Figure 4.

Local N Provision and N-Demand Long-Distance Signaling Controls PSR.

(A) Split-root conditions on N (schematic) were applied on P varying contexts. Roots in the same local environment are compared to evaluate the influence of distant treatments. CKNO₃ and CKCl indicate control conditions (homogeneous KNO₃ or KCl supply). SpKNO₃ and SpKCl indicate heterogeneous conditions with KNO₃ supply for one-half of the root system and KCl supply for the other part. Differences recorded between CKNO₃ and SpKNO₃ or between SpKCl and CKCl are due to treatments applied and sensed by the other side of the split root.

(B) Measurements of PSI genes by RT-qPCR in the N split-root context on two P conditions (see text for details of the experimental procedure). Values are mean ± se (n = 3). Results are from three independent experiments. Different letters indicate significant ANOVA followed by Tukey test (P < 0.05).