Physiological and biochemical bases of AMF-mediated antimony stress tolerance in Linum usitatissimum: enhancing growth, phytochemical production, and oxidative damage resilience

Antimony (Sb) pollution from industrial activities poses a severe global threat, particularly impacting valuable medicinal crops like linseed, which are highly sensitive to heavy metals. This study reveals the remarkable potential of arbuscular mycorrhizal fungi (AMF) as a sustainable solution to this challenge. Our research demonstrates that while Sb stress significantly impairs linseed growth and photosynthesis, it also triggers oxidative damage. AMF improved photosynthetic performance and water status, and notably enhanced the biosynthesis of crucial phytochemicals like phenolics, flavonoids, and citric acid. These compounds are vital for both plant defence and human health. Furthermore, AMF promoted the accumulation of essential detoxifying agents, leading to a better redox balance and significantly reducing Sb uptake and translocation by 47%. This dual action not only bolsters the plant's tolerance to Sb but also enhances its medicinal value by boosting health-promoting bioactive metabolites. These promising findings underscore AMF's dual role: a powerful tool for phytoremediation and a natural enhancer of phytochemical quality. Arbuscular mycorrhizal fungi provide a sustainable, nature-inspired approach to safely cultivate medicinal plants in environments contaminated with heavy metals, underscoring the vital role of plant-microbe interactions in alleviating environmental stresses.