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1.
Sci Total Environ ; 932: 173073, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38734103

RESUMO

The organic matter molecular mechanism by which combined hydrothermal carbonization (co-HTC) of municipal sludge (MS) and agricultural wastes (rice husk, spent mushroom substrate, and wheat straw) reduces the inhibitory effects of aqueous phase (AP) products on pak choi (Brassica campestris L.) growth compared to HTC of MS alone is not clear. Fourier-transform ion cyclotron resonance mass spectrometry was used to characterize the differences in organic matter at the molecular level between AP from MS HTC alone (AP-MS) and AP from co-HTC of MS and agricultural waste (co-Aps). The results showed that N-bearing molecules of AP-MS and co-Aps account for 70.6 % and 54.2 %-64.1 % of all molecules, respectively. Lignins were present in the highest proportion (56.3 %-78.5 %) in all APs, followed by proteins and lipids. The dry weight of co-APs hydroponically grown pak choi was 31.6 %-47.6 % higher than that of the AP-MS. Molecules that were poorly saturated and with low aromaticity were preferentially consumed during hydroponic treatment. Molecules present before and after hydroponics were defined as resistant molecules; molecules present before hydroponics but absent after hydroponics were defined as removed molecules; and molecules absent before hydroponics but present after hydroponics were defined as produced molecules. Large lignin molecules were broken down into more unsaturated molecules, but lignins were the most commonly resistant, removed, and produced molecules. Correlation analysis revealed that N- or S-bearing molecules were phytotoxic in the AP. Tannins positively influenced the growth of pak choi. These results provide new insights into potential implementation strategies for liquid fertilizers produced from AP arising from HTC of MS and agricultural wastes.


Assuntos
Agricultura , Esgotos , Agricultura/métodos , Brassica/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos/métodos
2.
J Hazard Mater ; 471: 134398, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38677124

RESUMO

Livestock manure is often contaminated with heavy metals (HMs) and HM resistance genes (HMRGs), which pollute the environment. In this study, we aimed to investigate the effects of the aqueous phase (AP) produced by hydrothermal carbonization (HTC) of sewage sludge (SS) alone and the AP produced by co-HTC of rice husk (RH) and SS (RH-SS) on humification, HM bioavailability, and HMRGs during chicken manure composting. RH-SS and SS increased the humic acid content of the compost products by 18.3 % and 9.7 %, respectively, and significantly increased the humification index (P < 0.05) compared to the CK (addition of tap water). The passivation of HMs (Zn, Cu, As, Pb, and Cr) increased by 12.17-23.36 % and 9.74-15.95 % for RH-SS and SS, respectively, compared with that for CK. RH-SS and SS reduced the HMRG abundance in composted products by 22.29 % and 15.07 %, respectively. The partial least squares path modeling results showed that SS and RH-SS promoted compost humification while simultaneously altering the bacterial community and reducing the bioavailability of metals and host abundance of HMRGs, which has a direct inhibitory effect on the production and distribution of HMRGs. These findings support a new strategy to reduce the environmental risk of HMs and HMRGs in livestock manure utilization.


Assuntos
Galinhas , Compostagem , Esterco , Metais Pesados , Esgotos , Animais , Metais Pesados/toxicidade , Substâncias Húmicas/análise , Carbono/química , Poluentes do Solo/toxicidade , Oryza/metabolismo
3.
Sci Total Environ ; 926: 171890, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38521280

RESUMO

A pilot-scale continuous-flow modified anaerobic-anoxic-oxic (MAAO) process examined the impact of external carbon sources (acetate, glucose, acetate/propionate) on ammonium assimilation, denitrifying phosphorus removal (DPR), and microbial community. Acetate exhibited superior efficacy in promoting the combined process of ammonia assimilation and DPR, enhancing both to 50.0 % and 60.0 %, respectively. Proteobacteria and Bacteroidota facilitated ammonium assimilation, while denitrifying phosphorus-accumulating organisms (DPAOs) played a key role in nitrogen (N) and phosphorus (P) removal. Denitrifying glycogen-accumulating organisms (DGAOs) aided N removal in the anoxic zone, ensuring stable N and P removal and recovery. Acetate/propionate significantly enhanced DPR (77.7 %) and endogenous denitrification (37.9 %). Glucose favored heterotrophic denitrification (29.6 %) but had minimal impact on ammonium assimilation. These findings provide valuable insights for wastewater treatment plants (WWTPs) seeking efficient N and P removal and recovery from low-strength wastewater.


