Abstract Detail

Plant epigenetics: phenotypic and functional diversity beyond the DNA sequence

Boquete Seoane , M. Teresa [1], Alonso, Conchita [2], Richards, Christina L. [3], Schmid, Marc W. [4], Herrera, Carlos [2].

Epigenetic modifications in response to heavy metal stress in two terrestrial bryophytes.

Bryophytes thrive in the most extreme habitats (e.g. poles, peatlands, deserts, drylands, heavily contaminated areas), suggesting that they are among the Earth’s most resilient taxa. However, the molecular underpinnings of this resilience are far from being fully understood. Recent experimental work suggests that the epigenome could contribute to plant adaptation to environmental stress by shaping plant phenotypes in response to abiotic cues. This contribution might be crucial for plants that frequently undergo asexual reproduction, such as many bryophytes. Here, we examine whether exposure to heavy metals (HM), that imposes a strong selective pressure on plants, induces significant changes in DNA methylation in the copper moss Scopelophila cataractae (Sc), and the cosmopolitan moss Ceratodon purpureus (Cp), two species with contrasting affinity to HM. We sampled four populations of Sc from different contamination levels within a former Cu mine, one population of Cp in an urban area, and a lab-maintained population of Cp growing in axenic conditions, in which male and female plants were separated. After clonally propagating all populations under control, Cd and Cu treatments, we measured plant performance and Cd and Cu accumulation to understand the response to HM, and used reduced representation bisulfite sequencing (epiGBS) to detect DNA methylation changes associated with HM exposure. The two species showed population-specific responses for HM tolerance. Sc isolates from the most polluted locations in the mine were more tolerant to both HM and the field-collected population of Cp grew better than the lab-maintained population under Cu. Further, males from the lab-maintained population of Cp grew worse than females and worse than the field-collected population under Cd. HM accumulation was similar across treatments except for the most Cd-sensitive isolate of Sc which accumulated more Cd than the others. Our treatments did not have a strong impact on average DNA methylation levels across all loci in either of the species. However, in Sc treatment explained 9 to 15% of the variation in pairwise epigenetic distances in the CHH context. We also found a number of differentially methylated cytosines (DMCs) between control and Cu-treated plants in both species (0.34 and 2.1% of cytosines were DMCs in Sc and Cp respectively) and between Cd-treated vs control (2.0 and 0.33% respectively, without considering the population-specific effects). These results provide evidence that HM exposure induces an epigenetic response that differs in magnitude between the two species.

Related Links:
Website of the project BRYOMICS
Lab website

1 - Estación Biológica de Doñana-CSIC (EBD-CSIC), Department of Ecology and Evolution, Avda. Américo Vespucio 26, Sevilla, Andalucía, E-41092, Spain
2 - Estacion Biologica de Doñana, CSIC, Evolutionary Ecology, Avda Americo Vespucio 26, Sevilla, E-41092, Spain
3 - University of South Florida, Integrative Biology, 4202 East Fowler Avenue SCA 127, Tampa, FL, 33620, USA
4 - MWSchmid GmbH, Möhrlistrasse 25, Zürich, CH-8006, Switzerland

Abiotic stress
epigenetic regulation
plant tolerance
Heavy metals.

Presentation Type: Symposium Presentation
Session: SY1, Plant epigenetics: phenotypic and functional diversity beyond the DNA sequence
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 10:45 AM
Number: SY1003
Abstract ID:317
Candidate for Awards:None

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