The effect of water stress on the vacuole‐extravacuole compartmentation of proline in potato cell suspension cultures

Abstract

Solute compartmentation in cells is an important component of metabolic regulation. There is only little information on how stress treatment of cells effects this component. Therefore, the effect of water stress [10% (w/v) PEG 6000] on the vacuolar‐extravacuolar proline compartmentation was studied in a cell suspension culture of Svlanum tuberosum L, cv, HH258, In non‐stressed cells 34% of the total cellular proline was located in the vacuole. After 20 h of water stress the proline pool of the cells was increased 4‐6 fold and only t6% of it was found in the vacuole. A negative correlation between the total cellular proline content and its percentage in the vacuole was observed, irrespective of the culture method (stress or non‐stress culture). The stress‐induced changes in proline compartmentation are discussed.