EOB-003: Suppression of endogenous gene silencing

Suppression of endogenous gene silencing by bidirectional cytoplasmic RNA decay in Arabidopsis

Xinyan Zhang1, Ying Zhu1, Xiaodan Liu1, Xinyu Hong1, Yang Xu2, Ping Zhu2, Yang Shen3, Huihui Wu1, Yusi Ji1, Xing Wen1, Chen Zhang1, Qiong Zhao1, Yichuan Wang1, Jian Lu1,3, Hongwei Guo1,3,*

Author Affiliations

1State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.    
2Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China.    
3Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.    
↵*Corresponding author. E-mail: hongweig@pku.edu.cn    

Science 3 April 2015: Vol. 348 no. 6230 pp. 120-123 DOI: 10.1126/science.aaa2618

URL: http://www.sciencemag.org/content/348/6230/120.full

Abstract

Plant immunity against foreign gene invasion takes advantage of posttranscriptional gene silencing (PTGS). How plants elaborately avert inappropriate PTGS of endogenous coding genes remains unclear. We demonstrate in Arabidopsis that both 5′-3′ and 3′-5′ cytoplasmic RNA decay pathways act as repressors of transgene and endogenous PTGS. Disruption of bidirectional cytoplasmic RNA decay leads to pleiotropic developmental defects and drastic transcriptomic alterations, which are substantially rescued by PTGS mutants. Upon dysfunction of bidirectional RNA decay, a large number of 21- to 22-nucleotide endogenous small interfering RNAs are produced from coding transcripts, including multiple microRNA targets, which could interfere with their cognate gene expression and functions. This study highlights the risk of unwanted PTGS and identifies cytoplasmic RNA decay pathways as safeguards of plant transcriptome and development.

Figure 1
Fig. 2 Disruption of bidirectional RNA decay exhibits RDR6-dependent developmental defects and transcriptomic alterations. (A) Rosette morphology of 3-week-old plants of indicated genotypes. Scale bar, 1 cm. (B) Clustering of transcriptome profiles of ein5-1, ski2-3, rdr6-11, and their combinations. The clustering results are based on expression levels of 15,663 genes that have the expression levels with reads per kilobase per million > 1 in the Col-0 background. (C) Relative expression of genes that regulate anthocyanin biosynthesis in 16-day-old plants. Error bars indicate SD; n = 3. (D) Quantification of anthocyanin accumulation in 16-day-old plants. Error bars indicate SD, n = 6.
Ming | 2015-04-07