Figure 1.

Effect of homogeneous low nitrate (homo LN) and local high nitrate (local HN) supplies on lateral root development in shoot-borne roots of maize. A, Shoot-borne roots were grown hydroponically in low nitrate (0.5 mm NO₃⁻). Subsequently, two shoot-borne roots were split supplied with low nitrate (0.5 mm NO₃⁻; left) or high nitrate (4 mm NO₃⁻; right) for a period of 6 d. Representative roots are displayed. Bar = 1 cm. Average length (in millimeters; B) and density (millimeters⁻¹; C) of lateral roots initiated from the whole shoot-borne roots. DAT, Days after treatment. D, Early pericycle cell divisions in shoot-borne roots 24 h after local HN stimulation. E, Frequency of lateral root primordia (LRP) in the region between 5 and 25 mm from the root tip at 24 h after treatment (HAT). Stages I to III, IV and V, VI to VII, and VIII are indicated according to Supplemental Figure S2. B to E, Error bars represent se for four biological replicates. Asterisks denote a significant difference according to paired Student’s t test. *, P ≤ 0.05; **, P ≤ 0.01.