Effect of Sublethal and Lethal Temperatures on Plant Cells '

A bstract. Soybean, Glycine max L., and elodea, Elodea canadensis Michx, leaves were exposed to sublethal and lethal temperatures and examined by light microscopy. Loss of ohlorophyll and swollen chloroplasts were observed in cells of elodea leaves exposed to sublethal temperatures. At the thermal death point of leaf cells of elodea and soybean, there was a disorganization of the tonoplast membrane, plasmalemma, and chloroplast membranes. Approximately 40% of the cells in elodea and 50 % of the cells in soybean leaves exhibited oriteria of cell death when exposed to a temperature which induced necrotic leaf tissue. Plasmolysis of leaf cells of elodea and soybean occurred at lethal temperatures, but did not appear to be the primary oause of cellular death. The primary effect of lethal temperatures