Identification of early gibberellin (GA) responsive genes in Arabidopsis hypocotyls

The aim of the experiment was to identify early gibberellin (GA) responsive genes in the roots of an Arabidopsis GA deficient mutant.The GA deficient mutant used in this study is a transgenic line overexpressing the PcGA2ox1 gene. This mutant has an identical phenotype to ga1-3, but it does not require exogenous GA treatment for germination.Seeds were germinated on 1xMS + 1% (w/v) sucrose plates containing 0.7% gelrite, and grown under continous light. The plates were orientated vertically.After six days growth the plates were treated with or without 5uM GA4 for 0, 30, 60 and 180 minutes.Approximately 400 hypocotyls were harvested per timepoint using a razorblade and after excision the hypocotyls were frozen in liquid nitrogen giving a total of 7 experimental samples (1: untreated, 2: 30 mins GA4, 3: 30 mins untreated, 4: 60 mins GA4, 5: 60 mins untreated, 6: 180 mins GA4, 7: 180 mins untreated. Three biological replicates were performed giving a total of 21 root samples. Total RNA was isolated from the roots using the QIAGEN RNeasy method. Keywords: Expression profiling by array 21 samples were used in this experiment