Figure 6.

Growth differences in transgenic plants are not correlated with nitrogen uptake. Differences (mean ± SE, n ≥ 5) in (A) total nitrogen and (B) ¹⁵ N-incorporation between transgenic lines (irSIPK, irWIPK, irLOX3, oeNahG, SxN) compared to competing wild type (WT) plants (calculated as described in Figure 4A). 7 days after transfer to 2 L pots, the oldest sink leaf was marked and each plant pair was pulse-labeled with 5.1 mg nitrogen delivered as K¹⁵NO_{3 .} Three days later, rosette leaves of transgenic plants and WT were OS-elicited as described for Figure 4. Leaves were harvested five days after last treatment. Total nitrogen and ¹⁵ N-incorpration were determined by IRMS (see Methods). The minimum adequate model is represented through small letters (a, b, c; total nitrogen: ANOVA, F_2,102 = 29.251, p < 0.001;¹⁵ N-incorporation). Asterics indicate significant differences between control and W + OS treatment (Welch two sample t-test, p < 0.01, n.s. = no significant difference).