Assuntos
Compostos de Amônio , Águas Residuárias , Esgotos/microbiologia , Eliminação de Resíduos Líquidos , Anaerobiose , Fósforo , Carbono , Propionatos , Desnitrificação , Reatores Biológicos/microbiologia , Nitrogênio , Acetatos , Glucose
4.
J Environ Manage ; 354: 120489, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38402786

RESUMO

Reed belts acting as basic nutrient filters are important parts of lake buffer riparian zones. However, little is known about their impacts on nutrient release and bacterial community during plant litter decomposition. In this study, a field experiment was conducted in west-lake Taihu to monitor the changes in nutrients, bacterial enzymatic activities, and bacterial community in plant debris during Hydrilla verticillata (H. verticillata) decomposition in open water (HvC) and reed belts (HvL) area for 126 days. We found that there was lower temperature but higher nutrient concentrations in overlying water in HvL than HvC. Partial least squares path modeling revealed that environmental parameters in overlying water had important impacts on bacterial activities and nutrient release (such as alkaline phosphatase, cellulase, and soluble sugar) and therefore affected dissolved organic matter components in plant debris. According to Illumina sequencing, 46,003 OTUs from 10 dominant phyla were obtained and Shannon index was higher in HvL than HvC at the same sampling time. Neutral community model explained 49% of bacterial community variance and immigration rate by the estimate of dispersal in HvC (Nm: 27,154) and HvL (Nm: 25,765), respectively. Null model showed stochastic factors governed the bacterial community assembly in HvC (66.67%) and HvL (87.28%). TP and pH were key factors affecting the bacterial community structure at the phylum level. More hubs and complex interactions among bacteria were observed in HvL than HvC. Function analysis showed bacterial community had important role in carbon, organic phosphorus, and nitrogen removal but phosphorus-starvation was detected in debris of H. verticillata. This study provides useful information for understanding the changes in nutrients and bacterial community in litter during H. verticillata decomposition and highlights the role of reed belts on retained plant litter to protect lake from pollution.


Assuntos
Hydrocharitaceae , Bactérias , Plantas , Água , Nutrientes , Nitrogênio/análise , Fósforo/análise
5.
J Environ Manage ; 353: 120116, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38280251

RESUMO

Nutrient removal from sewage is transitioning to nutrient recovery. However, biological treatment technologies to remove and recover nutrients from domestic sewage are still under investigation. This study delved into the integration of ammonium assimilation with denitrifying phosphorus removal (DPR) as a method for efficient nutrient management in sewage treatment. Results indicated this approach eliminated over 80 % of the nitrogen in the influent, simultaneously recovering over 60 % of the nitrogen as the activated sludge through ammonia assimilation, and glycerol facilitated this process. The nitrification/denitrifying phosphorus removal ensured the stability of both nitrogen and phosphorus removal. The phosphorus removal rate exceeded 96 %, and the DPR rate reached over 90 %. Network analysis highlighted a stable community structure with Proteobacteria and Bacteroidota driving ammonium assimilation. The synergistic effect of fermentation bacteria, denitrifying glycogen-accumulating organisms, and denitrifying phosphorus-accumulating organisms contributed to the stability of nitrogen and phosphorus removal. This approach offers a promising method for sustainable nutrient management in sewage treatment.


Assuntos
Compostos de Amônio , Purificação da Água , Esgotos , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Desnitrificação , Fósforo , Reatores Biológicos , Nitrificação , Nutrientes , Nitrogênio
6.
Bioresour Technol ; 389: 129811, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37776912

RESUMO

The effects of aqueous phases (AP) formed from hydrothermal carbonation of sewage sludge (with or without rice husk) as moisture regulators of nitrogen metabolism pathways during composting are currently unclear. Macrogenomic analyses revealed that both APs resulted in notably changes in bacterial communities during composting; increased levels of nitrogen assimilation, nitrification, and denitrification metabolic pathways; and decreased levels of nitrogen mineralization metabolic pathways. Genes associated with nitrogen assimilation and mineralization accounted for 34-41% and 32-40% of the annotated reads related to nitrogen cycling during composting, respectively, representing them as the most abundant nitrogen metabolism processes. The gudB and norB were identified as key genes for nitrogen mineralization and nitrous oxide emission, respectively. This research offers a better understanding of the effects of additional nitrogen sources on nitrogen metabolism pathways during composting.

