GERMINATING-SEEDS OF THE ROOT PARASITE OROBANCHE-AEGYPTIACA PERS EXCRETE ENZYMES WITH CARBOHYDRASE ACTIVITY

Germinating seeds of the root parasite Orobanche aegyptiaca Pers. were analyzed for the ability to excrete cell wall degrading enzymes, in a sterile environment, and without the host roots. Enzymatic activity w as detected by exposing the radicles and haustoria to different substr ates representing cell wall components. The extracellular activities o f polygalacturonase, carboxymethyl-cellulase and beta-glucosidase were detected. Optimum activity was observed on the second or third day fr om germination and it coincided with the time required by the parasite to penetrate the root cortex.