title: MdCOP1 ubiquitin E3 ligases interact with MdMYB1 to regulate light-induced anthocyanin biosynthesis and red fruit coloration in apple.
abstract: MdMYB1 is a crucial regulator of light-induced anthocyanin biosynthesis and fruit coloration in apple (Malus domestica). In this study, it was found that MdMYB1 protein accumulated in the light but degraded via a ubiquitin-dependent pathway in the dark. Subsequently, the MdCOP1-1 and MdCOP1-2 genes were isolated from apple fruit peel and were functionally characterized in the Arabidopsis (Arabidopsis thaliana) cop1-4 mutant. Yeast (Saccharomyces cerevisiae) two-hybrid, bimolecular fluorescence complementation, and coimmunoprecipitation assays showed that MdMYB1 interacts with the MdCOP1 proteins. Furthermore, in vitro and in vivo experiments indicated that MdCOP1s are necessary for the ubiquitination and degradation of MdMYB1 protein in the dark and are therefore involved in the light-controlled stability of the MdMYB1 protein. Finally, a viral vector-based transformation approach demonstrated that MdCOP1s negatively regulate the peel coloration of apple fruits by modulating the degradation of the MdMYB1 protein. Our findings provide new insight into the mechanism by which light controls anthocyanin accumulation and red fruit coloration in apple and even other plant species.
authors.affiliation: State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Li
authors.forename: Ke
authors.initials: K
authors.lastname: Mao
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhao
authors.forename: Xian-Yan
authors.initials: XY
authors.lastname: Zhao
authors.forename: Hua-Lei
authors.initials: HL
authors.lastname: Zhang
authors.forename: Huai-Rui
authors.initials: HR
authors.lastname: Shu
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Hao
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods; D003116:Color; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D003624:Darkness; D004789:Enzyme Activation; D057075:Enzyme Assays; D005638:Fruit / Q000201:enzymology*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D047468:Immunoprecipitation; D027845:Malus / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D010858:Pigmentation; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D055550:Protein Stability; D059748:Proteolysis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D000872:Anthocyanins; D018076:DNA, Complementary; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease