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Organophosphates ï¼OPEsï¼ are widely used as flame retardants and additives and thus are commonly detected in the environment. In order to explore their environmental behavior, the concentrations of 13 OPEs in the surface water and sediment of Dongting Lake were analyzed using UPLC-MS/MS. The results showed that 11 OPEs were detected, with detection frequencies of 5.26%-100% and 58.3%-100%, and the concentrations of OPEs were 2.06-2 028 ng·L-1 and 19.6-2 232 ng·g-1 in water and sediment, respectively. Overall, contamination concentrations were ranked in descending order as followsï¼ inflowing rivers, lake area, and outlet, whereas the spatial distribution of concentrations in sediment was inversely proportional to hydrodynamics. The concentration of OPEs in Dongting Lake was at a high level compared with that of domestic and foreign lakes. Among the detected 11 OPEs, tri-iso-butyl phosphate ï¼TnBPï¼ and ï¼TiBPï¼ were dominant in water, accounting for 52.3% and 22.4% of ∑OPEs, respectively. TPhP was the dominant OPEs in sediment, accounting for 31.2% of ∑OPEs. The correlation and principal component analysis indicated that OPEs pollution in Dongting Lake was mainly affected by industrial production emissions, fishery aquaculture, and atmospheric deposition. The assessment results of the risk entropy showed that most of the detected OPEs in water had relatively low ecological risks, whereas the ecological risk of 2-ethylhexyl diphenyl phosphate ï¼EHDPPï¼ at some sampling points requires further attention.
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Objective: Chronological age (CAge), biological age (BAge), and accelerated age (AAge) are all important for aging-related diseases. CAge is a known risk factor for benign prostatic hyperplasia (BPH); However, the evidence of association of BAge and AAge with BPH is limited. This study aimed to evaluate the association of CAge, Bage, and AAge with BPH in a large prospective cohort. Method: A total of 135,933 males without BPH at enrolment were extracted from the UK biobank. We calculated three BAge measures (Klemera-Doubal method, KDM; PhenoAge; homeostatic dysregulation, HD) based on 16 biomarkers. Additionally, we calculated KDM-BAge and PhenoAge-BAge measures based on the Levine method. The KDM-AAge and PhenoAge-AAge were assessed by the difference between CAge and BAge and were standardized (mean = 0 and standard deviation [SD] = 1). Cox proportional hazard models were applied to assess the associations of CAge, Bage, and AAge with incident BPH risk. Results: During a median follow-up of 13.150 years, 11,811 (8.690%) incident BPH were identified. Advanced CAge and BAge measures were associated with an increased risk of BPH, showing threshold effects at a later age (all P for nonlinearity <0.001). Nonlinear relationships between AAge measures and risk of BPH were also found for KDM-AAge (P = 0.041) and PhenoAge-AAge (P = 0.020). Compared to the balance comparison group (-1 SD < AAge < 1 SD), the accelerated aging group (AAge > 2 SD) had a significantly elevated BPH risk with hazard ratio (HR) of 1.115 (95% CI, 1.000-1.223) for KDM-AAge and 1.180 (95% CI, 1.068-1.303) for PhenoAge-AAge, respectively. For PhenoAge-AAge, subgroup analysis of the accelerated aging group showed an increased HR of 1.904 (95% CI, 1.374-2.639) in males with CAge <50 years and 1.233 (95% CI, 1.088-1.397) in those having testosterone levels <12 nmol/L. Moreover, AAge-associated risk of BPH was independent of and additive to genetic risk. Conclusions: Biological aging is an independent and modifiable risk factor for BPH. We suggest performing active health interventions to slow biological aging, which will help mitigate the progression of prostate aging and further reduce the burden of BPH.
