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 (Musa spp.), a globally important tropical fruit crop, remains unexplored. In this study, we identified eight putative MaCRF genes in the wild banana Musa acuminata 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, MaCRF4 exhibited contrasting expression patterns in response to Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) infection. MaCRF4 was strongly induced in the susceptible cultivar Z1 but transiently upregulated at early stages followed by downregulation in the resistant cultivar Z8. Furthermore, MaCRF3 and MaCRF4 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.

SPLs (SQUAMOSA promoter binding protein-like) are pivotal in regulating plant development and stress responses. Although SPL genes have been characterized in a series of plant species, no systematic analysis has been performed on bananas, one of the most consumed tropical fruits with immense economic importance worldwide. Here, 55 putative MaSPL genes were identified in Musa acuminata ssp. malaccensis var. Pahang and classified into seven groups based on phylogenetic analysis. The RNA-seq analysis revealed that the expression of MaSPLs presented distinct spatiotemporal patterns in different tissues at different developmental stages, indicating a potential role in banana growth and development. Furthermore, MaSPL1 was found to be predominantly expressed in banana fruits during the fruit development and the early postharvest stages. Notably, the transient overexpression of MaSPL1 accelerated the fruit ripening in bananas. In conclusion, this study provides comprehensive information for further investigation of the specific roles of SPL genes in banana developmental processes, particularly during fruit development and post-harvest stages, and may implement molecular strategies to regulate maturation and enhance fruit quality in bananas.

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.

Background: Banana Fusarium wilt inflicts enormous economic losses on global banana production; however, effective control strategies remain elusive. We previously demonstrated that overexpression of plantain (Musa paradisiaca) ICE1 (MpICE1) significantly enhances banana resistance to Fusarium wilt. This study aimed to screen and identify key resistance genes associated with banana Fusarium wilt resistance and further explore their molecular functions and regulatory mechanisms, so as to provide a solid theoretical basis for the genetic breeding and disease resistance improvement of banana. Methods: Based on our previous transcriptomic dataset and the current metabolomic analysis, we identified a key gene encoding 12-oxo-phytodienoic acid reductase, MaOPR1, involved in the linoleic acid metabolism pathway, and functionally validated its role via dsRNA-mediated gene silencing. Results: Silencing of MaOPR1 alleviated banana leaf-lesion response after Fusarium wilt. Conclusions: Integrating metabolomic and dsRNA-silencing evidence, MaOPR1 acts as a negative regulator of banana Fusarium wilt resistance, associated with alpha-linolenic acid metabolic reprogramming in the MpICE1-overexpressing background.