The Arabidopsis, VOZ1 and VOZ2 proteins were identified through Y1H screening of the V-PPase (AVP1) gene promoter with an A. thaliana cDNA library.  They were found to interact with a 38 bp pollen specific cis-acting region of AVP1 during pollen development. The AtVOZ1 and AtVOZ2 proteins, are so named because their distribution is specific to vascular plants and they harbor a zinc finger motif, consisting of conserved Domain-A and Domain-B regions. Domain B is known as the VOZ domain, and it comprises zinc-coordinating motif consisting of 3 cysteine and 1 histidine residues and basic region which is involved in AtVOZ2 dimerization and DNA binding. AtVOZ2 domain B binds in vitro as a dimer to the GCGTNx7ACGC palindromic sequence.

Based on in vivo transient effector reporter analysis, AtVOZ1 and AtVOZ2 act as transcriptional activators in Arabidopsis (Mitsuda et al., 2004). AtVOZ1 and AtVOZ2 regulate flowering time in Arabidopsis, since the atvoz1-1 and atvoz2-1 double mutant showed delayed flowering time. IN addition the double mutant exhibited an increase in floral repressor Flowering Locus C (FLC) mRNA level, its activators and nuclear pore protein MOS3/SAR3 involved in transition to flowering along with phenotypes such as smaller size, a delayed juvenile to adult transition phase, signs of senescence, and seed production defects (Celesnik et al., 2013). Based on DNA microarray analysis of atvoz1 and atvoz2 mutants, they appear to regulate stress response gene expression since they function as both negative and positive regulators of abiotic and biotic stress-responsive pathways (Nakai et al., 2013). The AtVOZ2 protein is localized from cytoplasm to stress granules and nucleus under heat stress (HS) condition.  In the nucleus, it is degraded via the ubiquitin/proteosome pathway and functions as a transcriptional repressor for Dehydration Responsive Element Binding Protein 2A (DREB2A), a HS responsive gene transcription factor, since DREB2A levels were significantly upregulated in voz1voz2 mutant (Koguchi et al., 2017). Transcriptome analysis of voz1-1 voz2-1 double mutant, VOZ2 complemented lines and wild type revealed that many salt stress responsive genes are regulated by VOZs since only the double mutants exhibited hypersensitivity to salt stress along with reduced expression of salt responsive genes. Thus, VOZs act as a positive regulator of several salt responsive genes and VOZ1 and VOZ2 play a redundant role (Prasad et al., 2018). AtVOZ1 and AtVOZ2 interacts with red/far- red photoreceptor phytochrome B (phyB) and redundantly promote flowering where only voz1 and voz2 double mutant exhibited delayed flowering under long day (LD) conditions and from expression analysis VOZ1 and VOZ2 upregulate FT expression and downregulate FLC expression. Therefore, VOZ2 might be involved in flowering regulating phyB signal transduction since under far-red light it localizes from the cytoplasm to the nucleus (Yasui et al., 2012). AtVOZs play negative role in phyB mediated seed germination possibly by interacting in vitro and in vivo with a gibberellin biosynthetic gene, Gibberellin 3-oxidase 1 (GA3ox1) (Luo et al., 2020). AtVOZ1 and AtVOZ2 were identified from protein interaction studies as aspartyl tRNA synthetase IBI1 interacting partners regulating Hyaloperonospora arabidopsis (Hpa) induced ABA signaling and simultaneously suppressing abiotic stress responsive genes (Schwarzenbacher et al., 2020)

In rice and sorghum there appear to be 2 VOZ genes in their respective genomes  (Gao et al., 2018) whereas the maize genome appears to harbor at  least 5 VOZ genes.  ZmVOZ1 has been found in a QTL study to be linked to chilling tolerance in maize (Ma et al., 2022).

Last updated June 2023 by Ankita Abnave and John Gray

References:

Mitsuda N, Hisabori T, Takeyasu K, Sato MH. VOZ; isolation and characterization of novel vascular plant transcription factors with a one-zinc finger from Arabidopsis thaliana. Plant Cell Physiol. 2004 Jul;45(7):845-54. doi: 10.1093/pcp/pch101. PMID: 15295067.