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Bacterial wilt of tomato caused by Ralstonia solanacearum is a critical soilborne disease that drastically reduces yield. In the current study, an endophytic strain NEAU-CP5 with strong antagonistic activity against R. solanacearum was isolated from tomato seeds and characterized. The strain was identified as Bacillus velezensis based on 16S rRNA gene and whole genome sequence analysis. NEAU-CP5 can secrete amylase, protease, and cellulase, and also produce known antibacterial metabolites, including cyclo (leucylprolyl), cyclo (phenylalanyl-prolyl), cyclo (Pro-Gly), 3-benzyl-2,5-piperazinedione, pentadecanoic acid, eicosane, 2-methyoic acid, isovaleric acid, dibuty phthalate, and esters of fatty acids (HFDU), which may be responsible for its strong antibacterial activity. Fourteen gene clusters associated with antibacterial properties were also identified in the whole genome sequence of NEAU-CP5. Pot experiment demonstrated that the application of 108 CFU/mL NEAU-CP5 on tomato plants significantly reduced the incidence of tomato bacterial wilt by 68.36 ± 1.67 %. NEAU-CP5 also increased the activity of defense-related enzymes (CAT, POD, PPO, SOD, and PAL) in tomato plants. This is the first report of an effective control of bacterial wilt on tomato plants by B. velezensis and highlights the potential of NEAU-CP5 as a potential biocontrol agent for the management of tomato bacterial wilt.
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Bacillus , Filogenia , Enfermedades de las Plantas , ARN Ribosómico 16S , Ralstonia solanacearum , Semillas , Solanum lycopersicum , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/microbiología , Ralstonia solanacearum/genética , Bacillus/aislamiento & purificación , Bacillus/genética , Bacillus/metabolismo , Bacillus/clasificación , Semillas/microbiología , ARN Ribosómico 16S/genética , Antibacterianos/farmacología , Antibacterianos/metabolismo , Endófitos/aislamiento & purificación , Endófitos/genética , Endófitos/metabolismo , Genoma Bacteriano , Secuenciación Completa del Genoma , Antibiosis , Familia de Multigenes , Amilasas/metabolismo , Amilasas/genética , ADN Bacteriano/genéticaRESUMEN
An aerobic, non-motile, Gram-stain-positive bacterium, designated strain NEAU-Y5T, was isolated from a soil sample collected from Northeast Agricultural University, Heilongjiang province. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-Y5T belonged to the genus and showed high 16S rRNA sequence similarity to Isoptericola variabilis (98.9â%), Isoptericola nanjingensis (98.9â%), Isoptericola cucumis (98.5â%), Isoptericola hypogeus (98.5â%), Isoptericola dokdonensis (98.5â%), Isoptericola jiangsuensis (98.3â%), and Isoptericola halalbus (98.1â%), followed by other members of the genus Isoptericola (<98â%), and phylogenetically clustered with I. dokdonensis and I. jiangsuensis. Strain NEAU-Y5T was found to grow at 4-40â°C (optimum, 28â°C), pH 6.0-12.0 (optimum, pH 7.0), and tolerated 0-6â% NaCl (w/v). The cell-wall peptidoglycan type was l-Lys-d-Asp. The whole-cell hydrolysates contained glucose, galactose, and ribose. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, and glucosamine unknown phospholipid. Major fatty acids were anteiso-C15â:â0 and anteiso-C17â:â0. The predominant menaquinone was MK-9(H4). The DNA G+C content was 73.4âmol%. The digital DNA-DNA hybridization and average nucleotide identity values between strain NEAU-Y5T and the type strains of the genus Isoptericola ranged from 18.6 to 23.5â% and from 77.3 to 81.6â%, respectively. Based on morphological, physiological, chemotaxonomic, and phylogenetic data, as well as digital DNA-DNA hybridization and average nucleotide identity values, the novel strain NEAU-Y5T could be differentiated from its closest relatives. Therefore, the strain represents a novel species of the genus Isoptericola, for which the name Isoptericola luteus sp. nov. is proposed. The type strain is NEAU-Y5T (=CCTCC AA 2019087T=DSM 110637T).
