Sequencing of RDR6-dependent double-stranded RNAs reveals novel features of plant siRNA biogenesis.
- Rajeswaran R Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
- Aregger M
- Zvereva AS
- Borah BK
- Gubaeva EG
- Pooggin MM
- 2012-03-22
Published in:
- Nucleic acids research. - 2012
Arabidopsis
Arabidopsis Proteins
Base Sequence
Gene Expression Regulation, Plant
Gene Knockdown Techniques
Genes, Plant
MicroRNAs
Molecular Sequence Data
Polyadenylation
RNA Cleavage
RNA Precursors
RNA Processing, Post-Transcriptional
RNA Replicase
RNA, Double-Stranded
RNA, Plant
RNA, Small Interfering
English
Biogenesis of trans-acting siRNAs (tasiRNAs) is initiated by miRNA-directed cleavage of TAS gene transcripts and requires RNA-dependent RNA polymerase 6 (RDR6) and Dicer-like 4 (DCL4). Here, we show that following miR173 cleavage the entire polyadenylated parts of Arabidopsis TAS1a/b/c and TAS2 transcripts are converted by RDR6 to double-stranded (ds)RNAs. Additionally, shorter dsRNAs are produced following a second cleavage directed by a TAS1c-derived siRNA. This tasiRNA and miR173 guide Argonaute 1 complexes to excise the segments from TAS2 and three TAS1 transcripts including TAS1c itself to be converted to dsRNAs, which restricts siRNA production to a region between the two cleavage sites. TAS1c is also feedback regulated by a cis-acting siRNA. We conclude that TAS1c generates a master siRNA that controls a complex network of TAS1/TAS2 siRNA biogenesis and gene regulation. TAS1/TAS2 short dsRNAs produced in this network are processed by DCL4 from both ends in distinct registers, which increases repertoires of tasiRNAs.
- Language
-
- English
- Open access status
- gold
- Identifiers
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- DOI 10.1093/nar/gks242
- PMID 22434877
- Persistent URL
- https://sonar.ch/global/documents/92737
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