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The effect of Zn on Cd accumulation in rice varies under flooding and drainage conditions, and the underlying mechanism during uptake and transport from the soil to grains remains unclear. Isotope fractionation and gene expression were investigated using pot experiments under distinct water regimes and with Zn addition to gain a deeper understanding of the molecular effects of Zn on Cd uptake and transport in rice. The higher OsHMA2 expression but constitutively lower expression of zinc-regulated, iron-regulated transporter-like protein (ZIP) family genes in roots under the drainage regime than the flooding regime caused the enrichment of nonheavy Zn isotopes in the shoots relative to roots but minimally affected Cd isotopic fractionation. Drainage regime seem to exert a striking effect on the root-to-shoot translocation of Zn rather than Cd, and increased Zn transport via OsHMA2. The changes in expression patterns in response to Zn addition were similar to those observed upon switching from the flooding to drainage regime, except for OsNRAMP1 and OsNRAMP5. However, soil solution-to-rice plants and root-to-shoot fractionation toward light Zn isotopes with Zn addition (Δ66Znrice plant-soil solution = -0.49 to -0.40, Δ66Znshoot-root = -0.36 to -0.27) indicated that Zn transport occurred via nonspecific uptake pathways and OsHMA2, respectively. Accordingly, the less pronounced and minimally varied Cd isotope fractionation suggested that OsNRAMP5 and OsHMA2 are crucial for Cd uptake and root-to-shoot transport, respectively, facilitating Cd accumulation in grains. This study demonstrated that a high Zn supply promotes Cd uptake and root-to-shoot transport in rice by sharing distinct pathways, and by utilizing a non-Zn-sensitive pathway with a high affinity for Cd.
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Cádmio , Oryza , Solo , Zinco , Oryza/metabolismo , Oryza/genética , Cádmio/metabolismo , Zinco/metabolismo , Solo/química , Raízes de Plantas/metabolismo , Transporte Biológico , Poluentes do Solo/metabolismoRESUMO
Three successive vegetable pot experiments were conducted to assess the effects on the long-term immobilization of heavy metals in soil and crop yield improvement after the addition of peanut shell biochar and an alkaline mineral to an acidic soil contaminated with lead and cadmium. Compared with the CK treatment, the change rates of biomass in the edible parts of the three types of vegetables treated with B0.3, B1, B3, B9, R0.2 and B1R0.2 were -15.43%~123.30%, 35.10%~269.09%, 40.77%~929.31%, -26.08%~711.99%, 44.14%~1067.12% and 53.09%~1139.06%, respectively. The cadmium contents in the edible parts of the three vegetables treated with these six additives reduced by 2.08%~13.21%, 9.56%~24.78%, 9.96%~35.61%, 41.96%~78.42%, -4.19%~57.07% and 12.43%~65.92%, respectively, while the lead contents in the edible parts reduced by -15.70%~59.47%, 6.55%~70.75%, 3.40%~80.10%, 55.26%~89.79%, 11.05%~70.15% and 50.35%~79.25%, respectively. Due to the increases in soil pH, soil cation-exchange capacity and soil organic carbon content, the accumulation of Cd and Pb in the vegetables was most notably reduced with a high dosage of 9% peanut shell biochar alone, followed by the addition of a low dosage of 1% peanut shell biochar blended with 0.2% alkaline mineral. Therefore, the addition of a low dosage of 1% peanut shell biochar blended with 0.2% alkaline mineral was the best additive in increasing the vegetable biomass, whereas the addition of 9% peanut shell biochar alone was the worst. Evidently, the addition of 0.2% alkaline mineral can significantly reduce the amount of peanut shell needed for passivating heavy metals in soil, while it also achieves the effect of increasing the vegetable yield.
