MicroRNAs Associated with Environmental Stress in Arabidopsis

Abstract

One way plants respond to environmental stress is by modifying their gene expression through the use of microRNAs (miRNAs). miRNAs are noncoding small RNAs that regulate gene expression at the posttranscriptional level by base pairing with complementary messenger RNA (mRNA) molecules, causing either mRNA cleavage or translational inhibition. To elucidate the roles of miRNAs in environmental stress responses, wild type plants and miRNA enriched mutant plants were subjected to various environmental stresses. Small RNA libraries from stress‐treated seedlings and flowers were constructed and sequenced using deep sequencing technologies. Computational analysis revealed differential expression of miRNAs between stress‐treated plants and control plants with some miRNAs upregulated and some downreguled by environmental stress. Additional analysis revealed potentially novel miRNAs in Arabidopsis as well. These results suggest that miRNAs play important roles in stress responses, and that miRNA identification in Arabidopsis has not been saturated. Future work will involve validating highly stress‐regulated miRNAs and prospective new miRNAs, and examining their potential target genes for regulation. Stress‐regulated miRNAs will be incorporated into multi‐network models and their biological roles will be hypothesized and tested through functional studies. R.S.H.B. was supported by the Howard Hughes Medical Institute, and NSF grant MCB#0548569 to P.J.G. provided research support.