7.
Environ Sci Pollut Res Int ; 26(25): 25725-25732, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31267388

RESUMO

The tailings produce acid mine drainage (AMD) due to sulfide minerals, especially pyrite oxidation. AMD has caused serious pollution to the surrounding aquatic and terrestrial ecosystems because of its famous low pH value and high metal and sulfate concentration, which is an urgent environmental problem faced by the world's ore mining industry. Here, we show that silicic protective surface films can suppress the oxidation of pyrite-bearing tailings for AMD control at-source without pre-oxidation of pyrite and solution pH adjuster and buffer. We found that the silicic protective surface films formed by calcium silicate can inhibit the oxidation of pyrite-bearing tailings and reduce the production of AMD through chemical leaching tests. Fourier transform infrared (FTIR) analyses and scanning electron microscopy with energy-dispersive spectrometry (SEM/EDS) confirmed the presence of silicic protective surface films of calcium silicate on the surface of pyrite-bearing tailings.


Assuntos
Ácidos/química , Ferro/química , Metais/química , Minerais/química , Sulfatos/análise , Sulfetos/análise , Ecossistema , Mineração , Oxirredução , Sulfatos/química , Sulfetos/química
8.
Biosci Rep ; 38(6)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30413609

RESUMO

N-myc downstream-regulated gene 3 (NDRG3), an important member of the NDRG family, is involved in cell proliferation, differentiation, and other biological processes. The present study analyzed NDRG3 expression in hepatocellular carcinoma (HCC) and explored the relationship between expression of NDRG3 in HCC patients and their clinicopathological characteristics. We performed quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) analysis and immunohistochemistry (IHC) analyses on HCC tissues to elucidate NDRG3 expression characteristics in HCC patients. Kaplan-Meier survival curve and Cox regression analyses were used to evaluate the prognoses of 102 patients with HCC. The results revealed that compared with non-tumor tissues, HCC tissues showed significantly higher NDRG3 expression. In addition, our analyses showed that NDRG3 expression was statistically associated with tumor size (P=0.048) and pathological grade (P=0.001). Survival analysis and Kaplan-Meier curves revealed that NDRG3 expression is an independent prognostic indicator for disease-free survival (P=0.002) and overall survival (P=0.005) in HCC patients. The data indicate that NDRG3 expression may be considered as a oncogenic biomarker and a novel predictor for HCC prognosis.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/diagnóstico , Proteínas do Tecido Nervoso/genética , Regulação para Cima , Carcinoma Hepatocelular/genética , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/genética , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/análise , Prognóstico
9.
Med Sci Monit ; 24: 6021-6028, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30157168

RESUMO

BACKGROUND Sperm-associated antigen 5 (SPAG5), a gene that encodes a mitotic spindle-associated protein, is closely related to tumor development and is involved in cell migration and proliferation. The objective of this research was to explore the clinical significance of SPAG5 expression in hepatocellular carcinoma (HCC) and the relationship between SPAG5 expression and HCC prognosis. MATERIAL AND METHODS Twenty pairs of fresh-frozen HCC samples and samples from 95 HCC patients in a tissue microarray were subjected to quantitative real-time reverse-transcription (qRT)-PCR and immunohistochemistry (IHC), respectively, to investigate the relationship between the expression of SPAG5 and the clinicopathological features of HCC patients. RESULTS PCR data showed that the messenger RNA (mRNA) expression level of SPAG5 in HCC tissue specimens was higher than that in adjacent non-tumor tissue specimens (p<0.05). IHC analyses demonstrated that SPAG5 expression was significantly correlated with tumor grade (p=0.003), tumor number (p=0.009), vascular invasion (p=0.001), and TNM stage (p=0.001). Survival analysis and Kaplan-Meier curves showed that SPAG5 expression is an independent prognostic indicator for disease-free survival (p=0.017) and overall survival (p=0.016) in HCC patients. CONCLUSIONS Our results indicate that SPAG5 expression may be considered as an oncogenic biomarker and a novel predictor for HCC prognosis.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular/genética , Neoplasias Hepáticas/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/metabolismo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima
10.
Int J Clin Exp Pathol ; 11(8): 4035-4043, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31949793

