Arbuscular mycorrhizal fungal symbiosis enhances salt stress tolerance in Sorghum bicolor, Sesbania sesban, and Senna tora

Soil salinity limits plant growth and productivity, creating a need for sustainable approaches to improve plant performance in salt-affected environment. Arbuscular mycorrhizal fungi (AMF) offer a potential biological strategy for mitigating salt stress, but their benefits may vary among host species and salinity levels. However, comparative evidence on these species-specific responses remains limited. This study evaluated the effects of AMF in inoculation on Sorghum bicolor (L.) Moench, Sesbania sesban (L.) Merr., and Senna tora (L.) Roxb., under four salinity levels (0, 2.5, 5.0, and 7.5 dS m − 1 ) in a four-month greenhouse experiment. Plant height, number of leaves, and fresh and dry weight of shoots and roots were measured. The percentage of root colonization by AMF structures (mycelium, vesicles, arbuscules) was also assessed. AMF colonization rates were highest at the lowest salinity level (2.5 dS m − 1 ) and declined significantly ( P < 0.001) at 7.5 dS m − 1 . S. sesban showed the highest colonization rate (90%), followed by S. bicolor and S. tora . Inoculation with AMF significantly ( P < 0.001) improved all growth parameters under salt stress, particularly at 2.5 dS m − 1 . S. bicolor demonstrated the highest tolerance, with AMF-inoculated plants showing remarkable improvements in RGR and biomass even at 7.5 dS m − 1 . The AMF symbiosis markedly enhances salt stress tolerance in the studied species, with the effectiveness being species-dependent and inversely correlated with salinity levels. S. bicolor exhibited the greatest potential for AMF-assisted cultivation in saline soils.