Identification of OsCML45 and OsCML36 as Candidate Regulators of Rice Resistance to Sheath Blight Caused by Rhizoctonia solani

Rice sheath blight (ShB), induced by the necrotrophic fungus Rhizoctonia solani, causes substantial losses in rice (Oryza sativa L.) production, and elucidating the resistance mechanisms is key to controlling pathogen spread. In this study, transcriptomics analysis of rice cultivar Shennong 9816 responding to R. solani AG1-IA infection identified 4542 differentially expressed genes (DEGs; p 2FC| ≥ 1). Subsequently, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses of the DEGs revealed significant enrichment in "protein phosphorylation", "plant-pathogen interaction", and "plant-type hypersensitive response". The calcium-binding protein 45 (CML45), calcium-binding protein 36 (CML36), CPK35, wall-associated kinase 2 (WAK2), MSL, Ca2+-binding protein, and WRKY70 genes were upregulated. Overexpression of OsCML45 and OsCML36 was associated with enhanced resistance to R. solani in rice. Moreover, the rice plants overexpressing OsCML45 and OsCML36 showed increased physiological traits. Taken together, these results indicate that OsCML45 and OsCML36 are candidate regulators in rice responses to sheath blight.