Fig. 1.

Network analysis of genes regulated by organic N suggests that CCA1 control N-assimilation in plants. Genes are drawn as triangles (transcription factors) and hexagons (metabolic genes), and metabolites are white circles. Dotted blue edges indicate transport, black and gray edges indicate enzymatic reactions, green edges indicate predicted transcriptional activation, and red edges indicate predicted transcriptional repression. Arrows, diamonds, or lines at the end of an edge indicate directionality of the interaction. Color of gene nodes indicates type of response as in Table 1. To simplify, some of the genes connecting to GLK1 and CCA1 are grouped and summarized based on their associated functions (the number in parentheses indicates the number of genes in the group).