PHENYLALANINE AMMONIA-LYASE (PAL) AND PEROXIDASE ACTIVITY IN BROWN RUST INFECTED TISSUES OF PAKISTANI WHEAT CULTIVARS

摘要

Besides other factors resistance and susceptibility is the outcome of biochemical processes such as activities of defenserelatedenzymes. So in this study, Phenylalanine ammonia-lyase (PAL) and Peroxidase activity of resistant (Inqilab-91) andsusceptible (Kirin-95) wheat cultivars were determined through spectrophotometer to address the biochemical aspect relatedto the disease after 8 hours, 24 hours, 48 hours and 72 hours of leaf rust inoculation. The results have shown that theseenzymes were present in both the resistant and susceptible cultivars but the activity was more pronounced in the resistantone. The effect of PAL and peroxidase activity was also investigated among inoculated and uninoculated plants within thesame cultivar. The activity of both PAL and peroxidase were more significant in inoculated ones. The results have shownthat the after 72 hours of inoculation Inqilab-91 had more PAL activity i.e., 5.47 IU/ml/min than in Kirin-95 i.e., 2.08IU/ml/min at 270 nm. While peroxidase activity in Inqilab-91 was 6.41 IU/ml/min and in Kirin-95, 3.66 IU/ml/min after 72hours of inoculation, observed under 470 nm wavelength. Increase in one’s activity increases the other enzyme’s activity.The activity was more prominent after 72 hours of infection as pathogen had successfully established itself in the host planttissue. The activities of these enzymes act as plants active defense mechanism against the attack of pathogen.