Hormonal and Environmental Regulation of the Carrot lea-Class Gene Dc3. Academic Article uri icon


  • Dc3 is a carrot lea-class gene belonging to a small gene family that encodes Dc3 and Dc3-like RNA sequences. We have examined the responsiveness to water deficit and abscisic acid (ABA) of the promoter/enhancer complex of Dc3 fused to a beta-glucuronidase (GUS) reporter gene in vegetative cells of transgenic tobacco. In 56-d tobacco, GUS expression in leaves increased about 200-fold during a 3-d drying cycle, during which there were small decreases (3 atmospheres or less) in leaf water potential and a 16-fold increase in free ABA. These effects were reversed by rewatering. Changes in GUS activity were closely paralleled by changes in GUS transcript levels during the desiccation/watering cycle, indicating transcriptional regulation of GUS gene expression. The Dc3 promoter responds to exogenous ABA; the effect is time and concentration dependent, with greater than 10-fold induction in 8 h with 10 mum ABA. Histochemical visualization of GUS activity in seedlings induced by water deficit or exogenous ABA revealed Dc3-driven GUS expression in all organs of transgenic tobacco seedlings. We suggest that the Dc3/GUS reporter system is a sensitive analytical tool to study various environmental effects on plant growth and development.

published proceedings

  • Plant Physiol

altmetric score

  • 6

author list (cited authors)

  • Vivekananda, J., Drew, M. C., & Thomas, T. L.

citation count

  • 27

complete list of authors

  • Vivekananda, J||Drew, MC||Thomas, TL

publication date

  • October 1992