title: Expression of the sweetpotato R2R3-type IbMYB1a gene induces anthocyanin accumulation in Arabidopsis.
abstract: R2R3-type MYB transcription factors (TFs) play important roles in transcriptional regulation of anthocyanins. The R2R3-type IbMYB1 is known to be a key regulator of anthocyanin biosynthesis in the storage roots of sweetpotato. We previously showed that transient expression of IbMYB1a led to anthocyanin pigmentation in tobacco leaves. In this article, we generated transgenic Arabidopsis plants expressing the IbMYB1a gene under the control of CaMV 35S promoter, and the sweetpotato SPO and SWPA2 promoters. Overexpression of IbMYBa in transgenic Arabidopsis produced strong anthocyanin pigmentation in seedlings and generated a deep purple color in leaves, stems and seeds. Reverse transcription-polymerase chain reaction analysis showed that IbMYB1a expression induced upregulation of several structural genes in the anthocyanin biosynthetic pathway, including 4CL, CHI, F3'H, DFR, AGT, AAT and GST. Furthermore, overexpression of IbMYB1a led to enhanced expression of the AtTT8 (bHLH) and PAP1/AtMYB75 genes. high-performance liquid chromatography analysis revealed that IbMYB1a expression led to the production of cyanidin as a major core molecule of anthocyanidins in Arabidopsis, as occurs in the purple leaves of sweetpotato (cv. Sinzami). This result shows that the IbMYB1a TF is sufficient to induce anthocyanin accumulation in seedlings, leaves, stems and seeds of Arabidopsis plants.
authors.affiliation: Infection Control Material Research Center, Bio-materials Research Institute, Korea Research Institute of Bioscience and Biotechnology- KRIBB, Jeongeup 580-185, Republic of Korea.
authors.forename: Hyosub
authors.initials: H
authors.lastname: Chu
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Jeong
authors.forename: Wook-Jin
authors.initials: WJ
authors.lastname: Kim
authors.forename: Dong Min
authors.initials: DM
authors.lastname: Chung
authors.forename: Hyo Kon
authors.initials: HK
authors.lastname: Jeon
authors.forename: Young Ock
authors.initials: YO
authors.lastname: Ahn
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Kim
authors.forename: Haeng-Soon
authors.initials: HS
authors.lastname: Lee
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
authors.forename: Cha Young
authors.initials: CY
authors.lastname: Kim
mesh_terms: D000872:Anthocyanins / Q000032:analysis / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D027723:Ipomoea batatas / Q000235:genetics*; D009928:Organ Specificity; D000073718:Pancreatitis-Associated Proteins; D010641:Phenotype; D010858:Pigmentation; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000872:Anthocyanins; D000073718:Pancreatitis-Associated Proteins; D010940:Plant Proteins; C000612141:REG3A protein, human; D014157:Transcription Factors; C017154:cyanidin