Epigenetic regulation and sexual reproduction in plants

Group leader : Pauline JULLIEN

Research area

Reproduction is a key step in any organism’s life cycle and its success relies on complex gene regulation. The fusion of highly specialized cells, the gametes, generate a totipotent embryo. We are studying the molecular mechanisms that regulate epigenetic marks, especially DNA methylation, transmission during sexual reproduction in the model plant Arabidopsis thaliana. As epigenetic marks can be modified by environmental factors, it is important to understand how DNA methylation is stably maintained while still allowing diversity in plants and other sexual organisms. We are also particularly interested in how small RNA molecules could act as a link between environmental stresses and transgenerational epigenetic changes.



Epigenetic dynamics during sexual reproduction

Epigenetic marks and their associated molecular pathways have been widely studied in plant somatic tissues. Our next challenge is to investigate if these mechanisms fit in a cell specific context, especially during sexual reproduction. By studying cell-specific DNA methylation and its players, we aim at establishing a spatial and temporal map of DNA methylation pathways during reproduction.

Epigenetic function during plant defense

Defense mechanisms against pathogens are key for organism’s survival. In plant, small RNA pathways are an integrated part of the plant defense machinery against pathogens such as bacteria, viruses or fungi. Recently more and more evidences are pointing at a key role of DNA methylation and small RNA during plant defense suggesting an epigenetic reprogramming akin to the one happening in reproductive tissue.

Influence of small RNA movement onto zygotic epigenome

It is well known that the epigenome can be modified by the environment. However, the mechanisms involved and the potential transmission of these modifications to the next generation remains poorly understood. We are particularly focused on how the signal might be transmitted from the mother plant tissues to the developing embryo or gametes with a particular interest onto Small RNA molecules.


Selected publications