The impact of Polycomb group (PcG) and Trithorax group (TrxG) epigenetic factors in plant plasticity

Abstract

SummaryCurrent advances indicate that epigenetic mechanisms play important roles in the regulatory networks involved in plant developmental responses to environmental conditions. Hence, understanding the role of such components becomes crucial to understanding the mechanisms underlying the plasticity and variability of plant traits, and thus the ecology and evolution of plant development. We now know that important components of phenotypic variation may result from heritable and reversible epigenetic mechanisms without genetic alterations. The epigenetic factors Polycomb group (PcG) and Trithorax group (TrxG) are involved in developmental processes that respond to environmental signals, playing important roles in plant plasticity. In this review, we discuss current knowledge of TrxG and PcG functions in different developmental processes in response to internal and environmental cues and we also integrate the emerging evidence concerning their function in plant plasticity. Many such plastic responses rely on meristematic cell behavior, including stem cell niche maintenance, cellular reprogramming, flowering and dormancy as well as stress memory. This information will help to determine how to integrate the role of epigenetic regulation into models of gene regulatory networks, which have mostly included transcriptional interactions underlying various aspects of plant development and its plastic response to environmental conditions.

FIE, a nuclear PRC2 protein, forms cytoplasmic complexes inArabidopsis thaliana

“…The epigenetic role of plant Polycomb proteins in regulating gene expression has been explored intensively over the recent years using genetics, molecular biology and biochemical approaches (Butenko and Ohad, 2011; Bemer and Grossniklaus, 2012; Derkacheva and Hennig, 2014; de la Paz Sanchez et al , 2015). In Arabidopsis, members of the three PRC2 complexes were shown to play a vital role in nearly every stage of the plant life cycle, as evident from the severe phenotypes of pcg mutants (Mozgova et al , 2015).…”

Epigenetic Regulation of Auxin-Induced Somatic Embryogenesis in Plants

“…The specific epigenetic marks that activate and repress gene transcription are indicated in green and red, respectively. Arrows and circle-shaped ends show the activation or repression of gene expression, respectively [14][15][16][17][18][19][20][21][22][23][24][25][26][27]. ( miRNAs, which are products of the MIRNA genes, are small (19 to 24 nucleotides long), single-stranded non-coding RNA molecules that regulate both the state of the chromatin-associated with their targets and the availability of the encoded transcripts for protein translation [26].…”

SET DOMAIN GROUP701 encodes a H3K4‐methytransferase and regulates multiple key processes of rice plant development

“…The Oryza sativa Trithorax 1 (OsTrx1; SDG723) recombinant protein has been shown to methylate histone H3 when oligonucleosomes are used as substrates in the in vitro enzyme activity assay and knockdown of OsTrx1/SDG723 delays rice plant flowering time (Choi et al ., ). The Trithorax (Trx) proteins in animals and in Arabidopsis are well‐known enzymes involved in H3K4 methylation (for a recent review, see de la Paz Sanchez et al ., ), yet whether OsTrx1/SDG723 specifically methylates H3K4 and/or whether its role in rice flowering time control is effectively associated with H3K4 methylation require future investigations.…”