Aubert J., Bellegarde F., Oltehua-Lopez O., Leblanc Olivier, Arteaga-Vazquez M. A., Martienssen R. A., Grimanelli Daniel. (2022). AGO104 is a RdDM effector of paramutation at the maize b1 locus. PLoS One, 17 (8), e0273695 [15 p.]. ISSN 1932-6203.
Titre du document
AGO104 is a RdDM effector of paramutation at the maize b1 locus
Although paramutation has been well-studied at a few hallmark loci involved in anthocyanin biosynthesis in maize, the cellular and molecular mechanisms underlying the phenomenon remain largely unknown. Previously described actors of paramutation encode components of the RNA-directed DNA-methylation (RdDM) pathway that participate in the biogenesis of 24-nucleotide small interfering RNAs (24-nt siRNAs) and long non-coding RNAs. In this study, we uncover an ARGONAUTE (AGO) protein as an effector of the RdDM pathway that is in charge of guiding 24-nt siRNAs to their DNA target to create de novo DNA methylation. We combined immunoprecipitation, small RNA sequencing and reverse genetics to, first, validate AGO104 as a member of the RdDM effector complex and, then, investigate its role in paramutation. We found that AGO104 binds 24-nt siRNAs involved in RdDM, including those required for paramutation at the b1 locus. We also show that the ago104-5 mutation causes a partial reversion of the paramutation phenotype at the b1 locus, revealed by intermediate pigmentation levels in stem tissues. Therefore, our results place AGO104 as a new member of the RdDM effector complex that plays a role in paramutation at the b1 locus in maize.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
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Sciences du monde végétal [076]
