These authors contributed equally to this study.
Expression of the sweetpotato R2R3-type IbMYB1a gene induces anthocyanin accumulation in Arabidopsis
Article first published online: 6 NOV 2012
Copyright © Physiologia Plantarum 2012
Volume 148, Issue 2, pages 189–199, June 2013
How to Cite
Chu, H., Jeong, J. C., Kim, W.-J., Chung, D. M., Jeon, H. K., Ahn, Y. O., Kim, S. H., Lee, H.-S., Kwak, S.-S. and Kim, C. Y. (2013), Expression of the sweetpotato R2R3-type IbMYB1a gene induces anthocyanin accumulation in Arabidopsis. Physiologia Plantarum, 148: 189–199. doi: 10.1111/j.1399-3054.2012.01706.x
- Issue published online: 11 MAY 2013
- Article first published online: 6 NOV 2012
- Accepted manuscript online: 5 OCT 2012 10:55AM EST
- Manuscript Accepted: 12 SEP 2012
- Manuscript Revised: 4 JUL 2012
- Manuscript Received: 25 APR 2012
- National Research Foundation of Korea
- Next-Generation BioGreen 21 Program. Grant Number: PJ008126
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.