Volatile Emissions Research Articles

The homeotic gene PhDEF regulates production of volatiles in petunia flowers by activating EOBI and EOBII

Abstract In petunia (Petunia x hybrida), MADS-box homeotic genes dictate floral organ identity. For instance, DEFICIENS (PhDEF), GLOBOSA1, and GLOBOSA2 (PhGLO1/2) are responsible for petal and stamen identity. However, whether homeotic genes, particularly PhDEF, have a function at the later stages of flower development, remains elusive. In petunia flowers, scent production initiates at anthesis, when the flower is ready for pollination, and is triggered by activation of EMISSION OF BENZENOIDS I (EOBI) and EOBII, MYB transcriptional regulators of scent-related genes. Here, we revealed the role of PhDEF in mature flowers, showing that it activates scent production. PhDEF suppression using a transient viral system in petunia flowers led to a significant reduction in volatile emission and pool levels, and in the transcript levels of scent-related transcriptional regulators and enzymes. Promoter activity assays demonstrated that PhDEF activates EOBI, EOBII and the phenylpropanoid biosynthesis genes L-PHENYLALANINE AMMONIA LYASE and PHENYLACETALDEHYDE SYNTHASE. Our findings underscore the importance of PhDEF in petunia flower development from initiation to maturation and in coordinating petal specification and the establishment of showy pollination-related traits.

Quantifying relevant exposure determinants and conditions of use for welding emissions

Background Conditions of Use (CoU) defines the operational conditions and risk management measures that result in adequately controlled exposure. It is mandatory to provide CoUs in Exposure Scenarios for the REACH legislation. CoU assessment based on similar exposure groups is a case-specific approach and not very efficient. We demonstrate how to quantify relevant exposure determinants and find optimal CoUs for welding using probabilistic exposure modelling. Methods Single and two-compartment models were applied to calculate exposure levels under specified conditions for five welding processes with the highest emissions. Model performance was tested using independently reported emissions and two field measurement studies. Results Welding fume concentrations were predicted within the range of 0.93 to 3.4 times the measured levels for three different welding scenarios, where two scenarios were repeated with four and five different ventilation rates. CoUs were quantified for welding with five different electrodes when welding is performed without controls, with a fume extraction torch, and with local exhaust ventilation. The exposure level was adequately controlled for three electrodes when controls were applied. Exposure assessment refinement proposals were given based on the relevant exposure determinants. The maximum emission factor was calculated for total fume emissions. A proposal for emission labelling was established. Conclusions CoU quantification was successfully demonstrated for total welding fume emissions. CoU results can be applied for welding processes where emissions are less than specified for the operational conditions specified here. Only total fume emissions were considered here, which may not be the limiting factor for risk; volatile and individual metal emissions were not considered. The approach applies to point sources for which emissions are adequately characterized. CoU assessment can be used to develop emission labelling and process specific safety actions. Compared to the traditional case-specific approach, modeling using this general approach will provide a significantly improved cost-effectiveness.

Attraction of Lygus lineolaris (Hemiptera: Miridae) to a ubiquitous floral volatile in the field.

Herbivorous insects utilize olfactory and visual cues to orient on suitable host plants, and such cues can be employed to facilitate insect monitoring. Lygus lineolaris Palisot de Beauvois is a polyphagous pest throughout North America. Monitoring this pest as it moves between crop and non-crop hosts remains challenging, and a lack of effective monitoring tools complicates management of this insect. In this study, we examined the electrophysiological and behavioral responses of L. lineolaris to the volatile emissions of 2 crop hosts: alfalfa and strawberry. Gas chromatography with electroantennographic detection was applied to identify antennally active compounds in headspace extracts of flowering host plants, before responses to individual compounds were examined in the field. Five compounds consistently elicited antennal depolarizations in adults of L. lineolaris and, of these, (±)-linalool increased the capture rate of L. lineolaris females in the field. Subsequent experiments examined the influence of visual cues and stereochemistry on capture rate, revealing that lures containing (±)-linalool and (S)-(+)-linalool significantly increased the capture rate of L. lineolaris females compared with traps baited with (R)-(-)-linalool and controls, indicating that L. lineolaris is attracted to (S)-(+)-linalool. While lures increased capture on red traps, this was not the case for white traps, emphasizing the importance of visual cues in the movements and monitoring of L. lineolaris. This study demonstrates that L. lineolaris is attracted to (S)-(+)-linalool in the field, and that attraction depends on trap color. This knowledge is expected to improve monitoring strategies for L. lineolaris in agricultural systems.

