Early transcriptional responses of Arabidopsis thaliana to ammonium and nitrate deprivation

Identification of the earliest transcriptional responses of adult Arabidopsis plant roots towards N-deprivation. Hydroponically grown Plants (35 days old) were 5 days adapted to nitrate or ammonium,respectively, as sole N-source to detect N-form specific transcripts. 24 Samples: 2 Pre-Treatments (5 Day adaptation to 3mM Ammonium/Nitrate) x 3 sampling time-points (0min, 15 min, 180 min) x 3 independent replications per time-point + 6 additional controls (2 x 15min, 1x 180min per Pre-Treatment)