Fig. 1.

Hierarchical clustering of the different nitrogen nutrition treatments according to the probesets differentially expressed in these conditions as determined by ANOVA using an FDR threshold of P<0.01. Plants were cultivated under four different nitrogen regimens: under symbiotic conditions (Nod) or with NH₄NO₃ (Mix), NO₃ ⁻ only, or NH₄ ⁺ only. The clustering analysis was carried out with the Expander software using average linkage. a and b indicate the biological replicates of the samples in the microarray (E-MTAB-4177).