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Coselected genes determine adaptive variation in herbivore resistance throughout the native range of Arabidopsis thaliana.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2015 Mar 31; Vol. 112 (13), pp. 4032-7. Date of Electronic Publication: 2015 Mar 16. - Publication Year :
- 2015
-
Abstract
- The "mustard oil bomb" is a major defense mechanism in the Brassicaceae, which includes crops such as canola and the model plant Arabidopsis thaliana. These plants produce and store blends of amino acid-derived secondary metabolites called glucosinolates. Upon tissue rupture by natural enemies, the myrosinase enzyme hydrolyses glucosinolates, releasing defense molecules. Brassicaceae display extensive variation in the mixture of glucosinolates that they produce. To investigate the genetics underlying natural variation in glucosinolate profiles, we conducted a large genome-wide association study of 22 methionine-derived glucosinolates using A. thaliana accessions from across Europe. We found that 36% of among accession variation in overall glucosinolate profile was explained by genetic differentiation at only three known loci from the glucosinolate pathway. Glucosinolate-related SNPs were up to 490-fold enriched in the extreme tail of the genome-wide [Formula: see text] scan, indicating strong selection on loci controlling this pathway. Glucosinolate profiles displayed a striking longitudinal gradient with alkenyl and hydroxyalkenyl glucosinolates enriched in the West. We detected a significant contribution of glucosinolate loci toward general herbivore resistance and lifetime fitness in common garden experiments conducted in France, where accessions are enriched in hydroxyalkenyls. In addition to demonstrating the adaptive value of glucosinolate profile variation, we also detected long-distance linkage disequilibrium at two underlying loci, GS-OH and GS-ELONG. Locally cooccurring alleles at these loci display epistatic effects on herbivore resistance and fitness in ecologically realistic conditions. Together, our results suggest that natural selection has favored a locally adaptive configuration of physically unlinked loci in Western Europe.
- Subjects :
- Alleles
Animals
Arabidopsis genetics
Biodiversity
Chromatography, Liquid
Epistasis, Genetic
Evolution, Molecular
Genomics
Genotype
Geography
Insecta
Linkage Disequilibrium
Methionine chemistry
Polymorphism, Single Nucleotide
Principal Component Analysis
Quantitative Trait Loci
Tandem Mass Spectrometry
Arabidopsis chemistry
Glucosinolates chemistry
Herbivory
Selection, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 112
- Issue :
- 13
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 25775585
- Full Text :
- https://doi.org/10.1073/pnas.1421416112