Fig 7.

GbdR regulates betaine catabolism under conditions of low and high osmotic stress. (A) qRT-PCR analysis of gbcA in B728a and the ΔgbdR mutant at 40 min (0.7 h) after amending cells with 0 to 0.7 M NaCl and betaine. Values are expressed relative to gbcA transcript levels in B728a at 0 M NaCl without betaine. (B) qRT-PCR analysis of gbcA in B728a and the ΔgbdR mutant at 0.7 and 24 h after amending cells with 0.6 M NaCl and betaine. (C) ¹⁴CO₂ released by B728a and the ΔgbdR mutant during their growth in MinA-pyruvate with 0.6 M NaCl and [methyl-¹⁴C]glycine betaine for 5 and 30 h. (D) B728a and the ΔgbcAB and ΔgbdR mutants were grown in MinA-succinate with 0.6 M NaCl and betaine, and growth in microtiter plates was monitored based on optical density. Asterisks indicate differences between B728a and the ΔgbdR mutant at the indicated concentrations or times (P < 0.05). Values are means ± SEM (n = 3 for panels A to C; n = 4 for panel D).