Location: Sugarbeet and Bean ResearchTitle: The beet Y locus encodes an anthocyanin-MYB-like protein that activates the betalain red pigment pathway Author
|Hatlestad, Greg - University Of Texas|
|Akhavan, Neda - University Of Texas|
|Sunnadeniva, Rasika - University Of Texas|
|Elam, Lee - University Of Texas|
|Cargyle, Scott - University Of Texas|
|Hembd, Austin - University Of Texas|
|Gonzalez, Antonio - University Of Texas|
|Mcgrath, J Mitchell - Mitch|
|Lloyd, Alan - University Of Texas|
Submitted to: Nature Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2014
Publication Date: 1/1/2015
Citation: Hatlestad, G., Akhavan, N., Sunnadeniva, R., Elam, L., Cargyle, S., Hembd, A., Gonzalez, A., McGrath, J.M., Lloyd, A. 2015. The beet Y locus encodes an anthocyanin-MYB-like protein that activates the betalain red pigment pathway. Nature Genetics. 47:92-96.
Interpretive Summary: In most plants, red and violet colors are produced from a class of compounds called anthocyanins. In beets and related species, these same colors are produced by a different set of compounds, the betalains, whose structure is quite different from anthocyanins. This difference has been an enigma for plant biologists since their discovery over a century ago. The structural genes for betalain biosynthesis have been recently described, however their regulation has remained enigmatic. In this report, the regulatory genes are shown to be co-opted from anthocyanin regulatory genes, and suggested to confer similar ranges of expression as anthocyanin genes from other plants. With this information, plant biologist can better explain and characterize the colorful diversity of plants on earth.
Technical Abstract: Almost all flowering plants produce red/violet, phenylalanine-based, anthocyanin pigments. A single order, the Caryophyllales, contains families that replace anthocyanins with tyrosine-based red and yellow betalain pigments. Close biological correlation of pigmentation patterns suggested that betalains were regulated by the conserved, anthocyanin, WD-bHLH-MYB complex. A novel, co-opted, anthocyanin-like, beet MYB is identified, that positively regulates the betalain biosynthetic pathway. Silencing the beet MYB downregulates and overexpression upregulates betalain biosynthetic genes and pigmentation, and truncated beet MYB acts as a dominant repressor. This MYB is identified as the betalain Y locus identified more than 75 years ago. Co-opting an anthocyanin regulator would result in betalain expression in the same developmental and environmentally induced patterns as anthocyanins, an important evolutionary event allowing betalains to replace anthocyanins.