Salicylic acid accumulates in the roots and hypocotyl after inoculation of cucumber leaves with Colletotrichum lagenarium.

Increased amounts of salicylic acid (SA) were detected in the roots and hypocotyl of cucumber plants (Cucumis sativus) using high-performance liquid chromatography following inoculation of the leaves with the anthracnose pathogen, Colletotrichum lagenarium. The concentrations of SA in the internodes immediately below the infected leaves increased to more than 1microg/g fresh weight. In contrast, the concentrations of SA in stems distant from, or above the infected leaves increased to 100-300ng/g.