Abstract Detail



Molecular Ecology

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

Timing is everything: Gene Expression Shifts with Sex Expression in a Syncrhonously Dichogamous Plant.

Synchronous dichogamy (SD) evolved as an adaptation to promote outcrossing in plants bearing multiple hermaphroditic flowers that have the potential for geitonogamous self-pollination. Dichogamy inhibits self-pollination within individual flowers. However, dichogamy does not reduce geitonogamous pollen transfer between flowers housed on the same plant because pollen transfer occurs between flowers as pollinators exploit floral resources. SD causes synchronized sexual expression between all flowers borne on a singe plant, i.e. all flowers that bloom on a plant will open expressing the same functional sex and then simultaneously switch sexual function at a later time, which functionally makes geitonogamous pollen transfer impossible. Although SD is taxonomically widespread there is little known about how SD functions to affect the reproductive biology of plant populations. Beyond a basic description of the floral biology, there is virtually nothing 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, I collected flowers flowers at each phase of sexual expression, immediately flash froze them using liquid nitrogen and then used a trizol-based RNA extraction kit to extract the total RNA from these flowers. 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. 


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

Keywords:
dichogamy
Gene Expression
RNA-seq.

Presentation Type: Oral Paper
Number: 0009
Abstract ID:978
Candidate for Awards:None


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