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São Cristóvão, Brazil

Guerrero-Zuniga L.A.,Mexican Institute of Petroleum | Rodriguez-Dorantes A.,Laboratorio Of Fisiologia Vegetal
International Journal of Oil, Gas and Coal Technology | Year: 2010

Since the initiation of the industrial age with its parallel reliance on the utilisation of the hydrocarbon reserves on earth, the biosphere has been increasingly exposed to an ever expanding chemical variety of anthropogenic origin. Phytoremediation is an environmental technology for the cleaning of polluted soils using plants that needs the knowledge about transport and fate of pollutants for the best clean-up strategy, this knowledge consists in understanding the physiological processes inside plants. Some of these biological processes that can contribute to the containment and/or remediation of contaminants and the mechanisms in phytoremediation are described in this manuscript. Copyright © 2010 Inderscience Enterprises Ltd.

Mendes B.S.S.,Laboratorio Of Fisiologia Vegetal | Willadino L.,Federal Rural University of Pernambuco | da Cunha P.C.,Federal Rural University of Pernambuco | Filho R.A.O.,Federal Rural University of Pernambuco | Camara T.R.,Federal Rural University of Pernambuco
Revista Caatinga | Year: 2011

The bromeliads are hardy plants with exotic beauty, appreciated by consumers worldwide. The species Ananas porteanus Hort ex C. Veitch Koch, in particular, shows great potential for floriculture. These plants acclimate easily to adverse environmental conditions like those found in semi-arid areas. To assess the salinity tolerance of A. porteanus there were two treatments, one without the addition of NaCl (control) and the other with 80 mmol L -1 NaCl. The experiment lasted 90 days and were evaluated in the shoot: shoot dry matter, chloride, sodium and potassium contents, Na + / K + rate, proline content, total soluble carbohydrates, total soluble proteins, total phenols, peroxidase activity, levels of chlorophyll "a" and "b" and membrane damage. Plants of A. porteanus treated with sodium chloride were able to maintain the integrity of the membrane at levels similar to those found in control plants and the maintenance of membrane integrity result in part from increased activity of peroxidase. The increase in proline and protein content also appears to be one of the strategies of this species to cope with damage caused by the excess of NaCl as well as the increase in levels of chlorophyll. Soluble carbohydrates are not used to adjust the osmotic potential in plants subjected to 80 mmol L -1 NaCl. The metabolic changes occurring in plants of A. porteanus treated with sodium chloride led to a new homeostasis that resulted in the plant tolerance to salt stress imposed.

Gharbi E.,Tunis el Manar University | Martinez J.-P.,Laboratorio Of Fisiologia Vegetal | Benahmed H.,Tunis el Manar University | Fauconnier M.-L.,University of Liege | And 2 more authors.
Physiologia Plantarum | Year: 2016

This study aimed to determine the effects of exogenous application of salicylic acid (SA) on the toxic effects of salt in relation to ethylene and polyamine synthesis, and to correlate these traits with the expression of genes involved in ethylene and polyamine metabolism in two tomato species differing in their sensitivity to salt stress, Solanum lycopersicum cv Ailsa Craig and its wild salt-resistant relative Solanum chilense. In S. chilense, treatment with 125 mM NaCl improved plant growth, increased production of ethylene, endogenous salicylic acid and spermine. The production was related to a modification of expression of genes involved in ethylene and polyamine metabolism. In contrast, salinity decreased plant growth in S. lycopersicum without affecting endogenous ethylene, salicylic or polyamine concentrations. Exogenous application of salicylic acid at 0.01mM enhanced shoot growth in both species and affected ethylene and polyamine production in S. chilense. Concomitant application of NaCl and salicylic acid improved osmotic adjustment, thus suggesting that salt and SA may act in synergy on osmolyte synthesis. However, the beneficial impact of exogenous application of salicylic acid was mitigated by salt stress since NaCl impaired endogenous SA accumulation in the shoot and salicylic acid did not improve plant growth in salt-treated plants. Our results thus revealed that both species respond differently to salinity and that salicylic acid, ethylene and polyamine metabolisms are involved in salt resistance in S. chilense. © 2016 Scandinavian Plant Physiology Society.

Pineda-Mendoza R.M.,National Polytechnic Institute of Mexico | Olvera-Ramirez R.,Laboratorio Of Fisiologia Vegetal | Martinez-Jeronimo F.,National Polytechnic Institute of Mexico
Hidrobiologica | Year: 2012

Cyanobacterial blooms are of great importance because of the toxic effects that these microorganisms are able to induce, particularly on aquatic organisms. Microcystins (MCs) are the principal toxins biosynthesized by cyanobacteria and are powerful inhibitors of the protein phosphatases 1 and 2A. Zooplankton filter feeders such as cladocerans are directly affected by MCs as a result of ingestion of cyanobacteria or contact with intracellular products when cyanobacterial cells break up during and after blooms. A total of 17 strains of filamentous cyanobacteria isolated from three urban lakes in Mexico City were characterized using the microcystin synthetase region mcyA-Cd. Acute 48-h toxicity was evaluated in different strains using the cladoceran Daphnia magna and total microcystin content was determined by enzyme-linked immunosorbent assay (ELISA). The mcyA-Cd region was amplified in 16 microcystin-producing strains; microcystins were detected in eight strains with values ranging from 0.1422 to 2.772 μg L-1. Nevertheless, all aqueous crude extracts induced acute toxicity in D. magna with LC50 values from 363.91 to 741.8 mg L-1 (dry weight). The toxicity observed in non-microcystin-producing strains may be induced by cyclic peptides other than microcystins (anabaenopeptins, microviridins and cyclamides). The results obtained warn of the toxigenic potential of filamentous cyanobacteria, since though Microcystis spp. is frequently predominant in blooms, other toxins and intracellular metabolites released by filamentous cyanobacteria may induce toxicity on aquatic organisms as well as humans.

Bianucci E.,National University of Rio Cuarto | Sobrino-Plata J.,Laboratorio Of Fisiologia Vegetal | Carpena-Ruiz R.O.,Autonomous University of Madrid | Del Carmen Tordable M.,National University of Rio Cuarto | And 3 more authors.
Metallomics | Year: 2012

Cadmium (Cd) is a well known heavy metal considered as one of the most toxic metals on Earth, affecting all viable cells that are exposed even at low concentration. It is introduced to agricultural soils mainly by phosphate fertilizers and causes many toxic symptoms in cells. Phytochelatins (PCs) are non-protein thiols which are involved in oxidative stress protection and are strongly induced by Cd. In this work, we analyzed metal toxicity as well as PCs implication on protection of peanut plants exposed to Cd. Results showed that Cd exposure induced a reduction of peanut growth and produced changes in the histological structure with a deposit of unknown material on the epidermal and endodermal cells. When plants were exposed to 10 μM Cd, no modification of chlorophyll, lipid peroxides, carbonyl groups, or hydrogen peroxide (H 2O2) content was observed. At this concentration, peanut leaves and roots glutathione (GSH) content decreased. However, peanut roots were able to synthesize different types of PCs (PC2, PC3, PC4). In conclusion, PC synthesis could prevent metal disturbance on cellular redox balance, avoiding oxidative damage to macromolecules. This journal is © The Royal Society of Chemistry 2012.

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