Selective Pressure along a Latitudinal Gradient Affects Subindividual Variation in Plants

Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution. © 2013 Sobral et al.This work was supported by the Spanish Ministry of Science and Education (project CGL2005-03826) and the European Commission (FEDER program). M.S. was the recipient of a María Barbeito fellowship (Galicia regional government, Spain) and a Fundación Pedro Barrié de la Maza grant. A.R.L. received financial support from the Spanish Research Council (JAEDoc program, partially funded by the European Social Fund) during the preparation of the manuscriptPeer Reviewe

Selective pressure along a latitudinal gradient affects subindividual variation in plants

Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution.This work was supported by the Spanish Ministry of Science and Education (project CGL2005-03826) and the European Commission (FEDER program). M.S. was the recipient of a María Barbeito fellowship (Galicia regional government, Spain) and a Fundación Pedro Barrié de la Maza grant. A.R.L. received financial support from the Spanish Research Council (JAEDoc program, partially funded by the European Social Fund) during the preparation of the manuscriptS

Mammal traits and soil biogeochemistry: Functional diversity relates to composition of soil organic matter

Mammal diversity affects carbon concentration in Amazonian soils. It is known that some species traits determine carbon accumulation in organisms (e.g., size and longevity), and are also related to feeding strategies, thus linking species traits to the type of organic remains that are incorporated into the soil. Trait diversity in mammal assemblages – that is, its functional diversity – may therefore constitute another mechanism linking biodiversity to soil organic matter (SOM) accumulation. To address this hypothesis, we analyzed across 83 mammal assemblages in the Amazon biome (Guyana), the elemental (by ED‐XRF and CNH analysis) and molecular (FTIR‐ATR) composition of SOM of topsoils (401 samples) and trait diversity (functional richness, evenness, and divergence) for each mammal assemblage. Lower mammal functional richness but higher functional divergence were related to higher content of carbonyl and aliphatic SOM, potentially affecting SOM recalcitrance. Our results might allow the design of biodiversity management plans that consider the effect of mammal traits on carbon sequestration and accumulation in soils.Xunta de Galicia | Ref. ED431C 2021/32Xunta de Galicia | Ref. ED481D 2019/024National Science Foundation | Ref. BE/CNH 05 0809

Differences in pollination success between local and foreign flower color phenotypes: a translocation experiment with Gentiana lutea (Gentianaceae)

Background. The adaptive maintenance of flower color variation is frequently at-tributed to pollinators partly because they preferentially visit certain flower phenotypes.We tested whetherGentiana lutea—which shows a flower color variation (from orangeto yellow) in the Cantabrian Mountains range (north of Spain)—is locally adapted tothe pollinator community.Methods. We transplanted orange-flowering individuals to a population with yellow-flowering individuals and vice versa, in order to assess whether there is a pollinationadvantage in the local morph by comparing its visitation rate with the foreign morph.Results. Our reciprocal transplant experiment did not show clear local morphadvantage in overall visitation rate: local orange flowers received more visits thanforeign yellow flowers in the orange population, while both local and foreign flowersreceived the same visits in the yellow population; thus, there is no evidence of localadaptation inGentiana luteato the pollinator assemblage. However, some floral visitorgroups (such asBombus pratorum,B. soroensis ancaricusandB. lapidarius decipiens)consistently preferred the local morph to the foreign morph whereas others (such asBombus terrestris) consistently preferred the foreign morph.Discussion. We concluded that there is no evidence of local adaptation to the pollinatorcommunity in each of the twoG. luteapopulations studied. The consequences forlocal adaptation to pollinator onG. luteaflower color would depend on the variationalong the Cantabrian Mountains range in morph frequency and pollinator community composition.S

Is there a hybridization barrier between Gentiana lutea color morphs?