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Actinomycetales , Suelo , Humanos , Filogenia , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Bacterias , NucleótidosRESUMEN
BACKGROUND: The involvement of quality of life as the UNAIDS fourth 90 target to monitor the global HIV response highlighted the development of patient-reported outcome (PRO) measures to help address the holistic needs of people living with HIV/AIDS (PLWHA) beyond viral suppression. This study developed and tested preliminary measurement properties of a new patient-reported outcome (PROHIV-OLD) measure designed specifically to capture influences of HIV on patients aged 50 and older in China. METHODS: Ninety-three older people living with HIV/AIDS (PLWHA) were interviewed to solicit items and two rounds of patient cognitive interviews were conducted to modify the content and wording of the initial items. A validation study was then conducted to refine the initial instrument and evaluate measurement properties. Patients were recruited between February 2021 and November 2021, and followed six months later after the first investigation. Classical test theory (CTT) and item response theory (IRT) were used to select items using the baseline data. The follow-up data were used to evaluate the measurement properties of the final instrument. RESULTS: A total of 600 patients were recruited at the baseline. Of the 485 patients who completed the follow-up investigation, 483 were included in the validation sample. The final scale of PROHIV-OLD contained 25 items describing five dimensions (physical symptoms, mental status, illness perception, family relationship, and treatment). All the PROHIV-OLD dimensions had satisfactory reliability with Cronbach's alpha coefficient, McDonald's ω, and composite reliability of each dimension being all higher than 0.85. Most dimensions met the test-retest reliability standard except for the physical symptoms dimension (ICC = 0.64). Confirmatory factor analysis supported the structural validity of the final scale, and the model fit index satisfied the criterion. The correlations between dimensions of PROHIV-OLD and MOS-HIV met hypotheses in general. Significant differences on scores of the PROHIV-OLD were found between demographic and clinical subgroups, supporting known-groups validity. CONCLUSIONS: The PROHIV-OLD was found to have good feasibility, reliability and validity for evaluating health outcome of Chinese older PLWHA. Other measurement properties such as responsiveness and interpretability will be further examined.
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Síndrome de Inmunodeficiencia Adquirida , Calidad de Vida , Humanos , Persona de Mediana Edad , Anciano , Calidad de Vida/psicología , Encuestas y Cuestionarios , Reproducibilidad de los Resultados , Medición de Resultados Informados por el Paciente , China , Psicometría/métodosRESUMEN
Algal blooms in lakes have been a challenging environmental issue globally under the dual influence of human activity and climate change. Considerable progress has been made in the study of phytoplankton dynamics in lakes; The long-term in situ evolution of dominant bloom-forming cyanobacteria in meso-eutrophic plateau lakes, however, lacks systematic research. Here, the monthly parameters from 12 sampling sites during the period of 1997-2022 were utilized to investigate the underlying mechanisms driving the superiority of bloom-forming cyanobacteria in Erhai, a representative meso-eutrophic plateau lake. The findings indicate that global warming will intensify the risk of cynaobacteria blooms, prolong Microcystis blooms in autumn to winter or even into the following year, and increase the superiority of filamentous Planktothrix and Cylindrospermum in summer and autumn. High RUETN (1.52 Biomass/TN, 0.95-3.04 times higher than other species) under N limitation (TN < 0.5 mg/L, TN/TP < 22.6) in the meso-eutrophic Lake Erhai facilitates the superiority of Dolichospermum. High RUETP (43.8 Biomass/TP, 2.1-10.2 times higher than others) in TP of 0.03-0.05 mg/L promotes the superiority of Planktothrix and Cylindrospermum. We provided a novel insight into the formation of Planktothrix and Cylindrospermum superiority in meso-eutrophic plateau lake with low TP (0.005-0.07 mg/L), which is mainly influenced by warming, high RUETP and their vertical migration characteristics. Therefore, we posit that although the obvious improvement of lake water quality is not directly proportional to the control efficacy of cyanobacterial blooms, the evolutionary shift in cyanobacteria population structure from Microcystis, which thrives under high nitrogen and phosphorus conditions, to filamentous cyanobacteria adapted to low nitrogen and phosphorus levels may serve as a significant indicator of water quality amelioration. Therefore, we suggest that the risk of filamentous cyanobacteria blooms in the meso-eutrophic plateau lake should be given attention, particularly in light of improving water quality and global warming, to ensure drinking water safety.
