MicroRNA mediated regulation of gene expression in response to soil-borne fungus Fusarium oxysporum f.sp.cubense (Foc1) infection in two contrasting banana genotypes
K. Pavitra, A. Rekha and K.V. Ravishankar
Division of Biotechnology, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru 560 089, India. Department of Biotechnology, Centre for Post Graduate Studies, Jain University, Jayanagar, Bengaluru 560 011, India. Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru 560 089, India.
Abstract: Fusarium wilt caused by the soil-borne fungus Fusarium oxysporum f.sp. cubense (Foc1) is one of the important diseases affecting banana production. MicroRNAs, the short non-coding RNAs containing 22 to 24 nucleotides function in post-transcriptional regulation of target gene expression. MicroRNAs (miRNAs) as gene expression regulators relate to several abiotic stress responses that have already been reported. However, the evidence for the interaction of miRNAs-mRNA in plant response to biotic stresses is very limited. Hence, this study mainly focuses on microRNAs and their target genes in fusarium wilt infection in banana. Here, we have examined the miRNA-mRNA expression patterns between two contrasting banana genotypes in response to fungal infection using quantitative Real-time PCR (qPCR). A total of 6 miRNAs and 9 targets were examined for their expression at two-time points after infection (3 and 10 days post inoculation (dpi)) in both uninfected control and infected root samples. Based on expression analysis, we observed early and continuous down regulation of miRNAs and up-regulation of the nine targets in tolerant genotype “Calcutta-4”. This negative relation was not observed in the susceptible genotype “Kadali”. The mode of expression level of miRNAs and their putative target genes will help in understanding the roles of miRNAs imparting tolerance to fusarium wilt in banana (Musa spp.).
