Journal Article

Roles for mannitol and mannitol dehydrogenase in active oxygen-mediated plant defense

Pharr, D.M, Ehrenshaft, M, Williamson, J.D, Jennings, D.B. (North Carolina State University, Raleigh.)

1998

Overview

Reactive oxygen species (ROS) are both signal molecules and direct participants in plant defense against pathogens. Many fungi synthesize mannitol, a potent quencher of ROS, and there is growing evidence that at least some phytopathogenic fungi use mannitol to suppress ROS-mediated plant defenses. Here we show induction of mannitol production and secretion in the phytopathogenic fungus Alternaria alternata in the presence of host-plant extracts. Conversely, we show that the catabolic enzyme mannitol dehydrogenase is induced in a non-mannitol-producing plant in response to both fungal infection and specific inducers of plant defense responses. This provides a mechanism whereby the plant can counteract fungal suppression of ROS-mediated defenses by catabolizing mannitol of fungal origin.

• Publisher: National Academy of Sciences of the United States of America,National Acad Sciences,National Academy of Sciences,The National Academy of Sciences
• Subject: ACTIVIDAD ENZIMATICA / ACTIVITE ENZYMATIQUE / ALCOHOL DEHYDROGENASE / ALCOHOL DESHIDROGENASA / ALCOHOL OXIDOREDUCTASES / ALCOOL DESHYDROGENASE / ALTERNARIA ALTERNATA / Biological Sciences / Biology / BIOSINTESIS / BIOSYNTHESE / BIOSYNTHESIS / Botany / CARBOHYDRATE METABOLISM / Celery / DEFENCE MECHANISMS / Defense mechanisms / Dehydrogenases / ENFERMEDADES FUNGOSAS / enzyme activity / Enzymes / ENZYMIC ACTIVITY / EXTRACTOS VEGETALES / EXTRAIT D'ORIGINE VEGETALE / Flowers & plants / FUNGAL DISEASES / fungal diseases of plants / Fungi / MALADIE FONGIQUE / MANITOL / MANNITOL / mannitol dehydrogenase / MECANISME DE DEFENSE / MECANISMOS DE DEFENSA / METABOLISME DES GLUCIDES / METABOLISMO DE CARBOHIDRATOS / NICOTIANA TABACUM / Oxygen / oxygen radicals / Pathogens / PLANT EXTRACTS / Plants / Reactive oxygen species / SECRECION / SECRETION