Identification of miRNAs differentially expressed in Fusarium wilt-resistant and susceptible banana varieties

MicroRNAs (miRNAs) are a class of endogenous non-coding small RNAs that regulate targeted mRNAs by post-transcription; thus, miRNAs are considered post-transcription regulators. Although numerous miRNAs have been found in model plants, information on miRNAs in banana is limited. In this study, 139 members in 38 miRNA families were determined by sequencing the small RNA (sRNA) transcriptomes of Fusarium wilt-resistant and susceptible banana varieties, and six out of eight new miRNAs were confirmed by RT-PCR. According to the sRNA transcriptome data and qRT-PCR verification, some miRNAs were differentially expressed between Fusarium wilt-resistant and susceptible banana varieties. A total of 293 and 31 target genes were predicted based on the draft maps of banana A genome and Fusarium oxysporum (FOC1, FOC4) genomes, respectively. Two important pathogenic genes in F. oxysporum genomes, namely, feruloyl esterase gene and proline iminopeptidase gene, were targeted by banana miRNAs. These novel findings may provide a new strategy for preventing and controlling Fusarium wilt in banana.