Dehydrating immature embryo split apices and rehydrating with Agrobacterium tumefaciens: A new method for genetically transforming recalcitrant sunflower

摘要

Split embryonic axes of 21-day-old immature sunflower (Helianthus annuus L. var. RHA266) embryos were bombarded, vacuum infiltrated, or dehydrated before being infected by Agrobacterium tumefaciens strain EHA 105, bearing a binary vector carrying the selectable marker NPTII and the scorable marker uidA gene. RHA266 was found to be particularly sensitive to in vitro culture and recalcitrant to organogenesis. Of the 3 methods used, only dehydration and rehydration with Agrobacterium gave rise to transient GUS expression in shoot apices and stably transformed plants as confirmed by Southern blotting analysis.