Skip to main content
. 2022 Jul 20;11:e79679. doi: 10.7554/eLife.79679

Figure 2. Tree root exudates increase with bacterial inoculation for both the drought and irrigation treatments (A) and decrease with bacterial inoculation after rewetting the droughted trees (B).

Total organic carbon (TOC) in exudate solutions from roots of irrigated and drought-exposed Cupressus sempervirens saplings, with and without bacterial inoculations. Intact roots were incubated for 48 hr to collect exudates during periods of drought (A) and re-irrigation (B). Boxplots show the log 2 of fold change from baseline exudation rate (at the beginning of the experiment) in µg C mg root–1 day–1. Asterisks indicate significant differences based on two-way ANOVA performed with Tukey’s HSD test (n=6, p<0.05) (see Figure 2—source data 2). Coefficients for the correlations between exudate rate (TOC) and rhizosphere abundance of Bacillus subtilis or Pseudomonas stutzeri (as in Figure 1) for the specific tree groups at 1, 3, and 7 days following inoculation (C).

Figure 2—source data 1. Statistical analysis of gas exchange parameters and sapling biomass.
Figure 2—source data 2. Statistical analysis of root exudates total organic carbon.

Figure 2.

Figure 2—figure supplement 1. Drought stress effect on tree physiological parameters.

Figure 2—figure supplement 1.

Leaf gas exchange dynamics of irrigated and drought-exposed Cupressus sempervirens saplings, with and without bacterial inoculations. Data points are means ± SE (n = 6) of (A) net assimilation; (B) transpiration; (C) stomatal conductance. Solid red and blue lines indicate irrigation cessation and re-irrigation, respectively. Dashed violet lines indicate the two bacterial inoculations (see Figure 2—source data 1 ).