Dose-, time-, and tissue-dependent effects of 5-bromo-2′ -deoxyuridine on the in-vitro organogenesis of Arabidopsis thaliana

Abstract

Vigorous organogenesis can be induced from hypocotyl and root explants of Arabidopsis thaliana using a two-step culture procedure consisting of preculture on callusinducing medium (CIM) and subsequent culture on shoot-inducing medium (SIM) or root-inducing medium (RIM). With this culture system, we examined the influence of 5-bromo-2¢-deoxyuridine (BrdU), a thymidine (dT) analogue, on plant organogenesis in vitro. Treatment with BrdU during SIM or RIM culture had negative effects on shoot and root redifferentiation over a broad range of concentrations. When explants were exposed to low concentrations of BrdU during preculture and then transferred onto BrdU-free SIM, shoot redifferentiation was accelerated significantly. At higher doses, BrdU treatment during the pre-culture inhibited shoot redifferentiation strongly in hypocotyl explants, but not in root explants. This suggests that a target of the BrdU action lies within the process of acquisition of cell proliferation competence specifically involved in hypocotyl dedifferentiation. These effects of BrdU were counteracted by the simultaneous addition of excess dT. BrdUpretreated and untreated explants did not differ significantly in the phytohormone dependency of shoot redifferentiation. Our results provide a basis for future studies on plant organogenesis combining pharmacological analysis with BrdU as a probe and molecular genetics with Arabidopsis mutants.

Callus formation and production of secondary metabolites by seedling explants of Chenopodium quinoa

“…The use of plant growth regulators is of fundamental importance for controlling the organogenic response of each plant tissue/organ under in vitro conditions (Che et al, 2002 andSugiyama &Imamura, 2006). Studies have shown that 2,4-D is one of the most effective auxins for induction and growth of callus (Lee et al, 2004 andBurbulis et al, 2007).…”

Development of an efficient callus proliferation system for Rheum coreanum Nakai, a rare medicinal plant growing in Democratic People’s Republic of Korea

“…The inducing rate of stem tip was more than 80% in the medium with the concentrations of 0.2 mg/l and 0.5 mg/l 2.4-D (Table 1). The use of plant growth regulators is of fundamental importance in directing the organogenic response of any plant tissue or organ under in vitro conditions (Sugiyama and Imamura, 2006).…”

Influence of 5′-azacitidine on promoting recovery of cell competence for shoot organogenesis in Arabidopsis

“…This might reflect the difference of cell state between hypocotyls and roots. Preculture with bromodeoxyuridine, an analog of thymidine, in CIM can inhibit shoot regeneration from hypocotyl explants but not from roots on SIM (Sugiyama and Imamura 2006). The methylation of DNA occurring in root explants might be irreversible and not be recovered by AzaC.…”