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Cianobacterias , Eutrofización , Lagos , Temperatura , Lagos/microbiología , Lagos/química , China , Monitoreo del Ambiente , Nitrógeno/análisis , Fitoplancton , Cambio Climático , Estaciones del Año , Fósforo/análisis , Nutrientes/análisis , Calentamiento GlobalRESUMEN
OBJECTIVE: Reward anticipation is important for future decision-making, possibly due to re-evaluation of prior decisions. However, the exact relationship between reward anticipation and prior effort-expenditure decision-making, and its neural substrates are unknown. METHOD: Thirty-three healthy participants underwent fMRI scanning while performing the Effort-based Pleasure Experience Task (E-pet). Participants were required to make effort-expenditure decisions and anticipate the reward. RESULTS: We found that stronger anticipatory activation at the posterior cingulate cortex was correlated with slower reaction time while making decisions with a high-probability of reward. Moreover, the substantia nigra was significantly activated in the prior decision-making phase, and involved in reward-anticipation in view of its strengthened functional connectivity with the mammillary body and the putamen in trial conditions with a high probability of reward. CONCLUSIONS: These findings support the role of reward anticipation in re-evaluating decisions based on the brain-behaviour correlation. Moreover, the study revealed the neural interaction between reward anticipation and decision-making.
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Anticipación Psicológica , Toma de Decisiones , Imagen por Resonancia Magnética , Tiempo de Reacción , Recompensa , Humanos , Masculino , Toma de Decisiones/fisiología , Anticipación Psicológica/fisiología , Femenino , Adulto Joven , Adulto , Tiempo de Reacción/fisiología , Giro del Cíngulo/fisiología , Giro del Cíngulo/diagnóstico por imagen , Mapeo Encefálico , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Sustancia Negra/fisiología , Sustancia Negra/diagnóstico por imagenRESUMEN
Aberrant autophagy could promote cancer cells to survive and proliferate in prostate cancer (PCa). LncRNAs play key roles in autophagy regulatory network. We established a prognostic model, which autophagy-related lncRNAs (au-lncRNAs) were used as biomarkers to predict prognosis of individuals with PCa. Depending on au-lncRNAs from the Cancer Genome Atlas and the Human Autophagy Database, a risk score model was created. To evaluate the prediction accuracy, the calibration, Kaplan-Meier, and receiver operating characteristic curves were used. To clarify the biological function, gene set enrichment analyses (GSEA) were performed. Quantitative real-time PCR (qRT-PCR) was employed to determine the au-lncRNAs expression in PCa cell lines and healthy prostate cells for further confirmation. We identified five au-lncRNAs with prognostic significance (AC068580.6, AF131215.2, LINC00996, LINC01125 and LINC01547). The development of a risk scoring model required the utilization of multivariate Cox analysis. According to the model, we categorized PCa individuals into low- and high-risk cohorts. PCa subjects in the high-risk group had a worse disease-free survival rate than those in the low-risk group. The 1-, 3-, and 5-year periods had corresponding areas under curves (AUC) of 0.788, 0.794, and 0.818. The prognosis of individuals with PCa could be predicted by the model with accuracy. Further analysis with GSEA showed that the prognostic model was associated with the tumor microenvironment, including immunotherapy, cancer-related inflammation, and metabolic reprogramming. Four lncRNAs expression in PCa cell lines was greater than that in healthy prostate cells. The au-lncRNA prognostic model has significant clinical implications in prognosis of PCa patient.
