Abstract:

Global food security is facing the growing threat of cropland salinization, urgently calling for the development of sustainable remediation solutions. Salt stress inhibits crop growth by inducing osmotic imbalance, ion toxicity, and oxidative damage. Although traditional physical and chemical remediation techniques are effective in the short term, they often lead to secondary pollution and high operational costs. In this context, bioremediation has emerged as a promising and environmentally sustainable alternative. This study systematically reviews recent advances in the mechanisms of plant-microbe interactions under salt stress. It firstly analyzes the impacts of salt stress on plants; then, it elucidates the intrinsic mechanisms of plant salt tolerance, including the synthesis of organic osmolytes, the regulation of hormone metabolism and photosynthetic pathways, and the activation of antioxidant enzymes and stress-responsive genes. It then focuses on rhizosphere-associated plant growth-promoting rhizobacteria (e.g., Bacillus, Pseudomonas) and endophytic fungi (e.g., arbuscular mycorrhizal fungi, Trichoderma), which enhance plant salt tolerance through multiple mechanisms such as maintaining ion homeostasis, improving nutrient uptake, activating antioxidant defense systems, and coordinating hormonal signaling. Finally, we emphasize the importance of integrating multi-omics approaches with synthetic biology technologies to elucidate the interactions among microorganisms, plants, and the environment, thereby facilitating the sustainable remediation of saline soils and the utilization of marginal lands.

Key words: salinization, plant growth promoting rhizobacteria, endophytic fungi, plant-microbe interactions, bioremediation