STUDY OF PEROXIDASE AND CATALASE DISTRIBUTION IN THE POTATO-TUBER

The activities of peroxidase and catalase were determined in consecutive segments from cores struck from heel to rose ends of potato tubers, cv. Majestic, which had been grown in plots of soil having nominal pH values of 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 and 7.5. Gradients of activity were computed and shown to be parabolic upwards for peroxidase and parabolic downwards for catalase at the higher soil pH levels but both tended to show linear trends in the more acid soils. The ratios of the activities of peroxidase to catalase were at a maximum between pH 5.5 and 6.0 and decreased towards either end of the pH range. © 1979, Annals of Botany Company.