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The incorporation of pentagon-heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon-heptagon pairs in helical nanographenes by the dehydrogenation of [6]helicene units was developed. Three helical nanographenes containing pentagon-heptagon pairs were synthesized and characterized using this approach. A wide variation in the molecular geometries and photophysical properties of these helical nanographenes was observed, with changes in the helical length of these structures and the introduction of the pentagon-heptagon pairs. The embedded pentagon-heptagon pairs reduced the oxidation potential of the synthesized helical nanographenes. The high isomerization energy barriers enabled the chiral resolution of the helicene enantiomers. Chiroptical investigations revealed remarkably enhanced circularly polarized luminescence and luminescence dissymmetry factors with an increasing number of the pentagon-heptagon pairs.
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Soilborne diseases cause significant economic losses in agricultural production around the world. They are difficult to control because a host plant is invaded by multiple pathogens, and chemical control often does not work well. In this study, we isolated and identified an endophytic Streptomyces sp. NEAU-DD186 from moss, which showed broad-spectrum antifungal activity against 17 soilborne phytopathogenic fungi, with Bipolaris sorokiniana being the most prominent. The strain also exhibited strong antibacterial activity against soilborne phytopathogenic bacteria Ralstonia solanacearum. To evaluate its biocontrol potential, the strain was prepared into biofertilizer by solid-state fermentation. Response surface methodology was employed to optimize the fermentation conditions for maximizing spore production and revealed that the 1:1 ratio of vermicompost to wheat bran, a temperature of 28°C, and 50% water content with an inoculation amount of 15% represented the optimal parameters. Pot experiments showed that the application of biofertilizer with a spore concentration of 108 CFU/g soil could effectively suppress the occurrence of tomato bacterial wilt caused by R. solanacearum and wheat root rot caused by B. sorokiniana, and the biocontrol efficacy was 81.2 and 72.2%, respectively. Chemical analysis of strain NEAU-DD186 extracts using nuclear magnetic resonance spectrometry and mass analysis indicated that 25-O-malonylguanidylfungin A and 23-O-malonylguanidylfungin A were the main active constituents, which showed high activity against R. solanacearum (EC50 of 2.46 and 2.58 µg ml-1) and B. sorokiniana (EC50 of 3.92 and 3.95 µg ml-1). In conclusion, this study demonstrates that Streptomyces sp. NEAU-DD186 can be developed as biofertilizer to control soilborne diseases.
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Enfermedades de las Plantas , Streptomyces , Enfermedades de las Plantas/prevención & control , Agricultura , Antibacterianos , AntifúngicosRESUMEN
The wild topmouth culter (Culter alburnus) from Xingkai Lake (XKL) is highly regarded for its delicious taste and unique flavor. In this study, based on muscle quality and aroma analysis, we first differentiated the XKL population from three wild populations in Heilongjiang Province and one artificially cultured population (from Xingkai Lake). Compared with the other populations, the XKL population has a significantly higher crude protein content, essential amino acid content, delicious amino acid content, and n-3/n-6 PUFA ratio. Additionally, it exhibits superior hardness, elasticity, chewiness, recoverability, and viscosity. E-nose detection analysis revealed that W1S, W2S, and W3S were the potential sensors contributing the most to the differences among the five populations. HS-SPME-GC-MS and multivariate regression analysis showed that 21 volatile flavor compounds were identified as key markers for geographical identification of the Xingkai Lake region. These findings will provide guidance for the geographical traceability and identification of the XKL population.
