Ricerc@Sapienza

Hypocotyl elongation is influenced by light and hormones, but the molecular mechanisms underlying
this process are not yet fully elucidated. We had previously suggested that the Arabidopsis DOF
transcription factor DAG1 may be a negative component of the mechanism of light-mediated inhibition
of hypocotyl elongation, as light-grown dag1 knock-out mutant seedlings show significant shorter
hypocotyls than the wild type. By using high-throughput RNA-seq, we compared the transcriptome

Hypocotyl elongation of Arabidopsis seedlings is influenced by light and numerous growth factors. Light induces inhibition of hypocotyl elongation (photomorphogenesis), whereas in the dark hypocotyl elongation is promoted (skotomorphogenesis). Abscisic acid (ABA) plays a major role in inhibition of hypocotyl elongation, but the molecular mechanism remains unclear.