Soil salinization poses an escalating threat to global crop production. Extracellular polysaccharides (EPSs) secreted by plant growth-promoting rhizobacteria have the potential to improve the salt tolerance of crops. Here, we tested the effects of Pantoea alhagi NX-11 EPSs on the growth, physiological traits, and root proteomic profiles of rice under salt stress. We found that NX-11 EPSs effectively increased the salt tolerance of rice in soil, with 50 mg/kg EPS exhibiting the strongest plant growth-promoting effect. This effect was associated with increased the K+/Na+ ratio and soluble protein content in roots induced by NX-11 EPSs as well as reduced stomatal aperture and transpiration rate in leaves. Proteomic analyses revealed that NX-11 EPSs markedly changed the protein profiles of roots. Specifically, proteins associated with cyanoamino acid metabolism, glycolysis/gluconeogenesis, and fatty acid degradation were downregulated. Together, these results suggest that NX-11 EPSs improve rice performance under salt stress, accompanied by changes in physiological traits and root protein profiles.
Zhang et al. (2026) studied this question.