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PURPOSE: This study aims to investigate the bleeding sites and their relationship with clinical characteristics in hospitalized epistaxis patients. METHODS: We retrospectively reviewed the data of 646 hospitalized epistaxis patients. RESULTS: The bleeding sites were identified in 395 (61.1%) patients and unidentified in 251 (38.9%). We found that age > 50 years (P = 0.030) and the history of cardiovascular diseases (P = 0.027) were more frequent in patients with unidentified bleeding sites. Among patients with identified sites, inferior meatus (n = 130, 32.9%) was the most common site, followed by the septal surface of the olfactory region (n = 102, 25.8%), nasal septum (n = 80, 20.3%), middle meatus (n = 60, 15.2%), and others (n = 23, 5.8%). After dividing patients into five groups by the area of the bleeding sites, we found significant differences in age (P = 0.026), history of hypertension (P = 0.001), cardiovascular diseases (P = 0.032), and nasal packing (P = 0.011). The logistic regression also revealed that these four factors were predictors for different bleeding sites. CONCLUSION: The bleeding sites can be identified in most epistaxis patients. Age > 50 years and the history of cardiovascular diseases are more frequent in patients with unidentified bleeding sites. In our patients, the most common bleeding site is inferior meatus, followed by the septal surface of the olfactory region, nasal septum, and middle meatus. Age, histories of hypertension, cardiovascular diseases, and nasal packing are factors associated with the bleeding risks of different bleeding sites. According to the different clinical characteristics of patients, the order of the nasal endoscopic examination should be adjusted to develop their treatment plans.
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OBJECTIVE: This study aims to find the difference in clinical and immunopathological characteristics between children and adults with antrochoanal polyps (ACPs) in the Chinese population. METHODS: The clinical data of 69 patients diagnosed with ACPs were retrospectively analyzed. Cytokine levels in 16 controls and 40 ACPs tissues were determined by quantitative real-time polymerase chain reaction (qPCR). The expression of matrix metalloproteinase (MMP)-9 was measured using qPCR, immunofluorescent staining, and western blot. RESULTS: There were 51 (73.9%) children (<18 years old) and 18 (26.1%) adults (≥18 years old). The sex ratio differed significantly between the two groups (p = 0.0032). There were no significant differences in the nasal side of ACPs and approaches to surgery between the two groups. In both groups, the most common symptom was nasal obstruction, followed by nasal discharge. As for associated nasal diseases, there was a significant difference between the two groups in septal deviation (p = 0.0223). Adult patients showed significantly higher expression of IL-8 mRNA than children (p = 0.0424). The mRNA and protein levels of MMP-9 were also significantly higher in adult patients than in children (p = 0.0498 and 0.0009, respectively). CONCLUSION: In the Chinese population, the comorbidities and immunopathological characteristics of adult ACP patients are different from those of children. The level of IL-8 and MMP-9 was significantly higher in ACPs of adults than in children, which may contribute to the more severe tissue remolding in adult ACP patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2093-2099, 2024.
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Metaloproteinase 9 da Matriz , Pólipos Nasais , Adulto , Criança , Humanos , Adolescente , Estudos Retrospectivos , Interleucina-8 , Seio Maxilar/patologia , Pólipos Nasais/complicações , RNA Mensageiro , China/epidemiologiaRESUMO
Heavy metals can severely influence the mineralisation of organic pollutants in a compound-polluted environment. However, to date, no study has focused on the effects of heavy metals on the active organic pollutant-degrading microbial communities to understand the bioremediation mechanism. In this study, toluene was used as the model organic pollutant to explore the effects of soils with different levels of heavy metal pollution on organic contaminant degradation in the same area via stable isotope probing (SIP) and 16 S rRNA high-throughput sequencing. Heavy metals can seriously affect toluene biodegradation and regulate the abundance and diversity of microbial communities. SIP revealed a drastic difference in the community structure of active toluene degraders between the unpolluted and heavy metal-polluted soils. All SIP-identified degraders were assigned to nine bacterial classes, among which Alphaproteobacteria, Gammaproteobacteria, and Bacilli were shared by both treatments. Among all active degraders, Nitrospira, Nocardioides, Conexibacteraceae, and Singulisphaera were linked to toluene biodegradation for the first time. Notably, the type of active degrader and microbial diversity were strongly related to biodegradation efficiency, indicating their key role in toluene biodegradation. Overall, heavy metals can affect the microbial diversity and alter the functional microbial communities in soil, thereby influencing the removal efficiency of organic contaminants. Our findings provide novel insights into the biodegradation mechanism of organic pollutants in heavy metal-polluted soils and highlight the biodiversity of microbes involved in toluene biodegradation in compound-polluted environments.
