Format: ORAL

Samuel F. Brockington

Department of Plant Science, University of Cambridge

The evolution of betalains within the order Caryophyllales, was a singular evolutionary event, both in the evolution of a completely new biosynthetic pathway to make pigments, but also in its replacement of the anthocyanin pathway. It has had profound implications for the ecology and evolution of Caryophyllales, from the evolution of floral colour to the structural arrangment of the genomes.In talk I will outline how our knowledge of the evolutionary fate of the betalain pathway and anthocyanin pathways in Caryophyllales has been transformed, through transcriptomic and genomic resources, coupled with synthetic biology approaches. I will address the role of modulation of the interface between primary and secondary metabolism, the prevailing importance of gene duplications, and the evidence for convergent origins of betalain pigmentation and iterative loss of anthocyanins. I will explore how flavonoid pathways have more generally changed in the context of a shift to betalain pigmentation, and discuss the impact of this on the variety of floral colour hues within Caryophyllales. Given the increasingly strong support for convergent evolution of betalains, I will revisit hypotheses for the evolution of betalains, and consider new and emerging evidence for their functions in the context of floral adaptation, and the unique adaptational advantages they offer with respect to flower-pollinator interactions.