Figure 4. Specific metabolites in tree root exudates enhance bacterial growth.
Growth curves of Bacillus subtilis (left) and Pseudomonas stutzeri (right) in defined media with specific metabolites identified in root exudate blends of drought-exposed Cupressus sempervirens saplings as exclusive carbon (A) or nitrogen (B) source. Glycerol and monosodium glutamate (MSG) were used as controls for carbon and nitrogen sources, respectively. Root-derived metabolites are 2,3-dihydroxybenzoate (2,3 DHB); 3,4 dihydroxymandelate (3,4 DHM); their 1:1 mixture; 3,5-dimethoxyphenol; N-acetylserine; L-citrulline; and D-quinate. Concentrations are 0.4% by weight for all compounds. OD600, optical density at a wavelength of 600 nm (n=4).
Figure 4—figure supplement 1. Growth curves of Bacillus subtilis (left) and Pseudomonas stutzeri (right) in defined media with specific metabolites identified in root exudate blends of drought-exposed Cupressus sempervirens saplings as exclusive carbon (A) or nitrogen (B) source.
Glycerol and monosodium glutamate (MSG) were used as controls for carbon and nitrogen sources, respectively. Root-derived metabolites are nicotinate, p-coumaric acid, and D-chiro-inositol. Concentrations are 0.4% by weight for all compounds. OD600, optical density at a wavelength of 600 nm (n=4).