Biotechnologie, Agronomie, Société et Environnement (Jan 2001)
Synthèse bibliographique: la divinyl éther synthase de plantes
Abstract
Divinyl ether synthase in plants: a review. Divinyl ether synthase, an enzyme of the lipoxygenase pathway transforms, in potato tubers, 9-hydroperoxides of fatty acids into colneleic and colnelenic acid, two divinyl ethers of fatty acids. The enzyme has been described in a limited number of quite different plants. The enzyme has also been detected in tomato roots, garlic bulbs, tobacco plants and in marine algae. The enzyme is bound to membranes and is located in the microsomal fraction. The molecular weight of the enzyme exceeds 100,000 Da, its optimal pH is around 9 and its high specificity for 9-hydroperoxides as substrate is described. The reactional mechanism has been elucidated using radio-labelled molecules. Colneleic and colnelenic acid can be degraded enzymatically or not into aldehydes and oxo-acids. Those last compounds are also formed by the action of hydroperoxide lyase on 9-hydroperoxides of fatty acids. As other enzymes of the lipoxygenase pathway, reaction products of divinyl ether synthase are involved in pathogenic resistance. Colneleic and colnelenic acid content in potato plants has been corelated with resistance to Phytophthora infestans.