Altered specific activites of peroxidase and IAA oxidase due to infection of Drechslera graminea in barley (Hordeum vulgare L.)

This study was planned to determine the alterations in specific activities of two oxidative enzymes Peroxidase (E.C.1.11.1.7) and IAA Oxidase (E.C.1.13.16) in barley due to Drechslera graminea, causal agent of Leaf Stripe disease with the objective to investigate the role of these oxidative enzymes in host pathogen interactions. Healthy, naturally infected and artificially inoculated seeds and their seedlings at different time intervals after sowing of barley were used. Estimations of enzyme activities were done by using standard protocols. In seeds, specific activities of Peroxidase and IAA oxidase increased as the severity of infection increased thus it was highest in heavily infected among categories of naturally infected seeds. In all categories of seedlings healthy, naturally infected and artificially inoculated, peroxidase activity increased throughout from 10 to 30 days. Specific activity of IAA oxidase decreased initially upto 20 days and then increased in healthy (control) and artificially inoculated seedlings whereas in all categories of naturally infected seedlings, IAA oxidase specific activity increased throughout from 10th to 30th day of sowing.