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.

冷胁迫是亚热带作物花粉发育的重大威胁，可导致作物产量下降。N6-甲基腺苷（N6-methyladenosine, m6A）是最为普遍的mRNA修饰形式，在植物发育过程中发挥多种生理功能。然而，目前尚不清楚m6A是否调控花粉发育，其在冷胁迫应答中的潜在作用也尚未明确。本研究发现，适度低温（moderate low-temperature, MLT）胁迫可诱导番茄产生花粉败育表型。该表型由绒毡层发育异常与花粉外壁形成受阻所导致，同时伴随番茄花药内m6A水平的降低。对m6A测序（m6A-seq）数据的分析显示，与常温条件下的花药相比，MLT胁迫处理的花药中共有1805个转录本的m6A水平出现下调，另有978个转录本的m6A水平出现上调。MLT胁迫下的差异m6A富集转录本主要富集于脂质代谢、腺苷三磷酸酶（ATPase）活性以及ATP结合通路相关的生物学过程。其中一个ATP结合转录本SlABCG31的m6A修饰水平显著上调，这与其表达水平的显著下调呈负相关。上述变化与低温胁迫下花药内脱落酸（ABA）水平升高以及花粉壁形成受阻密切相关。本研究明确了m6A是基因表达调控中一层全新的复杂调控维度，并建立了低温条件下m6A甲基化与番茄花药发育之间的分子关联。