Phenotypic plasticity of maritime pine to insect herbivory

PósterPeer Reviewe

Genetic variation and phenotypic plasticity of nutrient re-allocation and increased fine root production as putative tolerance mechanisms inducible by methyl jasmonate in pine trees

1. Plant plastic responses to herbivore damage may include rapid, active reallocation of plant resources to reduce the impact of herbivory on future plant fitness. However, whether these inducible tolerance responses can be extended to pine trees and how these responses could be modulated by genetic and environmental factors remains unclear.2. Biomass allocation and phosphorus (P) and nitrogen (N) concentrations in above- and belowground tissues were measured in Pinus pinaster juveniles belonging to 33 open-pollinated families grown under two P availabilities (P-deficient and complete fertilization). Measurements were taken 15 days after half of the plants received a foliar spray treatment of 22 mmol L)1 methyl jasmonate (MJ) to simulate above-ground herbivore attack.3. Simulated above-ground herbivory promoted a strong preferential allocation of biomass below ground in the form of fine roots, leading to an almost two-fold increase in fine root biomass in MJ-treated plants and a significant reduction in above-ground tissues and coarse roots. In addition, MJ signalling increased P andN concentrations in the shoots while reducing (P) or maintaining (N) concentrations in the roots. These results suggest that induced resource sequestration is not a generalized strategy in this pine species. Fine root biomass and concentration of N and P in plant tissues showed additive genetic variation, but responses to MJ signalling did not vary among families. Allocation of biomass to fine roots was not affected by P availability, whereas allocation of P to the shoot was more intense under complete fertilization.4. Synthesis: Two new putative tolerance mechanisms inducible by MJ signalling may help to minimize the impact of above-ground herbivore damage on the future fitness of young pine trees by (i) allocation of carbon to fine roots, this appeared to be a generalized strategy with weak environmental modulation and (ii) reallocation of P and N from roots to shoots, which was largely affected by P availability, and thus susceptible to greater phenotypic variation in heterogeneous environments. We provide evidence that changes in tolerance-related traits are rapidly inducible by herbivory cues in this pine species. These results should be integrated with induced resistance responses to fully understand the costs and benefits associated with induced responses to herbivory.This research was supported by the grants AGL2010-18724, RTA07-100, PSE310000. LS and XM received financial support from DOC-INIA and PREDOC-INIA grant programs respectively.INIAPeer Reviewe

Nutritional status and genetic variation in the response to nutrient availability in Pinus pinaster. A multisite field study in NW Spain

The low nutrient availability of the acidic and sandy soils of Galicia (Northwest Spain) is probably the main environmental factor limiting forest primary productivity in the area. These particular edaphic conditions could have imposed selective pressures on maritime pine populations leading to specific local adaptations. We first assessed the nutritional status of 22 young contemporary Pinus pinaster plantations in Northwest Spain, and then analysed the response to fertilization in three family × fertilization trials, and how this response varied across sites and genotypes. Growth of P. pinaster in Northwest Spain appeared to be largely limited by nutrient availability, where most of the plantations showed severe nutrient deficiencies, especially in P and Mg. According to these deficiencies, a strong positive response to nutrient additions was observed in the three trials, with height increments of up to 30% compared with the unfertilized control. However, the response to fertilizers was very variable from site to site, and in some cases did not agree with the foliar nutritional diagnosis. The response to fertilization was also significantly affected by pine genotype, suggesting that the plastic response to nutrient additions within each environment was under genetic control. However, the family response to nutrient availability was not consistent across sites, and no significant differences among families were observed for the RDPI plasticity index – a single index that summarizes the phenotypic change in multiple environments – when analysed across environments. The strong environmental component modulating phenotypic responses to fertilization could impose an important obstacle to evolve specific adaptations to the local edaphic conditions, as well as to artificially select genotypes adapted to different environments and silviculture regimes.This research was funded by the INIA projects RTA05-173 and RTA07-100.Peer reviewe

Genetics, phosphorus availability, and herbivore-derived induction as sources of phenotypic variation of leaf volatile terpenes in a pine species

