Expression analysis of phytohormone-regulated microRNAs in rice, implying their regulation roles in plant hormone signaling

Twenty-two conserved miRNAs were chosen to investigate the expression pattern in response to phytohormone treatments, in which the effects of five classic plant hormone stresses were surveyed in Oryza sativa. The results showed that 11 miRNAs were found to be dysregulated by one or more phytohormone treatments. The target genes of these miRNAs were validated in vivo and their expression pro. ling were revealed. We also analyzed the promoter regions of the 22 conserved miRNAs for phytohormone-responsive elements and the existence of the elements provided further evidences supporting our results. These findings enable us to further investigate the role of miRNAs in phytohormone signaling. (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.