Changes In Traits Research Articles

Primary succession and plant functional traits on an oceanic island

Abstract The discipline of functional island biogeography and studies on plant ecological strategies shaping island assemblages have emerged only recently. Due to volcanic activity, primary succession is an important natural process driving ecosystem dynamics on oceanic islands. However, our knowledge about plant functional traits in explaining the mechanism of ecological succession on these islands characterized by impoverished and disharmonic, but endemic‐rich floras, is limited. We investigated the distribution of plants with respect to nine functional traits related to resource use, reproduction, and growth as well as their overall functional diversity during primary succession using a chronosequence on 10 lava flows of La Palma, Canary Islands. We analysed changes of single traits with age using community‐weighted trait means and applied ordination techniques to evaluate changes in trait composition. Based on ecological succession theory, we tested several hypotheses for changes of functional traits along the successional gradient. We also analysed the role of endemic and introduced plants in structuring successional communities. Both the single‐trait and trait compositional approach revealed that the composition of plants displaying core traits related to leaf economics and dispersal ability shifted with substrate age showing a change from acquisitive to conservative traits and from anemochory to zoochory along the gradient. These shifts were entirely driven by endemic shrubs, while other growth forms contributed to the increase in species and functional richness with lava age but little to vegetation structure. Introduced species were almost absent in successional trajectories. Functional dispersion increased whereas trait turnover was constant and low during succession. Synthesis. Our island system reflects a directional succession governed by the selection of functional traits related to environmental conditions and acquisitive‐conservative strategies as well as to dispersal capacity in early stages followed by a gradual modification of the environment and an expansion of the niche space linked to functional divergence in later stages. Major changes in functional traits occurred five hundred years after the eruptions indicating that primary succession in this dry environment is very slow. The dominance of endemic shrubs and the lack of introduced plants at all successional stages highlight the importance of evolutionary processes in shaping species ecological strategies linked to disturbances like volcanism on this oceanic archipelago.

Multigenerational testing reveals delayed chronic toxicity of bisphenol A to Daphnia magna: A common characteristic of endocrine-disrupting chemicals?

Multigenerational testing reveals delayed chronic toxicity of bisphenol A to Daphnia magna: A common characteristic of endocrine-disrupting chemicals?

Creating a Superior Wx Allele with Temperature-Responsive Amylose Regulation and a Novel Transcriptional Pattern in Rice via CRISPR/Cas9-Mediated Promoter Editing

High quality stands as a pivotal competitive edge in the rice industry. Optimizing amylose content (AC) and the physicochemical properties of endosperm starch by regulating the Wx gene is crucial for enhancing rice grain quality. In this study, we created a novel Wxb-d25 allele by deleting a 25 bp segment (−26 to −2) within the Wx core promoter using CRISPR/Cas9. Compared with the wild type and the previously reported Wxb-i1, Wxb-d25 exhibited no significant changes in agronomic traits. However, its grains displayed temperature-dependent variations in AC and altered transparency and viscosity characteristics, holding the potential to synergistically improve both the eating and cooking quality (ECQ) and appearance quality (AQ) of rice. Further studies demonstrated that this promoter modification, by partially disrupting the transcription initiator, significantly downregulated the original Wx-01 transcript and generated a novel Wx transcript (ONT.7395.1) in Wxb-d25 grains. Despite its low expression abundance, the ONT.7395.1 transcript could be completely processed into mature Wx mRNA. The combined effects of the dual transcripts resulted in significantly increased Wx gene expression and AC in Wxb-d25 grains under conventional cultivation conditions. These findings provide a genetic resource and a theoretical foundation for utilizing the Wxb-d25 allele to improve rice grain quality.

