RESUMO
This study has been completed in the frames of activities on the environment assessment in the vicinity of the Far Eastern center (FEC) on radioactive waste treatment (a branch of Fokino, Sysoev Bay). Underground waters collected at the FEC technical site were surveyed both with instrumental techniques and bioassays. Concentrations of some chemicals (ranged to the third hazard category) in the samples collected are over the permitted limits. Activities of 137Cs and 90Sr in waters amount up to 3.8 and 16.2 Bq/l, correspondingly. The integral pollution index is over 1 in all the samples and could amount up to 165. The Allium-test application allows the detection of the sample points where underground waters have an enhanced mutagenic potential. Dependencies between biological effects and pollution levels are analyzed. The findings obtained could be used for the monitoring optimized and decision making on rehabilitation measures to decrease negative influence of the enterprise on the environment.
Assuntos
Dano ao DNA/efeitos da radiação , Água Subterrânea , Radioisótopos de Estrôncio , Poluentes Radioativos da Água , Allium/efeitos da radiação , Humanos , Monitoramento de Radiação , Resíduos RadioativosRESUMO
Regulation of stomatal (gs ) and mesophyll conductance (gm ) is an efficient means for optimizing the relationship between water loss and carbon uptake in plants. We assessed water-use efficiency (WUE)-based drought adaptation strategies with respect to mesophyll conductance of different functional plant groups of the forest understory. Moreover we aimed at assessing the mechanisms of and interactions between water and CO2 conductance in the mesophyll. The facts that an increase in WUE was observed only in the two species that increased gm in response to moderate drought, and that over all five species examined, changes in mesophyll conductance were significantly correlated with the drought-induced change in WUE, proves the importance of gm in optimizing resource use under water restriction. There was no clear correlation of mesophyll CO2 conductance and the tortuosity of water movement in the leaf across the five species in the control and drought treatments. This points either to different main pathways for CO2 and water in the mesophyll either to different regulation of a common pathway.
Assuntos
Acer/fisiologia , Allium/fisiologia , Dióxido de Carbono/metabolismo , Euphorbiaceae/fisiologia , Fraxinus/fisiologia , Impatiens/fisiologia , Água/fisiologia , Acer/efeitos da radiação , Adaptação Fisiológica , Allium/efeitos da radiação , Secas , Euphorbiaceae/efeitos da radiação , Florestas , Fraxinus/efeitos da radiação , Impatiens/efeitos da radiação , Luz , Oxigênio/metabolismo , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Transpiração Vegetal/fisiologiaRESUMO
Efficacy of bioassays of "aberrant cells frequency" and "proliferative activity" in root meristem of Allium cepa L. is studied in the present work for a cyto- and genotoxicity assessment of natural waters contaminated with 90Sr and heavy metals in the vicinity of the radioactive waste storage facility in Obninsk, Kaluga region. The Allium-test is shown to be applicable for the diagnostics of environmental media at their combined pollution with chemical and radioactive substances. The analysis of aberration spectrum shows an important role of chemical toxicants in the mutagenic potential of waters collected in the vicinity of the radioactive waste storage facility. Biological effects are not always possible to explain from the knowledge on water contamination levels, which shows limitations of physical-chemical monitoring in providing the adequate risk assessment for human and biota from multicomponent environmental impacts.
Assuntos
Allium/efeitos dos fármacos , Allium/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Allium/genética , Dano ao DNA/genética , Intoxicação por Metais Pesados , Humanos , Intoxicação , Resíduos Radioativos , Radioisótopos de Estrôncio/toxicidade , Poluentes Químicos da Água/toxicidade , Contaminação Radioativa da Água/efeitos adversosRESUMO
Plants from the Allium genus are valued worldwide for culinary flavor and medicinal attributes. In this study, 16 cultigens of bunching onion (Allium fistulosum L.) were grown in a glasshouse under filtered UV radiation (control) or supplemental UV-B radiation [7.0 µ mol·m(-2) · s(-2) (2.68 W · m(-2))] to determine impacts on growth, physiological parameters, and nutritional quality. Supplemental UV-B radiation influenced shoot tissue carotenoid concentrations in some, but not all, of the bunching onions. Xanthophyll carotenoid pigments lutein and ß -carotene and chlorophylls a and b in shoot tissues differed between UV-B radiation treatments and among cultigens. Cultigen "Pesoenyj" responded to supplemental UV-B radiation with increases in the ratio of zeaxanthin + antheraxanthin to zeaxanthin + antheraxanthin + violaxanthin, which may indicate a flux in the xanthophyll carotenoids towards deepoxydation, commonly found under high irradiance stress. Increases in carotenoid concentrations would be expected to increase crop nutritional values.
