Fusarium oxysporum and Verticillium dahliae ares soil-borne hemibiotrophic fungal pathogens that cause major losses in agricultural production worldwide. Herein we report that Fov7, putatively encoding a GLUTAMATE RECEPTOR-LIKE (GLR) protein, confers resistance to Fov race 7 in upland cotton. A single nucleotide polymorphism (SNP) (C/A) in GhGLR4.8, resulting in an amino acid change (L/I), was associated with Fov resistance. CRISPR/Cas9-mediated knockout of Fov7 resulted in cotton lines extremely susceptible to Fov race 7. This first report of a GLR-encoding gene that functions as an R gene.
 Meanwhile. Transcriptome analysis showed induction of genes potentially associated with Verticillium dahliae virulence are at the late stage of infection (Stage II), accompanied by a burst of reactive oxygen species (ROS), with more genes involved in the defense response in cotton. For further investigation, polyethyleneimine-coated MXene quantum dots (PEI-MQDs), which possess the ability to remove ROS, were employed. Cotton seedlings maintained ROS homeostasis with enhanced peroxidase and catalase after exogenous treatment with PEI-MQDs and showed significantly improved tolerance to V. dahliae. Furthermore, an elicitor VP2 which was highly up-regulated during the interaction was identified. Knock-out of VP2 attenuated the pathogenicity, while overexpression of VP2 in cotton enhanced resistance to V. dahliae with activated JA, SA signal pathways and lignin synthesis.