Induction by caterpillars of stored and emitted volatiles in terpene chemotypes from populations of wild cotton (Gossypium hirsutum)

BackgroundUpland cotton (Gossypium hirsutum) plants constitutively store volatile terpenes in their leaves, which are steadily emitted at low levels. Herbivory leads to a greater release of these stored volatiles. Additionally, damaged plants increase the accumulation of volatile terpenes in their leaves and begin to synthesize and emit other terpenes and additional compounds. This has been well characterised for cultivated G. hirsutum, but little is known about volatile production in response to herbivory in wild populations. We investigated how damage by a generalist herbivore species, the beet armyworm (Spodoptera exigua), affects leaf-stored and emitted volatiles in wild G. hirsutum plants and compared the responses of two known chemotypes. Wild cotton plants were grown in a greenhouse from seeds collected from four distinct locations covering sixteen populations, along the Yucatan coast (Mexico), from where this cotton species originates. We assessed whether the differences in leaf terpene profiles between the two chemotypes persisted upon herbivory, in leaves and in headspace emissions, and whether these chemotypes also differed in the production and release of herbivory-induced volatiles. In addition to chemotypic variation, we further investigated intraspecific variation in the volatile response to herbivory among genotypes, populations, and the four geographic regions.ResultsThe difference between the two chemotypes persisted after herbivory in the stored volatile profile of induced leaves, as well as in the emissions from damaged plants. Therefore, wild cotton chemotypes may differ in their airborne interactions with their environment. The specific terpenes distinguishing these chemotypes showed a weak inducibility, raising questions about their functions. Herbivory triggered changes in stored and emitted volatiles similar to what is known for cultivated varieties of G. hirsutum. However, we report for the first time on the emission of volatile aldoximes by cotton plants, which were only detected in the headspace upon herbivory, and displayed chemotypic and interpopulation variation. Intraspecific variation was also observed in the induced emissions of nitriles and certain terpenes. Moreover, chemotypes differed in their induction of (E)-β-ocimene stored in the leaves.ConclusionsThis comprehensive insight into herbivore-induced volatiles of wild cotton reveals variation in production and emission among populations. A full understanding of their ecological role may help in the development of future pest-management strategies for cotton crops.

Particulate Matter and Volatile Organic Compounds Emissions and Their Health Impact: Spotlight on Solid Fuel Combustion

Solid fuel combustion, while a crucial source of energy in many regions around the world, remains one of the primary contributors to air pollution, with significant implications for human health [...]

The GacS/GacA two-component system strongly regulates antimicrobial competition mechanisms of Pseudomonas fluorescens MFE01 strain.

Our model strain Pseudomonas fluorescens MFE01 uses an active type VI secretion system (T6SS) and volatile compounds (VCs) to outcompete other microorganisms in the natural environment. By investigating the cellular mechanism regulating the production of these weapons, we identified the two-component system GacS/GacA. Indeed, GacS cellular membrane sensor plays a crucial role in regulating T6SS activity and VC emission. Among the latter, 1-undecene and hydrogen cyanide are strong aerial inhibitors of the Legionella human pathogen and the Phytophtora infestans major plant pest, respectively. The aim is to improve the understanding of the regulation of these volatile molecule emission and the critical role of a global regulator in both plant and human health.

Opposing response of biogenic volatile organic compound and CO2 emissions to nitrogen addition during decomposition of two litter species

Opposing response of biogenic volatile organic compound and CO2 emissions to nitrogen addition during decomposition of two litter species

Computational Study of the 1,3-Dipolar Cycloaddition between Criegee Intermediates and Linalool: Atmospheric Implications.

