ABSTRACT
One of the most exciting biological finding in recent years is the discovery of many functional small RNA species that regulate diverse spatial and temporal function of the genome [1-4]. After the initial discovery of miRNAs in the worm C. elegans [5,6], they are emerging as an important class of endogenous gene regulators acting at the post-transcriptional level in both animals and plants. In plants, much of the effort to identify, experimentally validate, and functionally characterize miRNAs has been directed toward the model plant Arabidopsis thaliana. Consequently, dozens of miRNA-target pairs have been identified and studied [7-9]. It is now well-established that these gene circuits are crucial for many plant development processes as well as responses to environmental challenges [4,9,10].
