Abstract
Complex epigenetic changes occur during plant reproduction. These regulations ensure the proper transmission of epigenetic information as well as allowing for zygotic totipotency. In Arabidopsis, the main DNA methyltransferase is called MET1 and is responsible for methylating cytosine in the CG context. The Arabidopsis genome encodes for three additional reproduction-specific homologs of MET1, namely MET2a, MET2b and MET3. In this paper, we show that the DNA methyltransferase MET3 is expressed in the seed endosperm and its expression is later restricted to the chalazal endosperm. MET3 is biallelically expressed in the endosperm but displays a paternal expression bias. We found that MET3 expression is regulated by the Polycomb complex proteins FIE and MSI1. Seed development is not impaired in met3 mutant, and we could not observe significant transcriptional changes in met3 mutant. MET3 might regulates gene expression in a Polycomb mutant background suggesting a further complexification of the interplay between H3K27me3 and DNA methylation in the seed endosperm.Key messageThe DNA METHYLTRANSFERASE MET3 is controlled by Polycomb group complex during endosperm development.
Highlights
Sexual reproduction in Angiosperm is initiated by a double fertilization event
Our result shows that MET3 is principally expressed in siliques and its expression peaks at 5 Days After Pollination (DAP)
Our study highlights an additional connection between DNA Methylation pathways and Polycomb group H3K27 tri-methylation in the seed endosperm via the regulation of MET3 by the FIS Polycomb group complex (FIS-Polycomb group complex (PcG)) complex
Summary
Fertilization of the haploid egg cell by one of the sperm cells gives rise to the diploid embryo, whereas fertilization of the homodiploid central cell gives rise to the triploid endosperm (Berger 2003; Costa et al 2004). The endosperm represents a nourishing tissue supporting embryo growth and is key for proper seed development. Cell divisions in the endosperm are initiated very rapidly following fertilization. These divisions are initially occurring without cellularization and form a syncytium that will later cellularize (Brown et al 1999, 2003; Boisnard-Lorig et al 2001). An additional peculiarity of the endosperm, beyond its triploid syncytial nature, is being the seat of interesting epigenetic phenomena and complex epigenetic regulation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
