MdCRY2 was isolated from apple fruit skin, and its function was analyzed in MdCRY2 transgenic Arabidopsis. The interaction between MdCRY2 and AtCOP1 was found by yeast two-hybrid and BiFC assays. Cryptochromes are blue/ultraviolet-A (UV-A) light receptors involved in regulating various aspects of plant growth and development. Investigations of the structure and functions of cryptochromes in plants have largely focused on Arabidopsis (Arabidopsis thaliana), tomato (Solanum lycopersicum), pea (Pisum sativum), and rice (Oryza sativa). However, no data on the function of CRY2 are available in woody plants. In this study, we isolated a cryptochrome gene, MdCRY2, from apple (Malus domestica). The deduced amino acid sequences of MdCRY2 contain the conserved N-terminal photolyase-related domain and the flavin adenine dinucleotide (FAD) binding domain, as well as the C-terminal DQXVP-acidic-STAES (DAS) domain. Relationship analysis indicates that MdCRY2 shows the highest similarity to the strawberry FvCRY protein. The expression of MdCRY2 is induced by blue/UV-A light, which represents a 48-h circadian rhythm. To investigate the function of MdCRY2, we overexpressed the MdCRY2 gene in a cry2 mutant and wild type (WT) Arabidopsis, assessed the phenotypes of the resulting transgenic plants, and found that MdCRY2 functions to regulate hypocotyl elongation, root growth, flower initiation, and anthocyanin accumulation. Furthermore, we examined the interaction between MdCRY2 and AtCOP1 using a yeast two-hybrid assay and a bimolecular fluorescence complementation assay. These data provide functional evidence for a role of blue/UV-A light-induced MdCRY2 in controlling photomorphogenesis in apple.

中文翻译：

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苹果（Malusdomesica）蓝光受体基因MdCRY2的分子克隆及功能分析。

MdCRY2从苹果果皮中分离出来，在MdCRY2转基因拟南芥中进行功能分析。MdCRY2 和 AtCOP1 之间的相互作用是通过酵母双杂交和 BiFC 测定发现的。隐花色素是蓝色/紫外线-A (UV-A) 光受体，参与调节植物生长和发育的各个方面。对植物隐花色素结构和功能的研究主要集中在拟南芥 (Arabidopsis thaliana)、番茄 (Solanum lycopersicum)、豌豆 (Pisum sativum) 和水稻 (Oryza sativa) 上。然而，没有关于 CRY2 在木本植物中的功能的数据。在这项研究中，我们从苹果 (Malusdomestica) 中分离出了一个隐花色素基因 MdCRY2。推导出的 MdCRY2 氨基酸序列包含保守的 N 端光解酶相关域和黄素腺嘌呤二核苷酸 (FAD) 结合域，以及 C 端 DQXVP-酸性-STAES (DAS) 结构域。关系分析表明，MdCRY2 与草莓 FvCRY 蛋白的相似性最高。MdCRY2 的表达由代表 48 小时昼夜节律的蓝色/UV-A 光诱导。为了研究 MdCRY2 的功能，我们在 cry2 突变体和野生型 (WT) 拟南芥中过表达 MdCRY2 基因，评估所得转基因植物的表型，发现 MdCRY2 的功能是调节下胚轴伸长、根生长、开花开始和花青素积累。此外，我们使用酵母双杂交试验和双分子荧光互补试验检查了 MdCRY2 和 AtCOP1 之间的相互作用。这些数据为蓝光/UV-A 光诱导的 MdCRY2 在控制苹果光形态发生中的作用提供了功能证据。