Exploring the benefits of AMF colonization for improving wheat growth, physiology and metabolism, and antimicrobial activity under biotic stress from aphid infection

Background This study examines the effectiveness of arbuscular mycorrhizal fungi (AMF, Rhizophagus irregularis) as a bioprotection strategy to improve wheat's physiological and biochemical responses. This study utilized soil inoculation with AMF and plant-controlled infestation with aphids, conducted over four weeks with three replicates per treatment. Results Although aphid infestation reduced root colonization by 26.8% and hyphal length by 30.7%, with no effect on arbuscular numbers (p < 0.05), AMF treatment improved growth, physiology, and metabolism of AMF-treated plants, especially under aphid infestation. AMF-treated plants showed a 51% increase in fresh weight and a 38% improvement in photosynthetic rates under infestation, indicating enhanced photosynthetic efficiency compared to controls. At the metabolism level, AMF application, particularly in infested plants, increased the levels of several amino acids, such as asparagine and glutamine, which increased by 23% and 20%, respectively. AMF treatment significantly boosted nitrogen metabolism enzymes, with activity increasing up to 4.8-fold in infested plants and arginase activity rising by 49% in infested and 290% in non-infested conditions. This metabolic shift elevated antioxidant levels, increasing flavonoids by 40% and polyphenols by 95% under aphid infestation. Additionally, antimicrobial efficacy improved, with AMF-treated plant extracts showing 30-67% larger inhibition zones against pathogens like Staphylococcus epidermidis and Salmonella typhimurium than untreated plants (p < 0.05). Conclusions This research examined the potential of AMF as a sustainable pest management tool, specifically focusing on its ability to enhance crop health and boost defenses against biotic stress. The study further highlights how AMF treatment improves antimicrobial efficacy, which can be integrated into farming practices to maintain plant growth while offering distinct advantages over conventional pest management strategies.