miR430: the novel heat-responsive microRNA identified from miRNome analysis in wheat (Triticum aestivum L.)

miRNAs are 21–24 nt non-coding RNAs involved in negative regulation of the target gene expression in response to stress and developmental cues. Wheat, the major staple food crop, is highly sensitive to heat stress (HS). Even moderate high temperatures during critical stages causes reduction in yield and quality of the grains. Here, we identified a novel miRNA (candidate miR430) from wheat using de novo assembly, and cloned it from wheat cv. HD2985 using universal adaptor. The identified miRNA was mapped on to the Chromosome 3B and predicted to have more than 30 target genes. Most of the targets identified were associated with heat shock proteins. Expression analysis of miR430 in contrasting wheat cultivars by quantitative real-time PCR revealed significant genotypic variations under HS. Tissue specific expression analysis showed relatively low expression in leaves, as compared with stem and root under HS. A negative correlation was found between the expression of miR430 and their respective target genes under HS. MiR430 can be used to manipulate the expression of target genes under HS towards enhancing HS tolerance for the development of ‘climate-smart’ wheat crop.