Silicon in cell walls and papillae of Cucumis sativus during infection by Sphaerotheca fuliginea

Abstract

The role of silicon in the enhancement of cucumber defence reactions against powdery mildew fungi was examined. Scanning transmission electron microscopy coupled with energy dispersive X-ray analysis and image analysis were used to map in situ distribution of silicon in cucumber leaves infected with Sphaerotheca fuliginea . Silicon was found in the papillae, in host cell walls, around the haustorial neck and in deposits between the host cell wall and plasma membrane. The deposition of silicon in these sites could be a rapid mechanism for modifying the cell wall during pathogen attack.