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1.
J Plant Physiol ; 249: 153161, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32353607

RESUMEN

Optical leaf profiles depend on foliar pigment type and content, as well as anatomical aspects and cellular ultrastructure, whose effects are shown in several species. Monocotyledon and Dicotyledon plants presenting natural pigment content variations and anatomical alterations were analyzed. Each plant species displays its own spectral signatures, which are, in turn, influenced by foliar pigment class (composition) and concentration, as well as anatomical and ultrastructural plant cell characteristics. Plants with no anthocyanin displayed increased reflectance and transmittance in the green spectral region (501-565 nm), while values decreased in the presence of anthocyanin. At wavelengths below 500 nm (350-500 nm), strong overlapping signatures of phenolics, carotenoids, chlorophylls, flavonoids and anthocyanins were observed. Using a partial least squares regression applied to 350-700 nm spectral data allowed for accurate estimations of different foliar pigment levels. In addition, a PCA and discriminant analysis were able to efficiently discriminate different species displaying spectra overlapping. The use of absorbance spectra only was able to discriminate species with 100 % confidence. Finally, a discussion on how different wavelengths are absorbed and on anatomical interference of light interaction in leaf profiles is presented.


Asunto(s)
Pigmentos Biológicos/análisis , Hojas de la Planta/fisiología , Espectrofotometría/métodos , Cordyline/fisiología , Philodendron/fisiología , Poaceae/fisiología , Especificidad de la Especie , Tradescantia/fisiología
2.
Environ Pollut ; 240: 440-447, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29754093

RESUMEN

Biomonitoring is one of the tools used to assess the mutagenic potential of the atmosphere. In this study, the mutagenicity of Tradescantia pallida, a species of plant largely present in urban environments, was investigated. The objectives of this study was to estimate the mutagenic potential of vehicular flow through the TRAD-MCN bioassay in cities located at different altitudes in the southwest mesoregion of Mato Grosso do Sul, Brazil, to infer possible abiotic agents that may contribute to the effects of atmospheric pollutants, and finally to map the cities with greater risks to the health of the local population. To achieve these objectives, the Tradescantia-micronucleus test was performed on young buds of T. pallida collected between August 2015 and August 2016 in nine cities of Mato Grosso do Sul. These buds were exposed to traffic flows of various intensities. The data collected consisted of measurements of meteorological parameters and vehicular traffic counts for each city. The variables considered were: mean ambient temperature; micronuclei frequency; vehicular flow; altitude; relative humidity; pluviosity. The application of the Trad-MCN bioassay, with the consideration of environmental variables and altitudes, and the use of the Kernel interpolation technique, allowed us to map the areas with significant pollution risks to the population. The highest frequency of exposure to mutagens occurred in the cities with the highest vehicular traffic intensity. The average ambient temperature failed to show a linear association with the frequency of the micronuclei in the samples analyzed (r = 0.11ns). A positive correlation was observed between micronuclei frequency and vehicular flow, (r = 0.67; p ≤ 0.001%) and between micronuclei frequency and altitude (r = 0.24; p ≤ 0.05). A negative correlation was found between relative humidity and micronuclei frequency (r = -0.19; p ≤ 0.05%). Thus, higher micronuclei frequency tended to be present in locations with low relative humidity and high altitudes and vehicular flow.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Tradescantia/fisiología , Emisiones de Vehículos/toxicidad , Bioensayo/métodos , Brasil , Ciudades , Commelinaceae , Monitoreo del Ambiente/métodos , Contaminación Ambiental , Humedad , Pruebas de Micronúcleos , Mutágenos , Tradescantia/efectos de los fármacos , Tradescantia/genética
3.
Ecotoxicol Environ Saf ; 71(3): 717-21, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17996939

RESUMEN

The aims of this study were to determine clastogenic responses of Tradescantia pallida cv. Purpurea to naphthalene (NAPH) by means of the bioassay Trad-MCN with inflorescences of T. pallida cv. Purpurea and to verify if this assay might be an indicator of the potential risk imposed in a workplace, where solid insecticide containing NAPH is usually applied. The clastogenic potential of NAPH was assessed by using static and dynamic experimental systems. In both systems, increased micronucleus frequencies were observed in inflorescences submitted to increasing concentrations of solid or gaseous NAPH. The evident clastogenicity verified in inflorescences exposed experimentally to 25-50 mg m(-3) of NAPH during 6h points to a narrow threshold of plant sensitivity, indicating risks under lower NAPH levels than the standards established by OSHA and therefore revealing its suitability for biomonitoring purposes. However, the clastogenic risk should be carefully investigated by other monitoring methods if human health is taken into consideration.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Pruebas de Micronúcleos/métodos , Naftalenos/toxicidad , Tradescantia/efectos de los fármacos , Bioensayo , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente , Humanos , Insecticidas/toxicidad , Mutágenos/toxicidad , Estaciones del Año , Tradescantia/genética , Tradescantia/fisiología
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