The effect of salinization on protein composition and proline content in organs of Salix vimi­nalis L. plants

Abstract

The salinization effect on protein accumulation and proline content in organs of Salix viminalis L. plants was investigated. The plants had been growing in pots with Stebnyk’s tailing soil (during 30 days). The soil of tailing with renewed biocenosis was used like control, for experiment we used soil with spreading of hlikohalophytes. Under saline stress the accumulation of proteins in stems and roots of S. viminalis plants was noticed. This may indicate a plant adaptation to stress. Only low molecular weight polypeptides, in particular proteins with Mr 30, 23, 22, 20, 17, 15, 12, 10 and 8 kD, were found in the electropherograms of all analyzed organs of S. viminalis plants (leaves, stems, roots). Their content significantly varied depending on the organ of the plant. The spectrums of low molecular weight proteins in organs of S. viminalis plants had qualitative and quantitative differences under normal and stress conditions, especially changes of proteins in experimental organs were more expressive. Low molecular weight proteins with Mr 19—21 kD were found in the roots of S. viminalis plants, both in the control and in the experimental variants, but their quantity was higher under salinity stress. An increased content of 22 kD proteins were detected in the stems of the plant, compared to the control. Also, 17 kD Mr proteins were found in the stems during stress, unlike under normal conditions. Less proteins with a molecular weight of 20—23 kD were synthesized in the plants compared to the control. However, we have found an increased content of Mr 10 kD protein in experimental leaves. The accumulation of proline due to salinity in the shoots and roots of S. viminalis plants was established, compared with the control. This can be explained by the water stress that occurs during salinization. Thus, due to the effect of salt stress in the organs of S. viminalis plants, the accumulation of low molecular weight stress proteins and proline was observed, which may indicate certain peculiarities of plant adaptation to salinity conditions.