Biology subjects

De Moraes, C. M.

Publications and source records attributed to De Moraes, C. M..

9 recordsLinked to original sources

bioRxiv2026

Nectar chemistry reflects pollination strategies in alpine plant communities

Nectar is a primary floral reward, which can also deter non-specialist pollinators; yet, the role of complex nectar composition in plant-pollinator interactions and its relationship to other floral traits remain understudied, particularly in natural communities. We profiled the nectar metabolome of 43 co-occurring species in an alpine grassland to evaluate relationships among nectar chemistry, phylogeny, floral display traits and pollinator visitation. Field observations revealed a dominant bee vs fly visitation gradient. Several aggregated nectar traits tracked this gradient independently of plant phylogeny, indicating functional convergence: specifically, bee visitation was associated with higher nectar sucrose proportion, greater compound richness, and more divergent profiles of uncommon sugars. Nectar traits exhibited variable relationships to floral display traits, suggesting partial inter-trait phenotypic integration. Together, these findings indicate that detailed features of nectar composition, including phytochemical diversity, play a functional role in floral phenotypes, with previously unappreciated implications for plant-pollinator community ecology.

ecology↗

bioRxiv2026

Ecological context unmasks cryptic effects of glyphosate tolerance on soybean metabolism and performance of the virus vector Epilachna varivestis

O_LIGlyphosate-tolerant Roundup Ready (RR) soybean, engineered with the CP4 EPSPS gene, is one of the worlds most widely cultivated GM crops, yet its ecological consequences under realistic multi-species biotic conditions remain poorly understood. We investigated how RR soybean and its near-isogenic non-GM counterpart respond to concurrent colonization by two rhizobacteria, Bradyrhizobium japonicum and Delftia acidovorans, infection by Bean pod mottle virus (BPMV), and feeding by the virus vector Epilachna varivestis. C_LIO_LIUsing a fully factorial multi-species design, we combined LC-MS/GC-MS metabolomics, weighted co-expression network analysis (WGCNA), and herbivore performance bioassays to assess genotype-dependent shifts in soybean metabolism and their consequences for herbivore performance. C_LIO_LIUnder baseline conditions, RR and non-GM plants were metabolically indistinguishable. Under concurrent microbial and viral stress, RR plants diverged markedly, prioritizing selective isoflavonoid accumulation and lipid remodeling over broad-spectrum defenses, and showing attenuated rhizobacteria-mediated benefits for herbivore survival. These genotype-specific effects were entirely absent in single-species treatments. C_LIO_LITransgene effects on soybean metabolism and tritrophic interactions are cryptic under simplified experimental conditions but emerge clearly under ecologically realistic multi-species stress, with direct implications for how GM crops are evaluated in agricultural and regulatory contexts. C_LI

ecology↗

bioRxiv2025

Honeybees collect pollen from the buzz-pollinated flowers of invasive Solanum elaeagnifolium in Northern Greece

Around 6% of flowering plants, including most solanaceous species, have flowers specialized for buzz-pollination (sonication). The poricidal anthers of these flowers release pollen in response to frequency-specific vibrations, which buzz-pollinating bees, including bumble bees and many solitary bees, generate via rapid oscillation of flight muscles. Honeybees are incapable of sonication and typically avoid visiting buzz-pollinated plants, although they have previously been observed to scavenge residual pollen from petals of buzz-pollinated flowers in natural settings. Here, we report a novel interaction in which honeybees consistently visit and extract pollen from flowers of Solanum elaeagnifolium (silverleaf nightshade) within a large invasive plant population in Northern Greece. We postulate that honeybee foraging effort on S. elaeagnifolium reflects the shortage of alternative floral resources at the peak of the Mediterranean summer, consistent with observations for pollen-starved bees in captivity. This newly established behavioral shift of honeybees may convey important implications for plant invasions, particularly under climate change, and requires further investigation for untangling its ultimate drivers.