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Poluentes Ambientais , Metais Pesados , Microbiota , Poluentes do Solo , Tolueno/metabolismo , Microbiologia do Solo , Solo/química , Fazendas , Bactérias/metabolismo , Biodegradação Ambiental , Poluentes do Solo/metabolismoRESUMO
In situ stabilization technologies based on lime-derived materials are extensively used for remediating Cd-contaminated paddy soils. However, the environmental impacts and carbon budget associated with these technologies throughout the paddy soil remediation life cycle are gaining increasing attention. Herein, through paddy field trials, two representative lime-derived materials, quicklime and calcium-silicon composite (Ca/Si), are evaluated for their remediation effectiveness and environmental sustainability in the remediation of Cd-contaminated soils. The results demonstrate that both quicklime and Ca/Si can reduce Cd bioavailability and enable the safe use of rice grain. Nevertheless, the life cycle assessment score of the quicklime case is 4.4 times that of the Ca/Si case, indicating that the quicklime case has a greater negative impact on the environment. Furthermore, the net ecosystem carbon budget analysis reveals that both lime-derived materials exhibit outward carbon emissions throughout their life cycle, in which the carbon emission of the quicklime case (-20.2 t CO2-eq/ha) is 20 times that of the Ca/Si case (-1 t CO2-eq/ha). Moreover, the implementation of carbon capture technology results in the Ca/Si case achieving a positive carbon budget and contributing to a carbon neutrality plan. Conversely, the quicklime case falls short, affording only a 24.8 % reduction in carbon emissions. Overall, this study provides valuable insights into the environmental sustainability of different lime-derived materials for paddy soil remediation and carbon mitigation.
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This study investigated the mechanism underlying acetate-induced orphan G-protein-coupled receptor 43 (GPR43) expression and milk fat production. The mammary epithelial cells of dairy cows were treated with acetate, and the effects of GPR43 on acetate uptake and the expression of lipogenesis-related genes were determined by gas chromatography and quantitative polymerase chain reaction (qPCR), respectively. RNAi, inhibitor treatment, and luciferase assay were used to determine the effect of phosphoinositide 3-kinase-protein kinase B-specificity protein 1 (PI3K-AKT-SP1) signaling on acetate-induced GPR43 expression and function. The results showed that GPR43 was highly expressed in lactating cow mammary tissues, which was related to milk fat synthesis. 12 mM acetate significantly increased the GPR43 expression in mammary epithelial cells of dairy cows. In acetate-treated cells, GPR43 overexpression significantly increased the cellular uptake of acetate, the intracellular triacylglycerol (TAG) content, and acetate-induced lipogenesis gene expression. Acetate activated PI3K-AKT signaling and promoted SP1 translocation from the cytosol into the nucleus, where SP1 bound to the GPR43 promoter and upregulated GPR43 transcription. Moreover, the activation of PI3K-AKT-SP1 by acetate facilitated the trafficking of GPR43 from the cytosol to the plasma membrane. In conclusion, acetate upregulated GPR43 expression and function via PI3K-AKT-SP1 signaling in mammary epithelial cells, thereby increasing milk fat synthesis. These results provide an experimental strategy for improving milk lipid synthesis, which is important to the dairy industry.
