Expression data from Arabidopsis thaliana

Nitrogen and light are two major regulators of plant metabolism and development. While genes involved in the control of each of these signals have begun to be identified, regulators that integrate gene responses to nitrogen and light signals have yet to be determined. Here, we evaluate the role of bZIP1, a transcription factor involved in light and nitrogen sensing, by exposing wild-type (WT) and bZIP1 T-DNA null mutant plants to a combinatorial space of N and L treatment conditions. We use ANOVA analysis combined with clustering and Boolean modeling, to evaluate the role of bZIP1 in mediating L and N signaling genome-wide. Arabidopsis thaliana were growth on basal MS salts (custom-made; GIBCO) with 0.5 mM KNO3, 3 mM sucrose and 0.8% BactoAgar at pH 5.7. After 14 days under long-day (16 h light: 8 h dark) conditions with light intensity of 50 μE.m-2.s-1 and at 22°C, plants were transferred to new plates containing 20 mM KNO3 and 20 mM NH4NO3 (referred here as 1xN: concentrations in MS media) in the absence or presence of light for 2 h at the start of their light cycle.