Biology subjects

Bazaga, P.

Publications and source records attributed to Bazaga, P..

4 recordsLinked to original sources

bioRxiv2026

Transgenerational imprint of subindividual variation: somatic epigenetic divergence within trees cascades into epigenetic and phenotypic pollen divergence

The evolutionary significance of somatic mosaicism created within plants by random epigenetic drift or localized responses to the environment will rest on its transgenerational implications. This paper tests whether the epigenetic mosaicism exhibited by individuals of a long-lived tree leaves some discernible "imprint" in the next gametophytic generation. Paired samples of leaves and pollen from five distinct branches within each of five wild-growing Pistacia terebinthus (Anacardiaceae) trees were characterized epigenetically using genome-wide DNA cytosine methylation level and multivariate epigenetic fingerprinting. Pollen grains were also characterized phenotypically by size and shape. Individual trees were somatically heterogeneous with regard to both cytosine methylation level and multilocus epigenetic fingerprints of leaf tissue, and within-tree variance in leaf epigenetic features exceeded among-tree variance. Phenotypic and epigenetic features of pollen differed significantly among branches of individual trees, and intraplant variation in phenotype and epigenetic fingerprints of pollen was predicted by intraplant variation in epigenetic features of leaves. Results provide evidence that intraindividual epigenetic heterogeneity arising in long-lived plants can leave its imprint into subsequent sporophyte generations via the production of epigenetically and phenotypically heterogeneous haploid gametophytes. Testable hypotheses for future epigenetic research on wild populations of non-model plants are suggested.

Plant Biology↗

bioRxiv2024

Decoupled genetic and epigenetic variation at local scale in an endemic and a widespread Erodium (Geraniaceae) species

Epigenetic states offer an additional layer of variation besides genetic polymorphism that contribute to phenotypic variation and may arise either randomly or in response to environmental factors. We hypothesize that closely related species with different life-histories and habitat requirements could show distinct patterns of intraspecific epigenetic variation. We used Restriction-site Associated DNA sequencing (RADseq) and its bisulfite-converted variant (bsRADseq) to investigate in Sierra de Cazorla (SE Spain) the genetic and epigenetic population structure of two congeneric species, the endemic woody perennial Erodium cazorlanum and the widely distributed annual herb E. cicutarium. Population genomics analyses revealed no structure in either E. cazorlanum and E. cicutarium, suggesting substantial gene flow between the study populations. In contrast, we found that the mean proportion of global DNA methylation was different between populations and species, with E. cazorlanum DNA showing higher methylation average and across-individuals variation. For each species, we searched for the loci with the strongest epigenetic differentiation between populations (differentially methylated cytosines, DMCs), and summarized them across regions (differentially methylated regions, DMRs). Multivariate analysis and hierarchical clustering of single cytosines methylation percentages did not group individuals by population, pointing to high epigenetic variation within populations. DMRs were enriched in Copia transposable elements, putatively associated with stress response in plants. Our results suggest that variation at both genetic and epigenetic levels in our study area occur mainly within natural populations of E. cazorlanum and E. cicutarium, with stronger population structure in E. cicutarium, and highlight the relevance of analyzing short distance spatial patterns.

genomics↗

bioRxiv2023

Long-term methylome changes after experimental seed demethylation and their interaction with recurrent water stress in Erodium cicutarium (Geraniaceae)

O_LIThe frequency and length of drought periods are increasing in subtropical and temperate regions worldwide. Epigenetic responses to water stress could be key for plant resilience to this largely unpredictable challenge. Experimental DNA demethylation together with application of a stress factor stands as a suitable strategy to uncover the contribution of epigenetics to plant responses to stress. C_LIO_LIWe analysed leaf cytosine methylation changes in adult plants of the Mediterranean weed, Erodium cicutarium, after seed demethylation with 5-Azacytidine and/or recurrent water stress in a greenhouse. We used bisulfite RADseq (BsRADseq) and a newly reported reference genome for E. cicutarium to characterize methylation changes in a 2x2 factorial design, controlling for plant relatedness. C_LIO_LIIn the long-term, 5-Azacytidine treatment alone caused both hypo and hyper-methylation at individual cytosines, with substantial hypomethylation in CG contexts. In control conditions, drought resulted in a decrease in methylation level in all but CHH contexts. In contrast, the genome of plants that experienced recurrent water stress and had been treated with 5-Azacytidine increased DNA methylation level by ca. 5%. C_LIO_LISeed demethylation and recurrent drought exhibited a highly significant interaction in terms of global and context-specific cytosine methylation supporting an epigenetic contribution in response to stress at molecular level. C_LI

ecology↗

bioRxiv2020

Lifetime genealogical divergence within plants leads to epigenetic mosaicism in the long lived shrub Lavandula latifolia (Lamiaceae)

O_LIEpigenetic mosaicism is a possible source of within-plant phenotypic heterogeneity, yet its frequency and developmental origin remain unexplored. This study examines whether the extant epigenetic heterogeneity within long-lived Lavandula latifolia (Lamiaceae) shrubs reflects recent epigenetic modifications experienced independently by different plant parts or, alternatively, it is the cumulative outcome of a steady lifetime process. C_LIO_LILeaf samples from different architectural modules were collected from three L. latifolia plants and characterized epigenetically by global DNA cytosine methylation and methylation state of methylation-sensitive amplified fragment length polymorphism markers (MS-AFLP). Epigenetic characteristics of modules were then assembled with information on the branching history of plants. Methods borrowed from phylogenetic research were used to assess genealogical signal of extant epigenetic variation and reconstruct within-plant genealogical trajectory of epigenetic traits. C_LIO_LIPlants were epigenetically heterogeneous, as shown by differences among modules in global DNA methylation and variation in the methylation states of 6-8% of MS-AFLP markers. All epigenetic features exhibited significant genealogical signal within plants. Events of epigenetic divergence occurred throughout the lifespan of individuals and were subsequently propagated by branch divisions. C_LIO_LIInternal epigenetic diversification of L. latifolia individuals took place steadily during their development, a process which eventually led to persistent epigenetic mosaicism. C_LI

plant biology↗