In this research, we investigated the essential role of biogenic volatile organic compound emissions in regulating tropospheric ozone levels, atmospheric chemistry, and climate dynamics. We explored linalool ozonolysis and secondary organic aerosol formation mechanisms, providing key insights into atmospheric processes. Computational techniques, such as density functional theory calculations and molecular dynamics simulations, were employed for the analysis. Our study delves into the energetic and mechanistic aspects of the 1,3-dipolar cycloadditions involving linalool and its ozonolysis byproducts, known as Criegee intermediates. A total of 24 reactions were analyzed from the three possible Criegee intermediates formed, resulting from different reactant orientations and their endo/exo isomers. We found that only four of these reactions exhibit large rate constants that can compete with tropospheric reactions. This reactivity pattern was characterized by analyzing reactivity indices from conceptual density functional theory and determining that electron flux originates from linalool to the Criegee intermediates. Greater electrophilicity in the Criegee intermediates results in a lower reaction activation energy, confirmed by the global electrophilicity index. Furthermore, using the activation strain model and energy decomposition analysis, we found that differences in activation energies were primarily driven by nonorbital energy factors. Finally, molecular dynamics simulations showed that the final cycloaddition adducts of the most favorable 1,3-dipolar cycloaddition interact favorably with water molecules in an exergonic process, adsorbing up to 92% of the water molecules after 20 ns. Our findings provide insights that enhance our understanding of the interactions between natural emissions and atmospheric constituents.

Leaf Size Determines Damage- and Herbivore-Induced Volatile Emissions in Maize.

Stress-induced plant volatiles play an important role in mediating ecological interactions between plants and their environment. The timing and location of the inflicted damage is known to influence the quality and quantity of induced volatile emissions. However, how leaf characteristics and herbivore feeding behaviour interact to shape volatile emissions is not well understood. Using a high-throughput volatile profiling system with high temporal resolution, we examined how mechanical damage and herbivore feeding on different leaves shape plant-level volatile emission patterns in maize. We then tested feeding patterns and resulting consequences on volatile emissions with two generalist herbivores (Spodoptera exigua and Spodoptera littoralis), and assessed whether feeding preferences are associated with enhanced herbivore performance. We found maize seedlings emit more volatiles when larger leaves are damaged. Larger leaves emitted more volatiles locally, which was the determining factor for higher plant-level emissions. Surprisingly, both S. exigua and S. littoralis preferentially consumed larger leaves, and thus maximize plant volatile emission without apparent growth benefits. Together, these findings provide an ecophysiological and behavioural mechanism for plant volatile emission patterns, with potentially important implications for volatile-mediated plant-environment interactions.

Profiles of Killer Systems and Volatile Organic Compounds of Rowanberry and Rosehip-Inhabiting Yeasts Substantiate Implications for Biocontrol.

Yeasts produce numerous antimicrobial agents such as killer toxins, volatile organic compounds (VOCs), and other secondary metabolites, establishing themselves in developing natural and sustainable biocontrol strategies for agriculture and food preservation. This study addressed the biocontrol potential of yeasts, isolated from spontaneous fermentations of rosehips (Rosa canina L.) and rowanberries (Sorbus aucuparia L.), focusing on their killer phenotypes and VOCs production. Yeasts were isolated using spontaneous fermentations with Hanseniaspora uvarum and Metschnikowia pulcherrima identified as the dominant species, comprising approximately 70% of the yeast population. Among 163 isolated strains, 20% demonstrated killing activity, with Saccharomyces cerevisiae exhibiting the strongest killing efficiency, as well as Pichia anomala and M. pulcherrima showing broad-spectrum antagonistic activity. This study identified dsRNA-encoded killer phenotypes in S. cerevisiae, S. paradoxus, and Torulaspora delbrueckii, revealing multiple distinct killer toxin types. The biocontrol potential of wild berry-inhabiting yeasts was demonstrated in a real food system, grape juice, where the S. cerevisiae K2-type killer strain significantly reduced fungal contaminants. The selected H. uvarum, M. pulcherrima, S. cerevisiae, and S. paradoxus yeast strains representing both berries were applied for VOC analysis and identification by gas chromatography-linked mass spectrometry. It was revealed that the patterns of emitted volatiles are yeast species-specific. Statistically significant differences between the individual VOCs were observed among killing phenotype-possessing vs. non-killer S. paradoxus yeasts, thus revealing the involvement of killer systems in multi-level biocontrol enablement. The performed studies deepen our understanding of potential yeast biocontrol mechanisms, highlight the importance of produced antimicrobials and volatiles in ensuring antagonistic efficacy, and prove the relevance of isolated biocontrol yeasts for improving food safety.

