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1.
J Biochem Mol Toxicol ; 33(11): e22396, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31557364

RESUMEN

The furocoumarin backbone is a promising platform for chemical modifications aimed at creating new pharmaceutical agents. However, the high level of biological activity of furocoumarins is associated with a number of negative effects. For example, some of the naturally occurring ones and their derivatives can show genotoxic and mutagenic properties as a result of their forming crosslinks with DNA molecules. Therefore, a particularly important area for the chemical modification of natural furocoumarins is to reduce the negative aspects of their bioactivity. By studying a group of 21 compounds-1,2,3-triazolyl modified derivatives of furocoumarin and peucedanin-using the SOS chromotest, the Ames test, and DNA-comet assays, we revealed modifications that can neutralize the structure's genotoxic properties. Theoretical aspects of the interaction of the compound library were studied using molecular modeling and this identified the leading role of the polyaromatic molecular core that takes part in stacking-interactions with the pi-systems of the nitrogenous bases of DNA.


Asunto(s)
Cumarinas/química , Furocumarinas/química , Sustancias Intercalantes/química , Mutágenos/química , Extractos Vegetales/química , Allium/citología , Apiaceae/química , Ensayo Cometa , Roturas del ADN de Doble Cadena/efectos de los fármacos , Roturas del ADN de Cadena Simple/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Guanina/química , Enlace de Hidrógeno , Meristema/efectos de los fármacos , Simulación del Acoplamiento Molecular , Salmonella typhimurium/efectos de los fármacos
2.
Tsitol Genet ; 50(5): 3-16, 2016.
Artículo en Inglés, Ruso | MEDLINE | ID: mdl-30480911

RESUMEN

A comparative cytological analysis of intra- and intertissular cytomictic interactions in early micro-sporogenesis of mono- and dicotyledonous plants was performed by the example of the two cellular systems - microsporocytes and tapetum. It is found that cytomixis is the component of intratissular interactions mainly. In the tapetum cells cytomixis is notable for structural and temporary taxon specific features. The nuclear migration in microsporocytes is confined mainly to zygotene-pachytene meiotic stages and characterized by a certain synchronism with cytomixis at the tapetum. Intertissular cytomictic interactions (tapetum - microsporocytes) were found in the monocot anthers only. Intertissular interactions are likely to reflect the intensification of competitive relations between the tapetum and microsporocytes for area in the process of anther tissue differentiation. Polyploid tapetum nucleus and syncytia being powerful acceptors are able to compete with microsporocytes and direct the chromatin translocation to their favor. The absence of intertissular interactions in dicots probably reflects a better balance between the processes of differentiation at somatic and generative tissues into microsporangium compared to monocots.


Asunto(s)
Allium/metabolismo , Gametogénesis en la Planta/genética , Lilium/metabolismo , Nicotiana/metabolismo , Allium/citología , Comunicación Celular , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Cromatina/química , Flores/citología , Flores/metabolismo , Lilium/citología , Meiosis , Polen/metabolismo , Polen/ultraestructura , Nicotiana/citología
3.
Angew Chem Int Ed Engl ; 54(1): 318-22, 2015 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-25395248

RESUMEN

Microscopy in the mid-infrared spectral range provides detailed chemical information on a sample at moderate spatial resolution and is being used increasingly in the characterization of biological entities as challenging as single cells. However, a conventional cellular 2D imaging measurement is limited in its ability to associate specific compositional information to subcellular structures because of the interference from the complex topography of the sample. Herein we provide a method and protocols that overcome this challenge in which tilt-series infrared tomography is used with a standard benchtop infrared microscope. This approach gives access to the quantitative 3D distribution of molecular components based on the intrinsic contrast provided by the sample. We demonstrate the method by quantifying the distribution of an exogenous metal carbonyl complex throughout the cell and by reporting changes in its coordination sphere in different locations in the cell.


