Effects of alkaline salt stress on growth, physiological properties and medicinal components of clonal Glechoma longituba (Nakai) Kupr.

Background: Glechoma longituba, recognized as a medicinal plant, provides valuable pharmaceutical raw materials for treating various diseases. Saline-alkali stress may effectively enhance the medicinal quality of G. longituba by promoting the synthesis of secondary metabolites. To investigate the changes in the primary medicinal components of G. longituba under saline-alkali stress and improve the quality of medicinal materials, Na₂CO₃ was applied to induce short-term stress under different conditions and the biomass, physiologically active substances and primary medicinal components of G. longituba were measured in this study.

Results: Under alkaline salt stress, the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) were elevated in G. longituba, accompanied by increased accumulation of proline (Pro) and malondialdehyde (MDA). Furthermore, analysis of the medicinal constituents revealed that G. longituba produced the highest levels of soluble sugars, flavonoids, ursolic acid, and oleanolic acid under 0.6% Na₂CO₃ stress for 48 h, 0.2% Na₂CO₃ stress for 72 h, 0.4% Na₂CO₃ stress for 12 h, and 0.4% Na₂CO₃ stress for 8 h, respectively.

Conclusions: Short-term Na₂CO₃ stress enhances the synthesis of medicinal components in G. longituba. By manipulating stress conditions, the production of various medicinal substances could be optimized. This approach may serve as a basis for the targeted cultivation of G. longituba, offering potential applications in the treatment of diverse diseases.