Some Salt-Uptake and Tissue-Aging Phenomena Studied with Cultured Tobacco Cells

Abstract

Tobacco cells (Nicotiana tabacum cv. Wisconsin 38) growing in cell suspension culture follow an exponential growth curve. Cells removed from the culture at various times and subjected to "step-up" or "step-down" nutritional shIfts exhibit an aging response. The most marked response is observed as an increase or decrease in the rate of phosphate accumulation and in the rate of phosphate esterification. This response is maximal for mid exponential-phase and late stationary-phase cells. The implications of these findings are discussed.