Gene expression signatures in Arabidopsis thaliana roots under sufficient nitrogen or mild nitrogen deficiency

To optimize access to nitrogen under limiting conditions, root systems must continuously sense and respond to local or temporal fluctuations in nitrogen availability. In Arabidopsis thaliana and several other species, external N levels that induce only mild deficiency stimulate the emergence of lateral roots and especially the elongation of primary and lateral roots. However, the identity of the genes involved in this coordination remains still largely elusive. In order to identify novel genes and mechanisms underlying nitrogen-dependent root morphological changes, we investigated time-dependent changes in the root transcriptome of Arabidopsis thaliana plants grown under sufficient nitrogen or under conditions that induced mild nitrogen deficiency. Gene expression in whole roots of Arabidopsis thaliana was measured after transferring seven-day-old seedlings for 0, 1, 2 and 4 days to 11.4 mM nitrogen (N-sufficient; control) or 0.55 mM nitrogen (mild N deficiency). Three biological replicates were used.