Rice is one of the most important food crops in the world. However, stable rice production is constrained by various diseases, in particular rice blast, sheath blight, bacterial blight, and virus diseases. Breeding and cultivation of resistant rice varieties is the most effective method to control the infection of pathogens. Exploitation and utilization of the genetic determinants of broad-spectrum resistance represent a desired way to improve the resistance of susceptible rice varieties. Recently, researchers have focused on the identification of rice broad-spectrum disease resistance genes, which include R genes, defense-regulator genes, and quantitative trait loci (QTL) against two or more pathogen species or many isolates of the same pathogen species. The cloning of broad-spectrum disease resistance genes and understanding their underlying mechanisms not only provide new genetic resources for breeding broad-spectrum rice varieties, but also promote the development of new disease resistance breeding strategies, such as editing susceptibility and executor R genes. In this review, the most recent advances in the identification of broad-spectrum disease resistance genes in rice and their application in crop improvement through biotechnology approaches during the past 10 years are summarized.

CuO NPs (cupric oxide nanoparticles) are widely used in various fields due to their high electrical conductivity, electronic correlation effect, and special physical property. Notably, CuO NPs have good application prospects in agricultural production because of its antifungal activity to prevent crop diseases. However, the increasing release of CuO NPs into the environment has resulted in a serious threat to the ecosystem, including plants. Previous studies have reported the toxicity of CuO NPs on rice, but little is known about the underlying molecular mechanisms or specific genes involved in the response to CuO NPs. In this study, we found that the rice well-known receptor Chitin Elicitor Receptor Kinase 1 (OsCERK1), which is essential for basal resistance against pathogens, is involved in CuO NPs stress in rice. Knockout of OsCERK1 gene resulted in enhanced tolerance to CuO NPs stress. Furthermore, it was revealed that OsCERK1 reduces the tolerance to CuO NPs stress by regulating the anti-oxidant system and increasing the accumulation of H₂O₂ in rice. In addition, CuO NPs treatment significantly enhances the basal resistance against M. oryzae which is mediated by OsCERK1. In conclusion, this study demonstrated a dual role of OsCERK1 in response to CuO NPs stress and M. oryzae infection by modulating ROS accumulation, which expands our understanding about the crosstalk between abiotic and biotic stresses.