Figure 3.

Nodule formation in the presence of Ag⁺ and/or nitrate. Seedlings were grown in the presence of B. japonicum at low (0.5 mm) or moderately high (8.0 mm) concentrations of nitrate. Some plants also received Ag⁺ (as silver thiosulfate) at the designated concentrations. The number of nodules present on root systems of individual plants was recorded 14 d after inoculation. Data are presented as means ± a 95% confidence interval. ○, Wild-type (Hobbit 87) plants grown at low nitrate; □, etr1-1 (T119N54) plants grown at low nitrate; •, wild-type plants grown at high nitrate; and ▪, etr1-1 plants grown at high nitrate.