Sensitive whole mount in situ localization of small RNAs in plants

Abstract

Small regulatory RNAs are pivotal regulators of gene expression and play important roles in many plant processes. Although our knowledge of their biogenesis and mode of action has significantly progressed, we comparatively still know little about their biological functions. In particular, knowledge about their spatiotemporal patterns of expression rely on either indirect detection by use of reporter constructs or labor-intensive direct detection by in situ hybridization on sectioned material. None of the current approaches allows for a systematic investigation of small RNAs expression patterns.Here, we present a method for the sensitive in situ detection of micro-and siRNAs in intact plant tissues that utilizes both double-labelled probes and a specific cross linker. We determined the expression patterns of several small RNAs in plant roots and embryos.