FUNCTIONAL GENOMICS OF miRNA RESEARCH TOOLS

miRNAs, encoded by MIRNA genes, are represented by short, single stranded and non-coding RNA molecules which are commonly present in all Eukariotic genomes and involved in the regulation of the gene expression at post-transcriptional levels. In plants, miRNAs are involved in essential developmental processes, such as plant morphogenesis, hormone signaling, and developmental phase transition. Till now, miRNA functions were evaluated mostly indirectly by elucidation of the target genes. During the last 5 years, novel analytical methods based on the genetic engineering techniques have been developed to open new opportunities in research on the regulatory functions of plant miRNAs. These methods, described in the presented work, include: (i) amiRNA constructs encoding artificial miRNAs; (ii) MIM lines based on the mimicry of the specific miRNA-target sequence; (iii) STTM lines, based on MIM strategy and enabled to efficiently inhibit miRNA activity; (iv) constructs carrying the resistant to miRNA sequences of the target genes; (v) reporter sensor lines useful in spatio-temporal analysis of the miRNA-target interactions. Beside characterization of the constructs used in each of these methods, the applications of the novel strategies in research on miRNA functions in plants have been described. In addition, some perspective opportunities for practical use of the miRNA-based strategies for genetic modifications of crops in agriculture have been presented.