Home – Home – Jornals – Siberian Journal of Forest Science 2017 number 6

Microclones of perennial shrub Weigela florida «Variegata» were prepared, adapted to the conditions of salinity and increased copper ions proportion during the three-step in vitro experiment. The process and the degree of adaptation were studied by determining the concentration of total soluble cell protein, free proline, specific enzyme activities and isozyme spectra of peroxidase, glucose-6-phosphate dehydrogenase, NADH dehydrogenase, isocitrate lyase, malate dehydrogenase, and malic enzyme. In the course of long-term adaptation (120 days, 3 passages), the level of proline in experimental plants is reduced to values below the constitutive parameters in the control. Plants that are grown on copper have the most differences from control ones for changes in enzyme activities and protein content. Malate dehydrogenase and malic enzyme behavioral model are most specific during the long-term adaptation to stress as in control and experienced plants. According to the metabolic response adaptation is the multifactorial process. The first factor is the function of enzymes, their participation in various metabolic cycles: CTC (malate dehydrogenase complex), oxidative branch of the pentose-phosphate cycle (glucose-6-phosphate dehydrogenase), electron transport chain (NADH dehydrogenase), connection with CTC via glyoxylate with metabolism of glycine and serine (extra-glyoxysomal isocitrate lyase), and antioxidant enzyme peroxidase. The second and fourth factors are the conditions of influence of salt stress and copper stress, respectively. The metabolic responses of the enzymes are dissimilar at different stages of adaptation under the action of stresses of unequal nature. The third factor is the conditions of in vitro cultivation, which affect ontogenetic processes. Thus, in the process of ontogenetic mature in the control plants the activity of NADH dehydrogenase (1.9-fold), isocitrate lyase (5.4-fold) and malate dehydrogenase (12.3-fold) increase, of activity of glucose-6-phosphate dehydrogenase (1.8-fold) and malic enzyme (2-fold) decrease. The activity of peroxidase remains at a constant level. We would like to highlight the idea that specific activities of only two representative enzymes such as isocitrate lyase and glucoso-6-phosphate dehydrogenase are sufficient to determine the processes necessary for normal adaptation of woody plants.