Changes in global DNA methylation under climatic stress in two related grasses suggest a possible role of epigenetics in the ecological success of polyploids

Abstract

Polyploidization drives the evolution of grasses and can result in epigenetic changes, which may have a role in the creation of new evolutionary lineages and ecological speciation. As such changes may be inherited, they can also influence adaptation to the environment. Populations from different regions and climates may also differ epigenetically; however, this phenomenon is poorly understood. The present study analyzes the effect of climatic stress on global DNA methylation based on a garden collection of two related mountain grasses (the narrow endemic diploid Festuca tatrae and the more widely distributed mixed-ploidy F. amethystina) with different geographic ranges and ecological niches. A lower level of DNA methylation was observed for F. tatrae, while a higher mean level was obtained for the diploid and tetraploid of F. amethystina; with the tetraploids having a higher level of global methylated DNA than the diploids. The weather conditions (especially insolation) measured 24 h prior to sampling appeared to have a closer relationship with global DNA methylation level than those observed seven days before sampling. Our findings suggest that the level of methylation during stress conditions (drought, high temperature and high insolation) may be significantly influenced by the ploidy level and bioclimatic provenance of specimens; however an important role may also be played by the intensity of stress conditions in a given year.

Accession-specific parent-of-origin dependent and independent genome dosage effects on salt tolerance in Arabidopsis thaliana

“…In this study, we have identified such parent-of-origin dependent genome dosage effects on salt tolerance in three genetic backgrounds ( figure 3 ). Such parent-of-origin dependent genome dosage effects on salt tolerance between the reciprocal triploid plants could be due to a different distribution of epigenetic marks at the nuclear genome level (in the embryo or endosperm) [ 69 – 71 ], cytoplasmic differences between diploid and tetraploid maternal parents [ 56 ], or dosage-dependent factors in the maternal seed coat that differ between diploid and tetraploid maternal parents [ 10 , 72 , 73 ].…”

“…In this study, we have identified such parent-of-origin dependent genome dosage effects on salt tolerance in three genetic backgrounds (figure 3). Such parent-of-origin dependent genome dosage effects on salt tolerance between the reciprocal triploid plants could be due to a different distribution of epigenetic marks at the nuclear genome level (in the embryo or endosperm) [69][70][71], cytoplasmic differences between diploid and tetraploid maternal parents [56], or dosage-dependent factors in the maternal seed coat that differ between diploid and tetraploid maternal parents [10,72,73]. Importantly, the genome dosage effects between diploids and tetraploids, and the reciprocal F1 triploid pairs, are occurring in plants that are genetically identical (isogenic), apart from their differential genome dosage or whether their chromosome sets are maternally derived (madumnal) or paternally derived (padumnal).…”

“…Importantly, the genome dosage effects between diploids and tetraploids, and the reciprocal F1 triploid pairs, are occurring in plants that are genetically identical (isogenic), apart from their differential genome dosage or whether their chromosome sets are maternally derived (madumnal) or paternally derived (padumnal). Hence, all such accession-specific genome dosage effects are probably epigenetic in nature as they do not involve any changes in DNA sequence [69][70][71].…”

Physiology, gene expression, and epiphenotype of two Dianthus broteri polyploid cytotypes under temperature stress

“…5 ). However, the high inter-population variation in natural levels of global DNA methylation for the 12× cytotype probably due to the influence of specific ecological factors should be noted ( Alonso et al , 2016a ; Tomczyk et al , 2022 ). Still, absence of significant differences in this trait should not be interpreted as evidence of similarity in methylation patterns at specific loci because magnitude and patterns of cytosine methylation provide complementary but not identical information ( Alonso et al , 2016b ).…”