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DNA methylation dynamics during Arabidopsis embryogenesis and early growth

DNA methylation is a key epigenetic mark that is involved in many eukaryotes in the control of TE activity as well as the regulation of some genes. Whereas in both plants and mammals DNA methylation patterns are largely stable post-embryonically, extensive epigenetic reprogramming during the reproductive phase only occurs in the latter.
Nonetheless, we uncovered unexpected DNA methylation dynamics over TE sequences during Arabidopsis embryogenesis, leading to a peak of RNA directed DNA methylation (RdDM) activity in the mature embryo, which matches the loss of DNA methylation seen earlier in the endosperm. These findings support the notion that sRNAs produced in the endosperm can act in the embryo, thus contributing to the communication between these two organs. Moreover, we discovered a novel role for DNA methylation in regulating parental communication during fertilization and we are aiming at identifying the pathways and mechanisms involved in this process.