Effects of Salt Treatments of Cotton Plants (Gossypium hirsutum L.) on Leaf Mesophyll Cell Microstructure

Cotton plants (Gosspium hirsutum L.) were grown hydroponically in a controlled environment to study the effect of three salt treatments on the microstructure of leaf mesophyll cells. Sodium chloride was added to a basic nutrient solution in amounts to give low‐, medium‐, and high‐salt treatments. Leaves of the same chronological age from the fifth true node were used for electron microscopic studies of mesophyll cell microstructure. Electronmicrographs showed many crystalline deposits in leaf mesophyll cells for the low‐ and high‐salt treatments, but not for the medium‐ salt treatment. Heavy deposits of these crystals occurred in the cytoplasm, central vacuole, cell walls, and intercellular spaces. The high‐salt treatment also produced many necrotic mesophyll cells and changes in chloroplast ultrastructure, and more mitochondria than cells from the medium‐ and low‐salt treated leaves.