FIG 2.

Effects of ionic and osmotic compounds on the expression of sps₇₉₄₂ (a and b) and the sucrose-producing activity (c and d) in Syn7942. In panels a and b, Syn7942 cells were stressed by NaCl, sorbitol, mannitol, and PEG6000 at 602 mmol/kg for the indicated times, and the amounts of sps₇₉₄₂ transcript (a) and SPS₇₉₄₂ protein (b) were analyzed by RT-PCR and immunoblotting, respectively. In panels c and d, the sucrose-producing activity of Syn7942 was analyzed with extracts of Syn7942 cells grown under standard conditions. Different concentrations of NaCl, KCl, sorbitol, and mannitol were included in the enzymatic reactions. The produced sucrose was determined by ion-exchange chromatography (d) or HPLC (c). The data are presented as means from three independent replicates with the standard deviations.