Assuntos
Allium/fisiologia , Carotenoides/metabolismo , Clorofila/metabolismo , Pigmentação/efeitos da radiação , Brotos de Planta/fisiologia , Raios Ultravioleta , Allium/efeitos da radiação , Pigmentação/fisiologia , Brotos de Planta/efeitos da radiação , Doses de RadiaçãoRESUMO
Nitrate and nitrite concentrations were determined for sweet basil and scallions over 24h to determine if time of sampling or harvest impacts concentrations in raw vegetables. Also, nitrate and nitrite concentrations were determined separately for various edible parts of these plants. Basil had significant changes in nitrate and nitrite concentrations over a 24h period. Nitrate was correlated to changes in light intensity with a 3h lag time. The highest nitrate concentrations in basil (2777 ppm) occurred around 3h after the light intensity peaked and had low values (165-574 ppm) during the dark period. The scallion nitrate and nitrite concentrations were always low but nitrate showed a peak a few hours before sunrise. Nitrate and nitrite concentrations in some raw vegetables may be reduced by harvesting at the best time of day for each type of plant. Nitrate concentrations were different in the edible plant parts tested.
Assuntos
Allium/química , Nitratos/análise , Nitritos/análise , Ocimum basilicum/química , Extratos Vegetais/análise , Verduras/química , Allium/efeitos da radiação , Luz , Ocimum basilicum/efeitos da radiação , Fatores de Tempo , Verduras/efeitos da radiaçãoRESUMO
The chromosome aberrations in root meristem cells of welsh onion (Allium fistulosum L.) seeds after gamma-irradiation (5 and 10 Gy) of different-aged seeds (7, 19, 31, 43 and 55 months of storage) were studied. The irradiation dose of 5 Gy significantly increased the frequency of aberrant anaphases (FAA) for 31- and 43-months seeds; the dose of 10 Gy significantly increased the FAA in seeds of all age groups. The irradiation of young (7 months) seeds resulted in decreasing of the fraction of bridges to the control level of the old (55-months) seeds for the dose of 5 Gy and below the control level of the old seeds--for the dose of 10 Gy. Some peculiarities of cytogenetic parameters of genome instability and the germinating capacity of the seeds made it possible to suppose that the third year of storage is a critical period for the welsh onion seeds.
Assuntos
Allium/crescimento & desenvolvimento , Instabilidade Cromossômica/efeitos da radiação , Raios gama , Allium/genética , Allium/efeitos da radiação , Instabilidade Cromossômica/genética , Cromossomos de Plantas/genética , Cromossomos de Plantas/efeitos da radiação , Relação Dose-Resposta à Radiação , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/efeitos da radiação , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/efeitos da radiação , Fatores de TempoRESUMO
The average number of aberrations per aberrant cell was concluded to carry out information on chromosome instability peculiarities induced by different mutagens as it was shown in our previous work. The purpose of the current study was to present comparative analysis of intercellular distribution of number of aberrations and their theoretical approximations. Distribution of numbers of aberrations per cell in Allium cepa L. and Allium fistulosum L. root tip cells induced by different mutagenic factors (gamma-irradiation, thiotepa, formaldehyde and seed aging) have been studied. The results were approximated to theoretical Poisson, geometric and negative binomial distributions. The intercellular distribution of aberrations did not correspond to any of the used theoretical distributions when A. cepa seeds were gamma-irradiated. There was some, but not regular, accordance with theoretical distributions when chemical mutagens thiotepa in A. cepa and formaldehyde in A. fistulosum and seed aging in both species were evaluated. During seed aging frequency of aberrant cells increased more quickly in A. fistulosum in comparison with A. cepa.
Assuntos
Allium/genética , Instabilidade Cromossômica/genética , Cromossomos de Plantas/genética , Raios gama , Meristema/genética , Mutagênicos/toxicidade , Allium/efeitos dos fármacos , Allium/efeitos da radiação , Aberrações Cromossômicas/estatística & dados numéricos , Meristema/efeitos dos fármacos , Meristema/efeitos da radiação , Modelos Genéticos , Distribuição de PoissonRESUMO
Chromosomal aberrations (ChA) level was analyzed in the onion root meristem after the chronic irradiation with different dose capacities. It was shown that after the chronic irradiation with doses of 0.87 cGy, 2.61 cGy and 4.35 cGy the level of chromosomal aberrations depended on the dose capacity. Its value may also correspond to those which have been induced with accute irradiation. Biological efficacy of chronic irradiation may be from 20 to 1000 time folder in order to compare it with accute irradiation and this value depends on the irradiation regime.
