Large-Scale Screening\nand Function Analysis of Rhizoctonia solani Effectors Targeting Rice Chloroplasts

Rice sheath blight (RSB), caused byRhizoctonia\nsolani, is a major economic threat to global rice\ncrops. The genome of R. solani contains\nover 103 potential effectors,\nwith most functions still unknown. Previous studies show that chloroplast\nplays a crucial role in RSB resistance. However, whether R. solani effectors target plant chloroplasts to\npromote the pathogen infection remains unclear. This study leveraged\nfour RSB-resistant chloroplast proteins to identify five interacting\nsecreted proteins from a 430-protein R. solani yeast library. These proteins, which localize to rice chloroplasts,\nwere shown to cause cell death in Nicotiana benthamiana and rice protoplasts, suggesting that they potentially influence\nhost cellular processes by targeting chloroplasts. Bioinformatic analysis\nindicates that these five putative effectors almost all contained\nconserved structures related to pathogenicity. This study provides\na novel method for screening specific functional effectors and facilitates\nthe further study of the pathogenic mechanisms of R.\nsolani.