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Lactação , Leite , Feminino , Animais , Bovinos , Leite/química , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Glândulas Mamárias Animais/metabolismo , Acetatos/farmacologia , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismoRESUMO
This study investigated the role of the mammalian target of rapamycin complex 2 (mTORC2)-protein kinase B (AKT) signalling in methionine (Met)-induced L-type amino acid transporter 1 (LAT1) expression and milk protein production. Primary mammary epithelial cells (MECs) from mammary parenchymal tissues of three lactating cows and MAC-T bovine MECs were cultured with or without 0.6 mM Met. Rapamycin-insensitive companion of mTOR (RICTOR) siRNA, the mTORC1 inhibitor rapamycin and the AKT activator SC79 were used to evaluate the effects of mTORC2-AKT signalling on Met-induced LAT1 expression and function. Each experiment was performed three times. Data were analysed with a two-sided unpaired t test or ANOVA with the Bonferroni multiple-comparison test. Western blotting showed that Met stimulation increased RICTOR expression (~244.67%; p < 0.05; control, 0.15 ± 0.026; Met, 0.517 ± 0.109) and AKT-S473 levels (~281.42%; p < 0.01; control, 0.253 ± 0.067; Met, 0.965 ± 0.019) in both primary MECs and MAC-T cells. Rapamycin-induced mTORC1 signalling inhibition decreased only Met-induced ß-CASEIN expression by ~21.24% (p < 0.01; Met, 0.777 ± 0.01; Met and rapamycin, 0.612 ± 0.04) and did not affect Met-stimulated AKT-S473 levels, suggesting that mTORC2-AKT activation upon Met stimulation also contributes to milk protein synthesis. LAT1 participates in Met-induced ß-CASEIN expression. In dairy cow MECs, mTORC2 inhibition by RICTOR siRNA decreased LAT1 levels on the plasma membrane by ~45.13% (p < 0.01; control, 0.359 ± 0.006; siRICTOR, 0.197 ± 0.004). However, SC79-induced AKT activation had the opposite effect (p < 0.01). In primary MECs and MAC-T cells, Met stimulation increased cytosolic and plasma membrane LAT1 expression respectively (MECs, 113.98% and 58.43%; MAC-T, 165.85% and 396.39%; p < 0.05). However, RICTOR siRNA significantly reduced Met-induced plasma membrane LAT1 expression (~76.48%; Met, 0.539 ± 0.05; Met and siRICTOR, 0.127 ± 0.012; p < 0.05). Thus, Met increased LAT1 expression and function via mTORC2-AKT signalling, upregulating milk protein synthesis in dairy cow MECs.
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Caseínas , Proteínas Proto-Oncogênicas c-akt , Feminino , Bovinos , Animais , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Caseínas/genética , Caseínas/metabolismo , Metionina/farmacologia , Metionina/metabolismo , Lactação , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas do Leite/genética , Proteínas do Leite/metabolismo , Racemetionina/metabolismo , Fatores de Transcrição/metabolismo , RNA Interferente Pequeno/metabolismo , Células Epiteliais/metabolismo , Sirolimo , Mamíferos/metabolismoRESUMO
The environmental behavior of arsenic (As) is commonly affected by the biogeochemical processes of iron (Fe) and nitrogen (N). In this study, field experiments were conducted to explore As uptake in rice and As translation and distribution in As-contaminated iron-rich paddy soils after applying different forms of N fertilizers, including urea (CO(NH2)2), ammonium bicarbonate (NH4HCO3), nitrate of potash (KNO3), and ammonium bicarbonate + nitrate of potash (NH4HCO3 + KNO3). The results indicated that applying nitrate N fertilizer inhibited the reduction and dissolution of As-bearing iron minerals and promoted microbial-mediated As(III) oxidation in flooded soil, thus reducing the soil As bioavailability. The concentrations of total As and inorganic As ratio (iAs/TAs) in rice grain decreased by 32.4 % and 15.4 %, respectively. However, the application of ammonium nitrogen promoted the reductive dissolution of As-bearing iron minerals and stimulated microbial As(V) reduction in flooded soil, leading to the release of As from soil to porewater. The total As concentration and inorganic As uptake ratio in rice grain increased by 20.1 % and 6.2 %, respectively, when urea was applied, and by 29.6 % and 10.5 %, respectively, when ammonium bicarbonate was applied. However, the simultaneous application of NH4+ and NO3- had no significant effect on As concentration in rice grain and its transformation in paddy soils. Ammonium nitrogen enhanced the organic As concentration in rice grain because the increased As(III) promoted As methylation in soil. In contrast, nitrate decreased the organic As uptake by rice grain because the decreased As(III) diminished As methylation in soil. The results provide reasonable N fertilization strategies for regulating the As biogeochemical process and reducing the risk of As contamination in rice.
