Reverse Transcription-qPCR-Based Investigation of Antiviral miRNAs in Medicinal Plants

MicroRNAs (miRNAs) are endogenous regulators of gene expression that enable high adaptation to the living conditions of organisms. While plant antiviral miRNAs are effective in combating their viral pathogens, some plant miRNAs exhibit cross-kingdom interactions when targeting animal viruses. Current studies have reported that the miRNA contents of medicinal plants used in treating viral diseases are directly effective in combating the disease. Along with this study, the presence and expression levels of five plant miRNAs (miRNA765, miRNA954, miRNA1086, miRNA1328, and miRNA2911), known for their antiviral effects against human diseases, were analyzed in eight medicinal plants using the reverse transcription-quantitative real-time PCR (RT-qPCR) method. One of the test group medicinal plants was used as dry material for comparison purposes. Triticum aestivum L. fruits that contain high starch were preferred as the calibrator plant sample, and miRNA161 was used as the endogenous miRNA control. cDNAs were synthesized using stem-loop primers and amplified by RT-qPCR with SYBR green. Expression levels of antiviral miRNAs were analyzed using the fold change (Fc) and the relative quantification (RQ) data. At the end of this study, antiviral miRNAs were found in some medicinal plants and detected at high levels in preserved dried plant samples, such as Viscum album leaves.