RESUMO
MAIN CONCLUSION: The study is the first to reveal the proteomic response in plants to a single PAH stress, and indicates that NDPK3 is a positive regulator in the Arabidopsis response to phenanthrene stress. Polycyclic aromatic hydrocarbons (PAHs) are highly carcinogenic pollutants that are byproducts of carbon-based fuel combustion, and tend to persist in the environment for long periods of time. PAHs elicit complex, damaging responses in plants, and prior research at the physiological, biochemical, and transcriptional levels has indicated that reactive oxygen species (ROS) and oxidative stress play major roles in the PAH response. However, the proteomic response has remained largely unexplored. This study hypothesized that the proteomic response in Arabidopsis thaliana to phenanthrene, a model PAH, would include a strong oxidative stress signature, and would provide leads to potential signaling molecules involved. To explore that proteomic signature, we performed 2D-PAGE experiments and identified 30 proteins levels that were significantly altered including catalases (CAT), ascorbate peroxidase (APX), peroxiredoxins (POD), glutathione-S-transferase, and glutathione reductase. Also upregulated was nucleoside diphosphate kinase 3 (NDPK-3), a protein known to have metabolic and stress signaling functions. To address whether NDPK-3 functions upstream of the oxidative stress response, we measured levels of stress-responsive enzymes in NDPK-3 overexpressor, loss-of-function knockout, and wild-type plant lines. In the NDPK-3 overexpressor, the enzyme activities of APX, CAT, POD, as well as superoxide dismutase were all increased compared to wild type; in the NDPK-3 knockout line, these enzymes had reduced activity. This pattern occurred in untreated as well as phenanthrene-treated plants. These data support a model in which NDPK-3 is a positive regulator of the Arabidopsis stress response to PAHs.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Nucleosídeo NM23 Difosfato Quinases/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Catalase/genética , Catalase/metabolismo , Eletroforese em Gel Bidimensional , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Mutação , Nucleosídeo NM23 Difosfato Quinases/genética , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Proteoma/genética , Proteoma/metabolismo , Proteômica/métodos , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transcriptoma/efeitos dos fármacosRESUMO
In order to understand the possibility and spatial pattern of Benggang (collapsing hill) erosion in risk assessment and distinguish the primary and secondary areas in Benggang prevention, we took a small watershed in Anxi County (Fujian, China) as the study area and Benggang as the source, and constructed the Benggang expansion resistance surface using the minimum cumulative resistance (MCR) model and divided the risk zoning. The results showed that the area around Benggang displayed a low resistance value, while the northwest and southeast areas displayed a high resistance value. The Benggang expansion resistance surface had an island type form. Based on resistance surface, the research region was divided into very high-risk, high-risk, medium risk, low-risk and very low-risk zones. We proposed corresponding Benggang management suggestions for those zones. A total of 21 strategic saddle points were extracted based on the resistance surface morphology. The strategic points in the lower safety zone were considered as the priority areas for Benggang prevention. We compared the hazard results based on the MCR model and the information quantity method. These results were consistent in spatial distribution, indicating the reliability of the results of hazard zoning by the MCR model.
Assuntos
Planejamento de Cidades , Conservação dos Recursos Naturais , China , Conservação dos Recursos Naturais/métodos , Reprodutibilidade dos TestesRESUMO
With the seedlings of model plant Arabidopsis thaliana and the polycyclic aromatic hydrocarbon fluoranthene as test materials, this paper studied the physiological responses of plants to polycyclic aromatic hydrocarbons from the aspects of antioxidases and membrane protection system that are tightly related to abiotic stresses. The results showed that under fluoranthene stress, the seedlings experienced oxidative stress and membrane-lipid peroxidization. At 0.75 mmol x L(-1) of fluoranthene, the photosynthetic process was inhibited; at 1.00 mmol x L(-1) of fluoranthene, the malonaldehydic acid (MDA) content increased and the ascorbate peroxidase (APX) activity decreased significantly, indicating an accelerated membrane-lipid peroxidization; and at 1.25 mmol x L(-1) of fluoranthene, the peroxidase (POD) activity decreased significantly and H2O2 had a high accumulation, making the seedlings injured severely.