Germination is a crucial event in plant lifecycle mediated by a complex hormonal crosstalk. In this study, we revealed an antagonistic interaction between phytohormone abscisic acid (ABA) and gibberellins in epigallocatechin-3-gallate (EGCG)-retarded germination and early seedling growth in tomato. High concentrations of EGCG (0.5 mM and 1.0 mM) decelerated the seed germination and reduced the germination rate and biomass accumulation in seedlings. EGCG-induced inhibition in seedling growth was associated with oxidative stress and changes in antioxidant enzyme activity. Moreover, EGCG treatment increased the ABA content and decreased the GA 3 content, leading to a significant reduction in the ratio of GA 3 /ABA in a dose-dependent manner. EGCG-induced changes in ABA and GA levels were attributed to the changes in expression levels of genes involved in their metabolism. Either exogenous GA application or endogenous ABA deficiency both alleviated EGCG-induced inhibition in early seedling growth. These results suggest that EGCG inhibits seed germination and early seedling growth by affecting the balance between ABA and GA in tomato. These findings are important to better understand the role of flavonoids in seed germination and their implications in controlling seed dormancy.

中文翻译：

---

脱落酸和赤霉素拮抗作用介导番茄中表没食子儿茶素-3-没食子酸酯延迟种子萌发和早期幼苗生长

发芽是植物生命周期中由复杂的激素串扰介导的关键事件。在这项研究中，我们揭示了植物激素脱落酸 (ABA) 和赤霉素在表没食子儿茶素-3-没食子酸酯 (EGCG) 延迟发芽和早期幼苗生长中的拮抗相互作用。高浓度的 EGCG（0.5 mM 和 1.0 mM）会减缓种子发芽并降低幼苗的发芽率和生物量积累。EGCG 诱导的幼苗生长抑制与氧化应激和抗氧化酶活性的变化有关。此外，EGCG处理增加了ABA含量并降低了GA 3 含量，导致GA 3 /ABA比以剂量依赖性方式显着降低。EGCG 诱导的 ABA 和 GA 水平变化归因于参与其代谢的基因表达水平的变化。外源 GA 应用或内源 ABA 缺乏都减轻了早期幼苗生长中 EGCG 诱导的抑制。这些结果表明 EGCG 通过影响番茄中 ABA 和 GA 之间的平衡来抑制种子萌发和早期幼苗生长。这些发现对于更好地理解类黄酮在种子萌发中的作用及其在控制种子休眠中的意义非常重要。