Discovery of Key Brachypodium Regulators May Help Improve Bioenergy Feedstocks


The wild grass Brachypodium distachyon is a model system for temperate grasses, including biofuel plants such as switchgrass and Miscanthus. Because of its relatively small, sequenced genome and a large and growing number of genetic and genomic resources, Brachypodium is useful for studying bioenergy-relevant traits such as grass cell wall characteristics and regulation of plant processes. One key type of regulator is microRNAs (miRNAs), short RNA moleculas involved in many processes such as development and stress response. miRNAs regulate expression of specific genes by pairing with target mRNAs. While many miRNAs have been identified in plants, little is known about these critical regulators in temperate grasses. With funding from the joint U.S. Department of Agriculture-Department of Energy Plant Feedstocks Genomics for Bioenergy program, researchers sequenced small RNAs from different tissues and environmental stress-treated Brachypodium plants and identified miRNAs using a computational approach. Both conserved, newly discovered miRNAs and nonconserved miRNAs not found in other plants were detected. Newly identified regulation of a flowering time gene was found, as well as miRNAs differentially expressed in various tissues. The results improve understanding of the role of miRNAs and their target-specific regulation in Brachypodium and related grasses, and may suggest strategies for bioenergy crop improvement.


Jeong, D.-H., S. A. Schmidt, L. A. Rymarquis, S. Park, M. Ganssmann, M. A. German, M. Accerbi, J. Zhai, N. Fahlgren, S. E. Fox, D. F. Garvin, T. C. Mockler, J. C. Carrington, B. C. Meyers, and P. J. Green. 2013. “Parallel Analysis of RNA Ends Enhances Global Investigation of microRNAs and Target RNAs of Brachypodium distachyon,” Genome Biology 14, R145. DOI: 10.1186/gb-2013-14-12-r145.