Abstracts (first author)
Ecological epigenetics of non-model plants: exploring the evolutionary relevance of epigenetic variation in natural plant populations
Epigenetic variation is often an important source of phenotypic variation across species and conspecific individuals of wild plants. In addition, intraspecific epigenetic variation frequently is spatially structured and correlated with biotic and abiotic environmental factors. The evolutionary relevance of natural epigenetic variation is, however, contingent on its being transgenerationally heritable and largely autonomous from genetic differences. It is therefore crucial to investigate these two key issues on wild plant populations. Fingerprinting phenotypically distinct individuals from different populations using both molecular epigenetic and conventional genetic markers may allow to determine whether genetic and epigenetic variation are coupled across sites and individuals or tend instead to be independent of each other. The alternation of generations characteristic of higher plants, whereby a succession of diploid sporophytes and haploid gametophytes take place in populations, allows to evaluate the extent to which molecular epigenetic markers are robust or not to epigenetic checkpoints operating at gametogenesis. The application of this research programme to wild populations of the perennial herb Helleborus foetidus in southern Spain revealed that variation across individuals in genetic (SSR and AFLP) and epigenetic (MSAP; methylation-sensitive amplified fragment polymorphism) markers were largely decoupled. Although the strong epigenetic differentiation between populations was in large part caused by MSAP markers that were reset at gametogenesis, there was still a sizeable proportion of markers robust to gametogenesis whose variation contributed significantly to epigenetic differentiation of populations. Epigenetic differentiation of H. foetidus populations seems to reflect local adaptation to the variable environment mediated by an epigenetic inheritance system.