Co-Authors:
Watad, A.-E.A., Institute of Field and Garden Crops, Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet-Dagan 50250, Israel
Reuveni, M., Department of Entomology, Purdue University, West Lafayette, IN 47907, United States
Bressan, R.A., Ctr. Plant Environ. Stress Physiol., Department of Horticulture, Purdue University, West Lafayette, IN 47907, United States
Hasegawa, P.M., Ctr. Plant Environ. Stress Physiol., Department of Horticulture, Purdue University, West Lafayette, IN 47907, United States
Abstract:
Maintenance of intracellular K+ concentrations that are not growth-limiting, in an environment of high Na+, is characteristic of NaCl-adapted cells of the glycophyte, tobacco (Nicotiana tabacum/gossii). These cells exhibited a substantially greater uptake of 86Rb+ (i.e. an indicator of K+) relative to unadapted cells. Potassium uptake into NaCl-adapted cells was 1.5-fold greater than unadapted cells at 0 NaCl and 3.5-fold greater when cells were exposed to 160 millimolar NaCl. The difference in net K+ uptake between unadapted and NaCl-adapted cells was due primarily to higher rates of entry rather than to reduced K+ leakage. Presumably, enhanced K+ uptake into adapted cells is a result of electrophoretic flux, and a component of uptake may be linked to vanadate-sensitive H+ extrusion.