Figure 2.

High sucrose/low nitrate represses lateral root initiation in WT but not atnar2.1. (A) WT (WS, black) and mutant (atnar2.1-1, white) seedlings were grown for 13 days on media containing 7.5% sucrose, 0.1 mM NH₄Cl, and various nitrate concentration (0, 0.1, 0.5, 5 mM KNO₃).¹⁰ KCl was used to balance total salt concentrations between media. The values are means of the number of visible lateral roots per cm of primary root length ± SD of 12 seedlings. (B) Root ¹⁵NO₃⁻ influx measured at 0.2 mM. The values are means ± SD of three replicates (pooling four to eight plants).