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Compostos de Amônio , Arsênio , Arsenicais , Oryza , Poluentes do Solo , Arsênio/análise , Nitratos , Ferro , Minerais , Solo , Ureia , Nitrogênio , Fertilização , Poluentes do Solo/análise , Fertilizantes/análiseRESUMO
This research communication investigated the role and the underlying mechanism of sn-1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) in acetate-induced mTORC1 signaling activation and milk fat synthesis in dairy cow mammary epithelial cells. The data showed AGPAT6 knockdown significantly decreased acetate-induced phosphorylation of mTORC1 signaling molecules and intracellular triacylglycerol (TAG) content, whereas this inhibition effect was reversed after the addition of 16:0,18:1 phosphatidic acid (PA), suggesting that AGPAT6 could generate PA in response to acetate simulation, that in turn activates mTORC1 signaling. PPARγ is the upstream regulator of AGPAT6 upon acetate stimulation. Luciferase assay with clones containing various deletions and mutation in AGPAT6 promoter showed that there is a RXRα binding sequence located at -96 bp of AGPAT6 promoter. Acetate stimulation significantly increased the interaction between PPARγ and AGPAT6 via this RXRα binding site. Taken together, our data indicated that AGPAT6 could activate mTORC1 signaling by producing PA during acetate-induced milk fat synthesis, and PPARγ acts as a transcription factor to mediate the effect of acetate on AGPAT6 via RXRα.
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Leite , PPAR gama , Feminino , Bovinos , Animais , Leite/química , PPAR gama/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Glândulas Mamárias Animais/metabolismo , Triglicerídeos/metabolismo , Células Epiteliais/metabolismo , AcetatosRESUMO
The excessive accumulation of cadmium (Cd) in rice grains is highly determined by the expression of specific genes in different tissues. Targeted gene regulation in rice plants is a long-standing challenge. Herein, a new strategy for regulating target gene expression responsible for Cd absorption and translocation in roots and leaves was developed by complexing Fe(II) with organic matter (i.e., Fe-OM) with the optimal mass ratio of 1. Results showed that Fe-OM noticeably reduced the grain Cd content from 0.48 ± 0.04 mg kg-1 to 0.25 ± 0.03 mg kg-1, exhibiting a significantly higher capacity in mitigating Cd accumulation in grains than Fe(II) or OM alone. The translocation factor (TF) was reduced from 0.14 (control) to 0.08 by Fe-FA from root to grain, which could be due to the preferential Cd translocation to leaves (i.e., TFroot to leaves was enhanced four times by the complex of Fe(II) with fulvic acid (Fe-FA). Further gene analysis revealed that the cooperative effects of OsNramp1 and OsNramp5 downregulation in roots/stems and OsLCT1 upregulation in leaves contributed to the mitigation of Cd in grains. This work provides a new strategy to regulating target gene expression in specific tissues to alleviate Cd accumulation in grains.
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Oryza , Poluentes do Solo , Cádmio/análise , Grão Comestível/química , Expressão Gênica , Oryza/genética , Folhas de Planta/química , Folhas de Planta/genética , Solo , Poluentes do Solo/análiseRESUMO
The feasibility of chemical stabilization-based strategy for extensive field application is under debate due to lacking a proper framework for its sustainability assessment during its life cycle. Herein, a comprehensive framework consisting of crop production, soil quality, and carbon footprint was constructed for assessing agricultural land remediation based on a two-year paddy field trial. Results show that between the two representative agents, biochar scenario substantially benefits for environmental, social, and agricultural sustainability, because of its more positive impacts on human health and ecosystem, public acceptance, soil reproductive, and rice yield. A notably higher sustainability score of 80.7 for biochar scenario than that of 47.0 for lime is found, in spite of the economical sustainability of lime. The net ecosystem carbon budget of the biochar scenario exhibits an unprecedentedly positive value of 17.8 t CO2-eq ha-1, which can finely contribute to a positive carbon budget during remediation. Our finding demonstrates that biochar strategy enables a multi-objective achievement of soil quality - crop production - carbon budget during agricultural land remediation. This study provides new insights into sustainability assessment for restoring agricultural land for safe crop production and synergizing with carbon neutral plan.
