2025, Vol. 6, Issue 1, Part A

Quinoa (Chenopodium quinoa Willd.) has gained global attention as a climate-resilient pseudocereal due to its exceptional nutritional profile and capacity to thrive in marginal environments. However, yield and physiological stability remain challenged under severe abiotic stresses such as salinity and drought, necessitating innovative and sustainable approaches to improve resilience. This study aimed to evaluate the role of endophytic microbes—both bacterial and fungal—in enhancing stress tolerance of quinoa through integrated physiological and biochemical mechanisms. Endophytic isolates were obtained from quinoa tissues, screened for plant growth-promoting traits such as ACC deaminase activity, indole-3-acetic acid production, phosphate solubilization, siderophore secretion, and exopolysaccharide formation, and inoculated individually or in consortia. Greenhouse experiments were conducted under controlled salinity (200-400 mM NaCl and Na₂SO₄) and drought stress, with plant growth, biomass, chlorophyll content, relative water content, ion concentrations, and antioxidant enzyme activities measured to assess plant performance.

The results revealed that inoculated plants exhibited significant increases in shoot biomass, root length, and chlorophyll content compared to uninoculated controls. Among the treatments, Paraburkholderia phytofirmans PsJN and Pseudomonas sp. M30-35 improved growth and physiological stability, while native fungal consortia produced the most robust enhancements, with up to 51% increase in biomass. Antioxidant enzyme activities (SOD, APX, POD) were elevated, and malondialdehyde levels were reduced, indicating improved oxidative stress regulation. Ion analysis demonstrated a reduced Na⁺/K⁺ ratio in inoculated plants, confirming enhanced ionic homeostasis. Correlation and multivariate analyses highlighted strong associations between microbial functional traits and improved plant physiology.