Assuntos
Aberrações Cromossômicas/efeitos da radiação , Cromossomos de Plantas/efeitos da radiação , Meristema/efeitos da radiação , Allium/efeitos da radiação , Relação Dose-Resposta à Radiação , Raios gama , Raízes de Plantas/efeitos da radiação , Fatores de TempoRESUMO
The results of our study revealed a local biologically relevant surface water contamination in the radionuclide anomaly in the north of Russia (Perm region) by means of Allium shoenoprasum L. the anaphase-telophase chromosome aberration assay. This radionuclide anomaly was formed in 1971 as a result of an underground nuclear explosion with soil excavation. Specific activities of main dose-forming radionuclides in all examined reservoirs are below intervention levels officially adopted in Russia for drinking water. We found that 90Sr significantly contribute to induction of cytogenetic disturbances. Our previous and described here data suggest that metal ions and radionuclides combined exposure on the various biota species (with the dose below permissible exposure limits for human) may cause substantial biological effects in part be due to synergic response. The findings described here indicated that development of a new concept of radiation protection for humans and biota should be based on the clear understanding of biological effects of low doses of radiation in chronic exposure to multi-pollutant mixtures.
Assuntos
Água Doce/análise , Guerra Nuclear , Radioisótopos de Estrôncio/toxicidade , Contaminação Radioativa da Água/análise , Allium/genética , Allium/efeitos da radiação , Aberrações Cromossômicas , Relação Dose-Resposta à Radiação , Explosões , Testes de Mutagenicidade , Federação Russa , Radioisótopos de Estrôncio/análise , Radioisótopos de Estrôncio/normasRESUMO
The analysis of experimental data on the combined effect of 232Th and water from melted snow containing metal ions from industrally loaded territories on Tradescantia (clone 02) and on Allium shoenoprasum meristematic root tip cells treated with heavy natural radionuclides from natural water sources in the area of radioactive wastes storehouse is presented. It was demonstrated that plant meristematic cells response to heavy metals and heavy natural radionuclides, both from two-component model system and from natural water sources, have commom features.
Assuntos
Allium/genética , Metais Alcalinos/toxicidade , Metais Pesados/toxicidade , Resíduos Radioativos , Tradescantia/crescimento & desenvolvimento , Tradescantia/genética , Poluentes da Água/toxicidade , Allium/efeitos dos fármacos , Allium/efeitos da radiação , Análise Citogenética , Dano ao DNA , Meristema/efeitos dos fármacos , Meristema/efeitos da radiação , Estruturas Vegetais/efeitos dos fármacos , Estruturas Vegetais/efeitos da radiação , Tório/toxicidadeRESUMO
Analysis of chromosome instability (CI) is of great importance in view of pollution of the environment by genotoxic factors. Frequency of aberrant cells, spectrum of chromosome aberrations, damages of aberrant cell and distribution of aberrations in the cells are the most conventional parameters of CI. We have carried out the comparative analysis of the frequency of aberrant cells and the dynamics of aberrant cell damages induced by different mutagenic factors (alpha-irradiation from 241Am, gamma-irradiation from 60Co and tioTEPA) in Allium-test. This comparative analysis denotes that the studied parameters have different dynamics characterizing different mechanisms of CI in Allium cepa L.