Floral reward traits change between sexual phases in two Helleborus species

Nectar and pollen attractants as well as visitors in Helleborus viridis ssp. viridis and H. purpurascens (Ranunculaceae), i.e. European species, were studied during two flowering seasons. The long-lived flowers of these species are characterized by long nectar availability lasting 15–17 days, i.e. until the end of pollen presentation. On average, approx. 2-fold more nectar and sugar mass was available in the flowers of H. viridis ssp. viridis compared to H. purpurascens. Both species are protogynous, having an initial female phase lasting for 3 days. The nectar and sugar mass was consistently male-biased. At the end of the flower’s life span, the nectar mass and the sugar concentration decreased considerably. In both species, sucrose predominated in the nectar, which also contained small quantities of other disaccharides (maltose and trehalose) and monosaccharides (glucose and fructose). The chemical composition of the nectar sugar varied between the sexual phases; sucrose in the female-phase nectar was replaced mainly by fructose. In addition to nectar, the flowers offered pollen (between 2 and 4 and 10–17 days of anthesis). In the study area, both Helleborus species were foraged by queens of bumble bees and honey bees; however, their distribution differed between the species. Bumble bees dominated in H. viridis subsp. viridis, whereas both pollinator groups were noted with a similar frequency in H. purpurascens.

Volatile-mediated plant interactions: an innovative approach to cultivar mixture selection for enhanced pest resilience

Mixing different cultivars has been recognized as a promising strategy for the reduction of pest pressure and the enhancement of crop performance. However, this applies only in specific combinations, creating a need to select cultivars that interact synergistically in mixtures. We propose a trait-based laboratory method to identify complementary pairs of cereal cultivars based on their ability to prime one another’s defense response through volatile organic compounds (VOCs). In this study, we screened 25 locally-grown cultivars from six European countries to assess their responsiveness to volatile priming under controlled conditions. The tested cultivars exhibited three primary types of volatile interactions: no interaction, one-way interaction (where one cultivar responded to volatiles from another) and two-way interaction (where both cultivars reciprocally responded). Subsequently, the efficacy of these cultivar pairs was evaluated over a three-year period in field trials where aphid infestation, natural enemy abundance and plant traits (height, number of plants per 1-meter, Thousand Grain Weight (TGW) and yield) were assessed. Field trials results demonstrated that only specific cultivar mixtures led to a significant reduction in aphid infestation, indicating a robust genetic and environmental interaction. Mixtures in which both cultivars exhibited two-way interaction under controlled conditions, demonstrated reductions in aphid abundance in comparison to monoculture controls. In contrast, the abundance of natural enemies was not significantly affected by cultivar mixtures, and there were no notable changes in plant traits. We propose that the strategic pairing of cultivars, which actively engage in volatile interactions in the laboratory, can effectively reduce aphid pressure in the field without compromising plant traits or crop yield, thereby reducing reliance on chemical control. Given the role of aphids as vectors of economically significant viruses, reducing their population could also limit the spread of plant diseases in the field. This approach underscores the importance of understanding plant interactions at a chemical level to optimize cultivar pairing and develop sustainable pest management strategies.

Hydraulic and Photosynthetic Performance of Antarctic Plants Under Successive Freeze-Thaw Cycles.

Climate change projections predict warming and increased weather variability, mainly in polar regions, altering freeze-thaw patterns. However, the effects of rising temperatures and more frequent freeze-thaw events on the water and CO2 management of Antarctic plants remain unclear. To address this, we conducted a laboratory experiment to investigate how growth temperature (5°C and 15°C) and successive freeze-thaw cycles influence the hydraulic and photosynthetic performance of Deschampsia antarctica (D. antarctica) and Colobanthus quitensis (C. quitensis). Our results showed that warmer conditions improved hydraulic and photosynthetic performance in both species, driven by anatomical adjustments in leaf xylem vessels. Additionally, plants exposed to successive freeze-thaw cycles exhibited a coordinated decline in whole-plant hydraulic conductivity and leaf gas exchange, regardless of growth temperature. The magnitude of changes (%) in photosynthetic traits after freeze-thaw cycles varied between species, with D. antarctica showing similar responses at both growth temperatures, while C. quitensis experienced more pronounced changes at the lower temperature. Overall, these findings suggest that while Antarctic plants benefit from warmer temperatures, repeated freeze-thaw events could disrupt their hydraulic balance and limit photosynthesis, particularly under natural environmental conditions.

