National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032, Shanghai, China.
University of the Chinese Academy of Sciences, 100049, Beijing, China.
Nat Commun. 2020 Oct 22;11(1):5351. doi: 10.1038/s41467-020-19186-x.
MicroRNAs (miRNAs) and natural antisense transcripts (NATs) control many biological processes and have been broadly applied for genetic manipulation of eukaryotic gene expression. Still unclear, however, are whether and how NATs regulate miRNA production. Here, we report that the cis-NATs of MIR398 genes repress the processing of their pri-miRNAs. Through genome-wide analysis of RNA sequencing data, we identify cis-NATs of MIRNA genes in Arabidopsis and Brassica. In Arabidopsis, MIR398b and MIR398c are coexpressed in vascular tissues with their antisense genes NAT398b and NAT398c, respectively. Knock down of NAT398b and NAT398c promotes miR398 processing, resulting in stronger plant thermotolerance owing to silencing of miR398-targeted genes; in contrast, their overexpression activates NAT398b and NAT398c, causing poorer thermotolerance due to the upregulation of miR398-targeted genes. Unexpectedly, overexpression of MIR398b and MIR398c activates NAT398b and NAT398c. Taken together, these results suggest that NAT398b/c repress miR398 biogenesis and attenuate plant thermotolerance via a regulatory loop.
MicroRNAs (miRNAs) 和自然反义转录本 (NATs) 控制着许多生物过程，并被广泛应用于真核基因表达的遗传操作。然而，NATs 是否以及如何调节 miRNA 的产生尚不清楚。在这里，我们报告说 MIR398 基因的顺式-NATs 抑制其前体 miRNA 的加工。通过对拟南芥和芸薹属的 RNA 测序数据的全基因组分析，我们鉴定了 miRNA 基因的顺式-NATs。在拟南芥中，MIR398b 和 MIR398c 在血管组织中与它们的反义基因 NAT398b 和 NAT398c 共表达。NAT398b 和 NAT398c 的敲低促进了 miR398 的加工，导致由于 miR398 靶向基因的沉默而增强了植物耐热性；相反，它们的过表达激活了 NAT398b 和 NAT398c，导致由于 miR398 靶向基因的上调而导致耐热性较差。出乎意料的是，MIR398b 和 MIR398c 的过表达激活了 NAT398b 和 NAT398c。综上所述，这些结果表明 NAT398b/c 通过调控环抑制 miR398 的生物发生并减弱植物耐热性。
