umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Population differentiation in arthropod community structure and phenotypic association with inducible defense genes in European Aspen (Populus tremula L., salicaceae)
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
Umeå University, Faculty of Science and Technology, Department of Plant Physiology.ORCID iD: 0000-0002-7906-6891
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Plant-herbivore interactions are known to vary across a landscape due to both variation in abiotic and biotic factors. Such spatial variation tends to promoting local adaption of plants to the prevailing herbivore regime. Here we use data from a common garden to look for patterns across populations in the abundance and diversity of herbivorous insects. We also screen for variation in the untargeted metabolome of the foliage of a subset of the same trees. We also search for phenotypic associations between genetic variation in a number of wound-induced genes and phenotypic variation in herbivore abundance, diversity and in metabolomes. We observe significant genetic variation in a number of herbivore-related traits but low correlations between traits. We do observe substantial genetic structure in both herbivore community structure and in metabolic profiles and this structure is aligned with genetic structure we have previously documented for a set of defense genes. We also identify a number of significant associations between SNPs from wound-induced defense genes and a number of the herbivore traits and metabolic profiles. However, these associations are likely not causal, but are rather caused by the underlying population structure we observe. These results highlight to the importance of historical processes and the need to better understand both the current-day geographic distribution of different herbivore species as well as the post-glacial colonization history of both plants and herbivores.

Keyword [en]
adaptation, arthropod community, population structure, association mapping, Populus
National Category
Genetics Evolutionary Biology Ecology
Research subject
evolutionär genetik
Identifiers
URN: urn:nbn:se:umu:diva-54302OAI: oai:DiVA.org:umu-54302DiVA: diva2:517585
Available from: 2012-04-24 Created: 2012-04-24 Last updated: 2015-04-29Bibliographically approved
In thesis
1. Molecular population genetics of inducible defense genes in Populus tremula
Open this publication in new window or tab >>Molecular population genetics of inducible defense genes in Populus tremula
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Plant-herbivore interactions are among the most common of ecological interactions. It is therefore not surprising that plants have evolved multiple mechanisms to defend themselves, using both constitutive chemical and physical barriers and by induced responses which are only expressed after herbivory has occurred. Herbivores, on the other hand, respond to these plant defenses by evolving counter-adaptations which makes defenses less effective or even useless. Adaptation can occur at different geographical scales, with varying coevolutionary interactions across a spatially heterogenous landscape. By looking at the underlying genes responsible for these defensive traits and herbivore related phenotypic traits, it is possible to investigate the coevolutionary history of these plant- herbivore interactions. Here I use molecular population genetic tools to investigate the evolutionary history of several inducible defense genes in European Aspen (Populus tremula) in Sweden. Two genes, belonging to the Polyphenol oxidase gene-family (PPO1 and PPO2), show skews in their site frequency spectrum together with patterns of diversity and divergence from an outgroup which correspond to signatures of adaptive evolution (Paper II). 71 single nucleotide polymorphisms (SNPs) from seven inducible defense genes (PPO1-PPO3, TI2-TI5) show elevated levels of population differentiation compared to control genes (genes not involved in plant defense), and 10 of these defense SNPs show strong signatures of natural selection (Paper III). These 71 defense SNPs also divides a sample of Swedish P. tremula trees into three distinct geographical groups, corresponding to a Southern, Central and Northern cluster, a patterns that is not present in control SNPs (Paper III). The same geographical pattern, with a distinct Northern cluster, is also observed in several phenotypic traits related to herbivory in our common garden in Sävar (Paper IV). These phenotypic traits show patterns of apparent local maladaptation of the herbivore community to the host population which could indicate the presence of “information coevolution” between plants and herbivores (Paper IV). 15 unique defense SNPs also show significant associations to eight phenotypic traits but the causal effects of these SNP associations may be confounded by the geographic structure found in both the underlying genes and in the phenotypic traits. The co-occurrence of population structure in both defense genes and herbivore community traits may be the result from historical events during the post-glacial recolonization of Sweden.

