Arbuscular mycorrhizal fungi modulate the adaptation of aeluropus lagopoides in hypersaline environments.

Aeluropus lagopoides, a key halophytic perennial grass found in both inland and coastal sabkhat, shows tolerance to extreme salinity through physiological and morphological adaptations. Arbuscular Mycorrhizal Fungi are known to associate with the establishment, growth, and nutrient absorption of halophytic plants in diverse hypersaline ecosystems. This study investigated AMF root colonization and the diversity of the sporulating fraction of AMF community associated with A. lagopoides across hypersaline regions (Riyadh, Qaseem, Salwa, Jouf, and Jizan) and investigated their association with host plant phenotypic plasticity through nutrient-mediated morphological responses. AMF colonization, spore density, distribution, and diversity varied significantly among regions and were region-specific. Spore density was highest in Jizan and Qaseem and lowest in Salwa. Seventeen AMF morphotypes belonging to 5 families were isolated from the host rhizosphere based on spore morphology. The Glomeraceae family had the highest detected richness, accounting for 58% of the identified morphotypes. The wide distribution of Entrophospora etunicata, Gigaspora rosea, Funneliformis geosporum, Funneliformis mosseae, Glomus ambisporum, and Rhizophagus fasciculatus across all regions suggested broad ecological significance under saline conditions. Correlation and multivariate analysis revealed significant plant-soil-AMF interactions with edaphic parameters, particularly EC, which were identified as the primary drivers associated with AMF morpho-diversity and distribution among the detected sporulating taxa. AMF characteristics show a strong association with both macro and micronutrients in the plant tissues, suggesting that salt-tolerant AMF species, mainly from the Glomeraceae, may be associated with enhanced nutrient uptake and are correlated with phenotypic plasticity in A. lagopoides. These correlation findings emphasize the significance of native halotolerant AMF as a candidate organism supporting halophyte adaptation in severe saline habitats and highlight their potential role in restoring and rehabilitating these degraded saline ecosystems. However, given that the study is observational and morphology-based, a molecular approach with experimental validation is needed to confirm these associations and establish causality.