Plants have evolved light signaling mechanisms to optimally adapt developmental patterns to the ambient light environments. CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) and LONG HYPOCOTYL5 (HY5) are two critical components in the light signaling pathway in Arabidopsis thaliana. COP1 acts as an E3 ubiquitin ligase that targets positive regulators, such as HY5, leading to their degradation in darkness. However, functional analysis of the COP1-HY5 module in maize (Zea mays) has not been reported. Here, we investigated the expression patterns and roles of the COP1 and HY5 orthologs, ZmCOP1 and ZmHY5, in regulating photomorphogenesis. These two genes have high amino acid identities with their Arabidopsis homolog and were both regulated by light. Subcellular localization assay showed that ZmCOP1 was distributed in the cytosol and ZmHY5 localized in the nucleus. Exogenous expression of ZmCOP1 rescued the physiological defects of the cop1-4 mutant, and expression of ZmHY5 complemented the long hypocotyl phenotype of the hy5-215 mutant in Arabidopsis. Yeast two-hybrid and fluorescence resonance energy transfer assays showed that ZmCOP1 interacted with ZmHY5. Our study gains insight into the conserved function and regulatory mechanism of the COP1-HY5 signaling pathway in maize and Arabidopsis. This article is protected by copyright. All rights reserved.

中文翻译：

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ZmCOP1 和 ZmHY5 的功能分析揭示了玉米和拟南芥中保守的光信号机制

植物已经进化出光信号机制，以最佳地适应环境光环境的发育模式。CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) 和 LONG HYPOCOTYL5 (HY5) 是拟南芥光信号通路中的两个关键成分。COP1 作为 E3 泛素连接酶，靶向正调节因子，如 HY5，导致它们在黑暗中降解。然而，尚未报道玉米（Zea mays）中 COP1-HY5 模块的功能分析。在这里，我们研究了 COP1 和 HY5 直向同源物 ZmCOP1 和 ZmHY5 在调节光形态发生中的表达模式和作用。这两个基因与其拟南芥同源物具有高氨基酸同一性并且均受光调节。亚细胞定位分析表明ZmCOP1分布于细胞质中，ZmHY5定位于细胞核中。ZmCOP1 的外源表达挽救了 cop1-4 突变体的生理缺陷，ZmHY5 的表达补充了拟南芥中 hy5-215 突变体的长下胚轴表型。酵母双杂交和荧光共振能量转移试验表明 ZmCOP1 与 ZmHY5 相互作用。我们的研究深入了解了玉米和拟南芥中 COP1-HY5 信号通路的保守功能和调控机制。本文受版权保护。版权所有。我们的研究深入了解了玉米和拟南芥中 COP1-HY5 信号通路的保守功能和调控机制。本文受版权保护。版权所有。我们的研究深入了解了玉米和拟南芥中 COP1-HY5 信号通路的保守功能和调控机制。本文受版权保护。版权所有。