JAZ (Jasmonate ZIM-domain) proteins belong to a large protein family called TIFY. The TIFY domain (Pfam accession number PF06200) is named after the conserved motif (TIF [F/Y]XG), and members from this plant-specific TF family were previously known as Zinc-finger proteins expressed in the inflorescence meristem (ZIM) (Vanholme et al., 2007). Proteins containing a TIFY domain can be organized into four subfamilies: ZML, TIFY, PPD and JAZ (Jasmonate ZIM-domain protein) by presence of additional conserved domains (Sun et al., 2021). JAZ proteins are targeted by the E3-ubiquitin ligase SCF(COI1) for proteasome degradation in response to JA (Chung et al., 2008).

The members of the ZML subfamily contain a TIFY, C2C2-GATA zinc-finger, and CCT domain. Proteins unified with only the TIFY motif belong to the TIFY subfamily [13]. PPD proteins possess three domains: an N-terminal PPD domain, a TIFY domain, and a Jas domain located near the N-terminus. The JAZ subfamily members have two conserved domains: the TIFY domain at the N-terminal with the core sequence TIF [F/Y]XG, and a Jas domain at the C-terminal with a unique sequence SLX2FX2KRX2RX5PY. Unlike the variable TIFY domain, the sequence of the Jas domain is remarkably conserved among all JAZ subfamily members across different plant species. Many JAZ isoforms are characterized as transcriptional repressors and are commonly associated with co-repressors such as TOPLESS (TPL)/TPL-related proteins (TPPs) that interact with the adaptor protein, NOVEL INTERACTOR OF JAZ (NINJA). In the absence of JA, the TIFY domain interacts with the C-terminal of NINJA while the Jas domain binds and represses bHLH transcription factors (Sun et al., 2021, Heidari et al., 2021).

16 JAZ genes from the maize genome have been identified and classified. Phylogenetic analyses were performed from maize, rice, sorghum, Brachypodium, and Arabidopsis using deduced protein sequences, total six clades were proposed and conservation was observed in each group, such as similar gene exon/intron structures. Synteny analysis across four monocots indicated these JAZ gene families had a common ancestor, and duplication events in maize genome may drive the expansion of JAZ gene family, including genome-wide duplication (GWD), transposon, and/or tandem duplication (Han et al., 2021).  An updated census however indicates at least 38 JAZ, 5 TIFY, and 4 ZML genes in the maize genome (Sun et al., 2021). Six JAZ genes were found to have truncated Jas domain or an altered degron motif, suggesting resistance to classical JAZ degradation. In addition, seven membranes were found to have an LxLxL-type EAR motif which allows them to recruit TOPLESS (TPL)/TPL-related proteins (TPPs) co-repressors directly without association to NINJA (NOVEL INTERACTOR OF JAZ). Expression analysis revealed that ZmJAZ14 was specifically expressed in the seeds and ZmJAZ19 and 22 in the anthers, while the majority of other ZmJAZs were generally highly expressed across diverse tissue types. Additionally, ZmJAZ genes were highly responsive to wounding and JA treatment (Sun et al., 2021).

Gibberella stalk rot (GSR) by Fusarium graminearum causes significant losses of maize production worldwide. Jasmonates (JAs) have been broadly known in regulating defense against pathogens through the homeostasis of active JAs and COI-JAZ-MYC function module. Yeast Two-Hybrid, Split-Luciferase, and Pull-down assays revealed that the JA functional and structural mimic coronatine (COR) functions as an essential ligand to trigger the interaction between ZmCOIa and ZmJAZ15. A zmjaz15 mutant is more susceptible to GSR (Ma et al., 2021).  A tassel and endosperm-specific JAZ gene, ZmJAZ14, was overexpressed in Arabidopsis and was found to enhance plant tolerance to JA and ABA treatment, as well as PEG stress, while it promoted growth under GA stimulus (Zhou et al., 2015).

Last updated June 2023 by John Gray

References:

Chung HS, Koo AJ, Gao X, Jayanty S, Thines B, Jones AD, Howe GA. Regulation and function of Arabidopsis JASMONATE ZIM-domain genes in response to wounding and herbivory. Plant Physiol. 2008 Mar;146(3):952-64. doi: 10.1104/pp.107.115691. Epub 2008 Jan 25. PMID: 18223147; PMCID: PMC2259048.

Han Y, Luthe D. Identification and evolution analysis of the JAZ gene family in maize. BMC Genomics. 2021 Apr 10;22(1):256. doi: 10.1186/s12864-021-07522-4. PMID: 33838665; PMCID: PMC8037931.

Vanholme B, Grunewald W, Bateman A, Kohchi T, Gheysen G. The tify family previously known as ZIM. Trends Plant Sci. 2007 Jun;12(6):239-44. doi: 10.1016/j.tplants.2007.04.004. Epub 2007 May 10. PMID: 17499004.

Sun P, Shi Y, Valerio AGO, Borrego EJ, Luo Q, Qin J, Liu K, Yan Y. An updated census of the maize TIFY family. PLoS One. 2021 Feb 23;16(2):e0247271. doi: 10.1371/journal.pone.0247271. PMID: 33621269; PMCID: PMC7901733.

Ma L, Sun Y, Ruan X, Huang PC, Wang S, Li S, Zhou Y, Wang F, Cao Y, Wang Q, Wang Z, Kolomiets MV, Gao X. Genome-Wide Characterization of Jasmonates Signaling Components Reveals the Essential Role of ZmCOI1a-ZmJAZ15 Action Module in Regulating Maize Immunity to Gibberella Stalk Rot. Int J Mol Sci. 2021 Jan 16;22(2):870. doi: 10.3390/ijms22020870. PMID: 33467172; PMCID: PMC7830991.

Zhou X, Yan S, Sun C, Li S, Li J, Xu M, Liu X, Zhang S, Zhao Q, Li Y, Fan Y, Chen R, Wang L. A maize jasmonate Zim-domain protein, ZmJAZ14, associates with the JA, ABA, and GA signaling pathways in transgenic Arabidopsis. PLoS One. 2015 Mar 25;10(3):e0121824. doi: 10.1371/journal.pone.0121824. Erratum in: PLoS One. 2015;10(6):e0128957. PMID: 25807368; PMCID: PMC4373942.

Heidari P, Faraji S, Ahmadizadeh M, Ahmar S, Mora-Poblete F. New Insights Into Structure and Function of TIFY Genes in Zea mays and Solanum lycopersicum: A Genome-Wide Comprehensive Analysis. Front Genet. 2021 May 12;12:657970. doi: 10.3389/fgene.2021.657970. PMID: 34054921; PMCID: PMC8155530.