The University of Southampton
University of Southampton Institutional Repository

Adaptation and diversification in the Canary island endemic Descurainia (Brassicaceae)

Adaptation and diversification in the Canary island endemic Descurainia (Brassicaceae)
Adaptation and diversification in the Canary island endemic Descurainia (Brassicaceae)
Oceanic archipelagos provide striking examples of plant lineages that have radiated rapidly over steep ecological gradients, often demonstrating remarkable adaptations. Here, we investigate the evolutionary processes behind the diversification and adaptation of the Canary Island Descurainia (Brassicaceae), an island cousin of Arabidopsis. Canary Island Descurainia is comprised of seven species that have rapidly radiated across islands and along an elevation cline, with several species occupying high-elevation habitats. Genotyping-by-sequencing (GBS) was employed to infer the roles ecology, geographical isolation, and hybridisation have played in the diversification of these seven species. At least three geographical shifts and one ecological shift between high- and low elevation species were identified, as well as a putative hybrid origin for one species. A high-quality reference genome was generated for Descurainia millefolia, with a final size of 180 megabases and an N50 of 290 k. Through comparative phylogenomic, we confirmed the placement of Descurainia within Lineage I of Brassicaceae. Through whole-genome re-sequencing, representing the seven species of Canary Island Descurainia, we compare the low-elevation species and high elevation species to identify candidate genes that may incur adaptation to sub-alpine environments. A Gene Ontology (GO) enrichment analysis on positively selected genes (PSGs) revealed genes associated with changes in flowering times and genes likely related to adaptation to the harsher high-elevation environment (for instance, cold and UV tolerance). We further provided evidence that one of our candidate genes incurs drought tolerance through T-DNA knockouts and a greenhouse water stress experiment. Overall, using Canary Island Descurainia as a model, our analyses have helped to understand the evolutionary processes behind the diversification of island plants, as well as broader questions surrounding adaptation.
University of Southampton
Jackson, Amy Clare
732a7afe-b36d-421f-a6ba-624e4bc801b7
Jackson, Amy Clare
732a7afe-b36d-421f-a6ba-624e4bc801b7
Chapman, Mark
8bac4a92-bfa7-4c3c-af29-9af852ef6383
Carine, Mark A.
eeaed5aa-bc4b-43ec-a667-b6c45e3217ed

Jackson, Amy Clare (2024) Adaptation and diversification in the Canary island endemic Descurainia (Brassicaceae). University of Southampton, Doctoral Thesis, 219pp.

Record type: Thesis (Doctoral)

Abstract

Oceanic archipelagos provide striking examples of plant lineages that have radiated rapidly over steep ecological gradients, often demonstrating remarkable adaptations. Here, we investigate the evolutionary processes behind the diversification and adaptation of the Canary Island Descurainia (Brassicaceae), an island cousin of Arabidopsis. Canary Island Descurainia is comprised of seven species that have rapidly radiated across islands and along an elevation cline, with several species occupying high-elevation habitats. Genotyping-by-sequencing (GBS) was employed to infer the roles ecology, geographical isolation, and hybridisation have played in the diversification of these seven species. At least three geographical shifts and one ecological shift between high- and low elevation species were identified, as well as a putative hybrid origin for one species. A high-quality reference genome was generated for Descurainia millefolia, with a final size of 180 megabases and an N50 of 290 k. Through comparative phylogenomic, we confirmed the placement of Descurainia within Lineage I of Brassicaceae. Through whole-genome re-sequencing, representing the seven species of Canary Island Descurainia, we compare the low-elevation species and high elevation species to identify candidate genes that may incur adaptation to sub-alpine environments. A Gene Ontology (GO) enrichment analysis on positively selected genes (PSGs) revealed genes associated with changes in flowering times and genes likely related to adaptation to the harsher high-elevation environment (for instance, cold and UV tolerance). We further provided evidence that one of our candidate genes incurs drought tolerance through T-DNA knockouts and a greenhouse water stress experiment. Overall, using Canary Island Descurainia as a model, our analyses have helped to understand the evolutionary processes behind the diversification of island plants, as well as broader questions surrounding adaptation.

Text
Amy_Jackson_PhD_thesis_December22_FINAL_v.1_corrections_pdfa - Version of Record
Available under License University of Southampton Thesis Licence.
Download (7MB)
Text
Final-thesis-submission-Examination-Ms-Amy-Jackson
Restricted to Repository staff only

More information

Submitted date: January 2023
Published date: 2024

Identifiers

Local EPrints ID: 486091
URI: http://eprints.soton.ac.uk/id/eprint/486091
PURE UUID: 5e135940-cf00-4412-b397-69a3bec3f279
ORCID for Amy Clare Jackson: ORCID iD orcid.org/0000-0003-0660-0181
ORCID for Mark Chapman: ORCID iD orcid.org/0000-0002-7151-723X

Catalogue record

Date deposited: 09 Jan 2024 17:35
Last modified: 06 Jun 2024 02:04

Export record

Contributors

Thesis advisor: Mark Chapman ORCID iD
Thesis advisor: Mark A. Carine

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×