| Title: | Differentiation of persistent anatomical defensive structures is costly and determined by nutrient availability and genetic growth-defence constraints |
| Author(s): | Moreira X; Zas R; Solla A; Sampedro L; |
| Address: | "Institute of Biology, Laboratory of Evolutive Entomology, University of Neuchatel, Rue Emile-Argand 11, 2000 Neuchatel, Switzerland xmoreira1@gmail.com. Mision Biologica de Galicia (MBG-CSIC), Apdo 28, 36080 Pontevedra, Galicia, Spain. Ingenieria Forestal y del Medio Natural, Universidad de Extremadura, Avenida Virgen del Puerto 2, 10600 Plasencia, Spain" |
| ISSN/ISBN: | 1758-4469 (Electronic) 0829-318X (Linking) |
| Abstract: | "Conifers exhibit a number of chemical and anatomical mechanisms to defend against pests and pathogens. Theory predicts an increased investment in plant defences under limited nutrient availability, but while this has been demonstrated for chemical defences, it has rarely been shown for anatomical defensive structures. In a long-lived woody plant, we tested the hypothesis that limited nutrient availability may promote an improved differentiation of persistent anatomical defences. We also hypothesized that the costs of differentiation of those long-term anatomical structures may be determined by genetic constraints on early growth potential. Using Pinus pinaster Ait. juveniles, we performed a greenhouse study with 15 half-sib families subjected to experimental manipulation of phosphorus (P) availability and herbivory-related induced responses. When plants were approximately 30 cm high, half of the plant material was treated with methyl jasmonate to induce defences, and 2 weeks later plants were harvested and the abundance of resin canals in the cortex and xylem was assessed. Density of constitutive resin canals in the cortex and the total canal system was approximately 1.5-fold higher in plants under limited P availability than in fully fertilized plants. Availability of P did not significantly influence the inducibility of resin canal traits. We found negative genetic correlations between plant growth and the density of constitutive canals in the xylem and total canal system, but only under conditions of limited nutrition. These results demonstrate for the first time that differentiation of constitutive anatomical-based defences is affected by P limitation. Moreover, results also evidence the existence of genetic constraints between plant growth and constitutive defensive investment, where lineages with the highest growth potential showed the lowest investment in constitutive resin canals" |
| Keywords: | "*Adaptation, Physiological Fertilizers Herbivory Phosphorus/*metabolism Pinus/anatomy & histology/genetics/*physiology *Plant Diseases *Resins, Plant Seedlings *Stress, Physiological Xylem/*anatomy & histology Pinus pinaster growth-defence trade-offs grow;" |
| Notes: | "MedlineMoreira, Xoaquin Zas, Rafael Solla, Alejandro Sampedro, Luis eng Research Support, Non-U.S. Gov't Canada 2015/01/18 Tree Physiol. 2015 Feb; 35(2):112-23. doi: 10.1093/treephys/tpu106. Epub 2015 Jan 15" |
