TABLE 6.

Effect of unlabeled disaccharides on the uptake of [¹⁴C]sucrose by salt-stressed cultures of various rhizobial strains^a

Strain	% Inhibition of sucrose uptake by unlabeled disaccharidesb
	Sucrose	Trehalose	Maltose	Cellobiose
S. meliloti 444c	95c	90c	91c	92c
R. leguminosarum
bv. phaseoli H132d	96d	91d	90d	88d
bv. trifolii
T22	96	98	98	68
T8S	97	96	27	68
T17S	98	64	20	19

^aCultures were grown for 24 h in mannitol-aspartate minimal medium containing 1 mM sucrose plus NaCl at the following concentrations: S. meliloti 444, 0.5 M; R. leguminosarum bv. phaseoli H132, 0.3 M; R. leguminosarum bv. trifolii strains, 0.7 M. 

^bPercentages of inhibition of sucrose uptake were measured after a 5-min incubation in the presence of 0.5 mM [¹⁴C]sucrose (23.3 GBq/mmol) plus 25 mM of the indicated unlabeled analog. Uninhibited transport rates were 28 nmol mg of protein⁻¹ for both S. meliloti 444 and R. leguminosarum bv. phaseoli H132, and 17, 27, and 11 nmol mg of protein⁻¹ for R. leguminosarum bv. trifolii strains T22, T8S, and T17S, respectively. 

^cSimilar percentages of inhibition were observed in S. meliloti SU47, M5N1, and 2009. 

^dSimilar percentages of inhibition were observed in R. leguminosarum bv. phaseoli p12S and p15S.