| Abstract Detail
Development and Structure Nedblake, Haylee [1], Wessinger, Carolyn [2], Hileman, Lena [3]. Evolution of floral pigment intensity 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 floral 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). We plan to use an RNA-seq based approach to further examine the anthocyanin biosynthesis pathway and to determine whether cis- versus trans- regulatory effects are responsible for the gene expression changes we have previously determined.
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1 - University of Kansas, Ecology & Evolutionary Biology, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
2 - University Of South Carolina, Biological Sciences, 715 Sumter St, Columbia, SC, 29208, United States
3 - University of Kansas, Ecology & Evolutionary Biology, 1200 Sunnyside Ave, Lawrence, KS, 66045, USA
Keywords:
Penstemon
anthocyanin
F3'5'H
CHI
floral evolution
flower color.
Presentation Type: Poster
Session: P1, Development and Structure Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1DS004
Abstract ID:371
Candidate for Awards:Developmental and Structural Section best poster,Phytochemical Best Poster Award,Developmental and Structural Section Graduate Student Registration Award |
