NODULIN HOMEOBOX is required for heterochromatin homeostasis in Arabidopsis

• DOI: 10.1038/s41467-022-32709-y
• Publication Date: 2022-08-27T14:02:49Z
• Authors: Zsolt Karányi; Ágnes Mosolygó-L; Orsolya Feró; Adrienn Horváth; Beáta Boros-Oláh; Éva Nagy; Szabolcs Hetey; Imre Holb; Henrik Mihály Szaker; Márton Miskei; Tibor Csorba; Lóránt Székvölgyi
• Keywords: Euchromatin; Corepressor

Abstract Arabidopsis NODULIN HOMEOBOX (NDX) is a nuclear protein described as regulator of specific euchromatic genes within transcriptionally active chromosome arms. Here we show that NDX primarily heterochromatin functions in pericentromeric regions to control siRNA production and non-CG methylation. Most binding sites coincide with het-siRNA loci mediate transposon silencing, are antagonistic R-loop structures prevalent chromosomal Inactivation leads differential accumulation DNA methylation, which CHH/CHG hypomethylation colocalizes sites. Hi-C analysis shows significant chromatin structural changes the ndx mutant, decreased intrachromosomal interactions at pericentromeres where enriched wild-type plants, increased interchromosomal contacts between KNOT-forming regions, similar those observed methylation mutants. We conclude key functionally coupled pathways.