Figure 4.

Osmoprotectant concentrations in two Bradyrhizobium strains at various NaCl levels. (a) Proline concentrations; (b) Betaine concentrations; (c) Ectoine concentrations; (d) Trehalose concentrations. Bradyrhizobium strains were separately inoculated into liquid medium containing 0.0017 (CK), 0.1, 0.2, 0.3, 0.4, or 0.5 M NaCl and further incubated at 28 °C and 180 rpm. The osmoprotectant concentrations in the bacteria were detected after 8 days of NaCl treatment. A column represents mean value obtained from four biological replicates and bar represents standard error. An individual flask was considered one biological replicate. The same letter indicates no significant difference at p < 0.05 (Duncan’s test).