RESUMO

OBJECTIVE: Cathepsin V, also known as CTSL2, plays an important role in tumor development and progression. This study was designed to investigate the clinical significance of CTSL2 expression in hepatocellular carcinoma (HCC) and the relationship between CTSL2 expression and prognosis. METHODS: Quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were performed to determine the levels of CTSL2 mRNA and protein, respectively, in tumor tissue and matched non-tumor (NT) tissue. Moreover, the relationship between CTSL2 expression and hepatocellular carcinoma's clinicopathological features and survival was evaluated in HCC tissue. RESULTS: The levels of CTSL2 mRNA and protein were increased in HCC tissue. Moreover, for HCC patients, a high level of CTSL2 protein was significantly correlated with tumor number (P = 0.008), pathological grade (P = 0.001), vascular invasion (P = 0.001), T (P = 0.001), and TNM stage (P = 0.006). A Kaplan-Meier analysis showed that elevated CTSL2 expression was correlated with shorter disease-free survival (DFS) (P < 0.001) and overall survival (OS) (P < 0.001). Furthermore, a multivariate analysis showed that CTSL2 expression was an independent prognostic factor for DFS (P = 0.032) and OS (P = 0.025). CONCLUSION: This study showed that abnormal CTSL2 expression may contribute to HCC progression and that elevated CTSL2 expression is associated with an adverse prognosis in HCC.

11.
Mol Immunol ; 93: 9-19, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29121519

RESUMO

Inflammatory bowel disease (IBD) is an autoimmune disease with an abnormal and persistent immune response. Iguratimod, a novel anti-rheumatic drug, exhibits anti-inflammatory effects and regulates immune response. The role of iguratimod in intestinal mucosal inflammation and immunity has not been examined. The aim of this study was to investigate whether iguratimod ameliorates dextran sulphate sodium (DSS)-induced murine colitis and its potential regulatory mechanism. Murine colitis was induced by administering 2.5% DSS for 5days. Some mice were administered iguratimod (5, 30mg/kg) by oral gavage once daily for 7days, beginning on the day 3 after colitis induction. Our study showed that iguratimod alleviates the symptoms of colitis and suppresses intestinal tissue damage, including macroscopic and histopathological manifestations. Moreover, iguratimod reduced interleukin (IL)-6, IL-17, and tumour necrosis factor-α levels, and increased the expression levels of IL-10 and TGF-ß. In addition, iguratimod downregulated the proportion of Th17 cells, the level of transcription factor retinoic acid-related orphan receptor γt (RORγt), and the phosphorylation of signal transducer and activator of transcription-3 (STAT3), and upregulated the proportion of Treg cells, the level of transcription factor forkhead box p3 (Foxp3), and the phosphorylation of STAT5 in the colonic tissues. In conclusion, iguratimod plays a protective role in mice with DSS-induced colitis via anti-inflammatory effects and regulation of Th17/Treg cells. Therefore, use of iguratimod may serve as a novel therapeutic strategy for the treatment of IBD.


Assuntos
Cromonas/uso terapêutico , Colite/tratamento farmacológico , Imunossupressores/uso terapêutico , Sulfonamidas/uso terapêutico , Linfócitos T Reguladores/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Animais , Cromonas/química , Cromonas/farmacologia , Colite/induzido quimicamente , Colite/imunologia , Colite/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Imunossupressores/farmacologia , Doenças Inflamatórias Intestinais , Interleucinas/biossíntese , Interleucinas/genética , Mucosa Intestinal/patologia , Linfonodos/imunologia , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Distribuição Aleatória , Organismos Livres de Patógenos Específicos , Baço/imunologia , Baço/patologia , Sulfonamidas/química , Sulfonamidas/farmacologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Fator de Crescimento Transformador beta/biossíntese , Fator de Crescimento Transformador beta/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética
12.
Clin Lab ; 63(11): 1903-1909, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29226636