Assuntos
Aberrações Cromossômicas , Mutagênicos , Allium/efeitos dos fármacos , Allium/genética , Allium/efeitos da radiação , Partículas alfa/efeitos adversos , Amerício/toxicidade , Antineoplásicos Alquilantes/efeitos da radiação , Radioisótopos de Cobalto/efeitos da radiação , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Raios gama/efeitos adversos , Tiotepa/efeitos da radiaçãoRESUMO
Bulbing was studied in shallot plants cultured in vitro. Bulbing occurred under a 16 h photoperiod with fluorescent + incandescent light and 30-50 g 1(-1) sucrose in the culture medium. Exogenous gibberellin (10 microM GA3) inhibited leaf and root growth and bulbing. When added to the medium at a concentration of 10 microM, three inhibitors of gibberellin biosynthesis (ancymidol, flurprimidol and paclobutrazol) promoted bulb formation and the percentage of bulbing. When ancymidol was used in combination with GA3, it did not reverse the effect of GA3 applied alone. Under treatments with 30-70 g l(-1) sucrose, bulbing ratios greater than those found in control plants were achieved by addition of ancymidol, and bulb fresh weight was increased in the same way. Ancymidol caused a 66% decrease in sucrose content in leaf bases but greatly increased the glucose, fructose and fructan contents. The increase in fructan content by ancymidol could result from the three-fold rise in total [14C]sucrose uptake per plant from the culture medium associated with a marked increase in leaf base labelling at the expense of root labelling. The possible role of ancymidol is discussed and evidence supports a major regulatory role for gibberellins in bulbing.
Assuntos
Allium/crescimento & desenvolvimento , Metabolismo dos Carboidratos , Caules de Planta/crescimento & desenvolvimento , Pirimidinas/farmacologia , Sacarose/farmacologia , Allium/efeitos dos fármacos , Allium/efeitos da radiação , Transporte Biológico , Radioisótopos de Carbono , Técnicas de Cultura , Frutanos/metabolismo , Frutose/metabolismo , Giberelinas/antagonistas & inibidores , Giberelinas/biossíntese , Glucose/metabolismo , Luz , Fotoperíodo , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Caules de Planta/efeitos dos fármacos , Caules de Planta/efeitos da radiação , Triazóis/farmacologiaRESUMO
The purpose of this study was to elucidate the genome damage induced by 241Am-irradiation using different parameters of cytogenetic evaluation in Allium-test. The root tip cells test-system for the cytogenetic effects studying was used. 241AmCl3 of different concentrations was used (1.5 x 10(-9)-1.5 x 10(-7) g/l). Water solution-to-plant transfer factor for 241Am was found to be 0.18 +/- 0.04. The internal doses of 241Am accumulated during germination were 0.37-37.00 cGy. The impact of 241Am-irradiation was evaluated on the mitotic index (MI), the yield of aberrant anaphases (AA), the distribution of chromosome aberrations number in cells and the average level of lesion of aberrant cell (LAC). Probably all these parameters are differ in sensitivity to damage factor, but only some changes in MI was revealed. It is supposed, that the absence of any changes in the distribution of chromosome aberrations number in cells and the average level of LAC in 241Am-irradiated cells confirm the absence of significant 241Am-impact on chromosomes, as the alpha-irradiation should cause significant damages in chromosomes. Although solutions of 241Am were high-concentrated, the seedlings didn't accumulate high internal doses. It appears the distribution of 241Am is a significantly heterogeneous hence it is possible the absorbed doses in nuclei can't reach the level necessary for revealing of cytogenetic effects.
Assuntos
Allium/efeitos da radiação , Amerício/toxicidade , Aberrações Cromossômicas , Allium/genética , Genoma de PlantaRESUMO
The single-cell gel electrophoresis or comet assay, under high alkaline conditions, detects low levels of DNA damage. In it, broken DNA migrates from the nucleus to the anode providing images similar to comets. To adapt this assay to solid tissue cells, nuclei were directly obtained from Allium cepa L. roots. The surface of each single fresh sharply cut meristem was exposed to a small drop of 50 mM Sörensen buffer at pH 6.8, placed on a regular agarose-coated slide. By immediately adding low melting point agarose at 30 degrees C, nuclei resulted embedded in agarose. A final layer of this agarose ended the preparative steps. Conventionaly prepared leukocytes were used as a control. The treatment with detergent (lysis step of the conventional assay) proved to be unnecessary for the nude nuclei. A 20 min-long electrophoresis (at 0.65 V. cm-1, 230 mA and 10 degrees C) was more sensitive than a 10 min-long one for detecting the differential response of plant nuclei to 2 and 4 Gy of gamma-irradiation. A short fixation in methanol transformed the preparations into semi-permanent ones, without altering their later DNA staining by ethidium bromide. The use of instantaneously isolated nuclei simplifies and expands the use of this technique to any eukaryotic cell from solid tissues.
