Cyanogenesis Inhibits Active Defense Reactions in Plants

Abstract
In the course of fungal attack [Microcyclus alei] on the cyanogenic rubber tree (Hevea brasiliensis Muell.-Arg.) HCN is liberated from infected tissue. The HCN interferes with plant host and fungal pathogen. It becomes inhibitory to active defense responses which are dependent on biosynthetic processes as far as a threshold concentration is transgressed.