VIEW ARTICLE

Ultrastructure of Chloroplasts of Phaseolus vulgaris Leaves Treated with Benomyl and Ozone. Robyn Rufner, Graduate Assistant, Department of Biology and Plant Pathology, The Pennsylvania State University, University Park 16802; F. H. Witham(2), and H. Cole, Jr.(3). (2)(3)Associate Professor of Biology, and Professor of Plant Pathology, respectively, Department of Biology and Plant Pathology, The Pennsylvania State University, University Park 16802. Phytopathology 65:345-349. Accepted for publication 18 October 1974. DOI: 10.1094/Phyto-65-345.

The total chlorophyll content of the primary leaves of pinto bean plants treated with benomyl and exposed to ozone was significantly higher than that of leaves from control plants. The ultrastructure of chloroplasts in the palisade parenchyma cells of primary leaves from control plants consisted of a grana-fretwork system which comprised the greater part of the organelle. The stroma appeared as a fine granular matrix and the grana, for the most part, were regular in shape. Each granum appeared to be a compartmented structure. The other cellular membranes were intact. Palisade leaf cells of plants not treated with benomyl, but exposed to ozone, exhibited striking alterations in the chloroplast and cellular structure. There was almost complete disruption of the chloroplast membranes, the plasmalemma, and tonoplast. The chloroplasts of bean leaves treated with benomyl and exposed to ozone remained intact and were similar to those of the control plants. The results demonstrate that benomyl protects pinto bean leaf chloroplasts from ozone damage.