| Title: | Assessing the influence of biogeographical region and phylogenetic history on chemical defences and herbivory in Quercus species |
| Author(s): | Moreira X; Abdala-Roberts L; Galman A; Francisco M; Fuente M; Butron A; Rasmann S; |
| Address: | "Mision Biologica de Galicia (MBG-CSIC), Apartado de correos 28, 36080 Pontevedra, Galicia, Spain. Electronic address: xmoreira1@gmail.com. Departamento de Ecologia Tropical, Campus de Ciencias Biologicas y Agropecuarias, Universidad Autonoma de Yucatan, Apartado Postal 4-116, Itzimna, 97000 Merida, Yucatan, Mexico. Mision Biologica de Galicia (MBG-CSIC), Apartado de correos 28, 36080 Pontevedra, Galicia, Spain. Institute of Biology, Laboratory of Functional Ecology, University of Neuchatel, Rue Emile-Argand 11, 2000 Neuchatel, Switzerland" |
| DOI: | 10.1016/j.phytochem.2018.06.002 |
| ISSN/ISBN: | 1873-3700 (Electronic) 0031-9422 (Linking) |
| Abstract: | "Biogeographical factors and phylogenetic history are key determinants of inter-specific variation in plant defences. However, few studies have conducted broad-scale geographical comparisons of plant defences while controlling for phylogenetic relationships, and, in doing so, none have separated constitutive from induced defences. This gap has limited our understanding of how historical or large-scale processes mediate biogeographical patterns in plant defences since these may be contingent upon shared evolutionary history and phylogenetic constraints. We conducted a phylogenetically-controlled experiment testing for differences in constitutive leaf chemical defences and their inducibility between Palearctic and Nearctic oak species (Quercus, total 18 species). We induced defences in one-year old plants by inflicting damage by gypsy moth larvae (Lymantria dispar), estimated the amount of leaf area consumed, and quantified various groups of phenolic compounds. There was no detectable phylogenetic signal for constitutive or induced levels of most defensive traits except for constitutive condensed tannins, as well as no phylogenetic signal in leaf herbivory. We did, however, find marked differences in defence levels between oak species from each region: Palearctic species had higher levels of constitutive condensed tannins, but less constitutive lignins and less constitutive and induced hydrolysable tannins compared with Nearctic species. Additionally, Palearctic species had lower levels of leaf damage compared with Nearctic species. These differences in leaf damage, lignins and hydrolysable (but not condensed) tannins were lost after accounting for phylogeny, suggesting that geographical structuring of phylogenetic relationships mediated biogeographical differences in defences and herbivore resistance. Together, these findings suggest that historical processes and large-scale drivers have shaped differences in allocation to constitutive defences (and in turn resistance) between Palearctic and Nearctic oaks. Moreover, although evidence of phylogenetic conservatism in the studied traits is rather weak, shared evolutionary history appears to mediate some of these biogeographical patterns in allocation to chemical defences" |
| Keywords: | Phylogeny Quercus/*chemistry/*genetics Species Specificity Biogeography Induced defences Lymantria dispar Nearctic Palearctic Phenolic compounds Quercus; |
| Notes: | "MedlineMoreira, Xoaquin Abdala-Roberts, Luis Galman, Andrea Francisco, Marta Fuente, Maria de la Butron, Ana Rasmann, Sergio eng England 2018/06/11 Phytochemistry. 2018 Sep; 153:64-73. doi: 10.1016/j.phytochem.2018.06.002. Epub 2018 Jun 7" |
