College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
J Integr Plant Biol. 2017 Nov;59(11):797-804. doi: 10.1111/jipb.12565. Epub 2017 Aug 21.
The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses. THESEUS1 (THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth. However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4 (GEF4) and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea. Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes (such as defense-related, secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.
植物细胞壁是感知病原体攻击并激活信号通路的重要界面，这些信号通路促进植物免疫反应。THESEUS1（THE1）作为细胞壁完整性的传感器，控制植物生长过程中的细胞伸长。然而，目前尚未报道 THE1 在植物防御反应中的特定作用。在这里，我们发现 THE1 与鸟嘌呤交换因子 4（GEF4）相互作用，这两种蛋白质在植物对坏死真菌 Botrytis cinerea 的抗性中发挥调节作用。遗传分析表明，THE1 和 GEF4 作用于同一遗传途径，以介导植物防御反应。此外，我们使用转录组分析鉴定了各种基因（如防御相关、次生代谢物相关和转录因子基因），它们可能是 THE1-GEF4 信号通路中的下游靶标。我们的结果表明，THE1 作为 GEF4 信号的上游调节剂，正向调节拟南芥对 B. cinerea 的防御反应。
