Chito-oligosaccharide loaded with ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing bacteria improved soil microecology and cotton growth in salinized lands

Chitosan oligosaccharide, as a soil amendment, is widely used to cope with various environmental stresses. This study comparatively analyzed the effects of chitosan oligosaccharide-based polymer amendment (COS-PA), ACC deaminase-producing bacterial agent (A1), and their combination (COS loaded with ACC deaminase-producing strains, CAS) on cotton vegetative growth under salt stress. The results showed that the application of COS-PA, A1, and CAS significantly reduced soil pH and EC values compared with the control. Numerically, the CAS treatment showed the most significant effects among the treatments, with soil sucrase, urease, and alkaline phosphatase activities 27.84%, 111.4%, and 33.79% higher than those of the control, respectively. Additionally, this treatment also held significantly higher leaf peroxidase and catalase activities and cotton vegetative growth parameters. Microbial analysis showed that CAS mainly improved soil microecology by changing the relative abundance and composition of fungal (Basidiomycota) and bacterial (Atescibacteria and Actinobacteria) communities. In summary, under the specific conditions of this pot experiment, the CAS application was associated with improved soil enzyme activities and cotton growth parameters. Field validation is required. This study provides a reference for the development of new soil amendments and contributes to the sustainable utilization of salinized lands. Application of chito-oligosaccharide loaded with ACC deaminase-producing bacteria was associated with improved soil microecology. Application of chito-oligosaccharide loaded with ACC deaminase-producing bacteria was correlated with enhanced cotton growth under saline-alkali stress in pot experiments. Shifts in the soil fungal community were associated with changes in soil quality parameters.