Changes of water-relation characteristics and levels of organic cytoplasmic solutes during salinity induced transition of Mesembryanthemum crystallinum from C-photosynthesis to crassulacean acid metabolism.

NaCl was added to the nutrient solution of 4-6-week old Mesembryanthemum crystallinum plants so that the concentration rose by 50 mM per day. Ten to fifteen days after a concentration of 400 mM was reached, pronounced diurnal oscillations of malate levels indicated that plants had changed from C-photosynthesis to crassulacean acid metabolism (CAM). Due to the NaCl-treatment the solute potential (Ψ) decreased from about -6 bar to -25 bar, and the water potential (Ψ) changed from about -5 bar to -23 bar on average.