Air pollution and ascorbic acid

Well-lighted plants may contain considerable amounts of ascorbic acid (AA) particularly in their chloroplasts. AA is known to be a strong reductant which fulfils several functions in photosynthesis. AA may also influence detoxification of polluted plants, e.g. by reducing SO2. AA contents of forest tree species were distinctly decreased by shading, particularly in light demanding species. Continued SO2 fumigation depressed AA contents long before visible symptoms of injury appeared. AA thus deserves more attention in physiological air pollution research.