title: Involvement of gibberellin and cytokinin in the formation of embryogenic cell clumps in carrot (Daucus carota).
abstract: Somatic embryogenesis of carrots is a typical example of the totipotency of plant cells. However, little is known about the process of change from somatic cells to embryogenic cells. To test the involvement of plant hormones in the acquisition process of embryogenic potency, we investigated the effects of plant growth regulators and their inhibitors on auxin-induced direct somatic embryogenesis of carrots. Gibberellin (GA) inhibited the early stage of embryogenic cell differentiation/development to the globular stage and uniconazole, an inhibitor of GA synthesis, promoted the secondary embryogenesis from the primary embryo. Purine riboside, an anticytokinin, inhibited direct somatic embryogenesis, and this effect was nullified by the application of cytokinin (CK). These results show that GA and CK regulate the early stage of auxin-induced somatic embryogenesis in carrots.
authors.affiliation: Department of Bioresource Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan. tokuji@obihiro.ac.jp
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tokuji
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kuriyama
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D003583:Cytokinins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018552:Daucus carota / Q000187:drug effects* / Q000196:embryology* / Q000378:metabolism; D005875:Gibberellins / Q000494:pharmacology*; D007210:Indoleacetic Acids / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011684:Purine Nucleosides / Q000494:pharmacology; D012263:Ribonucleosides / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
chemical_list: D003583:Cytokinins; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D011684:Purine Nucleosides; D012263:Ribonucleosides; D014230:Triazoles; C005248:nebularine; C007842:gibberellic acid; C092705:uniconazole