AUTHOR=Ci Dong , Song Yuepeng , Tian Min , Zhang Deqiang 

TITLE=Methylation of miRNA genes in the response to temperature stress in Populus simonii

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00921

DOI=10.3389/fpls.2015.00921

ISSN=1664-462X

ABSTRACT=<p>DNA methylation and miRNAs provide crucial regulation of the transcriptional and post-transcriptional responses to abiotic stress. In this study, we used methylation-sensitive amplification polymorphisms to identify 1066 sites that were differentially methylated in response to temperature stress in <italic>Populus simonii</italic>. Among these loci, BLAST searches of miRBase identified seven miRNA genes. Expression analysis by quantitative real-time PCR suggested that the methylation pattern of these miRNA genes probably influences their expression. Annotation of these miRNA genes in the sequenced genome of <italic>Populus trichocarpa</italic> found three target genes (<italic>Potri.007G090400</italic>, <italic>Potri.014G042200</italic>, and <italic>Potri.010G176000</italic>) for the miRNAs produced from five genes (<italic>Ptc-MIR396e</italic> and <italic>g</italic>, <italic>Ptc-MIR156i</italic> and <italic>j</italic>, and <italic>Ptc-MIR390c</italic>) respectively. The products of these target genes function in lipid metabolism to deplete lipid peroxide. We also constructed a network based on the interactions between DNA methylation and miRNAs, miRNAs and target genes, and the products of target genes and the metabolic factors that they affect, including H<sub>2</sub>O<sub>2,</sub> malondialdehyde, catalase (CAT), and superoxide dismutase. Our results suggested that DNA methylation probably regulates the expression of miRNA genes, thus affecting expression of their target genes, likely through the gene-silencing function of miRNAs, to maintain cell survival under abiotic stress conditions.</p>