Genome-Wide Identification of the FKBP Gene Family in Rice and Its Potential Roles in Blast Resistance

Rice (Oryza sativa L.) is a major global staple crop, yet its productivity is severely constrained by rice blast disease caused by Magnaporthe oryzae. FK506-binding proteins (FKBPs) are peptidyl-prolyl cis-trans isomerases involved in protein folding, stress response, and signaling regulation, but their roles in rice blast resistance remain unclear. In this study, we performed a comprehensive identification and characterization of FKBP gene family members in two rice cultivars, Nipponbare (NIP) and Zhonghua 11 (ZH11), based on the latest T2T (telomere-to-telomere) genome assembly of ZH11 and the reference genome of NIP. A total of 24 and 29 FKBP genes were detected in NIP and ZH11, respectively, indicating a slight expansion in ZH11. Phylogenetic and collinearity analyses revealed strong conservation of FKBP family members between the two cultivars, while several ZH11-specific genes likely resulted from recent duplication events. Promoter analysis showed that FKBP genes are enriched in stress and hormone responsive cis-elements, particularly those related to ABA, MeJA, and SA signaling. Transcriptomic and RT-qPCR analyses demonstrated that multiple FKBP genes were significantly regulated during M. oryzae infection, suggesting their potential involvement in defense signaling pathways. This study provides a comprehensive overview of FKBP gene family evolution and expression in rice, identifies candidate genes potentially associated with blast resistance, and offers valuable insights for molecular breeding aimed at improving disease resistance in rice.