Although it is well-established that ethylene and light stimulate the process of chlorophyll degradation in mature apple peels, there is still a need for further exploration of the molecular mechanisms that regulate this process. This study identified MdEIL1 and MdHY5 as promoters of the chlorophyll degradation pathway in apple peels, activated by ethylene and light. Physiological and molecular tests demonstrated that MdEIL1 and MdHY5 are responsible for activating the expression of genes associated with chlorophyll degradation, including MdERF17, MdNYC1, MdPPH and MdPAO. Furthermore, the interaction between MdEIL1 and MdHY5 proteins enhances their regulatory activity on the target gene MdERF17. Moreover, MdEIL1 binds to the promoter of MdHY5, resulting in the upregulation of its expression, which is further enhanced in the presence of the MdEIL1-MdHY5 protein complex. These findings indicate that MdEIL1-MdHY5 module acts as positive regulator mediating ethylene and light signals that promote chlorophyll degradation in apple peels.

中文翻译：

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转录因子 MdEIL1 和 MdHY5 整合乙烯和光信号传导，促进成熟苹果皮中的叶绿素降解


尽管乙烯和光会刺激成熟苹果皮的叶绿素降解过程，但仍需要进一步探索调节这一过程的分子机制。本研究确定 MdEIL1 和 MdHY5 是苹果皮中叶绿素降解途径的启动子，被乙烯和光激活。生理和分子测试表明，MdEIL1 和 MdHY5 负责激活叶绿素降解相关基因的表达，包括 MdERF17、MdNYC1、MdPPH 和 MdPAO。此外，MdEIL1 和 MdHY5 蛋白之间的相互作用增强了它们对靶基因 MdERF17 的调节活性。此外，MdEIL1 与 MdHY5 的启动子结合，导致其表达上调，在 MdEIL1-MdHY5 蛋白复合物存在下进一步增强。这些发现表明，MdEIL1-MdHY5 模块充当介导乙烯和光信号的正调节因子，促进苹果皮中叶绿素的降解。