Silicon-driven approaches to salinity stress tolerance: Mechanisms, uptake dynamics, and microbial transformations

• Comprehensive insights into the molecular, physiological, and biochemical mechanisms by which silicon (Si) enhances plant tolerance to salinity stress. • Use of molecular docking studies to elucidate the interaction between Lsi1 proteins and silicic acid, highlighting the Si uptake pathway's role in stress mitigation. • Emphasis on silicate-solubilizing microorganisms, such as Bacillus spp., which improve Si bioavailability through organic acid production and mineral dissolution. • Positioning Silicate solubilizing microorganism as a sustainable alternative to synthetic fertilizers for improving crop productivity under saline conditions. Salinity stress poses a critical threat to global crop productivity, driven by factors such as saline irrigation, low precipitation, native rock weathering, high surface evaporation, and excessive fertilizer application. This abiotic stress induces oxidative damage, osmotic imbalance, and ionic toxicity, severely affecting plant growth and leading to crop failure. Silicon (Si) has emerged as a versatile element capable of mitigating various biotic and abiotic stresses, including salinity. This review offers a comprehensive analysis of Si's multifaceted role in alleviating salinity stress, elucidating its molecular, physiological, and biochemical mechanisms in plants. It explores Si uptake, transport, and accumulation in plant tissues, emphasizing its contributions to maintaining ionic balance, enhancing water uptake, and reinforcing cell structural integrity under saline conditions. Additionally, this review addresses Si transformations in saline soils and the factors influencing its bioavailability. A significant focus is placed on silicon-solubilizing microorganisms (SSMs), which enhance Si bioavailability through mechanisms such as organic acid production, ligand exchange, mineral dissolution, and biofilm formation. By improving nutrient cycling and mitigating salinity-induced stress, SSMs offer a sustainable alternative to synthetic silicon fertilizers, promoting resilient crop production in salt-affected soils.