Changes in polygalacturonase,pectin lyase and cellulase in tomato plants,associated withFusarium inoculation

Activities of polygalacturonase, pectin lyase, and cellulase increased in susceptible, catechol-treated, and resistant tomato plants, after inoculation withFusarium oxysporum f.lycopersici (Sacc.) Snyder and Hansen race 2. The catechol-treated and the resistant plants remained symptomless, while susceptible plants developed symptoms of disease. It is therefore suggested that increased activity of cell-wall-degrading enzymes in inoculated plants does not necessarily cause the development of disease symptoms.