Review: The evolution of betalain biosynthesis in Caryophyllales (New Phytol)
In the flowering plant order Caryophyllales (which includes beets), betalains substitute for anthocyanins, which are the most common form of pigmentation across the land plant phylogeny. Also found in the Basidiomycota fungal lineage, betalains are tyrosine-derived pigments that comprise of two groups of compounds, betaxanthins (yellow) and betacyanins (violet). Anthocyanins have never been detected within betalain-producing species and as such, the evolution of betalains has received much research. Here, Timoneda et al. discuss the evolution of betalain biosynthetic pathways in Caryophyllales. Further, the authors consider the impact of phylogenetics for informing our understanding of the evolutionary history of fundamental enzyme-coding genes. The review concludes by proposing a model for the evolution of betalain pigmentation (Summary by Alex Bowles) New Phytologist 10.1111/nph.15980.