Asunto(s)
Allium/citología , Imagenología Tridimensional/métodos , Análisis de la Célula Individual/métodos , Espectrofotometría Infrarroja/métodos , Tomografía Óptica/métodos , Allium/química , Allium/ultraestructura , Rayos Infrarrojos , Microscopía/métodos
4.
New Phytol ; 203(2): 378-387, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24787280

RESUMEN

The Scholander-Hammel pressure chamber has been used in thousands of papers to measure osmotic pressure, πc , turgor pressure, Pt , and bulk modulus of elasticity, ε, of leaf cells by pressure-volume (PV) curve analysis. PV analysis has been questioned in the past. In this paper we use micromechanical analysis of leaf cells to examine the impact on PV curve analysis of negative turgor in living cells (Pt ). Models predict negative Pt (-0.1 to -1.8 MPa) depending on leaf cell size and shape in agreement with experimental values reported by J. J. Oertli. Modeled PV curves have linear regions even when Pt is quite negative, contrary to the arguments of M.T. Tyree. Negative Pt is totally missed by PV curve analysis and results in large errors in derived πc and Pt but smaller errors in ε. A survey of leaf cell sizes vs habitat (arid, temperate, and rainforest), suggests that the majority of published PV curves result in errors of 0.1-1.8 MPa in derived πc and Pt , whereby the error increases with decreasing cell size. We propose that small cell size in leaves is an ecological adaptation that permits plants to endure negative values of water potential with relatively little water loss.


Asunto(s)
Células Vegetales/fisiología , Hojas de la Planta/fisiología , Allium/citología , Tamaño de la Célula , Simulación por Computador , Análisis de Elementos Finitos , Hojas de la Planta/citología , Presión , Robinia/citología
5.
Am J Bot ; 101(1): 63-85, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24384305

RESUMEN

PREMISE OF THE STUDY: Reconstructing ancestral states is a useful method to understand the pathway and patterns of character evolution and to test specific hypotheses within a phylogenetic context. Using a phylogenetic hypothesis of the subgenus Amerallium and related subgenera based on molecular data, we reconstructed the evolutionary history of leaf blade anatomical characters and identified those characters that are most congruent with phylogenetic relationships. Furthermore, we used these character histories to investigate the evolution of terete leaves and explore a possible correlation between environment and leaf anatomy in the North American species. METHODS: Sixty-seven North American and Old World species were sampled from all major infrageneric taxa and lineages for transectional leaf anatomy. To provide a phylogenetic framework for interpretation, representatives of Old World Amerallium and related subgenera were added to a published data matrix of North American taxa and ITS, ETS, trnL-F, and rpL32-trnL sequences. KEY RESULTS: Four anatomical characters, namely leaf-blade shape in transection, presence versus absence of palisade mesophyll, distribution and orientation of vascular bundles, and position of laticifer cells, were found to be congruent with phylogenetic relationships and useful diagnostic traits within North American species. Character reconstructions show that terete leaves in North American species evolved from flattened leaves via a possible transition from subterete to terete leaves. Furthermore, terete leaves possess traits that are indicative of possible adaptation to xeric environments. CONCLUSIONS: The findings from this study provide valuable information for understanding the evolution of leaf-blade anatomy in North American Allium species.


Asunto(s)
Allium/anatomía & histología , Evolución Biológica , Hojas de la Planta/anatomía & histología , Allium/citología , Bases de Datos Genéticas , Funciones de Verosimilitud , América del Norte , Filogenia , Hojas de la Planta/citología , Especificidad de la Especie
6.
Physiol Plant ; 147(1): 101-11, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23078395

RESUMEN

Allium fistulosum was investigated as a novel model system to examine the mechanism of freezing resistance in cold hardy plants. The 250 × 50 × 90 µm average cell size and single epidermal cell layer system allowed direct observation of endoplasmic reticulum (ER), functional group localization during acclimation, freezing and thawing on an individual cell basis in live intact tissues. Cells increased freezing resistance from an LT50 of -11°C (non-acclimated) to -25°C under 2 weeks of cold acclimation. Samples were processed using Fourier transform infrared technology (FTIR) on a synchrotron light source and a focal plane array detector. In addition, confocal fluorescent microscopy combined with a cryostage using ER selective dye of ER-Tracker allowed more detailed examination of membrane responses during freezing. Cold acclimation increased the ER volume per cell, and the freeze-induced cell deformation stopped ER streaming and ER vesiculation subsequently occurred through the breakdown in the ER network. Freeze-induced ER vesicles in cold-acclimated cells were larger and more abundant than those in non-acclimated cells. According to FTIR, the carbohydrate/ester fraction and α-helical/ß-sheet secondary structure localized in the apoplast/plasma membrane region were most visibly increased during cold acclimation. Results suggest the mechanism of cold acclimation and freezing resistance in very hardy cells may be associated with both alterations in the apoplast/plasma membrane region and the ER cryodynamics. Allium fistulosum appears to be a useful system to obtain direct evidence at both intra and extracellular levels during cold acclimation and the freezing process.


