Fig. 1.

Expression of AtIpk2β in S. cerevisiaearg82Δ. (a) AtIpk2β rescues growth defects of the yeast arg82Δ mutant under high salt or mannitol stress, and at 37°C. Ten-fold serial dilutions of the strain were plated and incubated at 30°C for 48 h on YPD medium supplemented with either 0.4- or 0.8-M NaCl, or with 0.4- or 0.8-M mannitol. Plates incubated at 37°C contained YPD medium without extra NaCl or mannitol. WT, wild type; arg82Δ, arg82Δ mutant; arg82Δ + AtIpk2ß, arg82Δ mutant harbouring plasmid pYX212-AtIpk2β. (b) Liquid yeast cultures. Cells were grown for three days to saturation in YPD medium (OD₆₀₀ = 12.0). Five μl of cell culture were then used to inoculate 3 ml of defined synthetic minimal medium supplemented with different concentrations of NaCl or mannitol. Cell density was determined at various time points as absorbance at 600 nm. Cells were grown at 30°C. WT, wild type; arg82Δ, arg82Δ mutant; arg82Δ + AtIpk2ß, arg82Δ mutant harbouring pYX212-AtIpk2β; arg82Δ + vector, arg82Δ mutant harbouring pYX212