Abstract Detail

Hybrids and Hybridization

Jensen, Laynie [1], Landis, Jacob [2], Otto, Garrett [3], McCarthy, Elizabeth [4].

Simulating evolution of flower color in Nicotiana.

Allopolyploidy, the presence of more than two genomes through whole genome duplication and hybridization, can be a driving factor of evolution in plants. In Nicotiana accessions, some of which exhibit allopolyploidy, the flavonoid biosynthetic pathway produces multiple anthocyanins and flavonols, which results in light pink, dark pink, or white flowers. We would like to understand how different floral colors have evolved across Nicotiana accessions. Wheeler and Smith (2019) developed a computational model to simulate the evolution of the flavonoid biosynthetic pathway to reach a specified pigment concentration optimum. In this model, mutations are introduced in three parameters which influence pigment production: the catalytic constant, which determines the rate of the reaction; the binding affinity, which determines how well an enzyme binds to the substrate; and the concentration of an enzyme, which influences the amount of substrate converted. One iteration of the simulation randomly introduces a single mutation in one of the three parameters into the pathway. Multiple iterations are performed until the user-defined pigment optimum is reached. The model is run 10,000 times, resulting in multiple evolutionary scenarios with the mutations required to produce a particular floral color. We have modified Wheeler and Smith’s (2019) model to address our questions. Our goals are to use previously collected pigment data from allopolyploid Nicotiana accessions and their diploid progenitors to define an optimum to determine which combinations of mutations result in a particular color. We will then compare the simulated enzyme concentration outputs of the model to previously obtained transcriptome data of structural genes from the pathway from these accessions to determine if there are similarities between simulated and empirical data. Additionally, we will simulate the evolution of floral color shifts by using the generated output parameters for one species, for example a white flower, as the initial parameters in the model and a pigment optimum based on another species, for example a pink flower, to determine the mutations necessary to shift flower color from white to pink.

1 - SUNY Cortland, Department of Biological Sciences, P.O. Box 2000, Cortland, 13045, USA
2 - Cornell University, Plant Biology and the L.H. Bailey Hortorium, School of Integrative Plant Science, 506 Mann Library Building, Ithaca, NY, 14850, USA
3 - SUNY Cortland, Department of Mathematics, P.O. Box 2000, Cortland, 13045, USA
4 - SUNY Cortland, Department Of Biological Sciences, P.O. Box 2000, Cortland, NY, 13045, United States

Keywords:
allopolyploidy
anthocyanin
evolution
Flower color
modelling
Nicotiana.

Presentation Type: Poster
Session: P, Hybrids and Hybridization Posters
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 5:00 PM Time and date to be determined
Number: PHH004
Abstract ID:485
Candidate for Awards:None