Commentary: Conservation of AtTZF1, AtTZF2, and AtTZF3 homolog gene regulation by salt stress in evolutionarily distant plant species

(2016) Commentary: Conservation of AtTZF1, AtTZF2, and AtTZF3 homolog gene regulation by salt stress in evolutionarily distant plant species. In the research article entitled " Conservation of AtTZF1, AtTZF2, and AtTZF3 homolog gene regulation by salt stress in evolutionary distant plant species " , D'Orso et al. (2015) have presented the genomic characterization of two homeologous zinc finger genes called TdTZF1-A and TdTZF1-B. The authors have utilized various bioinformatic and molecular tools to establish that Arabidopsis zinc finger genes AtTZF1-2-3 are putative orthologs of the durum wheat TdTZF1-A and TdTZF1-B genes. Additionally they have shown that zinc finger protein AtTZF3 is a negative factor controlling Arabidopsis seed germination in the presence of salt. Moreover, they have indicated the presence of highly conserved AtTZF1-2-3-like proteins in phylogenetically distant species such as bryophytes. The authors have thus argued that the function of AtTZF1-2-3-like proteins in regulating seed germination emerged from their role in pre-existing NaCl-stress signaling pathways controlling growth and development in lower plants. Expression level analysis of these genes during the period of seed germination and abiotic stress has revealed their functional analogy. In Arabidopsis, nearly all the members of RR-TZF subfamily have been characterized and it was found that the genes coding for RR-TZF protein exhibit differential response when exposed to different abiotic stresses and other growth stimuli. Studies reveal their close interaction with ABA, GA and jasmonic acid, which is probably one of the key mechanisms behind their mode of action. Another possible mechanism adapted by RR-TZF proteins in regulating gene expression in different organisms is by binding to newly synthesized mRNAs and modulating their processing and degradation, which might play a significant role in abiotic stress adaptive responses. In silico analysis reveals the presence of multiple putative RNA binding residues in the RR-TZF domain which serves as the RNA binding site (Qu et al., 2014). Zinc finger proteins comprise a large and diverse group of proteins whose members can readily form a stable finger like structure in presence of one or more zinc cations and are widely conserved across the eukaryotes. Tandem CCCH zinc finger (TZF) proteins comprise a small subfamily of zinc finger proteins that is characterized by presence of a unique tandem zinc finger domain and an arginine rich (RR) motif and hence referred as arginine rich tandem zinc finger (RR-TZF) protein