Texture of host cell walls in mycorrhizal leeks

Abstract

The ultrastructural texture of cell walls as revealed by subtractive and cytochemical techniques in mycorrhizal and non mycorrhizal roots of Allium porrum is described. Three different cell walls types are involved in the mycorrhizal symbiosis: epidermal, hypodermal and cortical cell walls. While the first types are thick, autofluorescent, and rich in encrusting substances, the cortical cell walls are thin, not autofluorescent and without encrustation. Morphological observations show that the fungal penetration causes i) a clearcut break in the fibrillar component of the epidermal and hypodermal walls together with a deposition of an amorphous material, and ii) a pushing of cortical walls around the penetrating branch.