The incorporation of H2A

The incorporation of H2A.Z on to nucleosomes is mediated through the SWR1 complex in Arabidopsis that consists of proteins transcribed from ACTIN-RELATED PROTEIN 6 (ARP6), SWC6 and PHOTOPERIOD-INDEPENDENT EARLY FLOWERING1 (PIE1) (Tasset, Yadav et al. 2018). Substantial reprogramming of transcription-associated with cell differentiation during development involves turning on and turning off of hundreds of genes (March-Diaz, Garcia-Dominguez et al. 2007). In plants, H2A.Z has been implicated in the response to high temperature, the phosphate starvation response, osmotic stress, the immune response, floral initiation, female meiosis, recombination, thalianol metabolism, and the control of microRNA abundance (Qin, Zhao et al. 2014, Xu, Leichty et al. 2018). This process demands massive changes in chromatin make up and structure as it has been conspicuous by the identification of chromatin-remodeling genes whose mutation compromise normal development at many distinct levels (March-Diaz, Garcia-Dominguez et al. 2007). Three primary biochemical mechanisms have been related to modify chromatin structure. The first involves the posttranslational covalent alteration of the amino- and carboxy-terminal tails of histones and the pattern of chemical modifications of histones within a nucleosome (acetylation, methylation, phosphorylation, ubiquitination, and SUMOylation) seems to constitute a code that can be interpreted by other nuclear machinery (March-Diaz, Garcia-Dominguez et al. 2007). Second consists of the ATP-dependent reorganization of interactions between DNA and histones, which stimulates the destabilization of the nucleosome structure. Third mechanism of chromatin remodelling lies in the substitution of canonical histones of the octamer by histone variants, which gives new stability and interactions to the nucleosome (Mizuguchi, Shen et al. 2004, Kamakaka and Biggins 2005, March-Diaz, Garcia-Dominguez et al. 2007).