Transcriptome-wide identification of microRNAs regulating plant immunity in Gossypium arboreum L.

Crop yields are linked to overall plant health, which is influenced by several regulatory processes responsible for normal gene functions. Any obstruction in gene expression causes abnormal regulatory processes, which ultimately may cause stunted growth and low yields. To cope with these stresses, plants reprogram gene expression at transcription and post-transcriptional levels, improving stress tolerance. MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs that regulate various biological processes and control the expression of active genes by cleavage or translational inhibition of target messenger RNA. In this study, 56 miRNAs belonging to 19 miRNA families targeting resistance genes (R-genes) were found in the sequenced genome of G. arboreum. Seventy-nine potential target disease R-genes were predicted to be regulated by these 19 miRNA families. The result showed that both cis-acting elements of proximal promoters of 19 miRNA genes and the expression level of these miRNAs help to mediate the expression of 79 target R-genes and carry out the regulation of essential cellular processes by messenger RNA cleavage or translational repression of these genes.