An Array Platform for Identification of Stress-Responsive MicroRNAs in Plants

MicroRNAs (miRNAs) are approximately 22-nucleotide (nt)-long non-coding RNAs that play a key role in plant development and abiotic stresses. We have developed a simple but effective array platform for profiling plant miRNAs from various plant species. The array is composed of 188 non-redundant miRNA probes that can detect both conserved and species-specific miRNAs from most plant species, including Arabidopsis , rice, and poplar. In this chapter, we describe a protocol for developing the miRNA array platform, which can be used to identify stress-responsive miRNAs in diverse plant species. Profiling of miRNAs in tobacco seedlings exposed to different abiotic stress conditions has revealed that a number of miRNAs, miR398, miR399, miR408, miR156, miR164, and miR168, were responsive to stresses. This comprehensive and easy-to-follow protocol will be useful for studying roles of miRNAs in plant stress response.