R-loops at microRNA encoding loci promote co-transcriptional processing of pri-miRNAs in plants

编号 040034905

推送时间 20220627

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 R-loops at microRNA encoding loci promote co-transcriptional processing of pri-miRNAs in plants

来源期刊 Nature Plants

期 第349期

发表时间 20220421

关键词 drought;  drylands;  gross primary production (GPP);  soil moisture;  vapor pressure deficit; 
warming; 

摘要 In most organisms, the maturation of nascent RNAs is coupled to transcription. Unlike in animals, the RNA polymerase II (RNAPII) transcribes microRNA genes (MIRNAs) as long and structurally variable pri-miRNAs in plants. Current evidence suggests that the miRNA biogenesis complex assembly initiates early during the transcription of pri-miRNAs in plants. However, it is unknown whether miRNA processing occurs co-transcriptionally. Here, we used native elongating transcript sequencing data and imaging techniques to demonstrate that plant miRNA biogenesis occurs coupled to transcription. We found that the entire biogenesis occurs co-transcriptionally for pri-miRNAs processed from the loop of the hairpin but requires a second nucleoplasmic step for those processed from the base. Furthermore, we found that co- and post-transcriptional miRNA processing mechanisms co-exist for most miRNAs in a dynamic balance. Notably, we discovered that R-loops, formed near the transcription start site region of MIRNAs, promote co-transcriptional pri-miRNA processing. Furthermore, our results suggest the neofunctionalization of co-transcriptionally processed miRNAs, boosting countless regulatory scenarios.

服务人员 孙小满

服务院士 尹伟伦

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