State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, China.
State Key Laboratory of Crop Biology, MOA Key Laboratory of Horticultural Crop Biology and Germplasm Innovation; Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, China.
J Integr Plant Biol. 2020 Apr;62(4):527-543. doi: 10.1111/jipb.12825. Epub 2019 Sep 5.
Isochorismate synthase (ICS) plays an essential role in the accumulation of salicylic acid (SA) and plant disease resistance. Diseases caused by Botryosphaeria dothidea affect apple yields. Thus, it is important to understand the role of ICS1 in disease resistance to B. dothidea in apple. In this study, SA treatment enhanced the resistance to B. dothidea. MdICS1 was induced by B. dothidea and enhanced the resistance to B. dothidea. MdICS1 promoter analysis indicated that the W-box was vital for the response to B. dothidea treatment. MdWRKY15 was found to interact with the W-box using yeast one-hybrid screening. Subsequently, the interaction was confirmed by EMSA, yeast one-hybrid, ChIP-PCR, and quantitative PCR assays. Moreover, luciferase and GUS analysis further indicated that MdICS1 was transcriptionally activated by MdWRKY15. Finally, we found the function of MdWRKY15 in the resistance to B. dothidea was partially dependent on MdICS1 from the phenotype of transgenic apples and calli. In summary, we revealed that MdWRKY15 activated the transcription of MdICS1 by directly binding to its promoter to increase the accumulation of SA and the expression of disease-related genes, thereby resulting in the enhanced resistance to B. dothidea in the SA biosynthesis pathway.
异分支酸合酶（ICS）在水杨酸（SA）的积累和植物抗病性中起着重要作用。由贝氏葡萄座腔菌引起的疾病会影响苹果的产量。因此，了解苹果中 ICS1 在对贝氏葡萄座腔菌抗性中的作用非常重要。本研究表明，SA 处理增强了对贝氏葡萄座腔菌的抗性。MdICS1 被贝氏葡萄座腔菌诱导，增强了对贝氏葡萄座腔菌的抗性。MdICS1 启动子分析表明，W 框对响应贝氏葡萄座腔菌处理至关重要。利用酵母单杂交筛选发现 MdWRKY15 与 W 框相互作用。随后，通过 EMSA、酵母单杂交、ChIP-PCR 和定量 PCR 实验证实了这种相互作用。此外，荧光素酶和 GUS 分析进一步表明，MdICS1 被 MdWRKY15 转录激活。最后，我们发现从转基因苹果和愈伤组织的表型中，MdWRKY15 在对贝氏葡萄座腔菌的抗性中的功能部分依赖于 MdICS1。总之，我们揭示了 MdWRKY15 通过直接结合其启动子来激活 MdICS1 的转录，从而增加 SA 的积累和与疾病相关基因的表达，从而在 SA 生物合成途径中增强对贝氏葡萄座腔菌的抗性。
