Chitosan–Se Engineered Nanomaterial Mitigates Salt Stress in Plants by Scavenging Reactive Oxygen Species

Soil salinity seriously hinders the sustainable development of green agriculture. The emergence of engineered nanomaterials has revolutionized agricultural research, providing a new means to overcome the limitations associated with current abiotic stress management and achieve highly productive agriculture. Herein, we synthesized a brand-new engineered nanomaterial (Cs–Se NMs) through the Schiff base reaction of oxidized chitosan with selenocystamine hydrochloride to alleviate salt stress in plants. After the addition of 300 mg/L Cs–Se NMs, the activity of superoxide dismutase, catalase, and peroxidase in rice shoots increased to 3.19, 1.79, and 1.85 times those observed in the NaCl group, respectively. Meanwhile, the MDA levels decreased by 63.9%. Notably, Cs–Se NMs also raised the transcription of genes correlated with the oxidative stress response and MAPK signaling in the transcriptomic analysis. In addition, Cs–Se NMs augmented the abundance and variety of rhizobacteria and remodeled the microbial community structure. These results provide insights into applying engineered nanomaterials in sustainable agriculture.