Oleoresin produced and stored in pine tree leaves provides direct resistance to herbivores, while leaf volatile terpenes (LVT) in the resin are also powerful airborne infochemicals. Resin concentration and profile show considerable spatial and temporal phenotypic variation within and among pine populations. LVT biochemistry is known to be under genetic control, and although LVT should be plastic to diverse abiotic and biotic environmental factors such as nutrient availability and herbivore attack, little is known about their relative contributions and interactive effects. The aim of this paper was to clarify whether reduced phosphorus availability could increase the LVT concentration and affect the expression of herbivore-derived induced defences, and how plasticity would contribute to the phenotypic variation of LVT. The constitutive and methyl-jasmonate (MeJa) induced LVT concentration and profile were analysed in 17 half-sib Pinus pinaster families growing under two levels of P-availability (complete and P-limited fertilization). Individual terpene concentrations showed large additive genetic variation, which was more pronounced in the control than in MeJa-induced pines. MeJa application did not affect the LVT concentration, but significantly modified the LVT profile by depleting the α-pinene content and reducing the sesquiterpene fraction. Low P-availability strongly reduced plant growth and foliar nutrient concentrations, but did not affect LVT concentration and profile, and did not interact with MeJa-induction. Results indicate a strong homeostasis of LVT concentration to P-availability, and minor changes in the LVT profile due to MeJa-induction. Genetic variation appears to be the main source of phenotypic variation affecting the LVT concentration in this pine species.This work was supported by the Spanish Instituto Nacional de Investigación y Tecnología Agraria y Agroalimentaria (grant number INIA-RTA07-100; and DOC-INIA and PREDOC-INIA fellows for LS and XM, respectively); the Spanish Agency of Science and Technology (grant numbers CGL2006-04025/BOS, CGL2010-17172, and CSD2008- 00040 for JP and JL; and AGL2010-18724 and PSE310000 for RZ and LS); and the Catalonian Government (grant number SGR 2009-1458).Peer reviewe

Densidad y área de los canales resiníferos de "Pinus pinaster" ante tratamientos de fertilización, y su relación con la defensa ante "Hylobius abietis"

6 páginas, 3 tablas -- Actas de la I Reunión sobre Sanidad Forestal celebrada en Palencia el 24 y 25 de septiembre de 2007.Las coníferas poseen una estructura de canales resiníferos que actúa como defensa contra el ataque de insectos y patógenos. Varios autores han observado que un aumento en la disponibilidad de nutrientes puede alterar el reparto de energía en las plantas, en detrimento de los sistemas defensivos. El presente estudio tiene como objetivo determinar el efecto de la fertilización de establecimiento sobre el desarrollo del sistema de canales resiníferos en Pinus pinaster. Mediante histología en brinzales de 3 savias sometidos a dos ensayos familia x fertilización se cuantificó la densidad y el área de los canales resiníferos del floema y del xilema tanto en el tallo principal como en ramas laterales en dos ensayos familia x fertilización. Se observó un efecto significativo de la fertilización en el desarrollo de los canales resiníferos del floema (p<0,05), con valores de 0,45 y 0,36 canales.mm-2 para brinzales no fertilizados y sí fertilizados, respectivamente. Este efecto no se observó en las variables del xilema. La densidad de canales resiníferos en el xilema fue significativamente diferente entre las dos parcelas estudiadas, siendo mayor en la atacada por el curculiónido Hylobius abietis. Por último, la relación tallo-rama de las variables cuantificadas no fue lo suficientemente consistente como para utilizar los canales en ramas de P. pinaster como indicadores de los canales en el tronco principal.Este trabajo se ha realizado bajo financiación del proyecto INIA-RTA05-173.Peer reviewe

Micro‑climatic efects on plant phenolics at the community level in a Mediterranean savanna

5 páginas.- 2 figuras.- 1 tabla.- 27 referenciasResearch has shown that warming and drought change plant phenolics. However, much of this work has centered on the effects of individual abiotic stressors on single plant species rather than the concurrent effects of multiple stressors at the plant community level. To address this gap, we manipulated rainfall and air temperature to test for their individual and interactive effects on the expression of leaf phenolics at the community level for annual plant species occurring in two habitat types (under oak tree canopies or in open grasslands) in a Mediterranean savanna. We found that augmented temperature had a significant positive effect on the community-weighted mean of total phenolics whereas reduced rainfall had no effect. In addition, we found no evidence of interactive effects between climatic stressors and these patterns remained consistent across habitat types. Overall, this study points at increasing efforts to investigate the linkages between climate change and community-level shifts in plant secondary chemistry.Tis study was funded by a Spanish National Research Project to IMPR (CGL2015-70123-R)Peer reviewe

Correction to: Aphid and caterpillar feeding drive similar patterns of induced defences and resistance to subsequent herbivory in wild cotton

Correction to: Planta (2023) 258:113 https://doi.org/10.1007/s00425-023-04266-1Peer reviewe

