Validamycin A (VMA) is an aminoglycoside antibiotic used to control rice sheath blight. Although it has been reported that VMA can induce the plant defense responses, the mechanism remains poorly understood. Here, we found that reactive oxygen species (ROS) bursts and callose deposition in Arabidopsis thaliana, rice (Oryza sativa L.), and wheat (Triticum aestivum L.) were induced by VMA and were most intense with 10 μg of VMA per milliliter at 24 h. Moreover, we showed that VMA induced resistance against Pseudomonas syringae, Botrytis cinerea, and Fusarium graminearum in Arabidopsis leaves, indicating that VMA induces broad-spectrum disease resistance in both dicots and monocots. In addition, VMA-mediated resistance against P. syringae was not induced in NahG transgenic plants, was partially decreased in npr1 mutants, and VMA-mediated resistance to B. cinerea was not induced in npr1, jar1, and ein2 mutants. These results strongly indicated that VMA triggers plant defense responses to both biotrophic and necrotrophic pathogens involved in salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) signaling pathways and is dependent on NPR1. In addition, transcriptome analysis further revealed that VMA regulated the expression of genes involved in SA, JA/ET, abscisic acid (ABA), and auxin signal pathways. Taken together, VMA induces systemic resistance involving in SA and JA/ET signaling pathways and also exerts a positive influence on ABA and auxin signaling pathways. Our study highlights the creative application of VMA in triggering plant defense responses against plant pathogens, providing a valuable insight into applying VMA to enhance plant resistance and reduce the use of chemical pesticides.

Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Validamycin A（VMA）是一种用于控制水稻鞘枯病的氨基糖苷类抗生素。尽管已经报道VMA可以诱导植物防御反应，但是其机理仍知之甚少。在这里，我们发现VMA诱导了拟南芥，水稻（水稻）和小麦（小麦）中的活性氧（ROS）爆发和call质沉积，并且最强，每毫升10μgVMA在24小时 此外，我们表明VMA诱导了拟南芥中对丁香假单胞菌，灰葡萄孢和禾谷镰刀菌的抗性叶，表明VMA诱导双子叶植物和单子叶植物的广谱抗病性。此外，在NahG转基因植物中未诱导出VMA介导的对丁香假单胞菌的抗性，在npr1突变体中部分降低了VMA介导的丁香假单胞菌，在npr1，jar1和ein2中未诱导出VMA对灰葡萄孢的抗性。突变体。这些结果强烈表明，VMA触发了对水杨酸（SA）和茉莉酸/乙烯（JA / ET）信号传导途径所涉及的生物营养和坏死病原体的植物防御反应，并且依赖于NPR1。此外，转录组分析进一步揭示了VMA调节了SA，JA / ET，脱落酸（ABA）和生长素信号通路中涉及的基因的表达。综上所述，VMA诱导涉及SA和JA / ET信号传导途径的系统性抗药性，并且对ABA和生长素信号传导途径也产生积极影响。我们的研究突出了VMA在触发植物对植物病原体的防御反应中的创造性应用，为应用VMA增强植物抗性和减少化学农药的使用提供了宝贵的见识。

版权所有©2020作者。这是根据CC BY-NC-ND 4.0 International许可分发的开放获取文章。