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Cyprinidae , Animales , Lagos , Odorantes , MúsculosRESUMEN
Benign prostatic hyperplasia (BPH) is a common disease that affects the quality of life of middle-aged and older men. We investigated the therapeutical effects of Chengshi Beixie Fenqing Decoction (CBFD), a classic traditional Chinese medicine prescription, on BPH through in vivo model and network pharmacology. Bioactives in CBFD were detected through UPLC-Q-Tof-MS/MS and GC-MS, and filtered by the modified Lipinski's rule. Target proteins associated with the filtered compounds and BPH are selected from public databases. Venn diagram identified the overlapping target proteins between the bioactives-interacted target proteins and the BPH-targeted proteins. The bioactive-protein interactive networking of BPH was analyzed through the KEGG pathway on STRING to identify potential ligand-target and visualized the rich factors on the R packet. After that, the molecular docking test (MDT) was performed between bioactives and target proteins. It showed that the mechanism of CBFD against BPH was related to 104 signaling pathways of 42 compounds. AKT1, 6-demethyl-4'-methyl-N-methylcoclaurine and relaxin signaling pathways were selected as a hub target, key bioactivitie and hub signaling pathway, respectively. In addition, three major compounds, 6-demethyl-4'-methyl-N-methylcoclaurine, isoliensinine and liensinine, had the highest affinity on MDT for the three crucial target proteins, AKT1, JUN and MAPK1. These proteins were associated with the relaxin signaling pathway, which regulated the level of nitric oxide and is implicated in both BPH development and CBFD. We concluded that the three key bioactivities found in Plumula nelumbinis of CBFD may contribute to improving BPH condition by activating the relaxin signaling pathways.Communicated by Ramaswamy H. Sarma.
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Medicamentos Herbarios Chinos , Hiperplasia Prostática , Relaxina , Masculino , Persona de Mediana Edad , Humanos , Anciano , Farmacología en Red , Simulación del Acoplamiento Molecular , Hiperplasia Prostática/tratamiento farmacológico , Calidad de Vida , Espectrometría de Masas en Tándem , Transducción de Señal , Medicamentos Herbarios Chinos/farmacologíaRESUMEN
Streptomyces is an effective source of new natural bioherbicides. In this study, a novel isolated strain NEAU-HV44 showed strong inhibitory activity against Amaranthus retroflexus L. and was concluded to the genus Streptomyces. Strain NEAU-HV44 fermentation conditions were optimized to maximize the herbicidal activity. The supernatant of strain NEAU-HV44 could significantly control the growth of weeds (A. retroflexus L., Setaria viridis, Portulaca oleracea L., and Chenopodium album) and crops (maize, soybean, wheat, Chinese cabbage, cucumber, tomato, and romaine lettuce) with dose-dependent in preemergence. Notably, weeds were more sensitive to a low-concentration supernatant extract than crops in preemergence. In postemergence, the 2 mg mL-1 supernatant extract could significantly reduce the height and >50% biomass (fresh weight) of tested weeds. The supernatant extract could cause cell membrane destabilization and the cell death of weeds. In addition, the growth of tomato was also inhibited at a high concentration, but no obvious symptoms were observed on soybean and romaine lettuce after spraying the supernatant extract. Then two novel julichrome monomers, julichromes Q12 (1) and Q13 (2), and two known julichromes, julichrome Q3.3 (3) and julichrome Q3.5 (4), were isolated from the supernatant extract of strain NEAU-HV44 by bioactivity-guided approach. This is the first report of the herbicidal activity of julichromes. These four herbicidal compounds could inhibit the shoot and root growth of weeds at 0.2 mg mL-1, and compound 4 could completely inhibit the growth of P. oleracea L. Thus, julichromes (Q12, Q13, Q3.3, Q3.5 1-4) may be new bioherbicidal candidates.
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Chiral materials with circularly polarized luminescence (CPL) have garnered significant attention owing to their distinctive luminescent properties and wide array of applications. CPL enables the selective emission of left and right circularly polarized light. The fluorescence quantum yield and dissymmetry factor play pivotal roles in the generation of CPL. Helical polymers exhibit immense promise as CPL materials due to their inherent chirality, structural versatility, modifiability, and capacity to incorporate diverse chromophores. This Review provides a brief review of the synthesis of CPL materials based on helical polymers. The CPL can be realized by aggregation-induced CPL of non-emissive helical polymers, and helices bearing chromophores on the pendants and on the chain end. Furthermore, future challenges and potential applications of CPL materials are summarized and discussed.
