Institute of Biology, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Saale), Germany.
Present address: Institute of Genetics, University of Munich (LMU), Großhaderner Straße 2, 82152 Martinsried, Germany.
New Phytol. 2010 Sep;187(4):1048-1057. doi: 10.1111/j.1469-8137.2010.03217.x. Epub 2010 Mar 19.
*Plant pathogenic bacteria of the genus Xanthomonas inject transcription activator-like effector (TALe) proteins that bind to and activate host promoters, thereby promoting disease or inducing plant defense. TALes bind to corresponding UPT (up-regulated by TALe) promoter boxes via tandemly arranged 34/35-amino acid repeats. Recent studies uncovered the TALe code in which two amino acid residues of each repeat define specific pairing to UPT boxes. *Here we employed the TALe code to predict potential UPT boxes in TALe-induced host promoters and analyzed these via beta-glucuronidase (GUS) reporter and electrophoretic mobility shift assays (EMSA). *We demonstrate that the Xa13, OsTFX1 and Os11N3 promoters from rice are induced directly by the Xanthomonas oryzae pv. oryzae TALes PthXo1, PthXo6 and AvrXa7, respectively. We identified and functionally validated a UPT box in the corresponding rice target promoter for each TALe and show that box mutations suppress TALe-mediated promoter activation. Finally, EMSA demonstrate that code-predicted UPT boxes interact specifically with corresponding TALes. *Our findings show that variations in the UPT boxes of different rice accessions correlate with susceptibility or resistance of these accessions to the bacterial blight pathogen.
植物病原细菌黄单胞菌属注射转录激活子样效应物(TALe)蛋白,这些蛋白与宿主启动子结合并激活,从而促进疾病或诱导植物防御。TALes 通过串联排列的 34/35 个氨基酸重复序列结合到相应的 UPT(TALe 上调)启动子盒上。最近的研究揭示了 TALe 密码,其中每个重复的两个氨基酸残基定义了与 UPT 盒的特定配对。在这里,我们利用 TALe 密码来预测 TALe 诱导的宿主启动子中的潜在 UPT 盒,并通过β-葡萄糖醛酸酶(GUS)报告基因和电泳迁移率变动分析(EMSA)对其进行分析。我们证明,来自水稻的 Xa13、OsTFX1 和 Os11N3 启动子分别被水稻黄单胞菌 pv.oryzae 的 TALes PthXo1、PthXo6 和 AvrXa7 直接诱导。我们鉴定并功能验证了每个 TALe 对应的水稻靶启动子中的 UPT 盒,并表明框突变抑制了 TALe 介导的启动子激活。最后,EMSA 表明,预测密码的 UPT 框与相应的 TALe 特异性相互作用。我们的研究结果表明,不同水稻品系的 UPT 盒的变异与这些品系对细菌性条斑病病原体的敏感性或抗性相关。