Characterization of Casein Kinase I Family Genes in Banana Reveals MaCKI16 as a Potential Regulator of Fusarium Wilt Resistance

Casein kinase I (CKI) proteins form a conserved protein kinase family with broad regulatory functions in plant growth, development, and adaptation to environmental cues. Despite their established roles in other plant systems, the diversity, evolutionary relationships, and biological functions of CKI genes in banana remain insufficiently characterized. Genome-wide analysis of Musa acuminata DH Pahang genome revealed 27 MaCKI genes, which were resolved into two major categories encompassing five distinct phylogenetic clades. Expression profiles of MaCKI genes were analyzed using publicly available transcriptome data from Musa acuminata L. cv. Cavendish ‘Baxijiao’ deposited in the NCBI database, revealing distinct spatial and temporal expression patterns across diverse tissues and developmental stages. Among these genes, MaCKI16 exhibited broad expression across the examined tissues, with particularly high expression in roots compared with other MaCKI members. To investigate its potential role in Fusarium wilt resistance, we employed a transient dsRNA-mediated gene-silencing approach in detached banana leaves followed by Foc TR4 infection. MaCKI16 silencing significantly increased disease severity following Foc TR4 inoculation, suggesting that MaCKI16 may contribute to banana responses to Foc TR4 infection. Overall, this work advances the understanding of CKI gene functions in banana and provides a foundation for further elucidating the role of MaCKI16 in responses to Foc TR4 infection.