Evolutionary history of Colobanthus quitensis and its associated micro-organisms

Lead Research Organisation: British Antarctic Survey
Department Name: Science Programmes

Abstract

The main goals of this proposal are to assess the evolutionary history of Colobanthus quitensis in Antarctica and southern South America by evaluating: (i) how its genetic diversity is distributed within and among populations, (ii) how historical processes have influenced the contemporary distribution of C. quitensis across its southern range of distribution, and (iii) whether geographical patterns of genetic variation are consistent with the diversity of microflora and their symbiotic effects. These predictions will be tested using experimental approaches as well as population genetic and phylogeographic analyses. This research proposal will shed fundamental new light on the evolutionary history of the flora between South America and the Antarctica.

Planned Impact

UK outreach activities in collaboration with Chilean team: The Antarctic is a charismatic region of significant interest to many in civil society, including the media, the general public and schools. The Antarctic Peninsula is particularly iconic and receives much media, public and policymaker attention because of collapse of ice shelves, accelerated discharge of glaciers, apparent increase in vegetation, shifting penguin species distributions and other environmental changes. We will establish a project web page on the BAS website (www.antarctica.ac.uk, c. 5000 hits per day), which will include a readily accessible version of the project activities and rationale and results as they emerge through the project, as well as a field and project blog for people to follow on-line. Excellence in communication is an integral part of BAS's science strategy, and also a proven element of the project Investigators' records. For schools we will trial a link with selected local schools for students to follow the course of the research as part of their coursework; this will entail 'meet the scientist' visits or weblinks to these schools throughout the course of the project. We will engage with early career researchers through the UK Polar Network (http://www.polarnetwork.org/) and its international parent body the Association of Polar Early Career Scientists (www.apecs.is); the UK Co-I has well-established links and is a 'mentor' for both groups, while the Chilean investigators are also well linked with their national APECS group. This will involve giving talks at their meetings and participating in web-based communication events. We will also use our established links with the SCAR international science community, for instance through their current and future science programmes and associated websites, to promote the outcomes of the project. We will fully participate in BAS's well-established media, education and public engagement programme to explain our science and its impacts to as wide an audience as possible. We will have access to the specialist skills of the Press, PR & Education teams at BAS and will issue press releases at key points in the research as results are published using the press officers of BAS.
 
Description Population genetic analyses revealed Maritime Antarctic populations of Colobanthus quitensis to consist of two different clusters, occupying the northern and southern maritime Antarctic, likely resulting from two independent dispersal events. Both of these population clusters shared haplotypes with sub-Antarctic South Georgia, suggesting higher connectivity across the Southern Ocean than previously thought. Molecular dating analyses suggested C. quitensis to be a young (<1 Myr) species, with contemporary Antarctic populations likely to have arrived on a recent (late- Pleistocene) timescale.
Exploitation Route The research outcomes may be used by other botanists and microbiologists studying polar environments.
Sectors Environment
 
Title Data from: Multiple late-Pleistocene colonisation events of the Antarctic pearlwort Colobanthus quitensis (Caryophyllaceae) reveal the recent arrival of native Antarctic vascular flora 
Description Aim: Antarctica's remote and extreme terrestrial environments are inhabited by only two species of native vascular plants. We assessed genetic connectivity amongst Antarctic and South American populations of one of these species, Colobanthus quitensis, to determine its origin and age in Antarctica. Location: Maritime Antarctic, sub-Antarctic islands, South America Taxon: Antarctic pearlwort Colobanthus quitensis (Caryophyllaceae) Methods: Four chloroplast markers and one nuclear marker were sequenced from 270 samples from a latitudinal transect spanning 21-68° S. Phylogeographic, population genetic and molecular dating analyses were used to assess the demographic history of C. quitensis and the age of the species in Antarctica. Results: Maritime Antarctic populations consisted of two different haplotype clusters, occupying the northern and southern Maritime Antarctic. Molecular dating analyses suggested C. quitensis to be a young (<1 Myr) species, with contemporary population structure derived since the late-Pleistocene. Main conclusions: The Maritime Antarctic populations likely derived from two independent, late-Pleistocene dispersal events. Both clusters shared haplotypes with sub-Antarctic South Georgia, suggesting higher connectivity across the Southern Ocean than previously thought. The overall findings of multiple colonisation events by a vascular plant species to Antarctica, and the recent timing of these events, are of significance with respect to future colonisations of the Antarctic Peninsula by vascular plants, particularly with predicted increases in ice-free land in this area. This study fills a significant gap in our knowledge of the age of the contemporary Antarctic terrestrial biota. Adding to previous inferences on the other Antarctic vascular plant species (the grass Deschampsia antarctica), we suggest that both angiosperm species are likely to have arrived on a recent (late-Pleistocene) timescale. While most major groups of Antarctic terrestrial biota include examples of much longer-term Antarctic persistence, the vascular flora stands out as the first identified terrestrial group that appears to be of recent origin. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL http://datadryad.org/stash/dataset/doi:10.5061/dryad.qrfj6q5bw
 
Title Plant biology variables under cold stress from published experiments (1975-2019) that include microbial symbionts as an experimental factor. 
Description The data compiles different aspects of plant biology (e.g., anatomy, physiology, fitness and gene-expression) reported in scientific articles that experimentally explored the role of plant microbial symbionts in plant tolerance to chilling (0-15 degrees Celsius) and freezing (<0 degrees Celsius) conditions. Each variable included in the dataset is composed of at least four values, representing the mean of the measured variable with or without a given microbial symbiont and under control or cold conditions in a factorial design. The data were generated for a meta-analysis, and so the level of replication and standard deviation or standard error, plus other relevant information such as plant and microbial species, and source, are also included. The search from which the articles were obtained used ISI-web of Science used ENDOPH* AND COLD and MYCORRHIZA* AND COLD in both title and keyword fields from 1975 to 2019. Funding was provided by Posdoctoral-FONDECYT 3180441, FONDECYT 11140607 and the NERC-CONICYT awards (NE/P003079/1 - PII20150126) 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes