Alternaria brassicae induced changes in the activity of cell wall degrading enzymes in leaves of Brassica juncea

After inoculation of Brassica juncea leaves with Alternaria brassicae, acti vities of the cell wall degrading enzymes, polygalacturonase (EC 3.2.1.15) and cellulase (EC 3.2.1.4) decreased in leaf blight resistant cultivar RC-7 81 and increased in the susceptible cultivar Varuna upto 3 d. In the leaves of both the cultivars 11 polypeptides were observed in the absence of A. b rassicae inoculation. After inoculation in the resistant cultivar RC-781 th ere was no change in the polypeptide pattern, while in the susceptible cult ivar Varuna, four polypeptides (43.7 to 58.8 kDa) disappeared only at 3(rd) day after inoculation.