ecology↗

bioRxiv2025

Butterflies Are Shrinking: Evidence from the Past Century

Climate change has had strong impacts on biodiversity, including well-documented shifts in the distributions and phenology of species. Reductions in body size represent a third pervasive biological response; it has garnered significantly less attention despite great ecological relevance. Theoretical frameworks-the temperature-size rule, Bergmanns rule, and Jamess rule-predict that warmer temperatures are associated with smaller body sizes in ectotherms. In contrast, empirical evidence concerning this pattern is mixed across both taxa and environments. In the present study, we applied computer vision techniques to historical data from two large butterfly museum collections, totaling 593 species across 10 terrestrial biomes over more than a century, in order to investigate long-term trends in butterfly body size. We measured forewing length through both manual image analyses and automated computer vision algorithms proxying body size and analyzed trends by using generalized additive models in order to consider a temporal, biome-specific pattern assessment. We have tested two hypotheses: that butterfly body size (1) declines over time, in conjunction with increasing ambient temperatures, in agreement with the temperature-size rule, and (2) its variation is more marked in warm, dry biomes. Results indicate a significant overall reduction in the body size of butterflies during the last century and that this reduction is indeed more pronounced in those biomes facing higher rises in temperature. These findings constitute large-scale evidence in support of the temperature-size rule and indicate a potential ecological impact of climate change on butterfly populations.

ecology↗

bioRxiv2025

Butterfly body size shrinkage: the impact of ecological traits across varied environments

Because of its close ties to numerous ecological and life history characteristics, body size is regarded as one of an organisms most important characteristics and is frequently considered a significant indicator of fitness. According to recent studies, ectotherms in particular, may see a reduction in body size with rising temperatures. How life history and ecological traits influence, however, shifts in butterfly body size in response to environmental changes, particularly focusing on the effects of temperature and land use is poorly studied. Using Generalized Additive Models (GAM), we analyzed forewing length data alongside various life history (phenology, overwintering developmental stage, voltinism, diet breadth, gender) and ecological traits (mobility, thermal tolerance) as well as environmental parameters for a period that lasts 110 years. Smaller body sizes were linked to early-season emergence and increasing forest cover, while larger sizes were linked to longer flight durations and later seasonal appearance. Males exhibited a pronounced decline in body size while females showed an opposite trend, suggesting sex-specific vulnerabilities to climate change. This research highlights the complex interplay between climate change, habitat fragmentation, and butterfly morphology, emphasizing the need for further investigation into sexual size dimorphism as anthropogenic influences continue to reshape butterfly populations.

ecology↗

bioRxiv2025

Fine-scale variation in pollen availability influences Bombus terrestris colony behaviour, development and fitness.

Climate change threatens the long-established synchronization of seasonal pollinator activity and flowering time. Bumble bees are particularly vulnerable to these shifts, with resource availability playing a significant role in colony establishment and success. Recently, we documented a mechanism whereby pollen-deprived bumble bees deliberately damaged plant leaves, speeding up the production of flowers in two different species. However, it is unknown whether bumble bees obtain a benefit through this behaviour, both on a spatial and temporal scale. In the current study, we evaluate the effects of pollen availability on colony development, behaviour and reproductive fitness in Bombus terrestris using semi-natural and laboratory experiments. We find that the close proximity of flowers has significant effects on reproductive investment and output of B. terrestris colonies in a small-scale rooftop experiment. Moreover, we find that small shifts in the timing of pollen availability (5 days) shape the behaviour and development of the first generation of offspring, with significant carry-over effects on reproductive fitness for B. terrestris microcolonies. This suggests that small changes in the distribution of food may have significant impacts on colony success that cannot be compensated for over the course of the season. Furthermore, our findings suggest bumble bee colonies can feasibly profit by altering the timing of pollen resources, even by a few days.

ecology↗

bioRxiv2024

Beneficial rhizobacteria and virus infection modulate the soybean metabolome and influence the feeding preferences of the virus vector Epilachna varivestis.

