Transcription from an upstream promoter controls methylation signaling from an inverted repeat of endogenous genes in Arabidopsis.

ABSTRACT: In plants, replication of RNA viruses and RNA from highly transcribed transgenes can trigger DNA methylation. These systems accumulate diced small RNA(smRNA) products of double-stranded RNA(dsRNA) precursors, but it is not known which RNA species directs methylation. The methylated PAI tryptophan biosynthetic genes in Arabidopsis allow the study of methylation signals for endogenous genes with lower expression levels. The PAI genes are arranged as a tandem inverted repeat plus two singlet genes at unlinked loci. Here we show that the predominant PAI transcript initiates at a novel unmethylated promoter that lies upstream of one of the inverted repeat PAI genes. Suppressed transcription from the upstream promoter using transgene-directed silencing reduces methylation on the singlet PAI gene

SUBMITTER: Melquist S 

PROVIDER: S-EPMC196257 | biostudies-literature | 2003 Aug

REPOSITORIES: biostudies-literature