Yumei Xie

Ficus carica L. is a fruit crop of notable nutritional and economic value. The ‘Xinjiang Zaohuang’ cultivar, rich in flavonoids, also holds considerable medicinal potential. To address the constraints of conventional propagation for mass production, this study developed an efficient and genetically stable generation protocol using healthy sprouted branches. MS medium was identified as the most effective basal medium for shoot growth. The highest adventitious bud induction rate (89.67%) and the greatest mean bud number (6.29) were achieved when explants were cultured on MS medium supplemented with 1 mg/L 6-BA and 0.1 mg/L IBA. In the organogenesis process, indole-3-butyric acid (IBA) promoted direct shoot formation with minimal callus intervention compared to naphthaleneacetic acid (NAA). The optimal combination for shoot elongation was 0.1 mg/L 6-BA and 0.01 mg/L IBA, which produced morphologically uniform shoots. For rooting, an IBA concentration of 1 mg/L was optimal, achieving a 96.7% success rate. Inter-simple sequence repeat (ISSR) analysis confirmed the genetic stability of all regenerated plants. These findings establish a reliable technical framework for the large-scale propagation of this valuable fig cultivar.

Camptotheca acuminata produces valuable camptothecin, a potent anticancer agent. To overcome the limitations of wild resources, we developed efficient in vitro regeneration and camptothecin production systems. Key findings include: Optimal sterilization of plant material was achieved using Plant Preservative Mixture (12 min). Axillary shoot induction was most effective on MS medium with 2.5 mg/L 6-BA and 0.25 mg/L NAA, while adventitious shoot regeneration showed a preference for 1 mg/L 6-BA and 0.1 mg/L NAA. Synchronous induction reached its peak at 83.45% using MS medium with 0.5 mg/L 6-BA, 0.05 mg/L NAA, and 0.5 mg/L GA₃. Shoot elongation benefited from 5 mg/L phloroglucinol and 20 mg/L CaCl₂. For biomass production, 2/3 MS macroelements yielded maximum adventitious shoot biomass (50.52 mg). Rooting reached 100% efficiency on 1/2 MS medium containing 1 mg/L IBA, 0.5 mg/L NAA, 5 mg/L phloroglucinol, and 2 g/L AC, averaging 10.50 roots per shoot. The four-stage camptothecin enrichment system produced shoots containing 795.10 µg/g DW camptothecin—fivefold higher than natural leaves. This breakthrough establishes: (1) the first in vitro camptothecin enrichment platform; (2) a sustainable alternative to wild harvesting; (3) a novel circular production model for endangered medicinal plants. The optimized protocols address the challenges of camptothecin supply while demonstrating remarkable productivity enhancements through controlled in vitro culture systems.

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.

Triadica sebifera, an economically and medicinally valuable tree species native to China, was investigated for its in vitro regeneration potential using leaf explants from nodal cuttings of young stems and sprouts. This study evaluated the effects of basal media, plant growth regulators (PGRs), explant sources, and incision methods on adventitious shoot induction, supplemented by histological analysis. The highest shoot regeneration frequency (98.89%) and maximum shoot number (72) were achieved via direct organogenesis using sucker-derived nodal cuttings cultured on MS medium with 2 mg/L 6- benzyladenine (6-BA), 0.3 mg/L kinetin (KT), and 0.2 mg/L α-naphthaleneacetic acid (NAA). Under identical conditions, branch-derived explants showed lower regeneration (84.44%, 64 shoots). Transverse midvein incision proved most effective, with sucker-derived leaves exhibiting superior regeneration. Shoots elongated completely (100%) on Murashige and Skoog (MS) medium containing 0.3 mg/L 6-BA, 0.03 mg/L NAA, and activated charcoal. Rooting was optimal on MS medium with 0.3 mg/L indole-3-butyric acid (IBA), yielding a 98% acclimatization survival rate. Histological analysis revealed de novo meristem formation from parenchyma cells, confirming direct organogenesis without callus intermediation, further validating the enhanced regenerative capacity of sprout-derived explants. This efficient in vitro regeneration system provides a foundation for large-scale propagation and germplasm conservation of T. sebifera, while offering insights for woody plant regeneration studies.

Paeonia ostii, a plant of substantial economic significance, continues to face constraints in achieving large-scale propagation. In vitro propagation offers a promising avenue for the production of disease-free plants and the genetic transformation of peonies to instill novel traits. However, significant challenges persist in tissue culture, particularly with regards to the reproduction coefficient of shoots and the rooting process. This study reports an efficacious protocol for P. ostii micropropagation, focusing on in vitro root development facilitated through the application of phloroglucinol (PG). Furthermore, the study unveils the molecular signature of P. ostii during in vitro root development. The results indicate that the modified Y3 medium (Y3M), supplemented with 1 mg/L 6-benzyladenine (BA) and 0.1 mg/L α-naphthaleneacetic acid (NAA), is optimal for adventitious bud induction, achieving a 96.67% induction rate and an average of 16.03 adventitious shoots per sample. The highest elongation percentage (92.15%) and the longest average shoot length (3.87 cm) were obtained with Y3M containing 0.3 mg/L BA and 0.03 mg/L NAA. Additionally, the optimal medium for inducing root formation in P. ostii was identified as WPM supplemented with 3 mg/L indole-3-butyric acid (IBA) and 100 mg/L phloroglucinol (PG). Lignin content detection, microscope inspection, and molecular signature results demonstrated that PG enhanced lignin biosynthesis, thereby promoting in vitro rooting of P. ostii.