title: Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?
abstract: The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but also the entire metabolome. Metabolomes are the final products of genotypes and are constrained by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from three closely related Pinus species with distant coevolutionary histories with the caterpillar of the processionary moth respond similarly to its attack. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of terpenes were in the attacked trees supporting the hypothesis that herbivores avoid plant individuals with higher concentrations. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.
authors.affiliation: Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Richland Washington 99354 USA; CREAF Cerdanyola del Vallès 08913 Catalonia Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Rivas-Ubach
authors.affiliation: Grupo de Ecología Terrestre Departamento de Biología Animal y Ecología Facultad de Ciencias Universidad de Granada 18071 Granada Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Hódar
authors.affiliation: CREAF Cerdanyola del Vallès 08913 Catalonia Spain; CSIC Global Ecology Unit CREAF-CEAB-CSIC-UAB Cerdanyola del Vallès 08913 Catalonia Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Sardans
authors.affiliation: Biological Sciences Division Pacific Northwest National Laboratory Richland Washington 99354 USA.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Kyle
authors.affiliation: Biological Sciences Division Pacific Northwest National Laboratory Richland Washington 99354 USA.
authors.forename: Young-Mo
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Global Change Research Centre Academy of Sciences of the Czech Republic Bĕlidla 4a CZ-603 00 Brno Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Oravec
authors.affiliation: Global Change Research Centre Academy of Sciences of the Czech Republic Bĕlidla 4a CZ-603 00 Brno Czech Republic.
authors.forename: Otmar
authors.initials: O
authors.lastname: Urban
authors.affiliation: Department of Earth System Science University of California Irvine California 92697 USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Guenther
authors.affiliation: CREAF Cerdanyola del Vallès 08913 Catalonia Spain; CSIC Global Ecology Unit CREAF-CEAB-CSIC-UAB Cerdanyola del Vallès 08913 Catalonia Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Peñuelas
keywords: Folivory; Pinus; macroevolutionary history; plant–insect coevolution; processionary moth