Ultrastructural Observations of Pterostilbene Fungitoxicity in Dormant Conidia of <i>Botrytis cinerea</i> Pers.

Abstract

Abstract Pterostilbene is a known phytoalexin produced by the Vitaceae. It was identified in the grape berries of Vitis vinifera (var. Gamay and Pinot). Its mode of action on conidia of Botrytis cinerea is a rapid destruction of ribosomes, endoplasmic reticulum, and of mitochondrial and nuclear membrane. Plasma membrane is completely disorganized in three hours. Respiration of the conidia is totally inhibited ten minutes after the addition of the phytoalexin. The physico‐chemical properties ofpterostilbene and the ultrastructural observations of its effects show that this compound could act on membrane proteins and interfere in mitochondrial respiration processes.