PORTUONDO FARIAS, Liane et al. Plasma Membrane Alterations in Phaseolus vulgaris L. Variety CC-25-9-N Induced by Metals. []. , 29, 2, pp. 53-63.   01--2020. ISSN 2071-0054.

It is in the early stages of the vegetative phase, when the plant manifests its greatest susceptibility to sudden changes in environmental conditions and unleashes adaptive pathways that include changes in the structure of cell membranes, as they are the first to respond to damage. The bean (Phaseolus vulgaris L.) is a crop of agricultural interest that can accumulate heavy metals and therefore, the possibility of developing mechanisms of tolerance to this type of stress. For these reasons, the work aimed to determine the existence of changes in the plasma membrane and in the antioxidant activity of leaves in bean plants germinated in presence of heavy metals. Seeds of the variety CC-25-9-N were germinated under controlled conditions with six specific concentrations of Pb2+, Ni2+ and Cu2+ cations. Fifteen days after seed´s germination, the tolerance limit, the lethal dose and changes in the permeability of the leaf membranes were determined through electrical conductivity, pH and the activity of total peroxidases and guaiacol peroxidase. The variability in the membrane permeability was checked from differences in the values of the electrical conductivity and the pH in each of the treatments, which depended on the metal and the concentration under study, as well as on the activity of the enzymes analyzed. These results suggest a possible specificity in the plant - metal interaction that implicate different response mechanisms.

: beans; toxic metals; oxidative stress; toxicity; peroxidases.

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