Behind the Cover: New Phytologist 217:2, January 2018

Beeten to it: the early origins of beetroot red

Millions of years ago, one family of plants — the beets and their cousins — hit upon a brand new pigment and discarded the red used by the rest of the plant world.

In the paper behind the cover of New Phytologist 217:2, Hiroshi Maeda and his colleagues describe an ancient loosening up of a key biochemical pathway that set the stage for the ancestors of beets to develop their characteristic red pigment. By evolving an efficient way to make the amino acid tyrosine, the raw material for the new red, this plant family freed up extra tyrosine for more uses. Later innovations turned the newly abundant tyrosine scarlet.

Image: Red and yellow beets accumulating betalain pigments, which are uniquely found in the plant order Caryophyllales and are made from an amino acid tyrosine. The cross section of beets were photographed by Sarah Friedrich, Media Specialist at the University of Wisconsin in Madison Botany Department.
Red and yellow beets accumulating betalain pigments, which are uniquely found in the plant order Caryophyllales and are made from an amino acid, tyrosine. The cross section of beets was photographed by Sarah Friedrich, Media Specialist at the University of Wisconsin in Madison Botany Department.

“Our study found that betalain-producing Caryophyllales, such as the beets in the image, have a tyrosine-synthesizing enzyme that is not feedback inhibited, and can therefore produce tyrosine efficiently,” explained Hiroshi. “Further biochemical and evolutionary analyses suggest that the elevated supply of tyrosine likely provided a stepping stone towards the evolution of betalain pigmentation in this unique plant lineage.”

Continue reading about this study here.

Read the paper: Lopez-Nieves, S., Yang, Y., Timoneda, A., Wang, M., Feng, T., Smith, S. A., Brockington, S. F. and Maeda, H. A. (2017) Relaxation of tyrosine pathway regulation underlies the evolution of betalain pigmentation in CaryophyllalesNew Phytologist. doi: 10.1111/nph.14822


 

Mike Whitfield (@mgwhitfield)
Development Coordinator
New Phytologist

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