Mechanically induced wall appositions of plant cells can prevent penetration by a parasitic fungus.

Localized, paramural wall appositions resembling appositions commonly induced by fungal attack, were induced in kohlrabi (Brassica oleracea L. gongyloides) by mechanical wounding (bending) of the root hairs before the hairs were inoculated with zoospores of a compatible parasitic fungus. The appositions were effective in preventing fungal penetration at the wound sites, which shows that wall appositions can prevent fungal ingress into plant cells.