Abstract The N6-methyladenosine (m6A) modification is the most common internal post-transcriptional modification, with important regulatory effects on RNA export, splicing, stability, and translation. Studies on the m6A modifications in plants have focused on Arabidopsis thaliana growth and development. However, A. thaliana is a salt-sensitive and model plant species. Thus, studies aimed at characterizing the role of the m6A modification in the salt stress responses of highly salt-tolerant crop species are needed. Sweet sorghum is cultivated as an energy and forage crop, which is highly suitable for growth on saline-alkaline land. Exploring the m6A modification in sweet sorghum may be important for elucidating the salt-resistance mechanism of crops. In this study, we mapped the m6A modifications in two sorghum genotypes (salt-tolerant M-81E and salt-sensitive Roma) that differ regarding salt tolerance. The m6A modification in sweet sorghum under salt stress was drastically altered, especially in Roma, where the m6A modification on mRNAs of some salt-resistant related transcripts increased, resulting in enhanced mRNA stability, which in turn was involved in the regulation of salt tolerance in sweet sorghum. Although m6A modifications are important for regulating sweet sorghum salt tolerance, the regulatory activity is limited by the initial m6A modification level. Additionally, in M-81E and Roma, the differences in the m6A modifications were much greater than the differences in gene expression levels and are more sensitive. Our study suggests that the number and extent of m6A modifications on the transcripts of salt-resistance genes may be important factors for determining and assessing the salt tolerance of crops.

中文翻译：

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N6-甲基腺苷的分析揭示了调节甜高粱耐盐性的新重要机制

摘要 N6-甲基腺苷（m6A）修饰是最常见的内部转录后修饰，对RNA输出、剪接、稳定性和翻译具有重要的调控作用。对植物中 m6A 修饰的研究集中在拟南芥的生长和发育上。然而，拟南芥是一种对盐分敏感的模式植物物种。因此，需要研究旨在表征 m6A 修饰在高度耐盐作物物种的盐胁迫响应中的作用。甜高粱是一种能源和饲料作物，非常适合在盐碱地生长。探索甜高粱中的 m6A 修饰对于阐明作物的抗盐机制可能很重要。在这项研究中，我们绘制了两种高粱基因型（耐盐 M-81E 和盐敏感 Roma）中的 m6A 修饰，它们在耐盐性方面存在差异。盐胁迫下甜高粱的 m6A 修饰发生了巨大变化，尤其是在罗马，一些耐盐相关转录本 mRNA 上的 m6A 修饰增加，导致 mRNA 稳定性增强，这反过来又参与了耐盐性的调节。甜高粱。尽管 m6A 修饰对于调节甜高粱耐盐性很重要，但调节活性受到初始 m6A 修饰水平的限制。此外，在 M-81E 和 Roma 中，m6A 修饰的差异远大于基因表达水平的差异，并且更加敏感。