Physiological analyses of WT plants and four transgenic TaeIF5A1 poplar lines. A–E. Comparison of soluble protein levels, POD activity, SOD activity, electrolyte leakage and relative chlorophyll content (RCC) between WT and transgenic poplar plants. Plantlets (60–100 cm in height, each sample contains at least ten plantlets) from wild-type (WT) and transgenic plants (1, 2, 3 and 5) grown in soil were watered with 0.8% (w/v) NaCl for 0, 1, 4, 7 and 14 d, respectively. The error bars represent standard deviations of the mean measurements. * means significant difference (P < 0.05) between WT and transgenic lines plants.