Abstract
Changes in the degree of lipid Peroxidation and the activity of enzymes which scavenge active oxygens were investigated during the development of pine wilt disease. Current branches of 4-year-old Japanese black pine seedlings inoculated with the pine wood nematode were used as test materials. Malondialdehyde (MDA) content, an indicator of lipid peroxidation, increased in both the bark and xylem of inoculated seedling until dying of seedling. The increment of MDA content and the population growth of the nematode seem to reflect the degree of tissue deterioration. Changes in soluble protein content and peroxidase activity corresponded considerably to the change of MDA content. Peroxidase activity in the xylem increased more rapidly than that in the bark. Superoxide dismutase (SOD) activity in the xylem decreased after 4th week of inoculation. Catalase activity in the xylem decreased gradually after the inoculation. Trace of SOD activity and no catalase activity were detected in the bark. The present study suggests that damage of membrane-membrane lipid peroxidation-is involved in the development of pine wilt disease.
