Table_11_Multi-Omics Analysis Reveals the Dynamic Changes of RNA N6-Methyladenosine in Pear (Pyrus bretschneideri) Defense Responses to Erwinia amylovora Pathogen Infection.XLSX

N6-methylated adenine (m6A) is the most prevalent modification of mRNA methylation and can regulate many biological processes in plants, such as mRNA processing, development, and stress response. Some studies have increased our understanding of its various roles in model plants in recent years. Nevertheless, the distribution of m6A and the impact of m6A on the regulation of plant defense responses against pathogen inoculation are virtually unknown in pear. In this study, MeRIP-seq and RNA-seq data from healthy and inoculated plants were analyzed to assess the changes in the transcript levels and posttranscriptional modification of pear in response to the fire blight pathogen Erwinia amylovora. Following the analysis of 97,261 m6A peaks, we found that m6A preferred to modify duplicate genes rather than singleton genes and that m6A-methylated genes underwent stronger purifying selection. A total of 2,935 specific m6A sites were detected at the transcriptome level after inoculation, which may increase defense-related transcript abundance to enhance pear resistance. In addition, 1,850 transcripts were detected only in the mock-inoculated groups. The hypomethylated transcripts were mainly related to transcriptional regulation and various biological processes, such as chloroplast organization and sucrose biosynthetic processes. In addition, we found that the extent of m6A methylation was significantly positively correlated with the transcript level, suggesting a regulatory role for m6A in the plant response.

N6-甲基腺嘌呤（N6-methylated adenine，m6A）是mRNA甲基化修饰中最为普遍的类型，可调控植物的诸多生物学过程，包括mRNA加工、生长发育与胁迫应答。近年来，相关研究不断加深了人们对模式植物中m6A多样功能的理解。然而，在梨中，m6A的分布特征及其对植物抵御病原菌侵染的调控作用，目前几乎仍属未知。本研究通过分析健康植株与接种植株的甲基化RNA免疫沉淀测序（MeRIP-seq）和RNA测序（RNA-seq）数据，评估梨在响应火疫病病原菌解淀粉欧文氏菌（Erwinia amylovora）时的转录水平与转录后修饰变化。对97261个m6A峰的分析表明，m6A更偏好修饰重复基因而非单拷贝基因，且经m6A甲基化的基因受到更强的纯化选择压力。病原菌接种后，研究团队在转录组水平共检测到2935个特异性m6A位点，这些位点或通过提升防御相关转录本的丰度，增强梨的抗病能力。此外，有1850个转录本仅在模拟接种组中被检测到。低甲基化的转录本主要参与转录调控及多种生物学过程，例如叶绿体组织构建与蔗糖生物合成等。本研究还发现，m6A的甲基化程度与转录本水平呈显著正相关，这提示m6A在植物应激响应过程中发挥调控作用。