In Vitro Plantlet Regeneration and Accumulation of Ginkgolic Acid in Leaf Biomass of Ginkgo biloba L.

This study established an efficient in vitro regeneration system using stem nodes from root collar suckers as explants. Subsequently, regenerated shoots were used to establish an in vitro medicinal production protocol that achieved ginkgolic acid production. The self-developed Ginkgo biloba medium (GBM), first reported in this study, was pivotal to system establishment. The plantlet propagation system showed that the bases of stem nodes dipped in GBM with 2 mg·L−1 6-benzyladenine (BA) and 0.2 mg·L−1 1-naphthaleneacetic acid (NAA) achieved near-complete axillary bud induction (99.56%). Adventitious shoot induction reached 82.22% (3.5 shoots/explant) using GBM with 0.2 mg·L−1 BA, 0.02 mg·L−1 kinetin (Kin) and 0.2 g·L−1 proline (Pro). Maximum adventitious shoot elongation (92.22%, average 3.35 cm) was observed on GBM containing 0.1 mg·L−1 zeatin (ZT) and 0.01 mg·L−1 BA. After 3-week preculture with 15 mg·L−1 phloroglucinol (PG), treatment with 0.6 mg·L−1 indole-3-butyric acid (IBA) and 0.2% activated carbon (AC) yielded 96.67% rooting (6.19 roots/explant) and 85% acclimatization survival. For medicinal resource production, bud cluster induction at 94.44% (20.89 buds/explant) on GBM with 1 mg·L−1 BA, 0.03 mg·L−1 Kin, and 0.2 g·L−1 Pro. Leaf organs in GBM with 0.3 mg·L−1 BA, 0.01 mg·L−1 Kin, 0.01 mg·L−1 IBA, 0.3 g·L−1 Pro, and 0.01 mg·L−1 glutamine (Gln) accumulated 20.64 g fresh weight and 41.910 mg·g−1 DW ginkgolic acids, representing a 4.93-fold increase over mother plants. This system enables large-scale Ginkgo biloba L. propagation and provides an in vitro strategy for producing medicinal compounds in endangered plants.