Os09g0439200

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OsJAZ8, a rice jasmonate ZIM-domain protein, acts as a repressor of JA signaling and negatively regulates the JA-induced resistance to Xoo in rice.

Annotated Information

Function

OsJAZ8 is a rice jasmonate ZIM-domain protein and acts as a repressor of JA signaling in rice.OsJAZ8 negatively regulates the JA-induced resistance toXooin rice. OsJAZ8 exhibited the highest up-regulation among the JA-responsive JAZ genes in rice. OsJAZ8 interacted with OsCOI1H, which is a component of the SCF complex,in a coronatine-dependent manner and was degraded via the 26S proteasome pathway in a COR-dependent manner. Furthermore, the JA-dependent OsJAZ8 degradation was mediated by the Jas domain. OsJAZ8 may function as a heterodimer with other JAZ proteins to repress JA signaling in rice, but did not form homodimer[1].

Mutation

Transgenic rice plants overexpressing OsJAZ8ΔC, which lacks the Jas domain, exhibited a JA-insensitive phenotype. The qRT–PCR experiment and a large-scale analysis using a rice DNA microarray both revealed that overexpression of OsJAZ8ΔC altered the expression of JA-responsive genes, including defense-related genes, in rice. Furthermore, OsJAZ8ΔC negatively regulated the JA-induced resistance to Xoo in rice[1].

Expression

OsJAZ8 gene response to JA and pathogen attack (from reference [1]).

OsTIFY family genes had distinct expression patterns. OsTIFY10c showed high expression in the callus and leaves[2]. The expression of OsTIFY10c could be induced by JA and wounding treatments[2]. QRT–PCR analysis of JAZ genes in rice after treatment with 100mM JA for 24 h, EightJAZ genes (OsJAZ 1, 3, 4, 7, 8, 9, 10and 12) were significantly up-regulated by JA, with OsJAZ8 exhibiting the highest up-regulation among the JA-responsive JAZ genes in rice (Fig. 2A). After JA treatment, OsJAZ8 expression reached a maximum level at 24 h in the tested period (Fig. 2B). However, after inoculation with virulent Xoo, OsJAZ8 expression was not up-regulated in the tested period (Fig. 2C).When the Jas domain-truncated OsJAZ8 (OsJAZ8ΔC) was overexpressed in rice, the transgenic rice plants exhibited JA-insensitive phenotypes, such as resistance to JA-induced inhibition of root growth and inhibition of JA-induced Chl reduction. These results indicate that expression of OsJAZ8ΔC inhibits JA responsiveness via the dominant-negative activity of the altered OsJAZ8 protein[1].

Evolution

Phylogenetic tree of the OsTIFY proteins and TIFY proteins of Arabidopsis (from reference [2]).

JAZ (JASMONATE ZIM-DOMAIN) is a subfamily of TIFY. The 12 members of this subfamily contain the TIFY domain and a C-terminal conserved domain designated as Jas which has a characteristic motif of SLX2FX2KRX2RX5PY[3]. The TIFY family owes its name to a conserved TIFY domain with a highly conserved amino acid pattern of TIF [F/Y]XG in the protein sequences. To analyze the evolutionary relationships of the OsTIFY genes, a phylogenetic tree was generated using the sequence alignments of 38 full-length TIFY proteins, including 20 from rice and 18 from Arabidopsis thaliana. The 38 TIFY proteins were also classified into two major groups (I and II) according to the unrooted phylogenetic tree (Fig.1). Four proteins with the GATA zincfinger and CCT domains (OsTIFY1a, 1b, 2a, and 2b) were clustered together in group I. The proteins without the GATA zinc-finger and CCT domains consist of the second major group (group II), and this group contains all the JAZ gene cluster (OsTIFY11e, OsTIFY11f, and OsTIFY11d)on chromosome 10. Among the 20 OsTIFY genes, 16 members are located either in tandem duplication (11a, 11b, and 11c; 1aand1b, and 11e, 11f, and 11d) or in the duplicated segmental regions of rice chromosomes (2a, 2b, 6a, 6b, 10a, 10b, 11a, 11b, 11c, 11d, 11e, 11f, 11g, and 5; Fig. 1). Only four OsTIFY members (OsTIFY3, 8, 9,and10c) are located in nonduplication regions[2].

Labs working on this gene

  • Faculty of Agriculture and Gene Research Center, Kagawa University, Miki, Kagawa, 761-0795 Japan
  • National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan)
  • College of Life Sciences and Technology, Huazhong Agricultural University, 430070 Wuhan, China

References

  1. 1.0 1.1 1.2 1.3 Shoko Yamada;Akihito Kano;Daisuke Tamaoki;Ayumi Miyamoto;Hodaka Shishido;Seika Miyoshi;Shiduku Taniguchi;Kazuya Akimitsu;Kenji Gomi Involvement of OsJAZ8 in Jasmonate-Induced Resistance to Bacterial Blight in Rice Plant and Cell Physiology, 2012, 53(12): 2060-2072
  2. 2.0 2.1 2.2 2.3 Haiyan Ye;Hao Du;Ning Tang;Xianghua Li;Lizhong Xiong Identification and expression profiling analysis of TIFY family genes involved in stress and phytohormone responses in rice Plant Molecular Biology, 2009, 71(3): 291-305
  3. Staswick PE (2008) JAZing up jasmonate signaling. Trends Plant Sci 13:66–71

Structured Information