Figure 2

Clustering analysis and QPCR reveals different patterns of expression in response to short-term NO ₃ ^- treatment. (a) Cluster analysis of the relative expression of 550 regulated genes (Log base 2(Signal KNO₃/Signal KCl)) between 0 and 20 minutes. These data correspond to ATH1 measurement of the samples collected for the RT-PCR shown in Figure 1 (see Materials and methods for further details). For clusters including genes with a significant over-representation of biological functions see Additional file 4. (b) Examples of three different gene behaviors (transitory, early, late responses) after NO₃^- provision.