Assuntos
Allium/efeitos da radiação , Dano ao DNA , Leucócitos/efeitos da radiação , Análise de Variância , Núcleo Celular/efeitos da radiação , Núcleo Celular/ultraestrutura , DNA/sangue , DNA/efeitos da radiação , DNA de Plantas/análise , DNA de Plantas/efeitos da radiação , Eletroforese/métodos , Raios gama , Humanos , Meristema , Microscopia de Fluorescência , Testes de Mutagenicidade/métodosRESUMO
Arabidopsis COP1 acts as a repressor of photomorphogenesis in darkness, and light stimuli abrogate this suppressive action. COP1, when fused to beta-glucuronidase (GUS), is enriched in the nucleus in darkness, but not in the light, in hypocotyl cells of Arabidopsis seedlings and epidermal cells of onion bulbs. In Arabidopsis hypocotyl cells, the nuclear GUS-COP1 level changes in response to dark-light transitions and quantitatively correlates with the extent of repression of photomorphogenic development. In root cells, GUS-COP1 is constitutively nuclear, consistent with an established role of COP1 in suppressing root chloroplast development in both light and darkness. We conclude that COP1 acts inside the nucleus to suppress photomorphogenesis and that light inactivation of COP1 involves a cell type-specific control of its nucleocytoplasmic partitioning.
Assuntos
Proteínas de Arabidopsis , Arabidopsis/efeitos da radiação , Proteínas de Transporte/metabolismo , Compartimento Celular , Proteínas de Plantas/metabolismo , Proteínas Repressoras/metabolismo , Ubiquitina-Proteína Ligases , Allium/efeitos da radiação , Arabidopsis/crescimento & desenvolvimento , Núcleo Celular/metabolismo , Cloroplastos/metabolismo , Citoplasma/metabolismo , Escuridão , Expressão Gênica , Glucuronidase/genética , Glucuronidase/metabolismo , Hipocótilo/metabolismo , Hipocótilo/efeitos da radiação , Luz , Modelos Biológicos , Morfogênese/efeitos da radiação , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Recombinantes de Fusão/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Transdução de Sinais , Distribuição TecidualRESUMO
The RBE of p(75) + Be neutrons relative to d(50) + Be neutrons has been determined for chromosome aberrations induced in Allium cepa (onion) roots. Two biological criteria were selected: the average number of aberrations (mainly fragments) per cell in anaphase and telophase, and the percentage of aberration-free cells. The influence of sampling time (3 to 7 h incubation) between irradiation and fixation was investigated systematically. This factor did not significantly influence the results. The RBE values of p(75) + Be neutrons compared to those of d(50) + Be neutrons were 0.85 (0.79-0.91) and 0.87 (0.80-0.95) for the first and the second criteria, respectively. In previous experiments for the same beams, we found an RBE of 0.90 (0.86-0.94) for survival of V79 cells (D0 ratio), 0.96 (0.93-0.99) for the intestinal crypt cell system, and 0.83 (0.70-0.96) for Vicia faba growth delay.
Assuntos
Aberrações Cromossômicas , Nêutrons , Allium/efeitos da radiação , Berílio , Deutério , Prótons , Radiogenética , Eficiência Biológica RelativaRESUMO
The influence of polyamines (e.g. putrescine, spermine and spermidine) on the survival rate of HeLa cells and the mitotic index of A. cepa meristem cells, as well as a change in a radiation response of cells under the effect of polyamines have been investigated. Putrescine was shown to produce the lowest cytotoxic effect on mammalian cells, whereas the cytotoxic effect on plant cells was either insignificant or absent at all. One-hour incubation of HeLa cells with putrescine of 5 x 10(-4)-5 x 10(-5) M prior to or after irradiation with a dose of 6 Gy increased the survived cell fraction. Spermine of 10(-3) M increased considerably the mitotic index of the exposed meristem as compared to irradiated meristem untreated with spermine. The role of polyamines in the formation of radiation damage to a cell is discussed.
Assuntos
Allium/efeitos da radiação , Células HeLa/efeitos da radiação , Poliaminas/farmacologia , Allium/citologia , Allium/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Relação Dose-Resposta a Droga , Raios gama , Humanos , Mitose/efeitos dos fármacos , Mitose/efeitos da radiação , Putrescina/farmacologia , Espermidina/farmacologia , Espermina/farmacologiaRESUMO
The photodynamic effect of harmine and UV light was studied by measuring the number of sister-chromatid exchanges and micronuclei induced by this treatment in Allium cepa meristematic cells. A significant increase in the frequencies of both cytogenetic events was observed when proliferating cells were treated for 4 h with harmine followed by irradiation with UV light for 3 min.