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Oryza , Poluentes do Solo , Agricultura/métodos , Cádmio , Carbono , Carvão Vegetal , Ecossistema , Humanos , SoloRESUMO
The inessential heavy metal/loids cadmium (Cd) and arsenic (As), which often co-occur in polluted paddy soils, are toxic to rice. Silicon (Si) treatment is known to reduce Cd and As toxicity in rice plants. To better understand the shared mechanisms by which Si alleviates Cd and As stress, rice seedlings were hydroponically exposed to Cd or As, then treated with Si. The addition of Si significantly ameliorated the inhibitory effects of Cd and As on rice seedling growth. Si supplementation decreased Cd and As translocation from roots to shoots, and significantly reduced Cd- and As-induced reactive oxygen species generation in rice seedlings. Transcriptomics analyses were conducted to elucidate molecular mechanisms underlying the Si-mediated response to Cd or As stress in rice. The expression patterns of the differentially expressed genes in Cd- or As-stressed rice roots with and without Si application were compared. The transcriptomes of the Cd- and As-stressed rice roots were similarly and profoundly reshaped by Si application, suggesting that Si may play a fundamental, active role in plant defense against heavy metal/loid stresses by modulating whole genome expression. We also identified two novel genes, Os01g0524500 and Os06g0514800, encoding a myeloblastosis (MYB) transcription factor and a thionin, respectively, which may be candidate targets for Si to alleviate Cd and As stress in rice, as well as for the generation of Cd- and/or As-resistant plants. This study provides valuable resources for further clarification of the shared molecular mechanisms underlying the Si-mediated alleviation of Cd and As toxicity in rice.
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Arsênio , Oryza , Poluentes do Solo , Arsênio/toxicidade , Cádmio/toxicidade , Oryza/genética , Raízes de Plantas , Plântula/genética , Silício/toxicidade , Poluentes do Solo/toxicidade , TranscriptomaRESUMO
Foliar application of Si can generally reduce As translocation from roots to shoots in rice; however, it does not always work, particularly under high As stress. Here, the effects of foliar application of nanoscale silica sol on As accumulation in rice were investigated under low (2 µmol/L) and high (8 µmol/L) arsenite stress. The results revealed that foliar Si application significantly decreased the As concentration in shoots under low arsenite stress, but showed different effects under high arsenite stress after 7 days of incubation. The reduction in root-to-shoot As translocation under the 2As+Si treatment was related to the down-regulation of OsLsi1 and OsLsi2 expression and up-regulation of OsABCC1 expression in roots. In the 8As+Si treatment, the expressions of OsLsi1, OsLsi2, and OsABCC1 were significantly promoted, which resulted in substantially higher As accumulation in both the roots and shoots. In the roots, As predominantly accumulated in the symplasts (90.6%-98.3%), in which the majority of As was sequestered in vacuoles (79.0%-94.0%) under both levels of arsenite stress. Compared with that of the 8As treatment, the 8As+Si treatment significantly increased the As concentration in cell walls, but showed no difference in the vacuolar As concentration, which remained constant at approximately 69.1-71.7 mg/kg during days 4-7. It appeared that the capacity of root cells to sequester As in the vacuoles had a threshold, and the excess As tended to accumulate in the cell walls and transfer to the shoots via apoplasts under high arsenite stress. This study provides a better understanding of the different effects of foliar Si application on As accumulation in rice from the view of arsenite-related gene expression and As subcellular distribution in roots.
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Arsênio , Arsenitos , Oryza , Arsenitos/toxicidade , Raízes de Plantas , Silício , Dióxido de SilícioRESUMO
Co-cropping is an eco-friendly strategy to improve the phytoremediation capacity of plants growing in soils contaminated with heavy metals such as cadmium (Cd). This study was conducted to investigate the effects of co-cropping Indian mustard (Brassicajuncea) and silage maize (Zeamays) and applying peat on the phytoremediation of a Cd-contaminated acid paddy soil via characterizing plant growth and Cd uptake in pot experiments. There were six planting patterns (Control: no plants; MI-2 and MI-4: mono-cropping of Indian mustard at low and high densities, respectively; MS: mono-cropping of silage maize; CIS-2 and CIS-4: co-cropping of Indian mustard at low and high densities with silage maize, respectively) and two application rates of peat (NP: 0; WP: 30 g kg-1). When Indian mustard and silage maize were co-cropped, the shoot biomass of Indian mustard plants per pot was significantly (p < 0.05) lower than that obtained in the mono-cropping systems, with a substantial reduction (55-72%) in the same plant density group. The shoot biomass of silage maize plants in the mono-cropping systems did not differ significantly from that in the co-cropping systems regardless of the density of Indian mustard. The growth-promoting effect of the peat application was more pronounced in Indian mustard than silage maize. Under the low density of Indian mustard, the co-cropping systems significantly (p < 0.05) decreased Cd uptake by silage maize. Additionally, soil amendment with peat significantly (p < 0.05) increased shoot Cd removal rate and Cd translocation factor value in the co-cropping systems. Taken together, the results demonstrated that silage maize should be co-cropped with Indian mustard at an appropriate density in Cd-polluted soils to achieve simultaneous remediation of Cd-contaminated soils (via Indian mustard) and production of crops (here, silage maize). Peat application was shown to promote the removal of Cd from soil and translocation of Cd into shoots and could contribute to enhanced phytoremediation of Cd-contaminated acid paddy soil.
