The effect of calcium stress on fluxes of calcium and potassium in wheat triticum aestivum cultivar svenno and cucumber cucumis sativus cultivar cilla
Physiologia Plantarum 56(4): 415-420
ISSN/ISBN: 0031-9317 DOI: 10.1111/j.1399-3054.1982.tb04534.x
Fluxes of Ca2+ (45Ca) and K+ (86Rb) were investigated in 12-day-old intact plants of cucumber (C. sativus L. cv. Cilla) and 7-day old intact plants of wheat (T. aestivum L. cv. Svenno) which had been cultivated in nutrient solution. The rate of K+ uptake was affected by the external Ca2+ concentration, which reduced the uptake of K+ when present above and below a certain level. Pretreatment of roots in high [Ca2+] during a 24 h period decreased the rate of both K+ and Ca2+ uptake. Reduced availability of Ca2+ in the nutrient solution during 24 h reduced the uptake of K+ and Ca2+. Separation of the Ca2+ and K+ retained in the roots from the amounts transported to the shoots in plants pretreated with low [Ca2+] showed that the influx of K+ retained in the roots decreased while Ca2+ influx increased. The transport of both ions towards the shoot was, however, reduced. Reduction of available Ca2+ in the nutrient solution was suggested to change the composition of the membranes, maintaining their permeability properties and metabolically regulated functions. Leakage of K+ (86Rb) from the vacuolar and cytoplasmic compartment of wheat roots increased at reduced Ca2+ concentration in the nutrient solution.