Figure 6. Incorporation of E. coli-derived ¹⁵N by leaves of tomato plants.

Roots of tomato grown in hydroponic culture were incubated with ¹⁵N-E. coli for 1 h. After washing of the roots, plants were further grown for 2 weeks. Then 2–3 new leaves were analyzed for ¹⁵N content. Control 1 are plants grown without ¹⁵N-E. coli. Control 2 are plants incubated for 2 h with filtered ¹⁵N-E. coli incubation solution. Results are depicted as mean ± SD (n = 7). Different letters indicate significant differences at p<0.001 (1-way ANOVA, Tukey's posthoc test).