SUMMARY
It was found, that the WSMV causes such nonspecific reactions of the plant cell as activation of lipid peroxidation and decrease of certain antioxidant enzymes (catalase et al.). It has been shown, that the activation of peroxidase, an increase of reduced glutathione content of cells, affected by WSMV, is the wheat plant protective reaction to the secondary oxidative stress that occurs in cells in the case of virus penetration.Conclusions. The study of the biochemical composition of wheat plants infected by WSMV, showed the presence of changes in some biochemical parameters which connected with the formation of plant defense mechanisms (content of photosynthetic pigments, protein, sugars, flavonoids, activity of PR proteins, intensity of oxidative and antioxidant processes). The obtained results can be used for selection of wheat varieties with economically valuable traits and complex resistance (both to climatic conditions of the environment and to phytoviral infections), which may be recommended for introduction into plant breeding and agricultural practice