Epigenetics – The Molecular Tool in Understanding Abiotic Stress Response in Plants

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in the engagement of histone as well as DNA methyltransferases (Holoch

& Moazed, 2015). These RNAs are produced from double-stranded RNA

(dsRNA) precursors as a 20–30 nucleotide long single-stranded RNA. The

architecture of chromatin got changed by the histone modification pathway

and alters gene expression (Singroha & Sharma, 2019). Gene activation

or silencing is associated with the open chromatin conformation or close

chromatin structure under the control of different developmental or environ­

mental factors (Figure 12.1).

FIGURE 12.1 Epigenetic programming under abiotic stresses in plants is shown, at three

levels: DNA modifications, histone modifications, and small RNAs.

Abbreviations: 7mG: 7-methylguanosine cap; AGO: argonaut; H2A: histone 2A; H2B:

histone 2B; H3: histone 3; H4: histone 4; ac: acetyl; me: methyl; ph: phosphate; ub: ubiquitin;

miRNAs: microRNAs; RISC: RNA-induced silencing complex; siRNAs: small interfering

RNAs.

Recently few studies have been conducted for the description of the

epigenomic control stress in plants that helps to understand how chromatin

modification takes place by diverse abiotic stresses, by their corresponding

transcriptional and physiological involvement (Demirel et al., 2020; Zhao et

al., 2021) (Figures 12.2–12.4).