In vitro regeneration strategy to revitalize Nyctanthes arbor-tristis L. using shoot stem explants: a sustainable way for medicinal plant conservation

The current endeavor aims to explore the regeneration capabilities of Nyctanthes arbor-tristis (Harsinghar), a medicinal plant, through shoot stem explants. This research is crucial, for both conservation of the plant and harnessing its properties. Fresh shoot stem explants were precisely procured and cultivated onto Murashige and Skoog (MS) medium, containing diverse concentrations of plant growth regulators like benzyl adenine (BA) or kinetin (KIN) at 0.5, 1.0, 2.5, 5.0, 7.5 and 10.0 mu M and indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) or alpha-napthalene acetic acid (NAA) at 0.1, 0.5, and 1.0 mu M concentrations. MS medium supplemented with 2.5 mu M Kinetin and 0.5 mu M NAA blend, proved to be the best combination for achieving a higher rate (90%) of shoot multiplication (20.33). Rhizogenesis was achieved best via ex vitro rooting method using 200 mu M IBA for 30 min forming 6.33 roots. Regenerated plants were also examined for antioxidant enzymatic activities and photosynthetic pigments to assess their ability to cope with the external environmental conditions during acclimatization. As compared from first day of ex vitro transfer of regenerated plants, the higher content of photosynthetic pigments contents and fluctuations in levels of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR)] activities during the course of acclimatization, indicates a better adaptive and resilient behavior to the external stressed environmental conditions. Beyond mere multiplication, this methodology sets the stage for comprehensive investigations into the pharmacological research and genetic enhancements of N. arbor-tristis, enriching its rank in the realm of sustainable botanical resources. The study develops an in vitro regeneration approach for conserving, adapting and utilizing N. arbor-tristis, by optimizing plant growth regulators regime, physiological and antioxidant enzymatic activities.