Abstract Detail

Comparative Genomics/Transcriptomics

Hernandez, Adriana [1], Landis, Jacob [2], Tribble, Carrie [3], Eifler, Evan [4], Givnish, Thomas [5], Strickler, Susan [6], Specht, Chelsea [7].

Comparative transcriptomics provides insights into the genetic mechanisms regulating functional floral traits across Calochortus (Liliaceae).

Floral traits such as flower size, shape, and scent, as well as petal color, patterning, and hairiness are implicated in pollination biology, providing cues for pollinator attraction or mechanisms for effective pollen transfer. Particular traits such as trichomes on petals can also help regulate abiotic stress, as these epidermal outgrowths provide protection from herbivory, disease, and temperature stress, indicating a complex relationship among floral traits, abiotic factors, and inter-organismal interactions. To understand the evolutionary processes and the genetic mechanisms that drive adaptive morphologies, we investigate the genetic regulatory mechanisms that give rise to the wide diversity of floral traits across the genus Calochortus. The highly charismatic genus Calochortus is an excellent model to investigate the genetic mechanisms underlying developmental evolution due to the high diversity of suites of traits or ‘floral syndromes’. The four floral syndromes are characterized by variation in trichome densities and placement on petals, diversity of flower size, a wide spectrum of floral pigments, and variation in floral posture (i.e., erect v nodding flowers). A three-pronged comparative transcriptomic approach using RNA-Sequencing data is employed to identify candidate regulatory genes expressed in floral tissue: 1) comparing expression patterns across three species at three developmental times points using a high quality reference transcriptome, 2) comparing expression patterns within each of three species across three developmental stages using species -specific transcriptomes, and 3) identifying ortho groups across six species and looking for signatures of selection on the coding regions of candidate genes identified from expression analyses. We can determine if the key players regulating the development of trichomes, flower size, and pigmentation in model species have been recruited across floral syndromes and examine if key genes are similarly expressed during the same developmental stage across syndromes. If expression of candidate genes does not change across floral syndromes we can determine if there are structural changes in the genes associated with different phenotypes.

1 - Cornell University, School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Ithaca, NY, 14853, United States
2 - Cornell University
3 - University Of Hawaii At Manoa, Department Of Biology, 2538 McCarthy Mall, Edmondson Hall 216, Honolulu, HI, 96822, United States
4 - UW Madison, Botany, 430 Lincoln Dr., Madison, WI, 53706, United States
5 - University Of Wisconsin-Madison, Department Of Botany, 315 Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, United States
6 - Boyce Thompson Institute For Plant Research , 533 Tower Road, Ithaca, NY, 14853, United States
7 - Cornell University, Plant Biology, Plant Science, 236 Tower Road, Ithaca, NY, 14851, United States

Keywords:
RNA-Seq
Floral traits
trichomes
comparative transcriptomics
gene expression.

Presentation Type: Oral Paper
Number: CGT1002
Abstract ID:319
Candidate for Awards:Margaret Menzel Award