RESUMO

BACKGROUND: The incidence of hepatocellular carcinoma (HCC) has increased over the past decades in China. Current screening methods of HCC such as detection of α-fetoprotein (AFP) combined with liver ultrasonography remain unsatisfactory. Many HCC patients have already missed the optimal treatment period when diagnosed. Our study aimed to evaluate the value of Glypican 3 (GPC3) and Golgi protein 73 (GP73) in the detection of HCC. METHODS: Thirty-nine patients with HCC and 31 patients with liver cirrhosis were enrolled. The level of serum GPC3 and GP73 were determined by ELISA. The expression of GPC3 mRNA and GP73 mRNA in peripheral blood mononuclear cell (PBMC) and liver tissues were also measured with qRT-PCR. Then, receiving operating characteristic (ROC) curves were plotted to detect the sensitivity and specificity of serum GPC3 and GP73 in the diagnosis of HCC. RESULTS: The levels of serum GPC3 and GP73 in the HCC group were significantly higher than in the cirrhosis group (p < 0.0001). Patients with GPC3 > 9.3 µg/L and GP73 > 77.68 ng/mL had a risk of HCC of 92.31%. The HCC diagnosis ROC curve analysis indicated that when setting the GPC3 cutoff value > 9.3 µg/L, AUC = 0.956. The sensitivity and specificity of GPC3 were 89.74% and 96.77%, respectively, with a positive predictive value of 97.2%, negative predictive value of 88.2%, + LR of 27.82 and - LR of 0.11. When setting GP73 cutoff value > 77.68 ng/mL, AUC = 0.937. The sensitivity and specificity of GP73 were 92.31% and 83.87%, respectively, with positive predictive value of 87.8%, negative predictive value of 89.7%, + LR of 5.72 and - LR of 0.092. No significant difference (p > 0.05) was found between GPC3 and GP73 AUC in ROC curves, indicating that these two biomarkers were equivalent in the prediction of HCC. CONCLUSIONS: The expression of serum GPC3 and GP73 was significantly higher in the HCC patients compared with the cirrhosis patients. GPC3 and GP73 might be effective non-invasive diagnostic indicators of HCC.


Assuntos
Carcinoma Hepatocelular/sangue , Glipicanas/sangue , Neoplasias Hepáticas/sangue , Proteínas de Membrana/sangue , Adulto , Carcinoma Hepatocelular/diagnóstico , Feminino , Humanos , Leucócitos Mononucleares/metabolismo , Fígado/metabolismo , Cirrose Hepática/sangue , Neoplasias Hepáticas/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
Nanoscale ; 6(21): 12792-7, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25226424

RESUMO

Nano-scale MoS2 thin films are successfully deposited on a variety of substrates by atmospheric pressure chemical vapor deposition (APCVD) at ambient temperature, followed by a two-step annealing process. These annealed MoS2 thin films are characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), micro-Raman, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-VIS-NIR spectrometry, photoluminescence (PL) and Hall Effect measurement. Key optical and electronic properties of APCVD grown MoS2 thin films are determined. This APCVD process is scalable and can be easily incorporated with conventional lithography as the deposition is taking place at room temperature. We also find that the substrate material plays a significant role in the crystalline structure formation during the annealing process and single crystalline MoS2 thin films can be achieved by using both c-plane ZnO and c-plane sapphire substrates. These APCVD grown nano-scale MoS2 thin films show great promise for nanoelectronic and optoelectronic applications.

14.
Water Sci Technol ; 67(5): 983-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23416588

RESUMO

This study explored the feasibility of utilizing lead-zinc tailings for phosphate removal in laboratory experiments. The adsorption isotherm, kinetics and pH effect were examined in batch experiments. The Freundlich and Langmuir isotherm models were used for data fitting. The adsorption kinetics can be best described by the simple Elovich equation. The phosphate adsorption tends to decrease with the increase of pH, from 0.37 mg P/g at pH 2.05 to 0.12 mg P/g at pH 7.01, and tends to increase from 0.12 mg P/g at pH 7.01 to 0.64 mg P/g at pH 12.52. The actual phosphate removal on the tailings could be a consequence of adsorption and precipitation reactions with Fe, Al and Ca. Due to their low cost, this type of tailings has the potential to be utilized for cost-effective removal of phosphate from wastewater.


