P-064 - Mutation of Receptor-Like Cytoplasmic Kinase confers resistance on soybean plants (Glycine max) to Pseudomonas syringae pv. syringae B728a infection.

Rapid environmental changes are making crop cultivation more challenging than ever. Despite the agricultural significance of soybeans, their immune response remains poorly understood compared to other model plants. To initiate a study about microbe-associated molecular pattern-triggered immunity in soybean plants, we have chosen several soybean genes with high sequence identities to key Arabidopsis immune regulators, such as BRI1-ASSOCIATED KINASE 1(BAK1), BOTRYTIS-INDUCED KINASE 1(BIK1), and MITOCEN-ACTIVATED PROTEIN KINASE 4(MPK4). Through CRISPR-Cas9 genome editing, we obtained nonsense mutated alleles of Glyma.08G074500 (encoding a receptor kinase) and Glyma.01G098400 and Glyma.02G247600 (encoding receptor-like cytoplasmic kinases) with indel frequencies exceeding 99%. Additionally, we introduced an in-frame deletion in Glyma.16G032900, which encodes MPK. To assess the role of these genes in disease resistance, we inoculated the mutants with Pseudomonas syringae pv. syringae B728a, which causes soybean brown spot disease. Notably, mutations in Glyma.01G098400 and Glyma.02G247600 loci resulted in disease resistance in soybean plants against Pseudomonas infection. We also examined the changes in disease resistance of mutant plants in response to fungal and oomycete infection. Our study provides previously unidentified genetic resources for studying soybean immunity and shows the roles of these genes in the immune responses against pathogen infection.