In plants, epitranscriptomic mark N6-adenine methylation (m6A) is dynamically regulated in response to environmental cues. However, little is known about m6A dynamics under biotic stresses and their role in environmental adaptation. Additionally, current methodologies limit the investigation of m6A dynamics at single-nucleotide resolution on specific RNA molecules. Using Oxford Nanopore Technology direct RNA sequencing (ONT-DRS) and a neural network model, we show transcript-specific dynamics of m6A modification at single-nucleotide resolution during Hyaloperonospera arabidopsidis (Hpa) infection in Arabidopsis (Arabidopsis thaliana). In wild-type seedlings, pathogen infection causes a significant reduction of global m6A ratios, which corresponds with the activation of m6A-modified transcripts. Defect of m6A deposition in the m6A mutant hakai-1 mimics m6A reduction from Hpa infection at ∼70% of sites, resulting in constitutive overexpression of basal defense genes and enhanced resistance against the pathogen. Our results demonstrate that m6A dynamics impact defense response against Hpa, providing a promising target for future crop improvement strategies.

中文翻译：

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RNA N6-腺嘌呤甲基化动态影响拟南芥中的透明霜霉抗性


在植物中，表观转录组标记 N6-腺嘌呤甲基化 (m6A) 会根据环境信号进行动态调节。然而，人们对生物胁迫下的 m6A 动力学及其在环境适应中的作用知之甚少。此外，当前的方法限制了对特定 RNA 分子的单核苷酸分辨率的 m6A 动力学研究。使用牛津纳米孔技术直接 RNA 测序 (ONT-DRS) 和神经网络模型，我们以单核苷酸分辨率展示了拟南芥 (Hpa) 感染拟南芥 (Arabidopsis thaliana) 期间 m6A 修饰的转录特异性动态。在野生型幼苗中，病原体感染导致整体 m6A 比率显着降低，这与 m6A 修饰转录本的激活相对应。 m6A 突变体 hakai-1 中 m6A 沉积的缺陷模拟了约 70% 位点 Hpa 感染导致的 m6A 减少，导致基础防御基因的组成型过度表达并增强了对病原体的抵抗力。我们的结果表明，m6A 动态影响 Hpa 的防御反应，为未来作物改良策略提供了一个有希望的目标。