Wheat stripe rust, caused by Puccinia striiformis West. f. sp. tritici Eriks. ＆Henn. (Pst), is a serious fungal disease. Identification of new genes associate with stripe rust resistance is important for developing disease resistant wheat cultivars and studying the mechanism of disease resistance. Trihelix is a plant specific transcription factor family, which is involved in regulation of growth and development, morphogenesis, and response to stresses. So far, no study reports on the relationship between the Trihelix family and wheat stripe rust. In this study, a gene in the GTγ subfamily of Trihelix family, designated TuGTγ-3, was cloned from Triticum urartu Tum. (2n=2x=14, AA). The results of sequencing demonstrated that TuGTγ-3 gene consisted of a complete open reading frame (ORF), and its coding sequence was 1329 bp in length, which encoded a protein with 442 amino acids. The predicted molecular weight of this protein was 50.31 kDa and the theoretical isoelectric point was 6.12. Bioinformatic analysis revealed that TuGTγ-3 protein had a monopartite nuclear localization signal (GLPMQKKMRYT), and had neither transmembrane domain nor signal peptide. The conserved trihelix domain, the fourth α-helix and the CC domain were located in the regions of Q115?R187, F234?Y241 and K362?K436, respectively. Dissection of secondary structure showed that TuGTγ-3 protein comprised of 43.89% α-helix, 9.51% extended strand, 9.95% β-turn and 36.65% random coil structures. Based on the BLAST search against the genome database of common wheat from IWGSC, TuGTγ-3 was located on the long arm of chromosome 5A. Transient expression experiment using onion inner epidermal cell showed that the fusion protein TuGTγ-3-GFP distributed mainly in nuclear and slightly in cytoplasm. Expression profiles in different organs indicated that expression level of TuGTγ-3 was much higher in leaves than that in roots or leaf sheaths, and the expression in leaves was extremely up-regulated by infection of the Pst race CYR32. Furthermore, the BSMV-VIGS experiment demonstrated that the transcription factor TuGTγ-3 positively regulated resistance to stripe rust in T. urartu.
[1] Luo JL, Zhao N, Lu CM. Plant Trihelix transcription factors family. Hereditas (Beijing), 2012, 34(12): 1551–1560.
罗军玲, 赵娜, 卢长明. 植物Trihelix转录因子家族研究进展. 遗传, 2012, 34(12): 1551–1560.
[2] Kay SA, Keith B, Shinozaki K, Chye ML, Chua NH. The rice phytochrome gene: structure, autoregulated expression, and binding of GT-1 to a conserved site in the 5' upstream region. Plant Cell, 1989, 1(3): 351–360.
[3] Park HC, Kim ML, Kang YH, Jeon JM, Yoo JH, Kim MC, Park CY, Jeong JC, Moon BC, Lee JH, Yoon HW, Lee SH, Chung WS, Lim CO, Lee SY, Hong JC, Cho MJ. Pathogen- and NaCl-induced expression of the SCaM-4 promoter is mediated in part by a GT-1 box that interacts with a GT-1-like transcription factor. Plant Physiol, 2004, 135(4): 2150–2161.
[4] Fang YJ, Xie KB, Hou X, Hu HH, Xiong LZ. Systematic analysis of GT factor family of rice reveals a novel subfamily involved in stress responses. Mol Genet Genom, 2010, 283(2): 157–169.
[5] Wang R, Hong GF, Han B. Transcript abundance of rml 1, encoding a putative GT1-like factor in rice, is up-regul?ated by Magnaporthe grisea and down-regulated by light. Gene, 2004, 324: 105–115.
[6] Wang XH, Li QT, Chen HW, Zhang WK, Ma B, Chen SY, Zhang JS. Trihelix transcription factor GT-4 mediates salt tolerance via interaction with TEM2 in Arabidopsis. BMC Plant Biol, 2014, 14(1): 339.
[7] Xie ZM, Zou HF, Lei G, Wei W, Zhou QY, Niu CF, Liao Y, Tian AG, Ma B, Zhang WK, Zhang JS, Chen SY. Soybean Trihelix transcription factors GmGT-2A and GmGT-2B improve plant tolerance to abiotic stresses in transgenic Arabidopsis. PLoS One, 2009, 4(9): e6898.
[8] Xi J, Qiu YJ, Du LQ, Poovaiah BW. Plant-specific trihelix transcription factor AtGT2L interacts with calcium/cal?modulin and responds to cold and salt stresses. Plant Sci, 2012, 185–186: 274–280.
[9] Li B, Jiang S, Yu X, Cheng C, Chen SX, Cheng YB, Yuan JS, Jiang DH, He P, Shan LB. Phosphorylation of Trihelix transcriptional repressor ASR3 by MAP KINASE4 negatively regulates Arabidopsis immunity. Plant Cell, 2015, 27(3): 839–856.
[10] Giuntoli B, Lee SC, Licausi F, Kosmacz M, Oosumi T, van Dongen JT, Bailey-Serres J, Perata P. A Trihelix DNA binding protein counterbalances hypoxia-responsive transcriptional activation in Arabidopsis. PLoS Biol, 2014, 12(9): e1001950.
[11] Yoo CY, Pence HE, Jin JB, Miura K, Gosney MJ, Hasegawa PM, Mickelbart MV. The Arabidopsis GTL1 transcription factor regulates water use efficiency and drought tolerance by modulating stomatal density via transrepression of SDD1. Plant Cell, 2010, 22(12): 4128–4141.
[12] Weng H, Yoo CY, Gosney MJ, Hasegawa PM, Mickelbart MV. Poplar GTL1 is a Ca2+/calmodulin-binding transcription factor that functions in plant water use efficiency and drought tolerance. PLoS One, 2012, 7(3): e32925.
[13] Griffith ME, Concei??o ADS, Smyth DR. PETAL LOSS gene regulates initiation and orientation of second whorl organs in the Arabidopsis flower. Development, 1999, 126(24): 5635–5644.
[14] Brewer PB, Howles PA, Dorian K, Griffith ME, Ishida T, Kaplan-Levy RN, Kilinc A, Smyth DR. PETAL LOSS, a trihelix transcription factor gene, regulates perianth architecture in the Arabidopsis flower. Development, 2004, 131(16): 4035–4045.
[15] O’Brien M, Kaplan-Levy RN, Quon T, Sappl PG, Smyth DR. PETAL LOSS, a trihelix transcription factor that represses growth in Arabidopsis thaliana, binds the energy-sensing SnRK1 kinase AKIN10. J Exp Bot, 2015, 66(9): 2475–2485.
[16] Tzafrir I, Pena-Muralla R, Dickerman A, Berg M, Rogers R, Hutchens S, Sweeney TC, McElver J, Aux G, Patton D, Meinke D. Identification of genes required for embryo development in Arabidopsis. Plant Physiol, 2004, 135(3): 1206–1220.
[17] Gao MJ, Lydiate DJ, Li X, Lui H, Gjetvaj B, Hegedus DD, Rozwadowski K. Repression of seed maturation genes by a Trihelix transcriptional repressor in Arabidopsis seedlings. Plant Cell, 2009, 21(1): 54–71.
[18] Willmann MR, Mehalick AJ,