Assuntos
Chumbo/química , Fosfatos/química , Água/química , Zinco/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Soluções , Termodinâmica
15.
Mol Biol Rep ; 39(4): 4145-53, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21779801

RESUMO

Members of the plant glycine-rich RNA-binding protein (GR-RBP) family play diverse roles in regulating RNA metabolism for various cellular processes. To understand better their function at the molecular level in stress responses, we cloned a GR-RBP gene, MhGR-RBP1, from Malus hupehensis. Its full-length cDNA is 558 bp long, with a 495-bp open reading frame, and it encodes 164 amino acids. The deduced amino acid sequence contains an RNA-recognition motif (RRM) at the amino terminal and a glycine-rich domain at the carboxyl terminal; these are highly homologous with those from other plant species. Multiple alignment and phylogenetic analyses show that the deduced protein is a novel member of the plant GR-RBP family. To characterize this gene, we also applied a model for predicting its homology of protein structure with other species. Both organ-specific and stress-related expression were detected by quantitative real-time PCR and semi-quantitative RT-PCR, indicating that MhGR-RBP1 is expressed abundantly in young leaves but weakly in roots and shoots. Transcript levels in the leaves were increased markedly by drought, hydrogen peroxide (H(2)O(2)), and mechanical wounding, slightly by salt stress. Furthermore, the transcript is initially up- and down-regulated rapidly within 24 h of abscisic acid (ABA) treatment. After 24 h of ABA and jasmonic acid (JA) treatments with different concentrations, the transcript levels of MhGR-RBP1 were significantly repressed. These results suggest that MhGR-RBP1 may be involved in the responses to abiotic stresses, H(2)O(2), ABA, or JA.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Malus/genética , Proteínas de Plantas/genética , Proteínas de Ligação a RNA/genética , Arabidopsis/genética , Clonagem Molecular , Modelos Moleculares , Dados de Sequência Molecular , Oryza/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estrutura Terciária de Proteína , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Análise de Sequência de DNA
16.
Plant Physiol Biochem ; 51: 81-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22153243

RESUMO

We compared two apple rootstocks -Malus prunifolia and Malus hupehensis - that differ in their tolerance to this abiotic stress. The former is considered drought-tolerant, the latter, sensitive. We monitored changes in their leaf ultrastructure and responses by their antioxidant defense systems. Irrigation was withheld for 12 d from two-year-old potted plants. Compared with the control, this treatment led to considerable ultrastructural alterations in organelles. Plants of M. prunifolia maintained their structural cell integrity longer than did M. hupehensis. M. hupehensis was more vulnerable to drought than was M. prunifolia, resulting in larger increases in the levels of H(2)O(2), O(2)(-), and MDA from the former. Except for catalase (CAT) and monodehydroascorbate reductase (MDHAR), the activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) analyzed here were enhanced to a greater extent in M. prunifolia than in M. hupehensis in response to drought. This was also true for levels of ascorbic acid (AsA) and glutathione (GSH). Under well-watered conditions, changes in lipid peroxidation and relevant antioxidant parameters were not significantly different between the two species throughout the experimental period. These results demonstrate that, in order to minimize oxidative damage, both the activities of antioxidant enzymes and antioxidant concentrations are increased in the leaves of M. prunifolia and M. hupehensis in response to water stress. Moreover, plants of M. prunifolia exhibit higher antioxidant capacity and a stronger protective mechanism, such that their cell structural integrity is better maintained during exposure to drought.


Assuntos
Secas , Malus/fisiologia , Folhas de Planta/ultraestrutura , Raízes de Plantas/fisiologia , Estresse Fisiológico , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Ativação Enzimática , Ensaios Enzimáticos , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Malus/metabolismo , Microscopia Eletrônica de Transmissão , NADH NADPH Oxirredutases/metabolismo , Células Vegetais , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Água/metabolismo
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