EFFECT OF APHID INFESTATION ON ENZYME-ACTIVITIES IN BARLEY AND WHEAT

The activities of three enzymes, glucose-6-phosphate dehydrogenase (G-6-PDH), 6-phosphogluconate dehydrogenase (6-P-GDH) and glutathione reductase (GlutRED) were determined in leaves and roots of barley and wheat non-infested and infested with Sitobion avenae. Glucose-6-P dehydrogenase activity increased 66% in leaves and 16% in roots of plants infested for 3 days, whereas the activity decreased 33 and 50% in roots and leaves respectively after 9 days of infestation. 6-Phospho-gluconate-dehydrogenase activity increased 45% in roots and 12% in leaves of barley infested for 3 days and 33 and 6% for 9 days. Glutathione reductase activity increased 75% in roots and 31% in leaves of barley infested for 3 days and 125 and 32% for 9 days. The activities of G-6-PDH and 6-P-GDH in roots of infested wheat for 9 days decreased 36 and 33%, respectively. GlutRED activity increased 30 and 58% in roots and leaves, respectively.