Faculty Opinions recommendation of Arabidopsis shoot stem cells display dynamic transcription and DNA methylation patterns.

Abstract

In plants, aerial organs originate continuously from stem cells in the center of the shoot apical meristem. Descendants of stem cells in the subepidermal layer are progenitors of germ cells, giving rise to male and female gametes. In these cells, mutations, including insertions of transposable elements or viruses, must be avoided to preserve genome integrity across generations. To investigate the molecular characteristics of stem cells in Arabidopsis, we isolated their nuclei and analyzed stage-specific gene expression and DNA methylation in plants of different ages. Stem cell expression signatures are largely defined by developmental stage but include a core set of stem cell-specific genes, among which are genes implicated in epigenetic silencing. Transiently increased expression of transposable elements in meristems prior to flower induction correlates with increasing CHG methylation during development and decreased CHH methylation, before stem cells enter the reproductive lineage. These results suggest that epigenetic reprogramming may occur at an early stage in this lineage and could contribute to genome protection in stem cells during germline development.© 2020 The Authors. Published under the terms of the CC BY 4.0 license. PMID: 32815560 Funding information This work was supported by: Marie Curie Action Cofund, Grant ID: EU FP7 Austrian Science Fund (FWF), Grant ID: I1477 Austrian Science Fund (FWF), Grant ID: I489 Austrian Science Fund (FWF), Grant ID: I3687