EFFECTS OF OZONE ON THE FINE STRUCTURE OF THE PALISADE PARENCHYMA CELLS OF BEAN LEAVES

Abstract

The effects of ozone on the fine structure of palisade parenchyma cells were of two phases. The first phase involved changes in the chloroplast stroma which consisted of either a granulation and an increase in electron density or a formation of ordered arrays of granules and fibrils. In the second phase, there was a general disruption of the cellular membranes and organelles and the cellular contents aggregated in the center of the cells. The characteristic components of this aggregate were remains of the chloroplast membrane system and numerous ordered arrays of granules and fibrils. These changes were identical with those previously observed in cells damaged by peroxyacetyl nitrate and were probably related to the oxidation properties of both molecules. In some cells there was a disruption of the organization of the grana within the chloroplasts.