Conditions favorable for the somatic embryogenesis in carrot cell culture enhance expression of the rolC promoter-GUS fusion gene

Abstract

We obtained carrot (Daucus carora) cells possessing the 5′-noncoding sequence of the ORF12 gene (ro/C) of TL-DNA of the Ri plasmid and a structural gene of bacterial β-glucuronidase by Agrobacierium mediated transformation. When such cells were cultured in medium containing 2,4-dichlorophenoxyacetic acid, substantial reduction in β-glucuronidase activity was observed. Upon transferring the cells from a 2,4-D-containing medium to one devoid of 2,4-dichlorophenoxyacetic acid, enhanced expression of β-glucuronidase in somatic embryo development was recorded. Activation by gibberillic acid and suppression by abscisic acid of β-glucuronidase activities, in concord with embryogenesis, were also noted.