Abiotic stress reduces plant yield and quality. WRKY transcription factors play key roles in abiotic stress responses in plants, but the molecular mechanisms by which WRKY transcription factors mediate responses to drought and osmotic stresses in apple ( × Borkh.) remain unclear. Here, we functionally characterized the apple Group III WRKY gene . qRT-PCR analysis showed that expression was up-regulated by drought and osmotic stresses. GUS activity analysis revealed that the promoter activity of was enhanced under osmotic stress. Subcellular localization and transactivation assays indicated that was localized to the nucleus and had a transcriptional activity domain at the N-terminal region. Transgenic analysis revealed that the overexpression of in plants and in apple callus markedly enhanced their tolerance to drought and osmotic stresses. DNA affinity purification sequencing showed that MdWRKY115 binds to the promoter of the stress-related gene . This binding was further verified by an electrophoretic mobility shift assay. Collectively, these findings suggest that MdWRKY115 is an important regulator of osmotic and drought stress tolerance in apple.

中文翻译：

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转录因子 MdWRKY115 的过表达通过直接结合到苹果中的 MdRD22 启动子来提高干旱和渗透胁迫耐受性


非生物胁迫会降低植物产量和质量。 WRKY转录因子在植物非生物胁迫反应中发挥关键作用，但WRKY转录因子介导苹果（×Borkh.）干旱和渗透胁迫反应的分子机制仍不清楚。在这里，我们对苹果 III 组 WRKY 基因进行了功能表征。 qRT-PCR 分析表明，干旱和渗透胁迫下表达上调。 GUS活性分析表明，在渗透胁迫下，启动子活性增强。亚细胞定位和反式激活测定表明，其定位于细胞核，并在 N 端区域具有转录活性结构域。转基因分析表明，在植物和苹果愈伤组织中过度表达显着增强了它们对干旱和渗透胁迫的耐受性。 DNA亲和纯化测序表明MdWRKY115与应激相关基因的启动子结合。通过电泳迁移率变动测定进一步验证了这种结合。总的来说，这些发现表明 MdWRKY115 是苹果渗透和干旱胁迫耐受性的重要调节剂。