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Cyclic polymers have very unique structure and properties, and thus have drawn intense research attention. However, controlled synthesis of cyclic polymers with predictable molar mass and narrow distribution is still a challenging task. In this study, we developed a novel cyclic catalyst that initiates the ring-expansion polymerisation of isocyanides, producing a series of cyclic helical polymers with predictable molecular weight and low dispersity. Interestingly, the ring-expansion polymerization of the isocyanide macromonomers gives well-defined cyclic bottlebrush polymers. The cyclic topology was demonstrated using transmission electron microscopy.
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To explore the effects of long-term balanced fertilization and straw mulching on soil nutrients and stoichiometric ratios in purple soil sloping cropland, nine plots (length 7 m×width 3 m) were established in Dianjiang County as the research sample area of long-term farmland nitrogen and phosphorus loss monitoring. The following three treatments were set up:conventional mode (CK), balanced fertilization mode (M1), and balanced fertilization+straw mulching mode (M2), with three replications for each treatment to compare the contents of carbon (C), nitrogen (N), phosphorus (P), and potassium (K) and their stoichiometric changes under different treatments from 2018 to 2020. The results showed:K contents showed significant differences among the three treatments in 2018, in the order of CK>M2>M1. NO3--N and NH4+-N contents showed significant differences among the three treatments in 2019, both in the order of M1>M2>CK. Other nutrient contents showed no significant difference among different treatments each year. Soil C and N contents showed non-significant differences among different years. The total K contents of CK, M1, and M2 in 2018 were significantly higher than that in other years and were 78.26% and 98.79%, 19.13% and 35.4%, and 54.49% and 41.76% higher than that in 2019 and 2020, respectively. The total P content in the CK and M2 treatments decreased with years, and that of CK and M2 in 2018 was 20.29% and 10.67% and 39.68% and 17.33% higher than that in 2019 and 2020, respectively. The available potassium (AK) content of the three treatments showed non-significant differences among different years, whereas the contents of nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N), and available phosphorus (AP) showed significant differences among the different treatments, with all being the highest in 2020. Soil C:P, C:K, N:P, N:K, and P:K ratios of each treatment showed significant differences among different years (P<0.05). Soil C:K, N:K, and AN:AP ratios all showed significant differences among different fertilization modes in 2018 and 2019, respectively (P<0.05). There was a significantly linearly positive relationship between soil C and N concentration and soil P and K concentration. There were very significant linear positive correlations between soil C:K and C:P, N:K, N:P, and P:K; N:K with C:P, P:K, and N:P; and N:P with C:P, N:P, and C:P. Soil P concentration was highly significantly linearly negatively correlated with C:K and N:K ratios. There were significant positive correlations between soil NO3--N, NH4+-N, AN:AP, and AN:AK; NH4+-N, AN:AP, and AN:AK; and AN:AP and AN:AK. The results suggested that balanced fertilization and straw mulching was a more suitable management mode for purple soil sloping cropland.
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Nitrógeno , Nutrientes , Fósforo , Potasio , Suelo , FertilizaciónRESUMEN
Soil-borne diseases cause significant economic losses in global agricultural production. These diseases are challenging to control due to the invasion of multiple pathogens into host plants, and traditional chemical control methods often yield unsatisfactory results. In this study, we isolated and identified an endophytic Streptomyces, designated as NEAU-ZSY13, from the leaf of Perilla frutescens. This isolate exhibited broad-spectrum antifungal activity against 17 soil-borne phytopathogenic fungi, with Bipolaris sorokiniana being the most prominent. Additionally, it displayed strong antibacterial activity against the soil-borne phytopathogenic bacterium Ralstonia solanacearum. To assess its biocontrol potential, the isolate was utilized to produce a biofertilizer through solid-state fermentation. The fermentation conditions were optimized using response surface methodology to maximize the spore production. The results revealed that more abundant spores were produced with a 1:2 ratio of vermicompost to wheat bran, 60% water content, 20% inoculation amount and 28°C. Subsequent pot experiments demonstrated that the application of the biofertilizer with a spore concentration of 108 CFU/g soil effectively suppressed the occurrence of tomato bacterial wilt caused by R. solanacearum and wheat root rot caused by B. sorokiniana, with biocontrol efficacies of 72.2 and 78.3%, respectively. Chemical analysis of NEAU-ZSY13 extracts, using nuclear magnetic resonance spectrometry and mass analysis, identified niphimycin C and niphimycin A as the primary active constituents. These compounds exhibited high activity against R. solanacearum (EC50 of 3.6 and 2.4 µg mL-1) and B. sorokiniana (EC50 of 3.9 and 3.4 µg mL-1). In conclusion, this study demonstrates the potential of Streptomyces sp. NEAU-ZSY13 as a biofertilizer for the control of soil-borne diseases.
