Genome-Wide Identification of Cytokinin Response Factors (CRFs) Involved in Stress Responses in Banana (Musa acuminata)

Cytokinin response factors (CRFs), belonging to AP2/ERF transcription factor family, play pivotal roles in regulating plant growth, hormone signaling, and stress responses. While CRF genes have been functionally characterized in multiple plant species, their systematic analysis in banana (<i>Musa</i> spp.), a globally important tropical fruit crop, remains unexplored. In this study, we identified eight putative MaCRF genes in the wild banana <i>Musa acuminata</i> ssp. malaccensis var. Pahang. Through comprehensive bioinformatic analyses, we characterized the MaCRF family and investigated their expression profiles across diverse tissues and under various biotic and abiotic stresses. Intriguingly, <i>MaCRF4</i> exhibited contrasting expression patterns in response to <i>Fusarium oxysporum</i> f. sp. cubense tropical race 4 (<i>Foc</i> TR4) infection. <i>MaCRF4</i> was strongly induced in the susceptible cultivar Z1 but transiently upregulated at early stages followed by downregulation in the resistant cultivar Z8. Furthermore, <i>MaCRF3</i> and <i>MaCRF4</i> were markedly induced by osmotic stress, low temperature, salinity, and ABA treatment. Our findings provide the systematic characterization of the MaCRF family in banana and offer valuable insights for future functional studies aimed at enhancing stress tolerance through molecular breeding strategies.