Asunto(s)
Aclimatación/fisiología , Allium/citología , Allium/fisiología , Retículo Endoplásmico/ultraestructura , Congelación , Frío , Modelos Biológicos
7.
Sex Plant Reprod ; 25(2): 123-31, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22438078

RESUMEN

We examined callase activity in anthers of sterile Allium sativum (garlic) and fertile Allium atropurpureum. In A. sativum, a species that produces sterile pollen and propagates only vegetatively, callase was extracted from the thick walls of A. sativum microspore tetrads exhibited maximum activity at pH 4.8, and the corresponding in vivo values ranged from 4.5 to 5.0. Once microspores were released, in vitro callase activity peaked at three distinct pH values, reflecting the presence of three callase isoforms. One isoform, which was previously identified in the tetrad stage, displayed maximum activity at pH 4.8, and the remaining two isoforms, which were novel, were most active at pH 6.0 and 7.3. The corresponding in vivo values ranged from pH 4.75 to 6.0. In contrast, in A. atropurpureum, a sexually propagating species, three callase isoforms, active at pH 4.8-5.2, 6.1, and 7.3, were identified in samples of microsporangia that had released their microspores. The corresponding in vivo value for this plant was 5.9. The callose wall persists around A. sativum meiotic cells, whereas only one callase isoform, with an optimum activity of pH 4.8, is active in the acidic environment of the microsporangium. However, this isoform is degraded when the pH rises to 6.0 and two other callase isoforms, maximally active at pH 6.0 and 7.3, appear. Thus, factors that alter the pH of the microsporangium may indirectly affect the male gametophyte development by modulating the activity of callase and thereby regulating the degradation of the callose wall.


Asunto(s)
Allium/enzimología , Flores/enzimología , Gametogénesis en la Planta/fisiología , Ajo/enzimología , Glucano 1,3-beta-Glucosidasa/metabolismo , Infertilidad Vegetal/fisiología , Allium/citología , Allium/ultraestructura , Fertilidad/fisiología , Flores/citología , Flores/ultraestructura , Ajo/citología , Ajo/ultraestructura , Glucanos/metabolismo , Concentración de Iones de Hidrógeno , Meiosis , Microscopía Fluorescente , Polen/citología , Polen/ultraestructura , Especificidad de la Especie
8.
Cryo Letters ; 33(1): 45-57, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22434122

RESUMEN

This paper reviews a 10-year experience in establishing a cryopreserved Allium germplasm collection at the genebank of the National Agrobiodiversity Center, Republic of Korea. A systematic approach to Allium cryopreservation included: 1. revealing the most critical factors that affected regeneration after cryostorage; 2. understanding the mechanisms of cryoprotection by analyzing the thermal behavior of explants and cryoprotectant solutions using DSC and influx/efflux of cryoprotectants using HPLC; 3. assessing genetic stability of regenerants; and 4. revealing the efficiency of cryotherapy. Bulbil primordia, i.e. asexual bulbs formed on unripe inflorescences, proved to be the most suitable material for conservation of bolting varieties due to high post-cryopreservation regrowth and lower microbial infection level, followed by apical shoot apices from single bulbs and cloves. A total of 1,158 accessions of garlic as well as some Allium species have been cryopreserved during 2005-2010 using the droplet-vitrification technique with a mean regeneration percentage of 65.9 percent after cryostorage. These results open the door for large-scale implementation of cryostorage and for simplifying international exchange for clonal Allium germplasm.


Asunto(s)
Allium/citología , Criopreservación/métodos , Crioprotectores , Células Germinativas de las Plantas/citología , Allium/fisiología , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Frío , Células Germinativas de las Plantas/fisiología , Enfermedades de las Plantas/virología , Raíces de Plantas/crecimiento & desarrollo , Brotes de la Planta/crecimiento & desarrollo , Virus de Plantas , Regeneración , República de Corea , Vitrificación
9.
Gig Sanit ; (3): 37-9, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-23088122

RESUMEN

The Purpose--an estimation mitotoxic and genotoxic activities of sediments from small Blyava and Kuraganka rivers (Orenburg region) with the use of ana- telophase method. The results have shown the reduction in mitotoxic and genotoxic activities of the sediments over the 2007-2010 period.


