Abstract
Drosera regia, an endangered carnivorous plant endemic to South Africa, holds ornamental and pharmacological potential due to its distinctive morphology and bioactive metabolites. However, protocols for its in vitro propagation and genetic transformation remain scarce. This study establishes an integrated biotechnological approach for clonal propagation, acclimatization, adventitious regeneration, and Rhizobium radiobacter-mediated transformation of D. regia. Seeds germinated efficiently (85%) on the MS salts derived basal medium MB3/3 after 45 days of culture. In addition, after testing six different media formulations, MB3/3 was found to be the best for maintenance and for axillary bud-derived multiplication. Auxin supplementation enhanced rooting, with solid media favoring roots and liquid media promoting shoot vigor. All three tested auxins yielded in better rooting performance with solid MB3/3 supplemented with 0.5 mg & centerdot;L--(1) IAA being the best when checking parameters such as root and aerial fresh weight as well as the root number. Highest adventitious shoot multiplication (up to 10.7 per explant) were regenerated on MB3/10 supplemented with zeatin 1 mg & centerdot;L-1. Flow cytometry confirmed ploidy stability in 25 regenerated plants. Genetic transformation using R. radiobacter achieved 14.5% efficiency. Transformation events were confirmed by kanamycin resistance, GFP expression and PCR. This is the first report of successful transformation in D. regia, providing a platform for conservation, functional genomics, and metabolic engineering. The survival rate of acclimatized plants reached 88% and was optimal in peat-perlite substrates. The developed protocols enable large-scale propagation of genetically stable plants and pave the way for metabolic engineering and enhancing production of pharmacologically relevant compounds such as plumbagin.
