title: Novel R2R3-MYB transcription factors from Prunus americana regulate differential patterns of anthocyanin accumulation in tobacco and citrus.
abstract: The level of anthocyanins in plants vary widely among cultivars, developmental stages and environmental stimuli. Previous studies have reported that the expression of various MYBs regulate anthocyanin pigmentation during growth and development. Here we examine the activity of 3 novel R2R3-MYB transcription factor (TF) genes, PamMybA.1, PamMybA.3 and PamMybA.5 from Prunus americana. The anthocyanin accumulation patterns mediated by CaMV double35S promoter (db35Sp) controlled expression of the TFs in transgenic tobacco were compared with citrus-MoroMybA, Arabidopsis-AtMybA1 and grapevine-VvMybA1 transgenics during their entire growth cycles. The db35Sp-PamMybA.1 and db35Sp-PamMybA.5 constructs induced high levels of anthocyanin accumulation in both transformed tobacco calli and the regenerated plants. The red/purple color pigmentation induced in the PamMybA.1 and PamMybA.5 lines was not uniformly distributed, but appeared as patches in the leaves, whereas the flowers showed intense uniform pigmentation similar to the VvMybA1 expressing lines. MoroMybA and AtMybA1 showed more uniform pink coloration in both vegetative and reproductive tissues. Plant morphology, anthocyanin content, seed viability, and transgene inheritance were examined for the PamMybA.5 transgenic plants and compared with the controls. We conclude that these TFs alone are sufficient for activating anthocyanin production in plants and may be used as visible reporter genes for plant transformation. Evaluating these TFs in a heterologous crop species such as citrus further validated that these genes can be useful for the metabolic engineering of anthocyanin production and cultivar enhancement.
authors.affiliation: a Department of Plant Sciences , UC Davis , Davis , CA , USA.|b Crop Improvement and Genetics Research Unit , Western Regional Research Center, USDA-ARS , Albany , CA , USA.
authors.forename: Kasturi
authors.initials: K
authors.lastname: Dasgupta
authors.affiliation: b Crop Improvement and Genetics Research Unit , Western Regional Research Center, USDA-ARS , Albany , CA , USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Thilmony
authors.affiliation: c USDA-ARS Subtropical Insects and Horticulture Research Unit , Fort Pierce , FL , USA.
authors.forename: Ed
authors.initials: E
authors.lastname: Stover
authors.affiliation: c USDA-ARS Subtropical Insects and Horticulture Research Unit , Fort Pierce , FL , USA.
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Oliveira
authors.affiliation: b Crop Improvement and Genetics Research Unit , Western Regional Research Center, USDA-ARS , Albany , CA , USA.
authors.forename: James
authors.initials: J
authors.lastname: Thomson
mesh_terms: D000872:Anthocyanins / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics*; D002957:Citrus / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D010858:Pigmentation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D027861:Prunus / Q000235:genetics*; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D019076:Transgenes; D027843:Vitis / Q000235:genetics*
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D014157:Transcription Factors
keywords: Anthocyanin; CaMV double35S promoter; R2-R3 MYB transcription factor; citrus; tobacco; transgenic plants