Quantitating plant microRNA-mediated target repression using a dual-luciferase transient expression system.

microRNA (miRNA) mediated repression of target genes plays essential roles in a variety of functions in plants. An easy-to-use method that can effectively validate functional miRNA-target interactions in plants thus is of particular interest. Here, we describe an Agrobacterium tumefaciens-mediated in vivo assay utilizing a dual-luciferase reporter system. With this method, the strength of miRNA-mediated target repression can be quantified at both the mRNA (via qRT-PCR) and protein (via dual-luciferase assay) levels quickly and accurately.