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BACKGROUND: Genes associated with arsenite uptake and transport in rice plants (i.e., OsLsi1, OsLsi2, OsLsi3, OsLsi6 and OsABCC1) have been identified to date. However, their expression over time during the whole growth period of rice under arsenite stress conditions is still poorly understood. In this study, the dynamics of gene expression associated with arsenite transport and arsenic concentrations in different organs of rice were investigated to determine the critical period(s) of arsenite uptake and translocation regulated by gene expression during the whole growth period. RESULTS: The relative expression of OsLsi2 and OsLsi1 in the roots was upregulated and reached its highest value (2-∆∆Ct = 4.04 and 1.19, respectively) at the jointing stage (9 weeks after transplantation), in which the arsenic concentration in roots also was the highest at 144 mg/kg. A range from 45.1 to 61.2% of total arsenic accumulated in the roots during seedling to heading stages (3-16 weeks), which was mainly associated with the relatively high expression of OsABCC1 (1.50-7.68), resulting in arsenic located in the vacuoles of roots. Subsequently, the As translocation factor from root to shoot increased over time from heading to milky ripe (16-20 weeks), and 74.3% of the arsenic accumulated in shoots at the milk stage. Such an increase in arsenic accumulation in shoots was likely related to the findings that (i) OsABCC1 expression in roots was suppressed to 0.14-0.75 in 18-20 weeks; (ii) OsLsi3 and OsABCC1 expression in nodes I, II, and III was upregulated to 4.01-25.8 and 1.59-2.36, respectively, in 16-20 weeks; and (iii) OsLsi6 and OsABCC1 expression in leaves and husks was significantly upregulated to 2.03-5.26 at 18 weeks. CONCLUSIONS: The jointing stage is the key period for the expression of arsenite-transporting genes in roots, and the heading to milky ripe stages are the key period for the expression of arsenite-transporting genes in shoots, both of which should be considered for regulation during safe rice production in arsenic-contaminated paddy soil.
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Arsênio/metabolismo , Arsenitos/metabolismo , Expressão Gênica/efeitos dos fármacos , Oryza/metabolismo , Arsênio/toxicidade , Arsenitos/toxicidade , Transporte Biológico/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Oryza/genética , Oryza/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidadeRESUMO
[This corrects the article DOI: 10.3892/ol.2019.10030.].
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A pot experiment was conducted to investigate uptake of cadmium (Cd), arsenic (As) and antimony (Sb) by rice from a lime-treated paddy soil contaminated with the three pollutants. The results showed that the content of Cd in the total rice plants decreased as the plant grew, whereas the As and Sb contents increased steadily. The concentration of As in the pore water showed steady increase throughout the growth period, likely due to the reductive dissolution of iron (Fe)-bearing minerals and the reduction of As(V). In contrast, the concentrations of Cd and Sb in the pore water increased initially, likely attributable to the reductive dissolution of Fe-bearing minerals, and then decreased likely due to their adsorptions onto carbonate and Fe sulfides, the reduction of Sb(V), and the formation of CdS. A random forest model was used to quantitatively evaluate the relative contributions of environmental factors to the accumulation of Cd, As, and Sb in the rice plants. The results suggest that sulfides produced through sulfate reduction and the formation of Cd forms associated with sulfur (S) might significantly affected the Cd content in the rice plants. In addition, the dissolved Fe species, the oxidation-reduction potential, and the abundance of the As(V)-respiring gene were major contributors to the As content in the rice plants, suggesting the important role of the reduction of Fe-bearing minerals and As(V). The results also showed that the Sb content in the rice plants was correlated with Fe species, Sb(V) reduction, and acid volatile S. The environmental behaviors of Cd, As, and Sb in the cocontaminated paddy soil exhibited significant differences. Such differences should be considered in remedy of soils contaminated with multiple heavy metals and metalloids.
