Figure 1.

Analysis of gene expression by real-time PCR. At3g03910 was used as an example of a nitrogen starvation-induced gene, while At4g32950 was used as an example of a gene induced by nitrate resupply after starvation. (a–c) Expression of At3g03910 in nitrogen-starved seedlings and after nitrate resupply (a), ammonium resupply (b) and KCl treatment (c). (d–f) Expression of At4g32950 in seedlings subjected to nitrate resupply (a), ammonium resupply (b) and KCl treatment (c). Values are means ± standard deviation of three biological replicate experiments. Different letters indicate significant differences (P < 0.05, Student's t-test).