
摘要：
Immobilizing zero-valent iron (ZVI) with modulated structure and good dispersibility is of great potential for the elimination of Cr(VI) in contaminated water or soil, but exploring how the support facilitate and prolong the removal of Cr(VI) by ZVI in terms of the electron transfer is inadequate. Coconut shell derived carbon could be promising for Cr(VI) removal due to the features of large specific surface area and porosity. Accordingly, ZVI particles are dispersed into low-cost and scalable coconut shell derived carbon (CSC) matrix uniformly in this study, with enhanced contact area and interaction of ZVI with CSC for effective elimination of Cr(VI). The optimal ZVI/CSC-0.65 demonstrates an equilibrium adsorption capacity of 307.8 mg/g and long-life Cr(VI) cleanup ability over 144 h. The interface reaction mechanism between ZVI/CSC and Cr contaminant have been systematically studied by various techniques including XRD, SEM/TEM and XPS, etc. ZVI's aggregation and passivation in ZVI/CSC-0.65 have been greatly alleviated. Further analysis by Tafel polarization and DFT computation suggests ZVI/CSC-0.65 undergoes fast electron transfer, with a much higher adsorption energy (-2.90 eV) than that of pristine ZVI (-0.63 eV). The Bader charge analysis demonstrates that there is 4.40 |e| charge transferring the ZVI to the carbon, encouraging the Cr(VI) adsorption. A micro-battery based mechanism is proposed which provides an additional electron transfer pathway in ZVI/CSC for long-term Cr(VI) removal.
摘要：
Ticks are blood-sucking ectoparasites that secrete immunomodulatory substances in saliva to hosts during engorging. Cystatins, a tick salivary protein and natural inhibitor of Cathepsins, are attracting growing interest globally because of the immunosuppressive activities and the feasibility as an antigen for developing anti-tick vaccines. This review outlines the classification and the structure of tick Cystatins, and focuses on the anti-inflammatory effects and molecular mechanisms. Tick Cystatins can be divided into four families based on structures and cystatin 1 and cystatin 2 are the most abundant. They are injected into hosts during blood feeding and effectively mitigate the host inflammatory response. Mechanically, tick Cystatins exert anti-inflammatory properties through the inhibition of TLR-NF-κb, JAK-STAT and p38 MAPK signaling pathways. Further investigations are crucial to confirm the reduction of inflammation in other cell types like neutrophils and mast cells, and fully elucidate the underlying mechanism (like the structural mechanism) to make Cystatin a potential candidate for the development of novel anti-inflammation agents.
摘要：
Microplastics (MPs) have attracted much attention in recent years, due to the difficulty of degradation and threats to ecological systems and humans. Based on the analysis of 1429 articles on MPs in soil, we found that we know little about the behavior and fate of manure-born MPs from the livestock and poultry production systems to agriculture soils. This review summarizes the analytical methods for sampling, separation, and identification and the occurrence of MPs in livestock and poultry manure, mainly based on 7 surveys related to manure-born MPs. Then, the sources, fate, and environmental risks of MPs in livestock and poultry manure are discussed. MPs, heavy metals, pathogens, antibiotic resistance genes, and persistent organic pollutants are common pollutants in livestock and poultry manure. Worse, manure-born MPs will become smaller, rougher, and more numerous and could easily form more toxic compound pollution after complicated processes of manure treatment, which seriously threatens agricultural soil safety. Finally, an outlook is offered for future research. We hope this article to attract attention to the risks of MPs in livestock and poultry manure and provide a reference for future research.
作者机构：
[Xia, Yongqiu; Han, Haojie; Li, Xiaohan; Yan, Xiaoyuan; Yan, Xing] Chinese Acad Sci, Inst Soil Sci, State Key Lab Soil & Sustainable Agr, Changshu Natl Agroecosyst Observat & Res Stn, Nanjing 210008, Peoples R China.;[Han, Haojie; Li, Xiaohan; Yan, Xing] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Wen, Jiong] Yueyang Agr Res Acad, Yueyang 414215, Peoples R China.;[Rong, Xiangmin] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Peoples R China.
通讯机构：
[Xia, YQ ] C;Chinese Acad Sci, Inst Soil Sci, State Key Lab Soil & Sustainable Agr, Changshu Natl Agroecosyst Observat & Res Stn, Nanjing 210008, Peoples R China.
