Genome-wide analysis of the RNA-DEPENDENT RNA POLYMERASE6/DICER-LIKE4 pathway in Arabidopsis reveals dependency on miRNA- and tasiRNA-directed targeting.
Plant Cell
; 19(3): 926-42, 2007 Mar.
Article
em En
| MEDLINE
| ID: mdl-17400893
ABSTRACT
Posttranscriptional RNA silencing of many endogenous transcripts, viruses, and transgenes involves the RNA-DEPENDENT RNA POLYMERASE6/DICER-LIKE4 (RDR6/DCL4)-dependent short interfering RNA (siRNA) biogenesis pathway. Arabidopsis thaliana contains several families of trans-acting siRNAs (tasiRNAs) that form in 21-nucleotide phased arrays through the RDR6/DCL4-dependent pathway and that negatively regulate target transcripts. Using deep sequencing technology and computational approaches, the phasing patterns of known tasiRNAs and tasiRNA-like loci from across the Arabidopsis genome were analyzed in wild-type plants and silencing-defective mutants. Several gene transcripts were found to be routed through the RDR6/DCL4-dependent pathway after initial targeting by one or multiple miRNAs or tasiRNAs, the most conspicuous example of which was an expanding clade of genes encoding pentatricopeptide repeat (PPR) proteins. Interestingly, phylogenetic analysis using Populus trichocarpa revealed evidence for small RNA-mediated regulatory mechanisms within a similarly expanded group of PPR genes. We suggest that posttranscriptional silencing mechanisms operate on an evolutionary scale to buffer the effects of rapidly expanding gene families.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ribonucleases
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RNA Polimerase Dependente de RNA
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Arabidopsis
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Genoma de Planta
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Proteínas de Arabidopsis
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MicroRNAs
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RNA Interferente Pequeno
Idioma:
En
Revista:
Plant Cell
Assunto da revista:
BOTANICA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos