GLYCOLIC ACID OXIDASE AND FUSARIOSE WILT OF TOMATOES

Abstract
When roots of tomato plants are infected with Fusarium, systemic changes are induced in the activities of glycolic acid oxidase and glyoxylic reductase of the leaves. A marked decrease in glycolic acid oxidase activity is apparent 8–16 days after inoculation when the leaves show chlorotic symptoms. The depressed activity of this enzyme is due to a general decrease in the concentration of its flavin coenzyme, FMN. Both FMN and FAD begin to decrease after 8 days. On the other hand glyoxylic acid reductase shows an increased activity 20 days after infection. These alterations in enzymic activity result in a twofold accumulation of glycolic acid 20 days after infection even though the fungus is never present in the leaves.