Environmental Drivers of Metabolic Plasticity in Rubia cordifolia From the Western Himalaya: Implications for Phytochemical Diversity and Antioxidant Potential

ABSTRACT

Rubia cordifolia L. is an important Himalayan medicinal plant valued for its diverse therapeutic properties. The present study investigated the influence of altitude, habitat conditions, and edaphic factors on nutritional composition, phytochemicals, and antioxidant activity of R. cordifolia populations collected from different habitats (open grassy, shady, and moist shady) in the western Himalaya. Significant variations ( p  ≤ 0.05) were observed in edaphic factors, nutritional components and phytochemicals, antinutritional factors and antioxidant activities. High‐altitude populations showed higher accumulation of total phenolics (52.59 mg GAE/g dw), flavonoids (120.84 mg QE/g dw), alizarin (2.68 mg/g dw), and mollugin (23.77 mg/g dw). Correlation analysis revealed a significant positive correlation of altitude with phenolics, flavonoids, alizarin, catechin, amino acids, and thiamine. Whereas, soil pH demonstrated negative correlations with several metabolites. In contrast, altitude was negatively correlated ( p  ≤ 0.01) with salicylic acid in leaves and stems and tannin content in roots. Moist shady habitats showed greater accumulation of nutritional and bioactive compounds compared with open grassy and shady habitats. The results suggest that altitude, habitat conditions, and soil factors collectively regulate metabolic plasticity and antioxidant potential in R. cordifolia . High‐altitude populations occuring in moist shady habitat may presents valuable germplasm for conservation, cultivation, and pharmaceutical applications.