Application of Space-Based Glyoxal Observation for Estimating Global Nonmethane Volatile Organic Compounds Emissions from Urban Sources and Biomass Burning

Application of Space-Based Glyoxal Observation for Estimating Global Nonmethane Volatile Organic Compounds Emissions from Urban Sources and Biomass Burning

Tomato Defenses Under Stress: The Impact of Salinity on Direct Defenses Against Insect Herbivores.

Abiotic stressors, such as salt stress, can reduce crop productivity, and when combined with biotic pressures, such as insect herbivory, can exacerbate yield losses. However, salinity-induced changes to plant quality and defenses can in turn affect insect herbivores feeding on plants. This study investigates how salinity stress in tomato plants (Solanum Lycopersicum cv. Better Boy) impacts the behavior and performance of a devastating insect pest, the tomato fruitworm caterpillar (Helicoverpa zea). Through choice assays and performance experiments, we demonstrate that salt-stressed tomato plants are poor hosts for H. zea, negatively affecting caterpillar feeding preferences and growth rates. While changes in plant nutritional quality were observed, the primary factor influencing insect performance appears to be direct ionic toxicity, which significantly impairs multiple life history parameters of H. zea including survival, pupation, adult emergence, and fecundity. Plant defense responses show complex interactions between salt stress and herbivory, with two proteinase inhibitor genes - PIN2 and AspPI, showing a higher induced response to insect herbivory under salt conditions. However, plant defenses do not seem to be the main driver of reduced caterpillar performance on salt-treated plants. Furthermore, we report reduced oviposition by H. zea moths on salt-treated plants, which was correlated with altered volatile emissions. Our findings reveal that H. zea exhibits optimal host selection behaviours for both larval feeding and adult oviposition decisions, which likely contribute to its success as an agricultural pest. This research provides insights into the complex interactions between abiotic stress, plant physiology, and insect behaviour, with potential implications for pest management strategies in saline agricultural environments.

Temporal variation in floral scent emission of a woody plant and flower visiting behaviour of male and female flies

Most flowering plants rely on insects for pollination and flowers are advertised using odor and visual cues. Flower scent consists of a complex blend of volatile compounds of which the emission can vary over time (and space) within species. Pollinator foraging behaviour, such as the choice for flowers and the time spent gathering nectar and/or pollen, can also show significant intraspecific variation. Underlying variation in pollinator behaviour can be sensory or foraging‐related biases among sexes or individuals. Investigating the role of temporal variation in floral volatiles on visitation behaviour of male and female pollinators is largely unexplored. We examined temporal variation in the emission of scent of yellowhorn Xanthoceras sorbifolium flowers, visitation behaviour of its main pollinators, male and female Bibio rufiventris flies, and their responses to floral volatile compounds using field experiments and controlled bioassays. Our results show significant daily fluctuations in floral volatile emission of X. sorbifolium in the field. The relative emission of 1‐octen‐3‐ol, 1‐octanol, benzaldehyde, and α‐farnesene increased from 9:00 to 15:00 h, while (Z)‐3‐hexen‐1‐ol, (E)‐2‐hexen‐1‐ol, (E)‐2‐hexenal, 2‐methyl‐6‐hepten‐1‐ol, (E)‐2‐nonenal, 2,6,6‐trimethyl‐2‐cyclohexene‐1‐methanol, (E)‐2‐nonenal and (E,Z)‐2,6‐nonadienal decreased. In concert, we observed an increase in visits and visitation duration for male pollinators, but a decrease for female visitation duration. Pollinators exhibited sex‐specific responses to floral volatiles, with attraction to 1‐octen‐3‐ol and 1‐octanol for B. rufiventris males, while (E)‐2‐nonenal, (E,Z)‐2,6‐nonadienal and (E)‐2‐hexenal attracted females. Our study shows that temporal variation in floral scent may explain differences in flower visitation by male and female pollinators through sex‐specific responses to floral volatiles. Investigating sex‐based differences exhibited by pollinators and temporal variation in floral scent emission will help understand the dynamic nature of plant–pollinator interactions.

Intraspecific and intra-individual chemodiversity and phenotypic integration of terpenes across plant parts and development stages in an aromatic plant.

