Abstract
Ion transporters play central roles in facilitating acquisition of nutrients in plants; however little is known about their regulation at the molecular levels. In Arabidopsis, 1968 genes are predicted to encode transcription factors. To investigate transcriptional regulation of nutrient uptake processes, we performed a large-scale RT-PCR-based screening of transcription factor mutant collection, focusing on starvation responses of the transcripts of major nutrient uptake transporters in Arabidopsis roots. All available candidates of transcription factor mutants were collected from RIKEN transposon-tag collection, and homozygous insertion lines representing the mutants of 265 transcription factors were established. SULTR1;2 sulfate transporter and NRT2;1 nitrate transporter, playing important roles in acquisition of sulfate and nitrate, respectively, were used as profilers in RT-PCR screening. From this screening, we isolated several primary mutant candidates whose induction of SULTR1;2 on sulfur deficiency or repression of NRT2;1 on sucrose deficiency were significantly altered from the wild-type responses.
