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

Abstract

Arginine-rich tandem zinc-finger proteins (RR-TZF) participate in a wide range of plant developmental processes and adaptive responses to abiotic stress, such as cold, salt, and drought. This study investigates the conservation of the genes AtTZF1-5 at the level of their sequences and expression across plant species. The genomic sequences of the two RR-TZF genes TdTZF1-A and TdTZF1-B were isolated in durum wheat and assigned to chromosomes 3A and 3B, respectively. Sequence comparisons revealed that they encode proteins that are highly homologous to AtTZF1, AtTZF2, and AtTZF3. The expression profiles of these RR-TZF durum wheat and Arabidopsis proteins support a common function in the regulation of seed germination and responses to abiotic stress. In particular, analysis of plants with attenuated and overexpressed AtTZF3 indicate that AtTZF3 is a negative regulator of seed germination under conditions of salt stress. Finally, comparative sequence analyses establish that the RR-TZF genes are encoded by lower plants, including the bryophyte Physcomitrella patens and the alga Chlamydomonas reinhardtii. The regulation of the Physcomitrella AtTZF1-2-3-like genes by salt stress strongly suggests that a subgroup of the RR-TZF proteins has a function that has been conserved throughout evolution.

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

“…This is congruent with earlier studies on arabidopsis carried out by different worker (Lopez-Molina et al, 2002 ; Piskurewicz et al, 2008 ). As described earlier, D'Orso et al ( 2015 ) have observed that these genes negatively regulate seed germination by delaying the process when exposed to salt stress. This could be an indicator of the role of RR-TZF encoding genes in developmental processes as well, thereby targeting genes that play integral role in seed germination, such as genes involved in ABA and GA signaling pathways.…”

“…Interestingly the presence of arginine rich motif in tandem zinc finger protein is a feature unique to plants (Bogamuwa and Jang, 2014 ). Extensive genomic studies have confirmed their presence in Arabidopsis thaliana, Oryza sativa, Medicago truncatula, Populas trichocarpa, Zea mays , bryophyte Physcomitrella patens , algae Chlamydomonus reinhardtii , and more recently in durum wheat (Wang et al, 2008 ; Chai et al, 2012 ; Peng et al, 2012 ; Zhang et al, 2013 ; D'Orso et al, 2015 ). Expression level analyses have revealed their involvement in multiple tissue specific developmental processes as well as other regulatory activities.…”

“…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.…”

“…D'Orso et al ( 2015 ) have investigated conservations of genes coding for arginine rich tandem zinc finger (RR-TZF) proteins during salt stress in evolutionary distant plant species. As mentioned earlier in this commentary, functions of some RR-TZF Arabidopsis and rice protein as abiotic stress modulator have already been established using various wet-lab and in silico techniques.…”

“…They function by decapping, deadenylating, and degrading mRNA targets, thus mediating unique stress adaptive responses. D'Orso et al ( 2015 ) have revealed that the expression of A. thaliana , Durum wheat and P. patens RR-TZF genes increase considerably with increase in environmental salt concentration, indicating their role in stress alleviation. But their primary target genes or the pathways which they regulate are yet to be discovered.…”