Biogenesis of phased siRNAs on membrane-bound polysomes in Arabidopsis
Shengben Li,
Brandon Le,
Xuan Ma,
Shaofang Li,
Chenjiang You,
Yu Yu,
Bailong Zhang,
Lin Liu,
Lei Gao,
Ting Shi,
Yonghui Zhao,
Beixin Mo,
Xiaofeng Cao,
Xuemei Chen
Affiliations
Shengben Li
Agricultural Genomics Institute, Chinese Academy of Agricultural Sciences, Shenzhen, China; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Brandon Le
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Xuan Ma
Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Beijing, China
Shaofang Li
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Chenjiang You
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States; Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
Yu Yu
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Bailong Zhang
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Lin Liu
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States; Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
Lei Gao
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States; Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
Ting Shi
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States; College of Horticulture, Nanjing Agricultural University, Nanjing, China
Yonghui Zhao
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States
Beixin Mo
Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
Xiaofeng Cao
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Beijing, China
Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, United States; Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China; Howard Hughes Medical Institute, University of California, Riverside, Riverside, United States
Small RNAs are central players in RNA silencing, yet their cytoplasmic compartmentalization and the effects it may have on their activities have not been studied at the genomic scale. Here we report that Arabidopsis microRNAs (miRNAs) and small interfering RNAs (siRNAs) are distinctly partitioned between the endoplasmic reticulum (ER) and cytosol. All miRNAs are associated with membrane-bound polysomes (MBPs) as opposed to polysomes in general. The MBP association is functionally linked to a deeply conserved and tightly regulated activity of miRNAs – production of phased siRNAs (phasiRNAs) from select target RNAs. The phasiRNA precursor RNAs, thought to be noncoding, are on MBPs and are occupied by ribosomes in a manner that supports miRNA-triggered phasiRNA production, suggesting that ribosomes on the rough ER impact siRNA biogenesis. This study reveals global patterns of cytoplasmic partitioning of small RNAs and expands the known functions of ribosomes and ER.
