Biological defence against cadmium stress in wheat with arbuscular mycorrhizal fungi and Trichoderma: Synergistic effects on plant and soil health.

Cadmium (Cd) contamination in agricultural soils presents a serious threat to crop productivity, soil health, and ecological sustainability. This study aims to elucidate the synergistic potential of two beneficial microorganisms-Funneliformis mosseae (Fm), an arbuscular mycorrhizal fungus (AMF), and Trichoderma harzianum (Th)-in mitigating Cd-stress in wheat (Triticum aestivum L.) under controlled conditions. Unlike previous studies that examined these microorganisms individually, this research focuses on their combined application to explore potential interactive effects on plant and soil health. Wheat plants were inoculated with Fm and treated with Th under Cd-stress. After ten-weeks, comprehensive physiological, biochemical, and rhizospheric evaluations were conducted. Cd exposure significantly reduced shoot length by 10 %, total dry-biomass by 24 %, and chlorophyll content by 14 % while increasing oxidative stress markers. In contrast, the Fm + Th treatment significantly improved plant-biomass (by 81 %), restored chlorophyll content (by 16 %), and reduced Cd-translocation from roots to shoots (by 20 %) compared to Cd-only. Antioxidant enzyme activities and phenolic compound levels were also enhanced, indicating co-activation of oxidative stress mitigation pathways. Additionally, Fm and Th acted as indicators of improved soil health, demonstrating increased enzyme activities, organic matter content, and enhanced glomalin production and mycorrhizal colonization. Significant increase in phosphorus uptake was observed in the Fm + Th treatment. This study thus indicates novel synergistic mechanisms of Fm and Th as opposing agents against Cd-toxicity in wheat. These results suggest that integrated microbial approaches can be efficient and sustainable tools for the remediation of plant resilience and soils functionality in contaminated agroecosystems.