Fruit ripening depends on the accurate control of ripening-related genes expression, with histone deacetylases (HDACs) playing crucial roles in transcriptional regulation. However, the functions of HDACs in fruit maturation remain largely unexplored. Here, we show that SlHDA7 acts as a suppressor of fruit ripening and functions as an H4ac HDAC in tomato. Deletion of SlHDA7 accelerated fruit ripening, while overexpression of SlHDA7 delayed maturation process. Additionally, ethylene production and carotenoid biosynthesis significantly increased in slhda7 mutant fruits but decreased in SlHDA7-overexpressing fruits. Furthermore, SlHDA7 repress the expression of ethylene production and signaling, carotenoid metabolism, cell wall modification, and transcriptional regulation-related genes. RT-qPCR and ChIP-qPCR analyses indicated that SlHDA7 may deacetylate H4ac, leading to reduced transcript levels of ACO1, GGPPS2, Z-ISO, EXP1, and XYL1 mRNA, consequently suppressing fruit ripening. Moreover, SlHDA7 suppresses fruit ripening by targeting specific ripening-associated transcription factors (TFs) like RIN, FUL1, and ERF.E1, ultimately leading to delayed ripening and prolonged fruit shelf life. In summary, our findings indicate that SlHDA7 negatively modulates tomato fruit maturation by adjusting H4ac levels of these ripening-associated genes and key TFs.

中文翻译：

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组蛋白脱乙酰酶 SlHDA7 影响番茄果实成熟和保质期


果实成熟取决于成熟相关基因表达的精确控制，其中组蛋白脱乙酰酶（HDAC）在转录调控中发挥着至关重要的作用。然而，HDAC 在果实成熟中的功能在很大程度上仍未被探索。在这里，我们证明 SlHDA7 作为果实成熟的抑制剂，并在番茄中充当 H4ac HDAC。 SlHDA7 的缺失加速了果实的成熟，而 SlHDA7 的过度表达则延迟了成熟过程。此外，slhda7突变体果实中乙烯产量和类胡萝卜素生物合成显着增加，但SlHDA7过表达果实中乙烯产量和类胡萝卜素生物合成显着增加。此外，SlHDA7 抑制乙烯产生和信号传导、类胡萝卜素代谢、细胞壁修饰和转录调控相关基因的表达。 RT-qPCR 和 ChIP-qPCR 分析表明，SlHDA7 可能使 H4ac 去乙酰化，导致 ACO1、GGPPS2、Z-ISO、EXP1 和 XYL1 mRNA 的转录水平降低，从而抑制果实成熟。此外，SlHDA7 通过靶向特定的成熟相关转录因子 (TF)（如 RIN、FUL1 和 ERF.E1）来抑制果实成熟，最终导致延迟成熟并延长果实保质期。总之，我们的研究结果表明，SlHDA7 通过调节这些成熟相关基因和关键 TF 的 H4ac 水平来负向调节番茄果实成熟。