Asunto(s)
Allium/crecimiento & desarrollo , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Mitosis/efectos de los fármacos , Pruebas de Mutagenicidad/métodos , Ríos , Contaminantes Químicos del Agua/análisis , Allium/química , Allium/citología , Animales , Humanos , Estudios Retrospectivos , Federación de Rusia
10.
Anal Chem ; 83(8): 2947-55, 2011 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-21388149

RESUMEN

Molecular imaging by mass spectrometry (MS) is emerging as a tool to determine the distribution of proteins, lipids, and metabolites in tissues. The existing imaging methods, however, mostly rely on predefined rectangular grids for sampling that ignore the natural cellular organization of the tissue. Here we demonstrate that laser ablation electrospray ionization (LAESI) MS can be utilized for in situ cell-by-cell imaging of plant tissues. The cell-by-cell molecular image of the metabolite cyanidin, the ion responsible for purple pigmentation in onion (Allium cepa) epidermal cells, correlated well with the color of cells in the tissue. Chemical imaging using single-cells as voxels reflects the spatial distribution of biochemical differences within a tissue without the distortion stemming from sampling multiple cells within the laser focal spot. Microsampling by laser ablation also has the benefit of enabling the analysis of very small cell populations for biochemical heterogeneity. For example, with a ∼30 µm ablation spot we were able to analyze 3-4 achlorophyllous cells within an oil gland on a sour orange (Citrus aurantium) leaf. To explore cell-to-cell variations within and between tissues, multivariate statistical analysis on LAESI-MS data from epidermal cells of an A. cepa bulb and a C. aurantium leaf and from human buccal epithelial cell populations was performed using the method of orthogonal projections to latent structures discriminant analysis (OPLS-DA). The OPLS-DA analysis of mass spectra, containing over 300 peaks each, provided guidance in identifying a small number of metabolites most responsible for the variance between the cell populations. These metabolites can be viewed as promising candidates for biomarkers that, however, require further verification.


Asunto(s)
Allium/citología , Antocianinas/análisis , Citrus/química , Células Epiteliales/citología , Imagen Molecular , Raíces de Plantas/citología , Allium/metabolismo , Antocianinas/metabolismo , Humanos , Análisis Multivariante , Hojas de la Planta/química , Raíces de Plantas/metabolismo , Espectrometría de Masa por Ionización de Electrospray
11.
BMC Plant Biol ; 10: 40, 2010 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-20196842

RESUMEN

BACKGROUND: Electron microscopy (EM) techniques enable identification of the main accumulations of lead (Pb) in cells and cellular organelles and observations of changes in cell ultrastructure. Although there is extensive literature relating to studies on the influence of heavy metals on plants, Pb tolerance strategies of plants have not yet been fully explained. Allium sativum L. is a potential plant for absorption and accumulation of heavy metals. In previous investigations the effects of different concentrations (10(-5) to 10(-3) M) of Pb were investigated in A. sativum, indicating a significant inhibitory effect on shoot and root growth at 10(-3) to 10(-4) M Pb. In the present study, we used EM and cytochemistry to investigate ultrastructural alterations, identify the synthesis and distribution of cysteine-rich proteins induced by Pb and explain the possible mechanisms of the Pb-induced cellular defense system in A. sativum. RESULTS: After 1 h of Pb treatment, dictyosomes were accompanied by numerous vesicles within cytoplasm. The endoplasm reticulum (ER) with swollen cisternae was arranged along the cell wall after 2 h. Some flattened cisternae were broken up into small closed vesicles and the nuclear envelope was generally more dilated after 4 h. During 24-36 h, phenomena appeared such as high vacuolization of cytoplasm and electron-dense granules in cell walls, vacuoles, cytoplasm and mitochondrial membranes. Other changes included mitochondrial swelling and loss of cristae, and vacuolization of ER and dictyosomes during 48-72 h. In the Pb-treatment groups, silver grains were observed in cell walls and in cytoplasm, suggesting the Gomori-Swift reaction can indirectly evaluate the Pb effects on plant cells. CONCLUSIONS: Cell walls can immobilize some Pb ions. Cysteine-rich proteins in cell walls were confirmed by the Gomori-Swift reaction. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification and tolerance under Pb stress. Vacuoles are ultimately one of main storage sites of Pb. Root meristematic cells of A. sativum exposed to lower Pb have a rapid and effective defense system, but with the increased level of Pb in the cytosol, cells were seriously injured.


