TY  - BOOK
AU  - Vermeersch Leen
AU  - Bleys Annick
AU  - Depicker Ann
AU  - Kovarik Ales
AU  - Nolf Jonah
AU  - Winne Nancy De
TI  - Transitive RNA silencing signals induce cytosine methylation of a transgenic but not an endogenous target
PY  - 2013///
PB  - The Plant Journal
KW  - Arbidopsis thaliana
KW  - Endogene
KW  - Intron
KW  - Post-transcriptional gene silencing
KW  - RNA-directed DNA methylation
KW  - Transgene
KW  - Transitive silencing
N2  - Post-transcriptional gene silencing of a primary target gene in plants can coincide with the production of secondary small interfering RNAs (siRNAs) of coding sequences adjacent to the target region and with de novo RNA-directed DNA methylation (RdDM) thereof. Here, we analyzed the susceptibility of transgenic and endogenous targets to RdDM induced by primary and seconday silencing signals. In three different configurations, primary silencing signals were able t direct in trans methylation of chimeric transgenes and the CATALASE2 (CAT2) endogene; however, extensive spreading of methylation occured only in the transgene, resulting in the methylation of the flanking CAT2 sequence, whereas methylation of the CAT2 endogene was restricted to the target region and the enclosed introns. The secondary silencing signals arising from this transgenic primary target simultaneously silenced a secondary transgene target and the CAT2 endogene, but were only capable of directing RdDM to the transgene. Our data indicate that RdDM is correlated with the in situ generation of secondary siRNAs, occuring in P35S-driven transgenes but not in most endogenes. We conclude that although both endogenes are equally sensitive to transitive silencing, differences exist in their susceptibility to undergo secondary RdDM
ER  -