Oxidoreductase activity of soybeen seedlings at the early stage of ontogenesis

Abstract

The results of analysis of specific activity and multiple forms of oxidoreductase class enzymes are presented: antioxidant complex (catalase and peroxidase) and dehydrogenases (alcohol dehydrogenase, NAD+-malate dehydrogenase, glucose-6-phosphate dehydrogenase). Seven varieties of soybean (Glycine max (L.) Merrill) served as the object of the study. Dormant seeds and 3- and 7-day-old soybean seedlings were used for the analysis. Protein content was determined by the Lowry method, peroxidase activity was determined by colorimetric, catalase and the studied dehydrogenases – by spectrophotometric methods, electrophoretic spectra of enzymes – by electrophoresis on 7.5% polyacrylamide gel columns. Identification of the zones with enzymatic activity on the gel was performed by appropriate histochemical methods. Analysis of specific activity of antioxidant enzymes in dormant soybean seeds revealed increased activity of peroxidase and low activity of catalase. During seed germination, the inverse relationship of the specific activity of these enzymes is observed. On the 7th day the specific activity of catalase increases, that of peroxidase decreases to a minimum. In soybean germination, 5 forms of catalase were detected, indicating low polymorphism and stability of the enzyme, and 18 forms of peroxidase, which confirm high polymorphism and the possibility of using this enzyme as a marker of biochemical processes. Alcohol dehydrogenase and glucose-6-phosphate dehydrogenase were found to be of low heterogeneity, with the specific activity of these enzymes decreasing during germination compared to the dormant period of soybean seeds. The specific activity of NAD+-malate dehydrogenase increases slightly during germination. Eight forms of this enzyme were detected in the soybean varieties studied indicating increased polymorphism. In dormant soybean seeds, the electrophoretic spectra of NAD+-malate dehydrogenase exhibited varietal diversity allowing the enzyme to be used as a marker for further studies.