Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Nedblake, Haylee [1], Wessinger, Carolyn [2], Hileman, Lena [3].

Evolution of floral pigments in Penstemon.

Shifts in pollination syndrome provide insight to how adaptive evolution can occur. Penstemon, the largest genus of flowering plants endemic to North America, is an ideal system for studying pollination syndrome evolution. During the diversification of the genus, hummingbird-adapted species have evolved 15 to 20 times independently from bee-adapted ancestors. Shifts in pollination syndrome result in many trait differences between bee-adapted and hummingbird-adapted Penstemon. Notably, bee-pollinated Penstemon flowers are generally blue due to delphinidin pigment production, while hummingbird-pollinated flowers are usually red due to pelargonidin or cyanidin pigment production. In addition, many bee- and hummingbird-adapted species pairs show striking differences in floral pigment intensity. The anthocyanin biosynthesis pathway, responsible for many color-producing flavonoids present in flowers, is well-studied. In fact, evolutionary changes to the anthocyanin pathway gene flavonoid 3’,5’-hydroxylase (F3’5’H) are associated with shifts from delphinidin- to pelargonidin-producing flowers in Penstemon and other flowering plant lineages. However, less is known about the genetic differences that facilitate shifts from flower morphs with low pigment intensity to those with high pigment intensity. In this study, we use an F2 mapping population derived from a cross between P. amphorellae with pale blue flowers and closely related P. kunthii with highly pigmented red flowers, to determine how shifts in both pigment production and color intensity have evolved.  Our results demonstrate that variation at F3’5’H is responsible for the shift from delphinidin to cyanidin pigment production. Our preliminary results point towards down-regulation of F3’5’H in P. kunthii as a possible mechanism. In addition, our preliminary results suggest that overall high pigment intensity in P. kunthii is due to regulatory changes upstream in the anthocyanin pathway, likely through changes at the gene chalcone--flavonone isomerase (CHI).

1 - University of Kansas, Ecology and Evolutionary Biology, 1200 Sunnyside Ave, Lawrence, KS, 66045, USA
2 - University of South Carolina, Biological Sciences, 631 Sumter St, Columbia, SC, 29208, USA
3 - University Of Kansas, Ecology And Evolutionary Biology, 1200 Sunnyside Avenue, Lawrence, KS, 66045, United States

floral pigment

Presentation Type: Poster
Session: P, Evolutionary Developmental Biology (Evo-Devo) Posters
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 5:00 PM Time and date to be determined
Number: PEV007
Abstract ID:290
Candidate for Awards:None

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