Impacts of urbanization on insect herbivory and plant defences in oak trees

Systematic comparisons of species interactions in urban versus rural environments can improve our understanding of shifts in ecological processes due to urbanization. However, such studies are relatively uncommon and the mechanisms driving urbanization effects on species interactions (e.g. between plants and insect herbivores) remain elusive. Here we investigated the effects of urbanization on leaf herbivory by insect chewers and miners associated with the English oak Quercus robur by sampling trees in rural and urban areas throughout most of the latitudinal distribution of this species. In performing these comparisons, we also controlled for the size of the urban areas (18 cities) and gathered data on CO emissions. In addition, we assessed whether urbanization affected leaf chemical defences (phenolic compounds) and nutritional traits (phosphorus and nitrogen), and whether such changes correlated with herbivory levels. Urbanization significantly reduced leaf chewer damage but did not affect leaf miners. In addition, we found that leaves from urban locations had lower levels of chemical defences (condensed and hydrolysable tannins) and higher levels of nutrients (nitrogen and phosphorus) compared to leaves in rural locations. The magnitude of urbanization effects on herbivory and leaf defences was not contingent upon city size. Importantly, while the effects of urbanization on chemical defences were associated with CO emissions, changes in leaf chewer damage were not associated with either leaf traits or CO levels. These results suggest that effects of urbanization on herbivory occur through mechanisms other than changes in the plant traits measured here. Overall, our simultaneous assessment of insect herbivory, plant traits and abiotic correlates advances our understanding of the main drivers of urbanization effects on plant–herbivore interactions.This research was financially supported by a Spanish National Research Grant (AGL2015-70748-R), a Regional Government of Galicia Grant (IN607D 2016/001) and the Ramón y Cajal Research Programme (RYC-2013-13230).Peer reviewe

Efecto de la variabilidad de las propiedades físico-químicas del suelo en el rendimiento de la halófita costera Crithmum maritimum L.

Póster presentado en el XV Congreso Nacional de la AEET. "El valor de la naturaleza par una sociedad global"18-21 de octubre, Plasencia, CáceresEl hinojo marino (Crithmum maritimum L.) es una planta halófita perenne perteneciente a la familia Apiaceae, típica de ecosistemas costeros de Europa Occidental. Dada su elevada calidad nutricional para consumo humano, en los últimos años diferentes estudios han resaltado su potencial como cultivo comercial para la agricultura salina, una alternativa sostenible y prometedora ante la creciente salinización de las tierras agrícolas. Sin embargo, existe una falta de información referente a los rangos de tolerancia de la especie frente a los principales factores ambientales ligados a su cultivo, a lo que se suman diversas dificultades prácticas ligadas al cultivo de una especie no domesticada. Además, varios estudios han puesto de manifiesto un alto grado de variabilidad en los rangos de tolerancia a la sal, así como en el perfil nutricional en función de la procedencia geográfica del material. En este estudio se analizó el rendimiento de la especie (en términos de crecimiento, productividad, éxito reproductivo y calidad nutricional) en relación a las propiedades físico-químicas del suelo (pH, conductividad eléctrica, textura, contenido en materia orgánica y macro- y micronutrientes) en siete poblaciones naturales, representativas de los diferentes tipos de hábitat de la especie, localizadas en el sur de la Península Ibérica. Los resultados de este estudio permiten avanzar en el conocimiento ecológico y los mecanismos de tolerancia de las halófitas frente a diferentes factores abióticos, como la salinidad y la riqueza nutricional del suelo, aportando asimismo información relevante de cara a la valorización de la especie para su explotación en agricultura salinaN

Differences in nutrient composition of sea fennel (Crithmum maritimum) grown in different habitats and optimally controlled growing conditions

10 páginas.- 1 figura.- 5 tablas.- referenciasCrithmum maritimum L. is an edible halophyte with large potential in human nutrition field. However, it is unclear whether its nutritional value is maintained throughout the contrasting habitats where it commonly grows (cliffs, sandy and rocky beaches) and the nutritional profile of cultivated plants still remains uncertain. In this work, we provided for the first time a comparison of the nutritional profile of C. maritimum across its different type of habitats in the south of Spain and between wild plants and plant material under optimal growing conditions. The protein, amino acids, lipids, fatty acids, minerals composition and phenolic content of plants were analysed. Plants under field conditions exhibited a nutritionally balanced composition (3.8–6.2 g protein/100 g DW, 4.9–7.5 mg lipids/g WW, 3.9–5.0 g Na/100 g DW), with high phenolic content (30.2–48.0 mg/g DW) regardless of the variability of the contrasting habitats. In contrast, under optimal conditions, C. maritimum showed a greater protein and lipid content (10.2 g/100 g DW and 9.6 mg/g WW, respectively), and lower sodium accumulation (1.2 g/100 g DW), allowing a greater consumption of this halophyte without exceeding the daily intake recommendations. Conversely, phenolics were strongly decreased in these plants (6.1 mg/g DW) likely due to the absence of stress factors. © 2021 Elsevier Inc.This work was financially supported by two grants from the Spanish Ministry of Science, Innovation and Universities (RTI2018-099260-A- I00 to J. Cambroll é and RTI2018-099322-B-100 to X. Moreira).Peer reviewe