Fig. 4.

Two- to fivefold higher BNI activity is released from BNI-MUNAL (i.e., MUNAL carrying T3BL.3Ns^bS) compared to MUNAL control (BNI isogenic lines) during a 6-d monitoring period using various root exudate trap solutions ( SI Appendix, Study 5b). 1) RE-NH₄-1 (1.8 L aerated solutions of 0.5 mM NH₄Cl + 200 μM CaCl₂ for 24 h—first day collection); 2) RE-nutr-NH₄-1 (1.8 L aerated solutions of one-quarter strength nutrient solution with 0.5 mM NH₄Cl for 24 h—second day collection); 3) RE-water-1 (1.8 L aerated solutions of 200 μM CaCl₂ for 24 h—third day collection); 4) RE-NH₄-2 (1.8 L aerated solutions of 1.0 mM NH₄Cl + 200 μM CaCl₂ for 24 h—fourth day collection); 5) RE-nutr-NH₄-2 (1.8 L aerated solutions of one-quarter strength nutrient solution with 1.0 mM NH₄Cl for 24 h—fifth day collection); and 6) RE-water-2 (1.8 L aerated solutions of 200 μM CaCl₂ for 24 h—sixth day collection). Values are means ± SE from four replications.