Zhou Leilei, Gao Guangtong, Tang Renkun, Liu Jinying, Wang Yuying, Liang Zhenchang, Tian Shiping, Qin Guozheng
State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
China National Botanical Garden, Beijing, China.
Nat Plants. 2025 Feb;11(2):218-233. doi: 10.1038/s41477-024-01893-8. Epub 2025 Jan 10.
Hydrogen peroxide (HO) functions as a critical signalling molecule in controlling multiple biological processes. How HO signalling integrates with other regulatory pathways such as epigenetic modification to coordinately regulate plant development remains elusive. Here we report that SlALKBH2, an mA demethylase required for normal ripening of tomato fruit, is sensitive to oxidative modification by HO, which leads to the formation of homodimers mediated by intermolecular disulfide bonds, and Cys39 serves as a key site in this process. The oxidation of SlALKBH2 promotes protein stability and facilitates its function towards the target transcripts including the pivotal ripening gene SlDML2 encoding a DNA demethylase. Furthermore, we demonstrate that the thioredoxin reductase SlNTRC interacts with SlALKBH2 and catalyses its reduction, thereby modulating mA levels and fruit ripening. Our study establishes a molecular link between HO and mA methylation and highlights the importance of redox regulation of mA modifiers in controlling fruit ripening.
过氧化氢（HO）在控制多种生物学过程中作为一种关键的信号分子发挥作用。HO信号如何与其他调控途径（如表观遗传修饰）整合以协调调节植物发育仍不清楚。在这里，我们报道SlALKBH2是番茄果实正常成熟所需的一种mA去甲基化酶，它对HO介导的氧化修饰敏感，这导致由分子间二硫键介导的同型二聚体形成，并且半胱氨酸39（Cys39）在此过程中作为关键位点。SlALKBH2的氧化促进了蛋白质稳定性，并促进其对包括编码DNA去甲基化酶的关键成熟基因SlDML2在内的靶转录本的作用。此外，我们证明硫氧还蛋白还原酶SlNTRC与SlALKBH2相互作用并催化其还原，从而调节mA水平和果实成熟。我们的研究建立了HO与mA甲基化之间的分子联系，并强调了mA修饰因子的氧化还原调节在控制果实成熟中的重要性。