Some plant species produce an extraordinary diversity of specialized metabolites. The diverse class of terpenes is characteristic for many aromatic plants, and terpenes can occur as both emitted volatiles and stored compounds. Little is known about how intraspecific chemodiversity and phenotypic integration of both emitted volatile and stored terpenes differ intra-individually across plant development and between different plant parts, and studies considering both spatial and temporal scales are scarce. To comprehensively investigate this diversity, we used the aromatic plant Tanacetum vulgare that differs in foliar terpene composition, forming chemotypes. We collected emitted volatile terpenes of both young and old leaves during the rosette, elongated stem, and flowering stage as well as emitted volatiles of flower heads at the flowering stage. Moreover, at the flowering stage, stored terpenes were extracted from different plant parts, including roots. Terpene profiles were measured with (TD)-GC-MS. The composition of emitted volatile terpenes depended on the specific combination of chemotype, plant part, and time point; the chemodiversity of emitted volatiles was mainly affected by the development stage, indicating that at specific development stages individuals require a higher chemodiversity, potentially to mediate different interactions. For stored terpenes, intra-individual differences, mostly between aboveground and belowground plant parts, were found only for specific components of chemodiversity, such as richness and evenness, but not for functional Hill diversity. Phenotypic integration differed mainly across development stage and plant part for emitted volatile terpenes, and across chemotype and plant part for stored terpenes. Our results suggest that intraspecific chemodiversity of terpenes and their integration is a highly plastic trait that may be shaped in dependence of interactions with the environment, and the value that each plant part contributes to the fitness of an individual. Such variation on different scales, both spatially and temporally, should be considered in chemical ecological studies.

Novel Perspectives for Sensory Analysis Applied to Piperaceae and Aromatic Herbs: A Pilot Study.

Spices and aromatic herbs are important components of everyday nutrition in several countries and cultures, thanks to their capability to enhance the flavor of many dishes and convey significant emotional contributions by themselves. Indeed, spices as well as aromatic herbs are to be considered not only for their important values of antimicrobial agents or flavor enhancers everybody knows, but also, thanks to their olfactory and gustatory spectrum, as drivers to stimulate the consumers' memories and, in a stronger way, emotions. Considering these unique characteristics, spices and aromatic herbs have caught the attention of consumer scientists and experts in sensory analysis for their evaluation using semi-quantitative approaches, with interesting evidence. In this pilot study as a first step, each studied botanical, belonging to Piperaceae or aromatic herbs, has been subjected to headspace solid phase micro-extraction (HS-SPME) coupled with gas-chromatography mass spectrometry (GC-MS) analysis to assess their spontaneous volatile emission, representing the complex chemical pattern, which encounters the consumers' olfactory perception. Furthermore, the present investigation, performed on 12 individuals, outlines the administration of a pilot study, merging the typical sensory analysis with emotional data collection and the innovative contribution related to the study around the Autonomic and Central Nervous System activation in consumers, performed using wearable technologies and related signal processing. The results obtained by our study, beyond demonstrating the feasibility of the approach, confirmed, both in terms of emotional responses and biomedical signals, the significant emotional potential of spices and aromatic herbs, most of which featuring an overall positive valence, yet with inter-subjects' variations. Future investigations should aim to increase the number of volunteers evaluated with such an approach to draw more stable conclusions and attempting a customization of product preferences based on both implicit and explicit sensory responses.

Natural selection on floral volatiles and other traits can change with snowmelt timing and summer precipitation.

Climate change is disrupting floral traits that mediate mutualistic and antagonistic species interactions. Plastic responses of these traits to multiple shifting conditions may be adaptive, depending on natural selection in new environments. We manipulated snowmelt date over three seasons (3-11 d earlier) in factorial combination with growing-season precipitation (normal, halved, or doubled) to measure plastic responses of volatile emissions and other floral traits in Ipomopsis aggregata. We quantified how precipitation and early snowmelt affected selection on traits by seed predators and pollinators. Within years, floral emissions did not respond to precipitation treatments but shifted with snowmelt treatment depending on the year. Across 3 yr, emissions correlated with both precipitation and snowmelt date. These effects were driven by changes in soil moisture. Selection on several traits changed with earlier snowmelt or reduced precipitation, in some cases driven by predispersal seed predation. Floral trait plasticity was not generally adaptive. Floral volatile emissions shifted in the face of two effects of climate change, and the new environments modulated selection imposed by interacting species. The complexity of the responses underscores the need for more studies of how climate change will affect floral volatiles and other floral traits.