Effect of body size on an age-structured food chainwith birth pulses in pests

An ecological challenge is to understand the effects of body size reduction in response to climate change, a phenomenon that could significantly disrupt agroecological systems. However, the effects of these changes in individual traits and trophic interactions on the structure of food webs in such systems have not yet been fully explored. In the Southern Hemisphere, the socioeconomic and cultural importance of agriculture justifies the need to investigate these systems. In this study, the selected host plant is watermelon (Citrullus lanatus), the pest corresponds to the cotton aphid (Aphis gossypii), and the potential biological control agent is the Chilean predatory mite (Eriopis chilensis). To theoretically understand the structure of this food chain, we developed a three-level model that includes biological control, two pests, and the host plant. The model combines a continuous dynamic system with discrete pulses representing births and the introduction of new individuals of the control agent. Holling’s type II functional responses, reproduction and mortality rates, and carrying capacity dependent on the body size of the species are integrated into the model. Additionally, a computational algorithm is presented, which enables the simulation of the behaviour of the agroecological system. This proposal offers a theoretical tool to improve the understanding of species interactions and to anticipate dynamics that could be useful in designing agroecological management and control strategies.

A replication attempt of personality change through randomized peer groups

Personality development theories and descriptive evidence highlight young adulthood as a period conducive to personality change. Young adults experience important transitions, such as starting university education, and establish new relationships. However, few empirical tests of the direct influence of university student peer groups on individual change in personality traits exist. Here, we conceptually replicated an earlier study and randomly allocated students ( N = 351) to study groups of 3 to 6 peers that met over the course of the first semester. This randomization approach allowed the estimation of peer group socialization effects unconfounded by selection effects. We conducted a series of robustness checks to determine whether regression to the mean constitutes an alternative explanation for the results. The preregistered, confirmatory models seemed to support the hypothesis of peer group influence for all Big Five traits, showing patterns of assimilation where an individual’s personality became more similar to the personality of the remaining group members over time. Robustness checks, however, demonstrated convincingly that these patterns were due to the statistical artifact of regression to the mean and should not be interpreted as substantive evidence for peer group influence. We discuss theoretical and methodological implications for studying personality development through social relationships.

Shrinking body size under climate warming is not associated with selection for smaller individuals in a migratory bird.

How species are responding to climate change is a key topic in evolutionary ecology. Increasing temperatures are expected to affect phenotypic traits involved in thermoregulation, thus decreasing body size and/or increasing body appendages associated with heat exchange, as predicted by Bergmann's and Allen's rules. Results from long-term studies of variation in morphology over time have generally provided results supporting these predictions. However, two outstanding questions are frequently raised in studies relating changes in phenotypes to increasing temperatures: (1) whether such changes involve a shift in animal shape through the non-proportional variation of different body parts; and (2) whether they result from adaptive evolutionary responses. Relying on capture-recapture histories of almost 9000 breeding individuals from a declining Italian population of an Afro-Palearctic migratory bird, the barn swallow (Hirundo rustica), we documented a decrease in some body size traits (body mass, keel and wing length) over a 31-year period (1993-2023), with body mass declining the most (up to 4.0% in males). However, this was not the case for bill and partly tarsus length. Intra-individual lifelong changes in morphological traits of sexually mature birds showed only a limited contribution to trends over time in phenotypically plastic morphological traits. Viability and fecundity selection analyses revealed that smaller individuals did not enjoy greater success compared to larger ones. For some traits, the opposite was actually the case. The shifts in body size and, partly, shape over time we observed were coherent with predictions deriving from Bergmann's and Allen's rules. Yet, natural selection did not consistently favour smaller individuals. We thus call for caution in interpreting recent decreases in body size as adaptive evolutionary responses to climate warming, as they may rather reflect phenotypically plastic responses to changing climatic/environmental conditions occurring during early ontogenetic stages.

Effects of thermal discharge on the structuring of macrobenthic biological traits around the Sanmen nuclear power plant in the East China Sea.

Effects of thermal discharge on the structuring of macrobenthic biological traits around the Sanmen nuclear power plant in the East China Sea.

The severity of SLC1A2-associated neurodevelopmental disorders correlates with transporter dysfunction.

The severity of SLC1A2-associated neurodevelopmental disorders correlates with transporter dysfunction.

