Affinity of flavanols to cell walls: Changes after wounding, infection, lignification, and suberization

Callus, shoots and fruits of cherry, leaf, petioles and gall-trichomes of b each as well as balsa xylem were pretreated with a partially purified Aescu lus hippocastanum fraction, which contained different polymeric flavanols. After pretreatment, the samples were stained with dimethylaminocinnamaldehy de (DMACA), leading to tissues either with or without blue cell walls. Cell walls without affinity for flavanols showed no staining reaction and were either lignified, suberized or oxidized, indicating that all available bind ing sites for flavanols were occupied. Cell walls of young fungal hyphae showed a blue colour after pretreatment a nd staining with DMACA.