关键词：
N removal kinetics;Small water bodies;Dissolved organic carbon;Intensive agricultural areas
摘要：
Small water bodies are extensively distributed and play critical roles in nitrogen (N) removal, primarily through sediment denitrification. However, our comprehension understanding of the N removal rate constant in these systems, particularly within the first-order kinetics model, remains limited. To address this gap, a one-year field study was conducted to investigate the N removal rate and N removal rate constant in various small water bodies within a typical intensive agricultural area. We observed a decrease in N removal rates in the downstream direction, from ditches to downstream ponds and streams, potentially due to upstream water bodies receiving higher nutrient inputs. Moreover, our findings revealed that the N removal process in small water bodies generally follows a first-order kinetics reaction model, with the N removal rate constant varying from 0.22 d-1 in streams and 0.48 d-1 in vegetated ditches. Both water dissolved organic carbon (DOC) and dissolved oxygen (DO) concentrations collectively influenced the N removal rate constants. By leveraging the relationship between the N removal rate constant and these environmental factors, we further estimated that, on average, small water bodies remove 68% of the N loading in the Dongting Lake Basin. We recommend implementing artificial management measures, such as vegetation, to enhance the N removal capacity of water bodies. However, the caution must be exercised in measures like concrete linings in ditches, as they can hinder N removal. These findings not only offer methods for estimating N removal in small water bodies, but also provide an insight into enhancing the N removal capacity of these systems to effectively mitigate non-point N pollution.
摘要：
Cytochrome P450s play critical roles in the metabolic resistance of insecticides in insects. Previous findings showed that enhanced P450 activity was an important mechanism mediating indoxacarb resistance, and multiple P450 genes were upregulated in indoxacarb resistant strains of Spodoptera litura. However, the functions of these P450 genes in insecticide resistance remain unknown. Here, the P450 inhibitor PBO effectively decreased the resistance of S. litura to indoxacarb. Ten upregulated P450 genes were characterized, all of which were overexpressed in response to indoxacarb induction. Knockdown of nine P450 genes decreased cell viability against indoxacarb, and further silencing of three genes (CYP339A1, CYP340G2, CYP321A19) in larvae enhanced the sensitivity to indoxacarb. Transgenic overexpression of these three genes increased resistance to indoxacarb in Drosophila melanogaster. Moreover, molecular modeling and docking predicted that these three P450 proteins could bind tightly to indoxacarb and N-decarbomethoxylated metabolite (DCJW). Interestingly, these three P450 genes may also mediate cross-resistance to chlorantraniliprole, λ-cyhalothrin and imidacloprid. Additionally, heterologous expression and metabolic assays confirmed that three recombinant P450s could effectively metabolize indoxacarb and DCJW. This study strongly demonstrates that multiple overexpressed mitochondrial and microsomal P450 genes were involved in insecticide resistance in S. litura.
摘要：
Temperature is an important environmental factor affecting plant color, and different temperatures have distinct effects on plant leaf color changes. In order to explore the effects of different temperatures on plant color, we measured the physiological characteristics, transcriptome, and metabolome of the pepper leaf yellowing mutant yl1 and its wild type 6421 under different temperature conditions. Results showed that high temperature treatment compared with the normal temperature treatment significantly increased the contents of chlorophyll a, chlorophyll b, and carotenoids in yl1. At the same time, a total of 28 carotenoid pathway metabolites were detected under three temperature conditions. Among them, beta-carotene, zeaxanthin, violaxanthin, neoxanthin, lutein, and antheraxanthin were higher in pepper leaves. The expression levels of ZEP, bHLH104, MYB1R1, and MYB1R1-like were significantly increased under high temperature compared with under normal temperature, while the expression level of crtZ-2 and VDE were significantly decreased. Co-expression network analysis showed that VDE was positively correlated with the bHLH71-like and negatively correlated with MYB1R1-like and bHLH104. These results led to significant differences in the amount of zeaxanthin and antheraxanthin accumulated at different temperatures, which may be the reason for the color change of pepper leaves. However, under the normal and low temperature treatment, it is the opposite, resulting in leaf yellowing. This study provides a reference for further research on the mechanism underlying the impact of temperature on carotenoid metabolism in pepper leaves.