Social Class and Personality: The Effects of Educational Mobility on Personality Trait Change

Transitioning into young adulthood often brings about significant changes in personality traits. However, the reasons behind these personality changes remain unclear. This study integrates insights from research on personality development and the psychology of social class to study how the construction of one’s social class identity in young adulthood might trigger changes in personality traits (i.e., Big Five, locus of control, and risk-taking). We tested our preregistered hypotheses in the context of educational mobility, using data from the German Socio-Economic Panel (SOEP) study ( N = 4,776). Specifically, we investigated personality changes of young adults whose parents did not go to university, comparing those who are educationally mobile (i.e., go to university) with those who do not during the study period. Overall, the results indicated that upward educational mobility only leads to changes in risk-taking. Theoretical implications for the psychology of class mobility (selection vs. socialization effects) are discussed.

Polygenic Associations between Motor Behaviour, Neuromotor Traits, and Active Music Engagement in Four Cohorts.

Phenotypic investigations have shown that actively engaging with music, i.e., playing a musical instrument or singing may be protective of motor decline in aging. For example, music training associated with enhanced sensorimotor skills accompanied by changes in brain structure and function. Although it is possible that the benefits of active music engagement "transfer" to benefits in the motor domain, it is also possible that the genetic architecture of motor behaviour and the motor system structure may influence active music engagement. This study investigated whether polygenic scores (PGS) for five behavioural motor traits, 12 neuromotor structural brain traits, and seven rates of change in brain structure traits trained from existing discovery genome-wide association studies (GWAS) predict active music engagement outcomes in four independent cohorts of unrelated individuals of European ancestry: the Canadian Longitudinal Study on Aging (CLSA; N=22,198), Wisconsin Longitudinal Study (WLS; N=4,605), Vanderbilt's BioVU Repository (BioVU; N=6,150), and Vanderbilt's Online Musicality study (OM; N=1,559). Results were meta-analyzed for each PGS main effect across outcomes and cohorts, revealing that PGS for a faster walking pace was associated with higher amounts of active music engagement. Within CLSA, a higher PGS for walking pace was associated with greater odds of engaging with music. Findings suggest a shared genetic architecture between motor function and active music engagement. Future intervention-based research should consider the genetic underpinnings of motor behavior when evaluating the effects of music engagement on motor function across the lifespan.

Extreme events induced by climate change alter nectar offer to pollinators in cross pollination-dependent crops

Both severe reductions and increases in rainfall can stress plants and modify floral traits involved in plant-pollinator interactions, such as nectar production. Animal pollination is responsible for most plant species’ reproduction including several crops that rely especially on bees for fruit and seed production. Thus, extreme climate events can cause disruptions in pollination mutualism and lead to a decrease in the production of many crops worldwide. This study investigated the effects of changes in rainfall on nectar availability to pollinators at flower-, plant- and agricultural-scale, using an outcrossing bee-pollinated model crop. We experimentally simulated four scenarios: Control, Heavy rainfall, Rainfall reduction and Drought. All treatments but Rainfall reduction affected nectar traits at flower-scale. At plant- and agricultural-scale, Heavy rainfall increased nectar caloric offer (+ 79% and + 74%, respectively), while Rainfall reduction and Drought decreased it (− 37% and − 34%; − 98% and − 95%, respectively). Thus, drought treatments resulted in less resources available to pollinators The predicted rainfall shifts mediated by climate change may negatively affect cross-pollinated crops worldwide, as changes in nectar traits are prone to affect pollinator foraging behaviour and energy intake rate, decreasing pollination and fruit production. In summary, food security for humans may be closely linked to food security for pollinators.

