engleski

The differences in biochemical mechanisms of cadmium tolerance in three soybean cultivars

An increased cadmium content in agricultural soils causes changes in the physiological and biochemical processes in plants, affecting their growth and yield. Different plant species, but also the different cultivars of the same species, widely vary in the terms of cadmium accumulation and tolerance. In this respect, the production of soybean (Glycine max L.) as a leading oil and protein culture is endangered by a low cadmium tolerance. Therefore, the aim of this study is to determine the differences in the biochemical mechanisms of cadmium tolerance in the leaves of three Croatian soybean cultivars (Korana, Ika, and Lucija), which differ in the capacity of cadmium accumulation. The soybean was hydroponically cultivated under the controlled conditions and exposed to cadmium (100 μmol L-1 ) for seven days. As the indicator of oxidative stress, the content of H2O2 and lipid peroxidation levels, expressed in terms of the thiobarbituric acid’s reactive substances, was determined, while an antioxidative status was determined by the activities of the antioxidative enzymes, such as the catalase, ascorbate peroxidase, glutathione peroxidase and guaiacol peroxidase. A cadmium treatment increased the lipid peroxidation levels in the leaves of all three soybean cultivars, indicating the presence of an oxidative stress. Also, the activity of glutathione peroxidase was increased in all cadmium‐treated plants, while other enzymes demonstrated different activity patterns in the investigated cultivars. The cultivar Korana, which manifested the highest level of cadmium accumulation, also manifested the highest level of tolerance with regard to two other cultivars. The most sensitive cultivar, Ika, with a moderate accumulation capacity, manifested the lowest level of an antioxidative response. The biochemical mechanisms of tolerance to a cadmium stress differed in the three investigated soybean cultivars, and a tolerance to cadmium was partly achieved by an increased antioxidative response.

antioxidative response; cadmium; oxidative stress; soybean; cultivars

nije evidentirano