title: PyMYB10 and PyMYB10.1 Interact with bHLH to Enhance Anthocyanin Accumulation in Pears.
abstract: Color is an important agronomic trait of pears, and the anthocyanin content of fruit is immensely significant for pear coloring. In this study, an anthocyanin-activating R2R3-MYB transcription factor gene, PyMYB10.1, was isolated from fruits of red sand pear (Pyrus pyrifolia cv. Aoguan). Alignments of the nucleotide and amino acid sequences suggested that PyMYB10.1 was involved in anthocyanin regulation. Similar to PyMYB10, PyMYB10.1 was predominantly expressed in red tissues, including the skin, leaf and flower, but it was minimally expressed in non-red fruit flesh. The expression of this gene could be induced by light. Dual-luciferase assays indicated that both PyMYB10 and PyMYB10.1 activated the AtDFR promoter. The activation of AtDFR increased to a greater extent when combined with a bHLH co-factor, such as PybHLH, MrbHLH1, MrbHLH2, or AtbHLH2. However, the response of this activation depended on the protein complex formed. PyMYB10-AtbHLH2 activated the AtDFR promoter to a greater extent than other combinations of proteins. PyMYB10-AtbHLH2 also induced the highest anthocyanin accumulation in tobacco transient-expression assays. Moreover, PybHLH interacted with PyMYB10 and PyMYB10.1. These results suggest that both PyMYB10 and PyMYB10.1 are positive anthocyanin biosynthesis regulators in pears that act via the formation of a ternary complex with PybHLH. The functional characterization of PyMYB10 and PyMYB10.1 will aid further understanding of the anthocyanin regulation in pears.
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Shouqian
authors.initials: S
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Xiaoliu
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Shujing
authors.initials: S
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Deyun
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.
authors.forename: Xuesen
authors.initials: X
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D031989:Pyrus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D014157:Transcription Factors