Lariat RNA debranching prevents harmful siRNA burst in plants
Abstract
Lariat RNAs are formed from introns during pre–messenger RNA splicing, after which they are degraded by the debranching enzyme DBR1. Impairment of DBR1 leads to developmental arrest, yet the mechanism remains unclear. In this study, we found that debranching of lariat RNA prevents production of 21- and 22-nucleotide lariat-derived small interfering RNAs (lasiRNAs), which causes a burst of exonic siRNAs, thereby safeguarding development and defense response. LasiRNA biogenesis relied on RNA-dependent RNA polymerases and Dicer-like proteins (DCLs). Upon pathogen infection and dysfunction of DBR1, many lariat RNAs were hijacked by DCL4 and DCL2 and processed into siRNAs that particularly target immunity genes, ultimately disrupting plant defense responses. Collectively, DBR1-mediated lariat RNA removal serves as a protective mechanism to prevent the activation of a small RNA–based defense system in plants.
Article Details
Journal Info
Science
American Association for the Advancement of Science
Authors (11)
Qi Tang
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Chenxi Ding
State Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Xiaotuo Zhang
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Taiyun Wang
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Mengjie Zhu
State Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Ruixue Cui
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Wenya Yang
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Jinbiao Ma
Guodong Ren
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.
Xiaoming Zhang
Binglian Zheng
State Key Laboratory of Genetics and Development of Complex Phenotypes, School of Life Sciences, Fudan University, Shanghai, China.