Asunto(s)
Allium/metabolismo , Plomo/metabolismo , Raíces de Plantas/metabolismo , Allium/citología , Membrana Celular/ultraestructura , Pared Celular/metabolismo , Citosol/metabolismo , Retículo Endoplásmico/ultraestructura , Meristema/metabolismo , Meristema/ultraestructura , Microscopía Electrónica de Transmisión , Mitocondrias/ultraestructura , Raíces de Plantas/ultraestructura , Vacuolas/metabolismo
12.
J Biomed Biotechnol ; 2010: 189252, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20617136

RESUMEN

I. viscosa has been used for years in folk medicine for its anti-inflammatory, antipyretic, antiseptic, and paper antiphlogistic activities. In this study, cytotoxic and genotoxic effects of I. viscosa leaf extracts on the root meristem cells of Allium cepa have been examined. Onion bulbs were exposed to 2.5 mg/ml, 5 mg/ml, and 10 mg/ml concentrations of the extracts for macroscopic and microscopic analysis. Tap water has been used as a negative control and Ethyl methanesulfonate (EMS) (2 * 10(-2) M) has been used as a positive control. The test concentrations have been determined according to doses which are recommended for use in alternative medicine. There has been statistically significant (P < .05) inhibition of root growth depending on concentration by the extracts when compared with the control groups. All the tested extracts have been observed to have cytotoxic effects on cell division in A. cepa. I. viscosa leaf extract induces the total number of chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells significantly when compared with control groups. Also, this paper shows for the first time the induction of cell death, ghost cells, cells with membrane damage, and binucleated cells by extract treatment. These results suggest the cytotoxic and genotoxic effects of the I. viscosa leaf extracts on A. cepa.


Asunto(s)
Allium , Inula/química , Extractos Vegetales/toxicidad , Hojas de la Planta/química , Allium/citología , Allium/genética , Análisis de Varianza , Membrana Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Aberraciones Cromosómicas/efectos de los fármacos , Análisis Citogenético , Meristema/citología , Meristema/genética , Micronúcleos con Defecto Cromosómico/efectos de los fármacos , Mitosis/efectos de los fármacos , Pruebas de Mutagenicidad , Raíces de Plantas/citología
13.
Plant J ; 56(1): 116-31, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18557839

RESUMEN

Transversely oriented cortical microtubules in elongating cells typically reorient themselves towards longitudinal directions at the end of cell elongation. We have investigated the reorientation mechanism along the outer epidermal wall in maturing leek (Allium porrum L.) leaves using a GFP-MBD microtubule reporter gene and fluorescence microscopy. Incubating leaf segments for 14-18 h with the anti-actin or anti-actomyosin agents, 20 microm cytochalasin D or 20 mM 2,3-butanedione monoxime, inhibited the normal developmental reorientation of microtubules to the longitudinal direction. Observation of living cells revealed a small subpopulation of microtubules with their free ends swinging into oblique or longitudinal directions, before continuing to assemble in the new direction. Electron microscopy confirmed that longitudinal microtubules are partly detached from the plasma membrane. Incubating leaf segments with 0.2% 1 degree-butanol, an activator of phospholipase D, which has been implicated in plasma membrane-microtubule anchoring, promoted the reorientation, presumably by promoting microtubule detachment from the membrane. Stabilizing microtubules with 10 microm taxol also promoted longitudinal orientation, even in the absence of cytoplasmic streaming. These results were consistent with confocal microscopy of live cells before and after drug treatments, which also revealed that the slow (days) global microtubule reorientation is superimposed over short-term (hours) regional cycling in a clockwise and an anti-clockwise direction. We propose that partial detachment of transverse microtubules from the plasma membrane in maturing cells exposes them to hydrodynamic forces of actomyosin-driven cytoplasmic streaming, which bends or shifts pivoting microtubules into longitudinal directions, and thus provides an impetus to push microtubule dynamics in the new direction.


Asunto(s)
Actomiosina/metabolismo , Allium/citología , Allium/ultraestructura , Corriente Citoplasmática , Microtúbulos/ultraestructura , Citoesqueleto de Actina/efectos de los fármacos , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestructura , Actinas/metabolismo , Allium/genética , Aumento de la Célula , Membrana Celular/metabolismo , Citocalasina D/farmacología , Diacetil/análogos & derivados , Diacetil/farmacología , Genes Reporteros , Proteínas Fluorescentes Verdes , Microscopía Confocal , Microscopía Electrónica de Transmisión , Microscopía Fluorescente , Microtúbulos/efectos de los fármacos , Microtúbulos/metabolismo , Paclitaxel/farmacología , Hojas de la Planta/citología , Hojas de la Planta/genética , Hojas de la Planta/ultraestructura , Técnicas de Cultivo de Tejidos , Transformación Genética
14.
Plant Mol Biol ; 70(1-2): 211-7, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19219406

