RNA-directed DNA methylation and plant development require an IWR1-type transcription factor

• Published in: EMBO reports Vol. 11; no. 1; pp. 65 - 71
• Main Authors: Kanno, Tatsuo, Bucher, Etienne, Daxinger, Lucia, Huettel, Bruno, Kreil, David P, Breinig, Frank, Lind, Marc, Schmitt, Manfred J, Simon, Stacey A, Gurazada, Sai Guna Ranjan, Meyers, Blake C, Lorkovic, Zdravko J, Matzke, Antonius J M, Matzke, Marjori
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.2010; Blackwell Publishing Ltd; Nature Publishing Group
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Deoxyribonucleic acid; DNA; DNA Methylation - genetics; DNA Methylation - physiology; DNA, Plant - genetics; DNA, Plant - metabolism; DNA-Directed RNA Polymerases - metabolism; Gene Expression Regulation, Plant - genetics; Gene Expression Regulation, Plant - physiology; Gene Silencing - physiology; Genotype & phenotype; Hypersensitivity; IWR1; Mutants; Mutation; Phenotype; Plant biology; Pol IV; Pol V; RNA polymerase; RNA, Plant - genetics; RNA, Plant - metabolism; RNA, Small Interfering - genetics; RNA, Small Interfering - metabolism; RNA, Untranslated - genetics; RNA, Untranslated - metabolism; RNA-directed DNA methylation; Scientific Report; Toxins; Transcription Factors - genetics; Transcription Factors - metabolism; Transgenic plants; Yeasts
• ISSN: 1469-221X; 1469-3178
• DOI: 10.1038/embor.2009.246

RNA‐directed DNA methylation (RdDM) in plants requires two RNA polymerase (Pol) II‐related RNA polymerases, namely Pol IV and Pol V. A genetic screen designed to reveal factors that are important for RdDM in a developmental context in Arabidopsis identified DEFECTIVE IN MERISTEM SILENCING 4 (DMS4). Unlike other mutants defective in RdDM, dms4 mutants have a pleiotropic developmental phenotype. The DMS4 protein is similar to yeast IWR1 (interacts with RNA polymerase II), a conserved putative transcription factor that interacts with Pol II subunits. The DMS4 complementary DNA partly complements the K1 killer toxin hypersensitivity of a yeast iwr1 mutant, suggesting some functional conservation. In the transgenic system studied, mutations in DMS4 directly or indirectly affect Pol IV‐dependent secondary short interfering RNAs, Pol V‐mediated RdDM, Pol V‐dependent synthesis of intergenic non‐coding RNA and expression of many Pol II‐driven genes. These data suggest that DMS4 might be a regulatory factor for several RNA polymerases, thus explaining its diverse roles in the plant. Kanno and colleagues identify DMS4, which is similar to yeast IWR1, as a novel factor required for RdDM in plants and find that dms4 mutants have pleiotropic developmental phenotypes. Mutations in DMS4 directly or indirectly affect PolIV‐dependent secondary siRNAs, PolV‐mediated RdDM, PolV‐dependent synthesis of intergenic noncoding RNA, and expression of many PolII‐driven genes.