Altitudinal Eco-Physiology, Bioactive Profiling and Multivariate Trait Associations of Seabuckthorn (Hippophae rhamnoides L.) in the High-Altitude Cold Desert of Leh-Ladakh, India
Description
Seabuckthorn (Hippophae rhamnoides L.), locally recognized as the 'Wonder Plant of Ladakh', thrives across extreme altitudinal gradients (2,900 to 4,500 m a.s.l.) in the trans-Himalayan cold desert of Leh-Ladakh. This investigation led evaluate to eco-physiological variations, lipid profiles and secondary metabolite dynamics across five distinct altitudinal zones: Sham (2,980 m), Nubra (3,150 m), Indus (3,500 m), Suru (3,750 m) and Changthang (4,200 m). Biochemical profiling revealed that wild populations exposed to extreme high-altitude stress (Changthang) accumulated significantly higher concentrations of L-ascorbic acid (Vitamin C: 705.0 mg/100g pulp), total phenolics (43.2 mg GAE/g) and rare palmitoleic acid (Omega-7: 42.4% of total pulp fatty acids) compared to lower-elevation populations. Multivariate Principal Component Analysis (PCA) explained 99.7% of total variance across PC1 (99.7%) and PC2 (0.2%), establishing clear clustering based on altitudinal abiotic stress adaptation. Pearson correlation heatmaps confirmed near-perfect positive correlations (r = 0.99 to 1.00) between elevation, ascorbic acid, seed oil content, and antioxidant radical scavenging capacity (IC50 = 27.9 µg/mL). Enzymatic assays revealed a 2.5-fold increase in Phenylalanine Ammonia-Lyase (PAL) activity and upregulation of Stearoyl-ACP Desaturase (SAD) gene expression at 4,200 m. These findings demonstrate that extreme altitude-induced UV-B radiation and sub-zero temperatures upregulate secondary metabolic pathways, positioning high-altitude Himalayan Seabuckthorn as a prime biological resource for nutraceutical and pharmaceutical exploitation.