RESUMEN

Bimolecular fluorescence complementation (BiFC) is an approach used to analyze protein-protein interaction in vivo, in which non-fluorescent N-terminal and C-terminal fragments of a fluorescent protein are reconstituted to emit fluorescence only when they are brought together by interaction of two proteins to fuse both fragments. A method for simultaneous visualization of two protein complexes by multicolor BiFC with fragments from green fluorescent protein (GFP) and its variants such as cyan and yellow fluorescent proteins (CFP and YFP) was recently reported in animal cells. In this paper we describe a new strategy for simultaneous visualization of two protein complexes in plant cells using the multicolor BiFC with fragments from CFP, GFP, YFP and a red fluorescent protein variant (DsRed-Monomer). We identified nine different BiFC complexes using fragments of CFP, GFP and YFP, and one BiFC complex using fragments of DsRed-Monomer. Fluorescence complementation did not occur by combinations between fragments of GFP variants and DsRed-Monomer. Based on these findings, we achieved simultaneous visualization of two protein complexes in a single plant cell using two colored fluorescent complementation pairs (cyan/red, green/red or yellow/red).


Asunto(s)
Allium/citología , Proteínas Luminiscentes/análisis , Microscopía Fluorescente/métodos , Proteínas de Plantas/análisis , Fluorescencia
15.
J Cell Biol ; 104(6): 1515-9, 1987 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3294855

RESUMEN

F-actin has been identified in the preprophase band of Allium cepa. Cells attached to subbed slides were obtained from formaldehyde-fixed root tips digested in EGTA and Cellulysin. The air-dried cells were extracted in Triton X-100, treated with rhodamine-phalloidin, rinsed briefly in PBS, and viewed in the fluorescence microscope. Interphase cells contain a network of actin fibers that extends into all areas of the cytoplasm. During preprophase, the network is replaced by a band of fibers aligned in the position of the preprophase band. Colocalization of F-actin with rhodamine-phalloidin and microtubules with tubulin immunocytochemistry confirms that the two bands are coincident. The actin appears to comprise a thin layer of fibers next to the plasmalemma. Like the microtubule preprophase band, the actin band narrows as preprophase progresses and disappears by midprophase. Fluorescent actin bands are not seen in fixed cells pretreated with excess unlabeled phalloidin before staining. They are also absent in roots exposed to cytochalasins B and D before fixation, but preprophase band microtubules at all stages of aggregation are still present. Colchicine treatment leads to the loss of both preprophase band microtubules and actin. The possible function of preprophase band actin is discussed.


Asunto(s)
Actinas/análisis , Microtúbulos/ultraestructura , Profase , Allium/citología , Membrana Celular/ultraestructura , Colchicina/farmacología , Citocalasina B/farmacología , Citocalasina D , Citocalasinas/farmacología , Técnica del Anticuerpo Fluorescente , Interfase , Tubulina (Proteína)/análisis
16.
Plant Cell Rep ; 28(4): 695-702, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19148647

RESUMEN

The effects of lead and copper on the arrangement of microtubule (MT) cytoskeleton in root tip cells of Allium sativum L. were investigated. Batch cultures of garlic were carried out under defined conditions in the presence 10(-4) M Pb/Cu of various duration treatments. With tubulin immunolabelling and transmission electron microscopy (TEM), we found four different types of MT structures depending on the cell cycle stage: the interphase array, preprophase band, mitotic spindle and phragmoplast were typical for the control cells. Pb/Cu affected the mechanisms controlling the organization of MT cytoskeleton, and induces the following aberrations in interphase and mitotic cells. (1) Pb/Cu induced the formation of atypical MT arrays in the cortical cytoplasm of the interphase cells, consisting of skewed, wavy MT bundles, MT fragments and ring-like tubulin aggregations. (2) Pb/Cu disordered the chromosome movements carried out by the mitotic spindle. The outcome was chromosome aberrations, for example, chromosome bridges and chromosome stickiness, as well as inhibition of cells from entering mitosis. (3) Depending on the time of exposure, MTs disintegrated into shorter fragments or they completely disappeared, indicating MT depolymerization. (4) Different metals had different effects on MT organization. MTs were more sensitive to the pressure of Cu ions than Pb. Moreover, TEM observations showed that the MTs were relatively short and in some places wavy when exposed to 10(-4) M Pb/Cu solutions for 1-2 h. In many sections MTs were no longer visible with increasing duration of treatment (>4 h). Based on these results, we suggested that MT cytoskeleton is primarily responsible for Pb/Cu-associated toxicity and tolerance in plants.