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Effects of climate change and nutrient load caused by human activities on lake phytoplankton blooms have attracted much attention globally. However, their roles and synergistic effects on phytoplankton biomass and community historical succession are not well understood, especially for meso-eutrophic plateau lakes. In this study, a multi-year (1997-2022) monthly dataset including hydro-chemical and meteorological indicators of the meso-eutrophic plateau lake Erhai in China, was used to explore the contributions of climate change and nutrients on phytoplankton biomass variation and community succession. Phytoplankton biomass increased from 1997 to 2006, slowly decreased from 2006 to 2015, then increased again from 2015 to 2022, according to a generalised additive model (GAM). Alongside warming, nitrogen, phosphorus and organic matter are key drivers of long-term interannual variation in phytoplankton biomass and historical succession of the phytoplankton community. The extensive blooms in recent years were strongly associated with both organic matter accumulation and global warming. Phytoplankton biomass in northern and southern districts was greater than in central areas, with Cyanophyta and Pyrrophyta dominating in the north and Chlorophyta prevalent in the south. Since 2015, phytoplankton diversity has increased significantly, and biomass has declined in the southern district but increased markedly in the northern district. Spatial heterogeneity was caused by the spatial distribution of nutrients and the buoyancy regulation capacity of cyanobacteria. The results demonstrate that bloom mitigation responds strongly to nitrogen and phosphorus control in meso-eutrophic lakes, therefore preventing and controlling blooms through nitrogen and phosphorus reduction is still an effective measure. Given the accumulation of organic matter in recent years, synergistic control of organic matter and total nitrogen and phosphorus could effectively reduce the risk of cyanobacterial and dinoflagellate blooms.
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Cianobacterias , Fitoplancton , Humanos , Fitoplancton/fisiología , Biomasa , Lagos/microbiología , Estaciones del Año , Cianobacterias/fisiología , China , Fósforo/análisis , Nitrógeno/análisis , EutrofizaciónRESUMEN
Despite the significant impacts of natural factors such as rainfall, topography, soil type, and river network as well as agricultural activities on the environmental water quality, little is known about the influence of their temporal and spatial variations in a fluvial-lacustrine watershed. In this study, a whole process accounting method based the export coefficient model (WP-ECM) was first developed to quantify how natural factors and agricultural activities distribution influenced water quality. A case study was performed in a typical fluvial-lacustrine area - Dongting basin, China. The simulated results indicated that the natural factors can promote and inhibit the migration and transformation of agricultural pollutants generated from the watershed and the spatial distribution of the natural factors displayed high variability. It should be priority to monitor the areas with greater natural impact in the basin. Moreover, the cultivated land area and the number of pig-breeding were positively correlated with the pollutant discharge. From the perspective of the spatial distribution of comprehensive influence, the comprehensive high-impact areas are mainly distributed in the Dongting Lake district in 2005-2010 and in Xiang River watershed in 2010-2020. A key strategy for controlling or reducing the cultivated land area and the intensity of livestock breeding in these high-impacts areas is recommended to reduce the impact of the environmental water quality for the entire basin.
Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Animales , Porcinos , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Ríos , ChinaRESUMEN
[This retracts the article DOI: 10.1016/j.omtn.2019.08.007.].