Impact of ecogenetic factors on cytogenetic variability of winter wheat

The study focused on the mutagenic potentials of ethylmethanesulfonate (EMS) and sodium azide (SA), their abilities to induce chromosomal aberrations, interactions with various winter wheat genotypes, and the nature of genotype-mutagenic interactions. Additionally, their feasibility for future applications was examined, particularly regarding their predictive value at the cellular level in determining mutation-inducing capacity at the plant level. The cytogenetic effects of ethylmethanesulfonate (EMS) and sodium azide (SA) were tested on two winter wheat varieties, Vezha and Ihrysta. The seeds were treated with EMS at concentrations of 0.025%, 0.05%, and 0.1%, and SA at 0.01%, 0.025%, 0.05% and 0.1%. The cytogenetic activity was assessed through pollen sterility and the frequency and spectrum of chromosomal abnormalities in mid-phase cell mitosis. The results provided significant insights into the genotype-mutagenic interactions in these wheat varieties. The study found that the winter wheat variety Ihrysta exhibited a higher genotype-mutagenic specificity, making it a strong candidate for inducing genetic variability and producing mutant forms. The most effective mutagenic response was observed following the use of EMS and SA concentrations ranging 0.025% to 0.05%, optimizing mutation induction while minimizing the adverse effects. The study identified the variety Vezha as particularly responsive and promising for breeding programs targeting mutagenic variability. Mode­rate concentrations of EMS and SA were found to be the most effective, striking a balance between inducing beneficial genetic changes and minimizing adverse effects. The key indicators of genetic susceptibility to mutagens included pollen fertility, the overall frequency of chromosomal aberrations, and the number of induced fragments, while rare chromosomal rearrangements had limited analytical value. The induction patterns of EMS and SA were consistent with other chemical supermutagens, although the responses varied depending on the plant's genetic background. The findings will be integrated with further studies on hereditary changes in biochemical and physiological traits, providing a basis for refining mutagenic strategies and optimizing breeding programs.

Salicaceae endophyte inoculation alters stomatal patterning and improves the intrinsic water-use efficiency of Populus trichocarpa after a water-deficit.

Microorganisms may enhance plant resilience to water stress by influencing their hosts' physiology and anatomy at the leaf-level. Bacterial and yeast endophytes, isolated from wild poplar and willow, can improve the intrinsic water-use efficiency (iWUE) of cultivated poplar (Populus) under water-deficits by lowering stomatal conductance (gsw). However, the relevance of stomatal anatomy underlying this reduction remains unclear. We hypothesized endophyte inoculation could change host stomatal anatomy, and this would relate to decreases in gsw. We subjected Salicaceae endophyte-inoculated and uninoculated Populus trichocarpa to well-watered and water-deficit treatments in greenhouse studies. We examined the changes of individual stomatal traits and related the composition of these parameters, termed stomatal patterning, to leaf gas-exchange under light saturation. After a water-deficit, inoculation improved iWUE at light saturation from preserving carbon assimilation (Anet) and lowering gsw, but these changes were independent of soil-moisture status. Drops in gsw corresponded to underlying shifts in stomatal patterning (Rconditional2 = 0.63; p = 0.002). Inoculated plants had smaller, more compact stomata and greater anatomical maximum stomatal conductance (gsmax) relative to the control (adj ηp2 = 0.1; p = 0.001). Salicaceae endophytes may alter stomatal density and size, lowering gsw and increasing iWUE. Future efforts may quantify endophyte colonization of the host to draw direct relationships between microbes and stomatal traits.

Artificial night light intensity modulates herbivory and phytochemistry in European beech

Abstract Artificial light at night (ALAN) is a recognized threat not only to urban areas but also to more remote habitats including forests. Advancements in LED technology offer potential for streetlight infrastructure with minimized disruptive impact on ecosystems. Light dimming ranges among the most promising ALAN‐mitigation measures. Despite being essential for understanding ALAN effects on ecosystems, little is known about how dimming may affect bottom‐up interactions, such as those between plants and herbivores. We conducted a forest‐located experiment on potted European beech saplings (Fagus sylvatica L.) that lasted 43 nights. We studied the impact of different LED streetlight intensities i.e. 70 lx (100% light intensity), 35 lx (50% light intensity), 21 lx (30% light intensity) and a dark control on leaf morphological and chemical traits, insect herbivory and the links between light‐induced changes in leaf traits and herbivory. The 100% and 50% light intensity treatments caused an increase in average leaf area but reduced specific leaf area. ALAN also induced changes in the specialised leaf metabolome, mainly affecting flavonols. Responses of individual metabolites to different ALAN intensities were highly variable, with many metabolites already responding to 30% light intensity. Insect herbivory was only reduced under 100% light intensity. The reduction in herbivory correlated with ALAN‐related changes in phytochemistry. Synthesis and applications: Our findings indicate that reducing LED light intensities (dimming) is a promising step towards sustainable outdoor lighting to mitigate ALAN effects on tree‐herbivore interactions. However, the effects of dimming on leaf physiology, phytochemistry and herbivory were variable, with detectable effects on phytochemistry even at high dimming levels. The varying light responses across trophic levels highlight the challenge of optimizing light parameters in order to minimize ALAN impacts on species interactions. To address this challenge, our study advocates for increased collaboration between ecologists and lighting engineers.

