Abstract Detail

Molecular Ecology

Garrett, Patrick [1], Moore, Rich [2].

The tempo of floral gene expression in Canella winterana, a synchronously dichogamous species.

Synchronous dichogamy (SD) evolved as an adaptation to promote outcrossing in plants bearing multiple hermaphroditic flowers that have the potential for geitonogamous self-pollination. SD causes synchronized sexual expression between all flowers borne on an individual plant, which prevents geitonogamous pollen transfer. Although SD is taxonomically widespread there is little known about how SD affects the genetic structure of populations and even less known about what genetic mechanisms regulate such a strict schedule of sexual expression in plants. This study seeks to elucidate how gene expression patterns differ as a result of SD. We are using Canella winterana as a model to study SD because this plant exhibits a highly conserved 3-phased schedule of synchronized sexual expression. At phase one of this cycle all sexually mature flowers open expressing pistillate function, which persists for 12-24 hours. Phase two marks a transition phase where flowers are neutered, expressing neither sexual function. The amount of time phase 2 lasts is highly variable, lasting anywhere from an hour to no longer than a full day. At phase three flowers exhibit staminate function, which persists for another 12-48 hours. The induction of female and male sexual expression of this cycle are synchronized between all blooming flowers within a plant. To determine if there are differences in gene expression patterns that are correlated with sexual expression in Canella, RNAseq was performed on flowers collected at each phase of sexual expression. RNA transcripts were sequenced using the Illumina Hi-Seq 2500 platform and separate libraries for each phase of sexual expression were created and Trinity was used to find patterns of differential gene expression. Differences in gene expression will be assessed between pistillate and staminate sexual expression, with a particular emphasis on how the tempo of gene expression associated with each sex changes over time. However the most interesting patterns we hope to explore are expression differences during the neutered transition phase between pistillate and staminate sexual expression. For instance, pistillate genes could be suppressed in the neutered phase or staminate gene expression could increase. As such we hope to find candidate genes for what causes synchronicity between all flowers within a plant and the genes responsible for the overall sexual expression patterns we have observed. This study sheds light on the genetic mechanisms associated with SD in Canella winterana and we hope that this will provide insight into how SD functions in other systems.

1 - Miami University, Biology, 700 East High Street, Oxford, OH, 45056, United States
2 - Miami University, Biology, 316 Pearson, Oxford, OH, 45056, United States

Keywords:
synchronous dichogamy
Differential Expression Analysis
RNAseq.

Presentation Type: Poster
Session: P, Molecular Ecology
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PME005
Abstract ID:986
Candidate for Awards:None