In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.This study is included in the project “Color polymorphism, geographic variation in the interactions and phenotypic selection. The case of Gentiana lutea L. in the Cantabrian Mountains” was financially supported by Secretary of State of I+D+I, Ministry of Science and Innovation, Government of Spain (2011–2013)S

Mammal and tree diversity accumulate different types of soil organic matter in the northern Amazon

Diversity of plants and animals influence soil carbon through their contributions to soil organic matter (SOM). However, we do not know whether mammal and tree communities affect SOM composition in the same manner. This question is relevant because not all forms of carbon are equally resistant to mineralization by microbes and thus, relevant to carbon storage. We analyzed the elemental and molecular composition of 401 soil samples, with relation to the species richness of 83 mammal and tree communities at a landscape scale across 4.8 million hectares in the northern Amazon. We found opposite effects of mammal and tree richness over SOM composition. Mammal diversity is related to SOM rich in nitrogen, sulfur and iron whereas tree diversity is related to SOM rich in aliphatic and carbonyl compounds. These results help us to better understand the role of biodiversity in the carbon cycle and its implications for climate change mitigation.Xunta de Galicia | ED481D 2019/024Xunta de Galicia | ED431C2021/32European Commission | Ref. H2020, n. 947921National Science Foundation (NSF) | BE/CNH 05 0809

Flower color preferences of insects and livestock: effects on Gentiana lutea reproductive success

Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution. Gentiana lutea shows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed in G.lutea, play a role in G. lutea flower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding on G. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affect G. lutea reproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation of G. lutea is not affected by insect herbivores or grazing livestockThis study is included in the project “Color polymorphism, geographic variation in the interactions and phenotypic selection. The case of Gentiana lutea L in the Cantabrian Mountains,” financially supported by Secretary of State of I+D+I, Ministry of Science and Innovation, Government of Spain (2011–2013). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS

Selective pressures explain differences in flower color among Gentiana lutea Populations

Flower color variation among plant populations might reflect adaptation to local conditions such as the interacting animal community. In the northwest Iberian Peninsula, flower color of Gentiana lutea varies longitudinally among populations, ranging from orange to yellow. We explored whether flower color is locally adapted and the role of pollinators and seed predators as agents of selection by analyzing the influence of flower color on (i) pollinator visitation rate and (ii) escape from seed predation and (iii) by testing whether differences in pollinator communities correlate with flower color variation across populations. Finally, (iv) we investigated whether variation in selective pressures explains flower color variation among 12 G. lutea populations. Flower color influenced pollinator visits and differences in flower color among populations were related to variation in pollinator communities. Selective pressures on flower color vary among populations and explain part of flower color differences among populations of G. lutea. We conclude that flower color in G. lutea is locally adapted and that pollinators play a role in this adaptation.This work was financed by the Plan Nacional de I + D + I (2008-2011), CGL2009-08959 Ministerio de Ciencia. T.V. was supported by a PhD grant from the Plan Galego de Investigación e Crecemento 2011/2015 (Plan I2C), Consellería de Educación e Ordenación Universitaria e InnovaciónS

Epigenetic and phenotypic responses to experimental climate change of native and invasive Carpobrotus edulis

Despite the recent discoveries on how DNA methylation could help plants to adapt to changing environments, the relationship between epigenetics and climate change or invasion in new areas is still poorly known. Here, we investigated, through a field experiment, how the new expected climate scenarios for Southern Europe, i.e., increased temperature and decreased rainfall, might affect global DNA methylation in relation to phenotypic variation in individuals of clonal plant, Carpobrotus edulis, from its native (Southern African) and invaded (northwestern Iberian Peninsula) area. Our results showed that changes in temperature and rainfall induced phenotypic but not global DNA methylation differences among plants, and the climatic effects were similar for plants coming from the native or invaded areas. The individuals from the Iberian Peninsula showed higher levels of global methylation than their native counterparts from South Africa. We also observed differences between natives and invasive phenotypes in traits related to the pattern of biomass partitioning and to the strategies for water uptake and use and found an epigenetic contribution to phenotypic changes in some leaf traits, especially on the nitrogen isotopic composition. We conclude that the increased temperature and decreased rainfall projected for Southern Europe during the course of the twenty-first century may foster phenotypic changes in C. edulis, possibly endowing this species with a higher ability to successful cope the rapid environmental shifts. The epigenetic and phenotypic divergence that we observed between native and invasive plants suggests an intraspecific functional variation during the process of invasion. This result could indicate that phenotypic plasticity and global DNA methylation are related to the colonization of new habitats. Our findings reinforce the importance of epigenetic plasticity on rapid adaptation of invasive clonal plantsFunding for this study was provided by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF; grant Ref. CGL2013-48885-C2-2-R and Ref. CGL2017-87294-C3-1P awarded to RR) and by the Autonomous Government of Galicia (grant ref. I2CB awarded to MS)S