DNA methylation mediates overgrazing-induced clonal transgenerational plasticity

• Published in: The Science of the total environment Vol. 897; p. 165338
• Main Authors: Yin, Jingjing, Ren, Weibo, Fry, Ellen L., Sun, Siyuan, Han, Huijie, Guo, Fenghui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-11-2023
• Subjects: Auxin pathway; DNA methylation; Leymus chinensis; Overgrazing; Plant dwarfism; Transgenerational effects; Plant dwarfism; Transgenerational effects; DNA methylation; Auxin pathway; Leymus chinensis; Overgrazing
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.165338

Overgrazing generally induces dwarfism in grassland plants, and these phenotypic traits could be transmitted to clonal offspring even when overgrazing is excluded. However, the dwarfism-transmitted mechanism remains largely unknown, despite generally thought to be enabled by epigenetic modification. To clarify the potential role of DNA methylation on clonal transgenerational effects, we conducted a greenhouse experiment with Leymus chinensis clonal offspring from different cattle/sheep overgrazing histories via the demethylating agent 5-azacytidine. The results showed that clonal offspring from overgrazed (by cattle or sheep) parents were dwarfed and the auxin content of leaves significantly decreased compared to offspring from no-grazed parents'. The 5-azaC application generally increased the auxin content and promoted the growth of overgrazed offspring while inhibited no-grazed offspring growth. Meanwhile, there were similar trends in the expression level of genes related to auxin-responsive target genes (ARF7, ARF19), and signal transduction gene (AZF2). These results suggest that DNA methylation leads to overgrazing-induced plant transgenerational dwarfism via inhibiting auxin signal pathway.
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•Overgrazing generally induces dwarfism in grassland plants.•Alteration of DNA methylation removes the overgrazing-induced dwarfism.•Demethylation activated auxin signal pathway in overgrazed offspring.•DNA methylation mediates overgrazing-induced transgenerational dwarfism.