Updated Mechanisms of GCN5—The Monkey King of the Plant Kingdom in Plant Development and Resistance to Abiotic Stresses

Abstract

Histone modifications are the main epigenetic mechanisms that regulate gene expression, chromatin structure, and plant development, among which histone acetylation is one of the most important and studied epigenetic modifications. Histone acetylation is believed to enhance DNA access and promote transcription. GENERAL CONTROL NON-REPRESSIBLE 5 (GCN5), a well-known enzymatic protein responsible for the lysine acetylation of histone H3 and H4, is a universal and crucial histone acetyltransferase involved in gene transcription and plant development. Many studies have found that GCN5 plays important roles in the different development stages of Arabidopsis. In terms of exogenous stress conditions, GCN5 is also involved in the responses to heat stress, cold stress, and nutrient element deficiency by regulating the related gene expression to maintain the homeostasis of some key metabolites (e.g., cellulose) or ions (e.g., phosphate, iron); in addition, GCN5 is involved in the phytohormone pathways such as ethylene, auxin, and salicylic acid to play various roles during the plant lifecycle. Some of the pathways involved by GCN5 also interwind to regulate specific physiological processes or developmental stages. Here, interactions between various developmental events and stress-resistant pathways mediated by GCN5 are comprehensively addressed and the underlying mechanisms are discussed in the plant. Studies with some interacting factors such as ADA2b provided valuable information for the complicated histone acetylation mechanisms. We also suggest the future focuses for GCN5 functions and mechanisms such as functions in seed development/germination stages, exploration of novel interaction factors, identification of more protein substrates, and application of advanced biotechnology-CRISPR in crop genetic improvement, which would be helpful for the complete illumination of roles and mechanisms of GCN5.

Auxin signaling: Research advances over the past 30 years

“…Histone acetylation and deacetylation catalyzed by HISTONE ACETYLTRANSFERASEs (HATs) and HDACs, respectively, also play important roles in gene transcription by affecting chromatin conformation dynamics (Yamamuro et al, 2016; Gan et al, 2021). Many auxin‐signaling‐related genes are upregulated by histone acetylation (Zhu, 2010), and the ARF‐mediated transcriptional activation of target genes also requires the assistance of histone acetylation (Navarro et al, 2006; Weiste et al, 2017).…”

“…The restriction or activation of gene transcription by histone modification is accompanied by the manipulation of the degree of chromatin compaction (Yamamuro et al, 2016; Gan et al, 2021). The mechanisms of the chromosomal remodeling machinery have been extensively studied in many species and appear to be conserved across eukaryotes (Narlikar et al, 2002; Cairns, 2005).…”

Histone acetyltransferase TaHAG1 interacts with TaPLATZ5 to activate TaPAD4 expression and positively contributes to powdery mildew resistance in wheat

“…In view of histone acetylation generally associated with activation of gene transcription (Gan et al, 2021), we mainly focused on the upregulated genes that affected by TaHAG1 in response to powdery mildew infection. Our genome-wide survey provided Ó 2022 The Authors New Phytologist Ó 2022 New Phytologist Foundation.…”

Histone Acetylation Changes in Plant Response to Drought Stress

“…Hyperacetylation of H3K9 is almost associated with the activation of transcription, whereas hypoacetylated histones are accompanied by transcriptional repression [13,[70][71][72]. The HAT family gene GCN5 is a well-known enzymatic protein responsible for the lysine acetylation of histone H3 and H4 [73]. In P. trichocarpa, drought stress results in histone acetylation changes at the whole genome level.…”