Natural Enemies Drive Geographic Variation in Plant Defenses

• Published in: Science (American Association for the Advancement of Science) Vol. 338; no. 6103; pp. 116 - 119
• Main Authors: Züst, Tobias, Heichinger, Christian, Grossniklaus, Ueli, Harrington, Richard, Kliebenstein, Daniel J., Turnbull, Lindsay A.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 05.10.2012; The American Association for the Advancement of Science
• Subjects: Adaptation, Biological - genetics; Agronomy. Soil science and plant productions; Animals; Aphididae; Aphidoidea; Aphids - physiology; Arabidopsis - genetics; Arabidopsis thaliana; Biological and medical sciences; Chemical defense; chemical defenses; Composition effects; Control; Evening; Feeding; Flowering; Fruits; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; Genetic Loci; Genetic resources; Genetic resources, diversity; Genetic variation; Genetics and breeding of economic plants; Genotype & phenotype; Genotypes; Geographical variation; Geography; Glucosinolates; Grants; Herbivores; Herbivory; Herbivory - physiology; Insects; loci; Natural enemies; Oenothera; Pesticides; Phenotypic traits; Phytopathology. Animal pests. Plant and forest protection; Plant material; Plant pathology; Plant populations; Plant resistance; Plants; Polymorphism, Genetic; Protozoa. Invertebrates; Relative abundance; Selection, Genetic; Species Specificity; Taraxacum; toxic substances; Trichomes; Weapons; Aphidoidea; Genetic resource; Insecta; Organism defense; Arabidopsis thaliana; Pest; Homoptera; Lipaphis erysimi; Cruciferae; Arthropoda; Dicotyledones; Brevicoryne brassicae; Insect resistance; Angiospermae; Aphididae; Population; Selection pressure; Spermatophyta; Invertebrata; Experimental plant; Locus; Geographical variation; Polymorphism
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1226397

Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces.