VIEW ARTICLE

Influence of Air Pollution on Quantities of Caffeic Acid Isolated from Leaves of Phaseolus vulgaris. Robert K. Howell, Research Plant Pathologist, Crops Research Division, ARS, USDA, Beltsville, Maryland 20705; Phytopathology 60:1626-1629. Accepted for publication 11 June 1970. DOI: 10.1094/Phyto-60-1626.

Phenolic composition was significantly altered in Tempo bean leaves cultured in polluted ambient air. Fluorescent compounds were concentrated in the reddish-brown leaves. Caffeic acid concentrations were present in injured leaves at twice the concentration detected in healthy leaves. An anthocyanin could not be detected in injured leaves. Air pollutants are now known to affect phenolic metabolism in plants, as do plant pathogens and other physiological stress factors.