DRD1-Pol V-dependent self-silencing of an exogenous silencer restricts the non-cell autonomous silencing of an endogenous target gene.

ABSTRACT: In plants, the exogenous transgene transcribing inverted-repeat (exo-IR) sequences produces double-stranded RNAs that are processed by DCL4. The 21-nt small interfering RNAs generated function as mobile signals to trigger non-cell autonomous silencing of target endogenes in the neighboring 10-15 cells. The potential involvement of nuclear silencing pathway components in signal spreading or sensing in target cells is not clear. Here, we demonstrate that the exo-IR silencer (exo-Pdsi) is negatively autoregulated through methylation spreading, which acts in cis to reinforce the self-silencing of the silencer. Mutations affecting nuclear proteins DRD1 and Pol V (NRPE1 or NRPD2) relieved exo-Pdsi self-silencing, resulting in higher levels of Pdsi transcripts, which increased the non-cell autono

SUBMITTER: Dong L 

PROVIDER: S-EPMC3204326 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature