Table_2_RNA N6-Methyladenosine Responds to Low-Temperature Stress in Tomato Anthers.XLSX

Cold stress is a serious threat to subtropical crop pollen development and induces yield decline. N6-methyladenosine (m6A) is the most frequent mRNA modification and plays multiple physiological functions in plant development. However, whether m6A regulates pollen development is unclear, and its putative role in cold stress response remains unknown. Here, we observed that moderate low-temperature (MLT) stress induced pollen abortion in tomato. This phenotype was caused by disruption of tapetum development and pollen exine formation, accompanied by reduced m6A levels in tomato anther. Analysis of m6A-seq data revealed 1,805 transcripts displayed reduced m6A levels and 978 transcripts showed elevated m6A levels in MLT-stressed anthers compared with those in anthers under normal temperature. These differentially m6A enriched transcripts under MLT stress were mainly related to lipid metabolism, adenosine triphosphatase (ATPase) activity, and ATP-binding pathways. An ATP-binding transcript, SlABCG31, had significantly upregulated m6A modification levels, which was inversely correlated to the dramatically downregulated expression level. These changes correlated with higher abscisic acid (ABA) levels in anthers and disrupted pollen wall formation under low-temperature stress. Our findings characterized m6A as a novel layer of complexity in gene expression regulation and established a molecular link between m6A methylation and tomato anther development under low-temperature conditions.

低温胁迫对亚热带作物花粉发育构成严重威胁，并导致产量下降。N6-甲基腺苷（m6A）是mRNA最常见的修饰形式，在植物发育过程中发挥着多种生理功能。然而，m6A是否调控花粉发育尚不明确，其在低温胁迫响应中的潜在作用亦未可知。本研究观察到，适度的低温胁迫（MLT）诱导了番茄花粉的败育。这一表型由药室内壁发育和花粉外壁形成的破坏所致，伴随着番茄药室内m6A水平的降低。m6A测序数据分析揭示了1,805个转录本在MLT胁迫的药室内m6A水平降低，而978个转录本在MLT胁迫的药室内m6A水平升高，与正常温度下药室内转录本相比。这些在MLT胁迫下m6A富集程度不同的转录本主要与脂质代谢、腺苷三磷酸酶（ATPase）活性和ATP结合途径相关。一个ATP结合转录本SlABCG31的m6A修饰水平显著上调，这与表达水平的显著下调呈负相关。这些变化与药室内脱落酸（ABA）水平的升高以及低温胁迫下花粉壁形成的破坏相关。本研究揭示了m6A作为基因表达调控中新的复杂性层次，并在低温条件下建立了m6A甲基化与番茄药室发育之间的分子联系。