N. Lisker - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Lea Cohen - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
E. Chalutz - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Y. Fuchs - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Ethylene-induced phenylalanine ammonia-lyase (PAL) activity in yellow grapefruit peel was inhibited by inoculation of the fruit with Penicillium digitatum, not only at a place close to the infection site but also in areas farther away from it. The degree of inhibition was related to the distance of the fungus from the assayed region. Other fungi tested such as a non-ethylene producing isolate of P. digitatum, an isolate of P. italicum and an isolate of Geotrichum candidum had a similar effect. This phenomenon was also found in orange fruit peel. PAL was not induced in the green fruit by ethylene and also not induced during natural infection of mature fruits by P. digitatum in spite of the production of ethylene during infection.
These findings indicate a mechanism whereby fungi are able to prevent the defence response of host cells to invasion.
N. Lisker - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Lea Cohen - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
E. Chalutz - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Y. Fuchs - Division of Fruit and Vegetable Storage, Institute for Technology and Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Ethylene-induced phenylalanine ammonia-lyase (PAL) activity in yellow grapefruit peel was inhibited by inoculation of the fruit with Penicillium digitatum, not only at a place close to the infection site but also in areas farther away from it. The degree of inhibition was related to the distance of the fungus from the assayed region. Other fungi tested such as a non-ethylene producing isolate of P. digitatum, an isolate of P. italicum and an isolate of Geotrichum candidum had a similar effect. This phenomenon was also found in orange fruit peel. PAL was not induced in the green fruit by ethylene and also not induced during natural infection of mature fruits by P. digitatum in spite of the production of ethylene during infection.
These findings indicate a mechanism whereby fungi are able to prevent the defence response of host cells to invasion.