title: The red sport of 'Zaosu' pear and its red-striped pigmentation pattern are associated with demethylation of the PyMYB10 promoter.
abstract: 'Zaosu' pear, a hybrid of Pyrus pyrifolia and Pyrus communis, is a popular cultivar developed in China. 'Zaosu Red' is a bud sport of 'Zaosu' with red shoots, young leaves, and fruit. After grafting of 'Zaosu Red', reverse mutations in some branches lead to a loss of colour in leaves and stems. Also, the mature fruit of 'Zaosu Red' exhibits two phenotypes; fully red and striped. The aim of this study was to establish the mechanism of the red colour mutation in 'Zaosu' and the striped pigmentation pattern in fruit of 'Zaosu Red'. The accumulation of anthocyanins and transcript levels of the genes PpUFGT2 and PyMYB10 were highly correlated. The open reading frames (ORF) and promoter regions of these two key genes were cloned and compared between 'Zaosu' and its bud sports, but no sequence differences were found. The R2R3 MYB, PyMYB10, can activate expression of genes encoding enzymes of the anthocyanin biosynthetic pathway. A yeast one-hybrid assay showed that PyMYB10 was associated with the -658 to -172bp fragment of the PpUFGT2 promoter, probably via a MYB binding site (MBS) located at -466bp. The PyMYB10 promoter had lower methylation levels in anthocyanin-rich tissues, indicating that the red bud sport of 'Zaosu' pear and the striped pigmentation pattern of 'Zaosu Red' pear are associated with demethylation of the PyMYB10 promoter.
authors.affiliation: Department of Horticulture, The State Agricultural Ministry Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou 310058, Zhejiang Province, China.
authors.forename: Minjie
authors.initials: M
authors.lastname: Qian
authors.affiliation: Department of Horticulture, The State Agricultural Ministry Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou 310058, Zhejiang Province, China.
authors.forename: Yongwang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Plant and Food Research, Mount Albert Research Centre, Auckland 1142, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1020, New Zealand.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Allan
authors.affiliation: Department of Horticulture, The State Agricultural Ministry Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou 310058, Zhejiang Province, China. Electronic address: ywteng@zju.edu.cn.
authors.forename: Yuanwen
authors.initials: Y
authors.lastname: Teng
authors.affiliation: Department of Horticulture, The State Agricultural Ministry Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Zhejiang University, Hangzhou 310058, Zhejiang Province, China; College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi Province, China. Electronic address: afant@nwsuaf.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000872:Anthocyanins / Q000032:analysis* / Q000378:metabolism; D002681:China; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D015394:Molecular Structure; D009154:Mutation; D010858:Pigmentation / Q000235:genetics*; D018515:Plant Leaves / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D031989:Pyrus / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000872:Anthocyanins; D018744:DNA, Plant; D014157:Transcription Factors
keywords: Anthocyanin; DNA demethylation; Pear; Pyrus hybrid; Red skin mutation; Rosaceae; Striped pattern