Histochemical changes of the epidermal cell wall of barley leaves infected by erysiphe graminis hordei

Summary

Chemical changes in the epidermal cell wall of barley leaves attacked byErysiphe graminis hordei were investigated by means of histochemical techniques and electron microscope. A very narrow area in the cuticle which was not stained by Sudan III was detected around the penetration point of this fungus. This is to indicate that the cuticle was changed either enzymatically or mechanically at the penetration point. According to the procedures using zinc-chloriodide and Schiff's reagent, it was obvious that the area of cellulose layer corresponding to the halo changed chemically, which suggested that the halo was attributable to the degeneration of the cellulose layer by the fungal enzyme, probably the cellulase. Electron micrographs showed that the cell wall around the penetration point was prominently electron dense and indicated an enzymic degeneration of the host cell wall.