Cell-based CRISPRa screen identifies a papillae-specific receptor kinase mediating broad-spectrum fungal resistance in rice.

Gain-of-function screens enable the discovery of gene functions and candidate targets for molecular breeding. Here we developed a protoplast-based dCas9-TV-mediated CRISPR activation screen in rice and identified OsTV1, an epidermal papillae-specific receptor kinase, as a positive regulator of fungal resistance. OsTV1 overexpression enhanced silicon deposition, leaf rigidity and basal defence gene expression, conferring broad-spectrum fungal resistance without compromising growth. This study establishes a high-throughput gain-of-function screen adaptable for investigating diverse cellular processes in plants and provides insights into the roles of silicon in rice defence.