Abstract Sugar beet ( Beta vulgaris L.) is a significant sugar crop worldwide. However, environmental stress and excessive use of synthetic fertilizers, which compromise yield and soil health, are increasingly affecting it. Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with most plants, enhancing nutrient uptake, growth, and stress resistance. Therefore, this work aimed to investigate the effects of AMF on sugar beet physiology, defense gene expression, and rhizosphere microbiome. Plants were inoculated with a mix of spores from the AMF consortium. Plants treated with AMF showed significant improvements in root development and quality, with root diameter reaching 4.2 cm and root weight 64 g, compared to the control plants, 2.4 cm and 26.8 g, respectively. Nutrient uptake of the roots increased significantly (phosphorus by 37% and nitrogen by 24%), accompanied by a 17% rise in sugar yield. The expression of defense-related genes ( BvJac, BvProt, BvJI, and BvPR10 ) was assessed via qPCR and showed a 1.5–2.4-fold increase, suggesting a possible role for AMF in enhancing plant stress adaptation and strengthening plant defense responses. Analysis of the rhizosphere microbiome via 16S rRNA and ITS amplicon sequencing, utilizing MOTHUR, CosmosID, and MicrobiomeAnalyst, revealed distinct shifts in bacterial and fungal communities, including an increase in the potentially beneficial phylum Patescibacteria (12.5% vs. 7.1% in controls), along with a ~ 50% reduction in Fusarium . These findings highlight the potential of AMF to enhance sugar beet performance while promoting soil health and beneficial plant–microbe interactions, providing a sustainable strategy for crop production and reducing reliance on chemical inputs.
Youssef et al. (Wed,) studied this question.