Environmentally Induced Changes in the Cell Walls of Tomato Leaves in Relation to Cell and Protoplast Release

Factors involved in the isolation of protoplasts from the leaves of tomato plants grown over a wide range of environmental conditions have been studied. Increases in calcium pectate in summer grown ("hard") plants are suggested as a barrier to cell wall degradation. A one-step method involving the addition of sodium citrate to pectinase plus cellulase gives high yield of protoplasts from hard plants. Attempts to convert isolated palisade cells to protoplasts have failed. The plant culture conditions are described such that protoplasts may be isolated throughout the year using low enzyme concentrations.