Asunto(s)
Allium/citología , Cobre/farmacología , Interfase/efectos de los fármacos , Plomo/farmacología , Microtúbulos/efectos de los fármacos , Microscopía Electrónica de Transmisión , Microscopía Fluorescente , Microtúbulos/ultraestructura , Mitosis/efectos de los fármacos , Raíces de Plantas/citología
17.
Environ Monit Assess ; 153(1-4): 351-7, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18548325

RESUMEN

Fly ash is a by-product of coal-fired electricity generation plants. Its utilization and disposal is of utmost importance. Using onion (Allium cepa) root tip system, the present study was carried out to evaluate the potential toxic and genotoxic effects of fly ash, collected from a thermal power plant in West Bengal, India. Prior to testing, the collected fly ash sample was mixed with sand in different proportions. Allium bulbs were allowed to germinate directly in fly ash and after five days the germinating roots were processed for the Allium test. Additionally, the Allium test was adapted for detecting DNA damage through comet assay. The results from the Allium test indicate that fly ash at 100% concentration inhibits root growth and mitotic indices; induces binucleated cells as a function of the proportion, but is not toxic at very low concentration. In the comet assay, a statistical increase for DNA strand breaks was found only at higher concentrations. The sample was analyzed by flame atomic absorption spectrometer for Zn, Pb, Cu, Ni, Cd and As, whose presence could partly be responsible for the toxicity of fly ash. The study concludes that the classical Allium test can give a more comprehensive data when done in combination with the comet assay, which is faster, simpler and independent of mitosis. Also when fly ash is used for other purposes in combination with soils, it should be judiciously used at very low concentrations in order to protect the ecosystem health from any potential adverse effects.


Asunto(s)
Allium/efectos de los fármacos , Carbono/toxicidad , Ensayo Cometa/métodos , Material Particulado/toxicidad , Allium/citología , Allium/genética , Aberraciones Cromosómicas/inducido químicamente , Ceniza del Carbón , Daño del ADN/efectos de los fármacos , Raíces de Plantas/citología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética
18.
Biomed Pharmacother ; 97: 26-37, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29080455

RESUMEN

Lactoferrin has been known to have antimicrobial properties. This research was conducted to investigate the toxicity of Alginate/EUDRAGIT® S 100-enclosed chitosan-calcium phosphate-loaded Fe-bLf nanocapsules (NCs) by in vitro and in vivo assays. Brine shrimp lethality assay showed that the LC50 value of NCs was more than 1mg/mL which indicated that NCs was not toxic to Brine shrimp. However, the LC50 values for the positive control potassium dichromate at 24h is 64.15µg/mL, which was demostrated the toxic effect against the brine shrimp. MTT cytotoxicity assay also revealed that NCs was not toxic against non-cancerous Vero cell line with IC50 values of 536µg/mL. Genotoxicity studies by comet assay on Vero cells revealed that NCs exerted no significant genotoxic at 100µg/mL without tail or shorter comet tail. Allium cepa root assay carried out at 125, 250, 500 and 1000µg/mL for 24h revealed that the NCs was destitute of significant genotoxic effect under experimental conditions. The results show that there is no significant difference (p>0.05) in mitotic index between the deionized water and NCs treated Allium cepa root tip cells. In conclusion, no toxicity was observed in NCs in this study. Therefore, nontoxic NCs has the good potential to develop as a therapeutic agent.


Asunto(s)
Alginatos/toxicidad , Fosfatos de Calcio/toxicidad , Quitosano/toxicidad , Lactoferrina/toxicidad , Nanocápsulas , Ácidos Polimetacrílicos/toxicidad , Alginatos/administración & dosificación , Allium/citología , Allium/efectos de los fármacos , Animales , Artemia , Fosfatos de Calcio/administración & dosificación , Bovinos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Quitosano/administración & dosificación , Chlorocebus aethiops , Relación Dosis-Respuesta a Droga , Ácido Glucurónico/administración & dosificación , Ácido Glucurónico/toxicidad , Ácidos Hexurónicos/administración & dosificación , Ácidos Hexurónicos/toxicidad , Hierro/administración & dosificación , Hierro/toxicidad , Lactoferrina/administración & dosificación , Dosificación Letal Mediana , Mitosis/efectos de los fármacos , Mitosis/fisiología , Nanocápsulas/administración & dosificación , Ácidos Polimetacrílicos/administración & dosificación , Células Vero
19.
Afr Health Sci ; 17(1): 147-153, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29026388

