PTGS is dispensable for the initiation of epigenetic silencing of an active transposon in Arabidopsis.

Autor:	Trasser M; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria.; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria.; Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY, 11724, USA., Bohl-Viallefond G; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria., Barragán-Borrero V; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria., Diezma-Navas L; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria., Loncsek L; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria., Nordborg M; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria., Marí-Ordóñez A; Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, 1030, Austria. arturo.mari-ordonez@gmi.oeaw.ac.at.
Jazyk:	angličtina
Zdroj:	EMBO reports [EMBO Rep] 2024 Dec; Vol. 25 (12), pp. 5780-5809. Date of Electronic Publication: 2024 Nov 07.
DOI:	10.1038/s44319-024-00304-5
Abstrakt:	Transposable elements (TEs) are repressed in plants through transcriptional gene silencing (TGS), maintained epigenetic silencing marks such as DNA methylation. However, the mechanisms by which silencing is first installed remain poorly understood in plants. Small interfering (si)RNAs and post-transcriptional gene silencing (PTGS) are believed to mediate the initiation of TGS by guiding the first deposition of DNA methylation. To determine how this silencing installation works, we took advantage of ÉVADÉ (EVD), an endogenous retroelement in Arabidopsis, able to recapitulate true de novo silencing with a sequence of PTGS followed by a TGS. To test whether PTGS is required for TGS, we introduce active EVD into RNA-DEPENDENT-RNA-POLYMERASE-6 (RDR6) mutants, an essential PTGS component. EVD activity and silencing are monitored across several generations. In the absence of PTGS, silencing of EVD is still achieved through installation of RNA-directed DNA methylation (RdDM). Our study shows that PTGS is dispensable for de novo EVD silencing. Although we cannot rule out that PTGS might facilitate TGS, or control TE activity, initiation of epigenetic silencing can take place in its absence. Competing Interests: Disclosure and competing interests statement. The authors declare no competing interests. (© 2024. The Author(s).)
Databáze:	MEDLINE
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