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Differential gene expression associated with a floral scent polymorphism in the evening primrose Oenothera harringtonii (Onagraceae)

Differential gene expression associated with a floral scent polymorphism in the evening primrose Oenothera harringtonii (Onagraceae)

Authors :
Matthew G. Johnson
Tania Jogesh
Robert A. Raguso
Krissa A. Skogen
Lindsey L. Bechen
Norman J. Wickett
Rick P. Overson
Rachel A. Levin
Jeremie B. Fant
Geoffrey T. Broadhead
Publication Year :
2021
Publisher :
Cold Spring Harbor Laboratory, 2021.

Abstract

BackgroundPlant volatiles play an important role in both plant-pollinator and plant-herbivore interactions. Intraspecific polymorphisms in volatile production are ubiquitous, but studies that explore underlying differential gene expression are rare. Oenothera harringtonii populations are polymorphic in floral emission of the monoterpene (R)-(-)-linalool; some plants emit (R)-(-)-linalool (linalool+ plants) while others do not (linalool-plants). However, the genes associated with differential production of this floral volatile in Oenothera are unknown. We used RNA-Seq to broadly characterize differential gene expression involved in (R)-(-)-linalool biosynthesis. To identify genes that may be associated with the polymorphism for this trait, we used RNA-Seq to compare gene expression in six different Oenothera harringtonii tissues from each of three linalool+ and linalool-plants.ResultsThree clusters of differentially expressed genes were enriched for terpene synthase activity: two were characterized by tissue-specific upregulation and one by upregulation only in plants with flowers that produce (R)-(-)-linalool. A molecular phylogeny of all terpene synthases identified two putative (R)-(-)-linalool synthase transcripts in Oenothera harringtonii, a single allele of which is found exclusively in linalool+ plants.ConclusionsBy using a naturally occurring polymorphism and comparing different tissues, we were able to identify genes putatively involved in the biosynthesis of (R)-(-)-linalool. Expression of these genes in linalool-plants suggests a regulatory polymorphism, rather than a population-specific loss-of-function allele. Additional terpene biosynthesis-related genes that are up-regulated in plants that emit (R)-(-)-linalool may be associated with herbivore defense, suggesting a potential economy of scale between plant reproduction and defense.

Details

Database :
OpenAIRE
Accession number :
edsair.doi...........fb723dce3142460d76c1c638c31bdd16
Full Text :
https://doi.org/10.1101/2021.01.12.426409