RESUMEN

BACKGROUND: The unrefined nature of the herbal preparations from Vernonia amygdalina (VA) and toxicity potentials of Sniper may both have severe consequences on the biochemical and genetic systems. OBJECTIVES: To assess the microscopic and macroscopic effects of these substances. METHODS: VA leafs and Sniper were prepared and dissolved in distilled water to give different concentrations. Series of baseline tests were carried out to establish concentration range for root growth. Series of twelve onion bulbs of three per series was prepared, with a series of three onion bulbs serving as control. Chromosomal aberrations were statistically analysed using chi- squared test. Root bundle mean length was obtained after 96 hours and EC50 values at 95% confidence interval was determined from a plot of root length against sample concentrations using Microsoft Excel software. RESULTS: Total cytotoxic effect was induced by 2% sniper and 70% VA. EC50 for VA and sniper were 33.07 and 0.346 respectively. The two substances induced chromosomal aberrations and the effect was concentration dependent. CONCLUSION: There are risks of these widely used substances for therapeutic and environmental purposes.


Asunto(s)
Allium , Diclorvos/toxicidad , Pruebas de Mutagenicidad , Cebollas/efectos de los fármacos , Extractos Vegetales/toxicidad , Hojas de la Planta/química , Raíces de Plantas/química , Vernonia/química , Allium/citología , Análisis Citogenético , Diclorvos/farmacología , Humanos , Cebollas/toxicidad , Raíces de Plantas/citología
20.
Mater Sci Eng C Mater Biol Appl ; 58: 396-408, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26478326

RESUMEN

Antimony(III) halide complexes of the formulae {[SbBr(Me2DTC)2]n} (1), {[SbI(Me2DTC)2]n} (2) and {[(Me2DTC)2Sb(µ2-I)Sb(Me2DTC)2](+).I3(-)} (3) (Me2DTC = dimethyldithiocarbomate) were synthesized from SbX3, (X = Br or I) and tetramethylthiuram monosulfide (Me4tms) or tetramethylthiuram disulfide (Me4tds). The complexes were characterized by melting point (m.p.), elemental analysis (e.a.), Fourier-transform Infra-Red (FT-IR), Fourier-transform Raman (FT-Raman), Nuclear Magnetic Resonance ((1)H,(13)C-NMR) spectroscopy and Thermogravimetric-Differential Thermal Analysis (TG-DTA). Crystal structures of complexes 1-3 were determined with single crystal X-ray diffraction analysis. Complexes 1 and 2 are polymers with distorted square pyramidal (SP) geometry in each monomeric unit, whereas complex 3 is ionic, containing an iodonium linkage Sb-I(+)-Sb and an I3(-) counter anion; to the best of our knowledge, this is the first ionic antimony(III) iodide complex. The in vitro cytotoxic activity of 1-3 against human adenocarcinoma cells: breast (MCF-7) and cervix (HeLa) cells and non-cancerous cells: MRC-5 (normal human fetal lung fibroblast cells) was evaluated with trypan blue (TB) and sulforhodamine B (SRB) assays. Among antimony(III) compounds with sulfur containing ligand, those of dithiocarbamates exhibit significant cytotoxic activity. Hirshfeld surface volumes were analyzed to clarify the nature of the intermolecular interactions by the 2D fingerprint plot. Molecules with lower H-all atoms inter-molecular interactions exhibit the higher activity against MCF-7 cells. The in vivo genotoxicity of 1-3 was evaluated by the mean of Allium cepa test. Alterations in the mitotic index values due to the chromosomal aberrations were observed in the case of complexes 2 and 3. Since, no such alteration is caused by 1, it makes this compound candidate for further study as potential drug.


Asunto(s)
Antimonio/farmacología , Ditiocarba/farmacología , Halógenos/farmacología , Tiram/química , Allium/citología , Allium/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Aberraciones Cromosómicas , Cristalografía por Rayos X , Ditiocarba/síntesis química , Ditiocarba/química , Células HeLa , Humanos , Enlace de Hidrógeno , Concentración 50 Inhibidora , Ligandos , Células MCF-7 , Espectroscopía de Resonancia Magnética , Conformación Molecular , Mutágenos/toxicidad , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Temperatura , Tiram/síntesis química , Tiram/toxicidad , Vibración
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