Cellular competence for regeneration and transformation has been monitored in a recalcitrant crop, i.e. sugarbeet (Beta vulgaris L.). Explants for Agrobacterium inoculation were taken from the transition zone between hypocotyl and cotyledonary petioles. De novo generation of adventitious shoots was very efficient (60%-70%) from these cotyledonary node explants. Regeneration could not be further stimulated by manipulation of cytokinin type or concentration. The mode of regeneration was direct, without a callus phase. Dedifferentiation, as induced by a preculture period on 2,4-D, gave significantly higher gene transfer frequencies, but regeneration was irreversibly impaired. NAA mimicked the effect of 2,4-D on gene transfer. However, explants retained their regenerative capacity upon pretreatment with NAA. Using the procedure described here, transgenic sugarbeet plants were obtained after selecting on 250 mg/l kanamycin at a frequency of 1%.