Within-species floral evolution reveals convergence in adaptive walks during incipient pollinator shift

Understanding how evolution proceeds from molecules to organisms to interactions requires integrative studies spanning biological levels. Linking phenotypes with associated genes and fitness illuminates how adaptive walks move organisms between fitness peaks. Floral evolution can confer rapid reproductive isolation, often converging in association with pollinator guilds. Within the monkeyflowers (Mimulus sect. Erythranthe), yellow flowers within red hummingbird-pollinated species have arisen at least twice, suggesting possible pollinator shifts. We compare two yellow-flowered forms of M. cardinalis and M. verbenaceus to their red counterparts in floral phenotypes, biochemistry, transcriptomic and genomic variation, and pollinator interactions. We find convergence in ongoing adaptive walks of both yellow morphs, with consistent changes in traits of large effect (floral pigments, associated gene expression), resulting in strong preference for yellow flowers by bumblebees. Shifts in scent emission and floral opening size also favor bee adaptation, suggesting smaller-effect steps from hummingbird to bee pollination. By examining intraspecific, incipient pollinator shifts in two related species, we elucidate adaptive walks at early stages, revealing how convergent large effect mutations (floral color) may drive pollinator attraction, followed by smaller effect changes for mechanical fit and reward access. Thus, ongoing adaptive walks may impact reproductive isolation and incipient speciation via convergent evolution.

Pangenomes suggest ecological-evolutionary responses to experimental soil warming.

Below-ground carbon transformations that contribute to healthy soils represent a natural climate change mitigation, but newly acquired traits adaptive to climate stress may alter microbial feedback mechanisms. To better define microbial evolutionary responses to long-term climate warming, we study microorganisms from an ongoing in situ soil warming experiment where, for over three decades, temperate forest soils are continuously heated at 5°C above ambient. We hypothesize that across generations of chronic warming, genomic signatures within diverse bacterial lineages reflect adaptations related to growth and carbon utilization. From our bacterial culture collection isolated from experimental heated and control plots, we sequenced genomes representing dominant taxa sensitive to warming, including lineages of Actinobacteria, Alphaproteobacteria, and Betaproteobacteria. We investigated genomic attributes and functional gene content to identify signatures of adaptation. Comparative pangenomics revealed accessory gene clusters related to central metabolism, competition, and carbon substrate degradation, with few functional annotations explicitly associated with long-term warming. Trends in functional gene patterns suggest genomes from heated plots were relatively enriched in central carbohydrate and nitrogen metabolism pathways, while genomes from control plots were relatively enriched in amino acid and fatty acid metabolism pathways. We observed that genomes from heated plots had less codon bias, suggesting potential adaptive traits related to growth or growth efficiency. Codon usage bias varied for organisms with similar 16S rrn operon copy number, suggesting that these organisms experience different selective pressures on growth efficiency. Our work suggests the emergence of lineage-specific trends as well as common ecological-evolutionary microbial responses to climate change.IMPORTANCEAnthropogenic climate change threatens soil ecosystem health in part by altering below-ground carbon cycling carried out by microbes. Microbial evolutionary responses are often overshadowed by community-level ecological responses, but adaptive responses represent potential changes in traits and functional potential that may alter ecosystem function. We predict that microbes are adapting to climate change stressors like soil warming. To test this, we analyzed the genomes of bacteria from a soil warming experiment where soil plots have been experimentally heated 5°C above ambient for over 30 years. While genomic attributes were unchanged by long-term warming, we observed trends in functional gene content related to carbon and nitrogen usage and genomic indicators of growth efficiency. These responses may represent new parameters in how soil ecosystems feedback to the climate system.

Skyglow and especially direct streetlight pollution alter moth communities.

Skyglow and especially direct streetlight pollution alter moth communities.