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Oryza , Arsênio , Cádmio , Solo , Poluentes do SoloRESUMO
Under flooded conditions in paddy soil, the mobility of As increases while the mobility of Cd decreases. The opposite geochemical behavior of As and Cd makes it difficult to reduce their mobilities simultaneously. Our recent study found that combined applications of biochar and zero-valent iron successfully reduced the mobilities of As and Cd simultaneously. On this basis, in the present study, an iron-modified biochar (Fe-BC) was developed, and its effect on decreasing the accumulations of As and Cd in rice was verified in a 2-year field trial. In addition, previous studies indicated that silicon fertilizer can also reduce As and Cd accumulation in rice grain. Hence, the effect of the combined or separate application of Fe-BC and silica sol on As and Cd accumulation in rice grain was investigated. Over the 2-year field trial, the grain yields decreased in the following order: iron-modified biochar plus silica sol (Fe-BC plus Si) > silica sol (Si) > Fe-BC > control (CK). Concentrations of As and Cd in brown rice were in the order: Fe-BC plus Si < Si ≈ Fe-BC < CK. The treatments of Fe-BC and Fe-BC plus Si significantly increased the soil pH and thus decreased available As and available Cd in the soil. In addition, significantly positive correlations between available As and As in brown rice and between available Cd and Cd in brown rice were found. In conclusion, co-application of iron-modified biochar and silica sol should be a recommended strategy to reduce the accumulation of As and Cd in rice grains.
Assuntos
Arsênio/análise , Cádmio/análise , Grão Comestível/química , Ferro/química , Oryza/efeitos dos fármacos , Dióxido de Silício/química , Silício/metabolismo , Arsênio/química , Cádmio/química , Carvão Vegetal , Poluição Ambiental/análise , Ferro/análise , Silício/farmacologia , Poluentes do Solo/análiseRESUMO
BACKGROUND: Organizing pneumonia (OP) is a rare disease that is often easily misdiagnosed as a malignancy. The diagnosis of OP can prove quite challenging. Patients typically receive treatment with high-dose corticosteroids. Relapse is common if corticosteroid treatment is reduced or stopped. However, given that long-term corticosteroid treatment often results in significant side-effects, the aim of this study was to discuss the diagnosis and surgical treatment of OP. MATERIAL AND METHODS: The medical records of 24 patients with pathologically diagnosed OP between October 2007 and January 2019 were retrospectively reviewed. All patients underwent thoracic computed tomography (CT) and transbronchial biopsy or CT-guided percutaneous needle aspiration. We analysed the clinical manifestations, radiological findings, diagnostic methods, treatment, and follow-up outcomes of all patients. RESULTS: In total, 24 patients with OP were identified. The study included 17 (70.8%) men and 7 (29.2%) women, and the mean age was 61.25 ± 11.33 years (range: 31-82). The most common symptom was cough (n = 16; 66.6%), and the most common radiological finding was consolidation (n = 13; 54.2%) on thoracic CT. The diagnosis of OP was made by transbronchial biopsy in 11 patients (45.8%), and percutaneous needle aspiration biopsy in 13 (54.2%). We performed 11 wedge resections, 9 segmentectomy, and 4 lobectomies. Twenty patients underwent video-assisted thoracoscopic surgery (VATS), and 4 underwent thoracotomy. Complete lesion resection was obtained in all patients, and all patients were discharged from the hospital between 5 and 11 days after surgery. The mean follow-up period was 59.1 ± 34.5 (range: 2-134) months. Residual lesions or local or distant recurrence were not observed. CONCLUSIONS: OP is a rare disease, and the exact aetiology remains unclear. Preoperative diagnosis is difficult to achieve despite the use of transbronchial biopsy or CT-guided percutaneous needle aspiration. Complete surgical resection represents an effective method for the treatment of OP.