Essay On Arabidopsis Thaliaa

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Unlike animals, plants are sessile though having the ability to adapt adverse stresses in their environment such as drought, cold, high salt, etc. When plants are stressed with these conditions, ABSCISIC ACID (ABA) level is increased in plants. The ABA triggers the adaptive responses which are required for the survival and productivity of plants. ABA is crucial phyto-hormone that mediates 10% of total transcriptional factors (TFs), which is higher compared to other phyto-hormones in Arabidopsis thaliana (Fujita et al., 2011). The vast numbers of genes which are induced by environmental conditions are activated by ABA. Among those genes, the members of bZIP family are expressed in ABA dependent manner during stressed conditions.…show more content…
They are Conserved domain 1 (C1), C2, C3 C4, and bZIP domain. Conserved domains 1, 2, and 3 have phosphorylation sites, so that these proteins are phosphorylated by kinase. Members of Sucrose Non-Fermenting 1 (SNF1)-Related protein Kinase 2s (SnRK2s) phosphorylate and positively control the AREBs/ABFs TFs (Fujita et al., 2013). bZIP domain has two regions, basic region which is responsible for DNA binding; and leucine zipper region responsible for homo or hetero dimerization (Mark, 2002). MECHANISM OF AREBs/ABFs REGULATION Once the plants go through abiotic stresses like drought, temperature, and salinity, ABA is produced to rescue the plants from these harsh conditions. ABA evokes signal transduction pathway leading to the activation of the members of SnRK2s, namely SnRK2.2, SnRK2.3 and SnRk2.6 (Fujita et al., 2013). The SnRK2s leads the activation of downstream AREBs/ABFs. SnRK2s are responsible for ABA-dependent phosphorylation of AREBs/ABFs in multiple phosphorylation sites (RXXS/T) in protein sequence (Figure 2) (Nicolas et al., 2014). AREB1/ABF2, AREB2/ABF4, ABF3, and ABF1 are the major TFs which are downstream of ABA-activated SnRK2s in ABA signalling pathway during vegetative growth. ABA and abiotic stresses induce gene expression through cis elements which include ABA response element (ABRE) in their promoters. AREBs/ABFs bind to the ABRE containing promoters in vitro or in yeast (Choi, et al., 2000; Finkelstein et al., 2000). ABRE is
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