Isolation and characterization of a novelcis-acting sequences regulating root-specific gene fromDaucus carota L

Abstract

Aquaporins are ubiquitous channel proteins that facilitate the transport of water across cell membranes. Most of aquaporins are represent in more than one tissues, but some of them performed highest in roots. They are belived to participate in water transport.DcRB7, a member of the aquaporin family, was isolated from somatic embryos of carrot and identified as a homologous gene ofTobRB7. Further studies showed that the expression ofDcRB7 was particular in carrot root. To investigate the transcription regulation ofDcRB7, a 650-bp upstream sequence ofDcRB7 was isolated by inverse PCR, and was fused to the β-glucuronidase (GUS) report gene. After the recombined vectors were transformed into tobacco, the expression pattern was performed by histochemical staining and the quantitative analysis of GUS activity. The results indicated that the cis-acting element ofDcRB7 gene directs GUS expression not only as root-specific but also as drought inducible.