There is growing evidence that microbial plant symbionts shape interactions between plants and other organisms by modulating gene expression and metabolism. However, the detailed mechanisms mediating such effects are not well understood, particularly in systems where plants interact simultaneously with multiple symbionts and antagonists. In this study, we employed a multi-factorial design to explore the individual and combined effects of two plant-beneficial rhizobacteria (Delftia acidovorans and Bradyrhizobium japonicum) and a pathogen (Bean pod mottle virus: BPMV) on gene expression and metabolite production by soybean plants, as well as downstream effects on plant interactions with a beetle vector of BPMV Epilachna varivestis. Our results document microbial effects on basic metabolism and defense pathways, resulting in increased levels of primary metabolites and depletion of secondary metabolites. These changes are consistent with the observed feeding preferences of beetles for rhizobia-inoculated and virus-infected plants. Together, our results indicate that BPMV infection and rhizobacteria colonization cause dramatic changes in plant metabolites related to nutrition and defense, with significant consequences for an agriculturally important pathosystem.

ecology↗

bioRxiv2022

Vascular fungi alter the apoplastic purinergic signaling in plants by deregulating the homeostasis of extracellular ATP and its metabolite adenosine

Purinergic signaling activated by extracellular nucleotides and their derivative nucleosides trigger sophisticated signaling networks. The outcome of these pathways determine the capacity of the organism to survive under challenging conditions. Both extracellular ATP (eATP) and Adenosine (eAdo) act as secondary messengers in mammals, essential for immunosuppressive responses. Despite the clear role of eATP as a plant damage-associated molecular pattern, the function of its nucleoside, eAdo, and of the eAdo/eATP balance in plant stress response remain to be fully elucidated. This is particularly relevant in the context of plant/microbe interaction, where the intruder manipulates the extracellular matrix. Here, we identify Ado as a main elicitor secreted by the vascular fungus Fusarium oxysporum. We show that eAdo modulates the plants susceptibility to fungal colonization by altering eATP-mediated physiological immune responses, such as apoplastic pH and calcium homeostasis. Our work indicates that plant pathogens actively imbalance the eAdo/eATP levels as a virulence mechanism. One Sentence SummaryThe apoplastic Adenosine/ATP balance is a messenger for plant defense and can be manipulated by the fungal pathogen F. oxysporum.

plant biology↗

bioRxiv2020

An invasive plant species enhances biodiversity in overgrazed pastures but inhibits its recovery in protected areas

Anthropogenic environmental change exposes biological communities to concurrent stressors (e.g., changes in climate and land-use, overexploitation, biotic invasions) that frequently persist over prolonged periods. Predicting and mitigating the consequences of human action on nature therefore requires understanding how exposure to multiple interacting stressors alters biological communities over relevant (e.g., multi-decadal) time periods. Here, we explore the effects of overgrazing and plant species invasion on plant community diversity and ecosystem functioning (productivity), as well as the patterns of recovery of plant communities following cessation of grazing pressure. In a Mediterranean pasture system, we utilized a "natural" experiment involving long-term exclusion of grazers (for 15-25 years in parks) and also conducted short-term grazing-exclusion and invasive species removal experiments. Our results reveal that invasion by a grazing-resistant plant (prickly burnet) has net positive effects on plant diversity under overgrazing conditions but inhibits the recovery of biodiversity once grazing ceases. Furthermore, while the diversity-productivity relationship was found to be positive in pastures, the interactive effects of overgrazing and species invasion appear to disrupt ecosystem functioning and inhibit the recovery of pasture productivity. These findings highlight the potential for prolonged exposure to anthropogenic stressors, such as overgrazing, to cause potentially-irreversible changes in biological communities that, in turn, compromise ecosystem functioning and resilience. In such cases, sustainable ecosystem management may require direct intervention to boost biodiversity resilience against centennial overgrazing.

ecology↗