Chongchong Lu，Zimeng Li, Taizhong Huang，Muhammad Zunair Latif，Haifeng Liu，Mingxia Hao，Yanke Jiang，Yingzhe Yue，Jian Zhang，Miaomiao Deng，Qian Du，Sifan Yang，Zihan Zhang，Muhammad Humza，Ziyi Yin， Yang Li，Xiangling Shen，Xinhua Ding 

Abstract

Bacterial leaf streak (BLS) is a significant disease that can cause yield losses of up to 40 %. This study demonstrates the potential of copper hydroxide nanoparticles (Cu(OH)2NPs) to increase rice resistance to BLS, drought, and salinity stress, even at a remarkably low concentration of 5 μg/mL compared with 500 μg/mL Cu2+ and Kocide 3000. Cu(OH)2NPs activate various immune responses in rice, including accumulation of reactive oxygen species (ROS), callose deposition, the upregulation of disease resistance-related genes, and stomatal closure. Interestingly, the immune resistance induced by Cu(OH)2NPs does not depend on the salicylic acid signaling pathway but rather partially relies on ethylene signal transduction. This finding highlights the unique mechanism by which Cu(OH)2NPs activate plant immunity, distinguishing them from traditional copper-based treatments. Concurrently, Cu(OH)₂NPs mitigated salt stress by upregulating sodium/chloride efflux genes, reducing root NaCl accumulation by more than 75 %. Under drought conditions, Cu(OH)2NPs reduce the water loss rate and stomatal aperture, thereby increasing the survival rate of rice seedlings. This research provides innovative insights and potential treatment solutions for managing BLS and improving plant resistance to abiotic stresses, offering a promising direction for future agricultural practices.

Paper Linkage:https://doi.org/10.1016/j.cej.2026.172632