Abstract [sv]

Interaktioner mellan växter och herbivorer är bland de vanligaste ekologiska interaktionerna och det är därför inte förvånande att växter har utvecklat flera olika mekanismer för att försvara sig. Dessa försvarsmekanismer består både av konstitutiva kemiska och fysiska barriärer så väl som inducerade försvar som bara är uttryckta efter att en växt har blivit skadad genom betning. Herbivorerna å sin sida svarar på dessa försvar genom att utveckla motanpassningar som gör växternas försvar mindre effektiva eller till och med verkningslösa. Dessa anpassningar kan ske över olika geografiska skalor beroende på om de samevolutionära interaktionerna varierar i ett rumsligt heterogent landskap. Genom att studera de underliggande gener som kontrollerar dessa försvarsegenskaper tillsammans med herbivorrelaterade fenotypiska egenskaper är det möjligt att undersöka den samevolutionära historien av interaktionerna mellan växter och herbivorer. Här använder jag mig av molekylärpopulationsgenetiska verktyg för att undersöka den evolutionära historien i flera inducerade försvarsgener hos asp (Populus tremula) i Sverige. Två gener, som tillhör genfamiljen Polyphenol-oxidaser (PPO1 och PPO2), uppvisar ett frekvensmönster som man förväntar sig vid positiv selektion. Detta mönster kan också ses i dessa geners diversitet samt i divergens från en utgrupp (Uppsats II). 71 ”single nucleotide polymorphisms” (SNPar) från 7 inducerade försvarsgener (PPO1-PPO3, TI2-TI5) visar förhöjda nivåer av populationsdifferentiering jämfört med kontrollgener (gener som inte är involverade i trädens försvar), och 10 av dessa försvars-SNPar visar även tecken på naturlig selektion (Uppsats III). Dessa 71 försvars-SNPar delar in ett urval av svenska aspar i tre distinkta geografiska grupper som beskriver ett sydligt, centralt och nordligt kluster som inte förekommer hos kontroll-SNPar (Uppsats III). Samma geografiska mönster, med ett distinkt nordligt kluster, återfinns däremot i ett antal fenotypiska egenskaper som är relaterade till herbivori i ett odlingsförsök utanför Sävar (Uppsats IV). Dessa fenotypiska egenskaper visar tecken på lokal felanpassning hos herbivorsamhället till den lokala värdpopulationen, vilket kan indikera förekomsten av ett ”samevolutionärt informationsutbyte” mellan växter och herbivorer (Uppsats IV). 15 unika försvars-SNPar påvisar också signifikanta associationer med 8 olika fenotypiska egenskaper, men om dessa har en verklig effekt eller inte är svårt att säga på grund av den geografiska strukturen som förekommer både hos de underliggande generna och hos de fenotypiska egenskaperna. Att denna populationsstruktur förekommer hos både försvarsgener och egenskaper som är förknippade med herbivorsamhället kan däremot vara ett resultat av historiska händelser som skett under aspens post-glaciala återkolonisation av Sverige.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet, 2012. 34 p.
Keyword
Populus, herbivore defense, adaptation, population genetics, population structure, association mapping, complex traits
National Category
Evolutionary Biology Ecology Genetics
Research subject
evolutionär genetik
Identifiers
urn:nbn:se:umu:diva-54361 (URN)978-91-7459-415-7 (ISBN)
Public defence
2012-05-16, KBC-huset, Stora hörsalen, KB3B1, Umeå Universitet, Umeå, 10:00 (English)
Opponent
Supervisors
Available from: 2012-04-25 Created: 2012-04-24 Last updated: 2015-04-29Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Bernhardsson, CarolinaRobinson, Kathryn M.Abreu, Ilka N.Jansson, StefanIngvarsson, Pär K.Albrectsen, Benedicte R.
By organisation
Department of Ecology and Environmental SciencesDepartment of Plant Physiology
GeneticsEvolutionary BiologyEcology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 105 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf