College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.
Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, Guangdong, 518108, China.
BMC Plant Biol. 2024 Nov 23;24(1):1114. doi: 10.1186/s12870-024-05818-7.
Cold stress poses a serious challenge to tropical fruit production, particularly in mango. N-methyladenosine (mA) modifications are key regulators of gene expression, enabling plants to respond to stress responses, enhance adaptation and improve resilience to environmental challenges.
In our study, transcriptome-wide mA methylation profiling under cold stress identified 6,499 differentially methylated mA peaks and 2,164 differentially expressed genes (DEGs) in mango seedlings. Among these genes, six exhibited both significant increases in mA modification levels and gene expression, 21 showed a significant increase in mA levels but a concurrent downregulation of gene expression, and 26 showed reduced mA levels but exhibited increased gene expression, highlighting distinct regulatory patterns in mA-mediated gene expression control. Gene Ontology (GO) enrichment analysis revealed significant involvement in pathways such as potassium ion import, nitrate response, and transcription regulation. Notably, HSP70 was one of the upregulated genes in response to cold stress. RNA immunoprecipitation (RNA-IP) assays confirmed the association of HSP70 with mA-modified RNAs in vivo, supporting its role in regulating stress-responsive transcripts. Additionally, immunofluorescence analysis demonstrated the formation of HSP70 condensates in plant cells under cold stress, indicating a potential mechanism for localized RNA stabilization. Fluorescence polarization assays demonstrated that HSP70 binds preferentially to mA-modified RNAs, suggesting its role in forming protective condensates under cold conditions. This interaction between mA modification and HSP70 points to a potential mechanism that helps stabilize stress-responsive transcripts, contributing to the plant's enhanced cold tolerance.
mA modifications play a vital role in regulating gene expression under cold stress, offering new insights into mango's stress responses and potential breeding strategies for cold tolerance.
冷应激对热带水果生产造成了严重挑战，尤其是芒果。N6-甲基腺苷（m6A）修饰是基因表达的关键调节因子，使植物能够响应胁迫反应，增强适应性，并提高对环境挑战的恢复能力。
在我们的研究中，冷胁迫下的全转录组 m6A 甲基化谱分析在芒果幼苗中鉴定出 6499 个差异甲基化 m6A 峰和 2164 个差异表达基因（DEGs）。在这些基因中，有 6 个基因的 m6A 修饰水平和基因表达均显著增加，21 个基因的 m6A 水平显著增加，但基因表达同时下调，26 个基因的 m6A 水平降低，但基因表达增加，突出了 m6A 介导的基因表达调控中的不同调节模式。基因本体论（GO）富集分析表明，这些基因显著参与了钾离子导入、硝酸盐反应和转录调控等途径。值得注意的是，HSP70 是冷应激响应上调的基因之一。RNA 免疫沉淀（RNA-IP）实验证实了 HSP70 与体内 m6A 修饰 RNA 的关联，支持其在调节应激响应转录本中的作用。此外，免疫荧光分析表明，在冷胁迫下，HSP70 在植物细胞中形成了 HSP70 凝聚物，表明其在局部稳定 RNA 方面的潜在机制。荧光偏振实验表明，HSP70 优先结合 m6A 修饰的 RNA，表明其在冷条件下形成保护凝聚物的作用。m6A 修饰与 HSP70 之间的这种相互作用为稳定应激响应转录本提供了一个潜在的机制，有助于提高植物的耐寒性。
m6A 修饰在冷胁迫下调节基因表达中起着至关重要的作用，为芒果的应激反应和潜在的耐寒性育种策略提供了新的见解。
