376

Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

linked to the transcription of the pathway-targeted genomic regions. Because

plant DNA methylation methods are inherited, such modifications are typi­

cally passed on from one generation to its offspring in a stable manner. The

most important function of RdDM is to inhibit TE activity in a steady and

transgenerational manner. RdDM is a key mechanism in plants that controls a

variety of activities by developing and maintaining particular DNA methyla­

tion profiles that may have trans-generational epigenetic impacts upon gene

expression as well as phenotype (Erdmann & Picard, 2020). When plants are

subjected to heat stress, multiple elements connected with the RdDM system

are activated, and mutations in specific RdDM machinery components

diminish heat tolerance, implying that RdDM plays a key function during

heat stress (Liu et al., 2015; Popova et al., 2013). RdDM can regulate genes

to produce an effective stress response, in addition to regulating TEs during

stress. When the humidity is low, leaves produce fewer stomata as RdDM­

mediated downregulation of two genes are involved in stomatal formation

(Tricker et al., 2012). Saline stress downregulates of RdDM which has been

shown to stimulate the production of a salt stress resistance transcription

factor (Xu et al., 2015).

12.5 TECHNIQUES USED FOR UNDERSTANDING EPIGENETIC

CHANGES IN PLANTS

Detection of epigenetic changes in plants can be done utilizing a variety of

methods; the most well-known of them are discussed in subsections.

12.5.1 HISTONE MODIFICATION

The different post-translational modifications on the protruding amino acids

in the N-terminal end of histone proteins are studied by the techniques given

in subsections.

12.5.1.1 CHROMATIN IMMUNOPRECIPITATION (CHIP) TECHNIQUE

ChIP is a technique for determining DNA protein interaction. The technique

involves cross-linking of chromatin (DNA-protein) by using mild formal­

dehyde. The next step is the shearing of genomic DNA into smaller frag­

ments of 200–800 base pairs with the help of either physically (Sonication)