Multimechanism Collaborative Superior Antioxidant CDzymes To Alleviate Salt Stress-Induced Oxidative Damage in Plant Growth

Salt stress has become one major environmental challenge threatening global crop yield. Targeting salt-induced oxidative stress, nanozymes with high-efficiency antioxidant activity and good biocompatibility represent an effective way to improve plant salt tolerance. In this study, carbon dot nanozymes (CDzymes) derived from glucose and histidine are designed to alleviate salt-induced oxidative stress in plant growth. The CDzymes are comprehensively characterized to exhibit broad-spectrum antioxidant capability, allowing them to efficiently scavenge reactive oxygen species (·OH, O2–·, H2O2), reactive nitrogen species (·NO and ONOO–), and stable free radicals (DPPH·, ABTS·+, PTIO·). Due to their unique structure, CDzymes exhibit multiple antioxidant mechanisms involving electron transfer, H atom transfer, and enzyme-like catalytic behavior. CDzymes have good biocompatibility and can help promote the growth of Pisum sativum Linn and Eucommia under salinity. CDzyme treatment can significantly (p < 0.001) relieve salt stress-induced oxidative damage of biological components (including chlorophyll, proline, carbohydrate, and protein) and redox enzyme activity, which underlies the mechanism of salt-induced plant wilt. This study demonstrates that CDzymes can act as a potential antioxidant to modulate the level of oxidative stress in biological systems, opening up new avenues for agricultural salt stress management in crops.