Celesnik H, Ali GS, Robison FM, Reddy AS. Arabidopsis thaliana VOZ (Vascular plant One-Zinc finger) transcription factors are required for proper regulation of flowering time. Biol Open. 2013 Mar 4;2(4):424-31. doi: 10.1242/bio.20133764. PMID: 23616927; PMCID: PMC3625871.

Nakai Y, Nakahira Y, Sumida H, Takebayashi K, Nagasawa Y, Yamasaki K, Akiyama M, Ohme-Takagi M, Fujiwara S, Shiina T, Mitsuda N, Fukusaki E, Kubo Y, Sato MH. Vascular plant one-zinc-finger protein 1/2 transcription factors regulate abiotic and biotic stress responses in Arabidopsis. Plant J. 2013 Mar;73(5):761-75. doi: 10.1111/tpj.12069. Epub 2013 Feb 12. PMID: 23167462.

Koguchi M, Yamasaki K, Hirano T, Sato MH. Vascular plant one-zinc-finger protein 2 is localized both to the nucleus and stress granules under heat stress in Arabidopsis. Plant Signal Behav. 2017 Mar 4;12(3):e1295907. doi: 10.1080/15592324.2017.1295907. PMID: 28277968; PMCID: PMC5399895.

Prasad KVSK, Xing D, Reddy ASN. Vascular Plant One-Zinc-Finger (VOZ) Transcription Factors Are Positive Regulators of Salt Tolerance in Arabidopsis. Int J Mol Sci. 2018 Nov 23;19(12):3731. doi: 10.3390/ijms19123731. PMID: 30477148; PMCID: PMC6321167.

Yasui Y, Mukougawa K, Uemoto M, Yokofuji A, Suzuri R, Nishitani A, Kohchi T. The phytochrome-interacting vascular plant one-zinc finger1 and VOZ2 redundantly regulate flowering in Arabidopsis. Plant Cell. 2012 Aug;24(8):3248-63. doi: 10.1105/tpc.112.101915. Epub 2012 Aug 17. PMID: 22904146; PMCID: PMC3462629.

Luo D, Qu L, Zhong M, Li X, Wang H, Miao J, Liu X, Zhao X. Vascular plant one-zinc finger 1 (VOZ1) and VOZ2 negatively regulate phytochrome B-mediated seed germination in Arabidopsis. Biosci Biotechnol Biochem. 2020 Jul;84(7):1384-1393. doi: 10.1080/09168451.2020.1740971. Epub 2020 Mar 18. PMID: 32186471.

Schwarzenbacher RE, Wardell G, Stassen J, Guest E, Zhang P, Luna E, Ton J. The IBI1 Receptor of β-Aminobutyric Acid Interacts with VOZ Transcription Factors to Regulate Abscisic Acid Signaling and Callose-Associated Defense. Mol Plant. 2020 Oct 5;13(10):1455-1469. doi: 10.1016/j.molp.2020.07.010. Epub 2020 Jul 25. PMID: 32717347; PMCID: PMC7550849.

Ma Y, Tan R, Zhao J. Chilling Tolerance in Maize: Insights into Advances-Toward Physio-Biochemical Responses' and QTL/Genes' Identification. Plants (Basel). 2022 Aug 9;11(16):2082. doi: 10.3390/plants11162082. PMID: 36015386; PMCID: PMC9415788.

Gao B, Chen M, Li X, Liang Y, Zhu F, Liu T, Zhang D, Wood AJ, Oliver MJ, Zhang J. Evolution by duplication: paleopolyploidy events in plants reconstructed by deciphering the evolutionary history of VOZ transcription factors. BMC Plant Biol. 2018 Oct 26;18(1):256. doi: 10.1186/s12870-018-1437-8. PMID: 30367626; PMCID: PMC6204039.