Active phytoextraction of toluene shifts the microbiome and enhances degradation capacity in hybrid poplar.

Hybrid poplars are widely recognized for their effectiveness in remediating subsurface aromatic hydrocarbon contaminants, including benzene, toluene, ethylbenzene, and xylene isomers (BTEX). While BTEX compounds are frequently found in the transpiration streams of poplars at contaminated sites, the microbial dynamics within these trees, particularly in response to hydrocarbon exposure, remain underexplored. This study utilized high-throughput amplicon sequencing to investigate the trunk microbiome in hybrid poplars at a field-scale toluene phytoremediation site. Across the plant growth season (spring to late summer), we observed a significant seasonal increase in bacterial diversity and richness, particularly in trees located in areas with the highest groundwater and in planta toluene concentrations. During late summer, the microbiomes of these trees were enriched with hydrocarbon-degrading taxa, including Acinetobacter, Pseudomonas, Burkholderia, Sandaracinobacter, and Allorhizobium-Rhizobium, and exhibited enhanced capacities for aerobic toluene degradation based on functional predictions. These findings reveal selective pressures exerted by hydrocarbons on endophytic microbial communities and underscore their role in mitigating volatile contaminant emissions. This study advances our understanding of microbial dynamics in phytoremediation systems and highlights the potential for leveraging endophytes to optimize contaminant degradation.

Simulated Herbivory Induces Volatile Emissions of Oak Saplings, but Parasitoid Communities Vary Mainly Among Forest Sites

We know little about how parasitoids of herbivorous insects use herbivore-induced volatile organic compounds (VOCs) to locate potential hosts on saplings in forests, and how this depends on tree composition. Therefore, we performed an experiment in a forest in Poland where we placed pairs of oak saplings (Quercus robur or Q. petraea) in neighborhoods dominated by oak, beech, or pine trees. We treated one sapling in each pair with the phytohormone methyl jasmonate, which triggers induced responses in plants. We measured the VOC emissions of thirty-six saplings and placed Malaise traps with five of the pairs. We counted the parasitoids in the ten Malaise samples and identified them using DNA metabarcoding. We used parasitoids reared from oak-feeding caterpillars to estimate which species are associated with oaks. The two species of oak differed in both the proportions of VOCs and the specific VOCs that were elevated following the application of methyl jasmonate. We did not detect any overall effects of treatment on parasitoid abundance or community composition. However, some parasitoid species that were associated with oaks appeared to be attracted to elevated emissions of specific induced VOCs. The parasitoid communities differed significantly between sites and showed marginally significant differences between neighborhoods. Overall, our results suggest that parasitoids in the understory are affected by tree composition of the canopy, but the effects of VOC emissions are limited.

Muffled olfactory and sensory cues from the reproductive stage soybean selectively reduce oviposition of a major polyphagous herbivore, fall armyworm (Spodoptera frugiperda).

While the mother knows best/preference performance hypothesis has been well tested in natural ecosystems, how these ecological principles differ in agroecosystems is less explored. In this study, we investigated the ovipositional preference and offspring performance of fall armyworm (FAW) across vegetative and reproductive stages of soybean. We examined trichomes, volatile organic compounds (VOCs) and assessed electroantennogram (EAG) measurements to understand how olfactory responses are affected by volatiles at different phenological stages during photoperiodism (photophase and scotophase). We found that gravid FAW preferred the vegetative compared to reproductive stage of soybean. Although VOC and EAG responses was not statistically different (P > 0.05) between photophase and scotophase, but vegetative stage exhibited significantly (P ≤ 0.05) higher emissions and responses than the reproductive stage during both photophase and scotophase. Additionally, reproductive stage had lower trichomes compared to the vegetative stage. Interestingly, no significant difference was observed in offspring performance between the vegetative and reproductive stages of soybean. This suggests that oviposition preference does not necessarily correlate with offspring performance, which was confirmed through offspring mass and mass gain studies. Olfactory and sensory cues from soybean at reproductive stage reduced oviposition by mother FAW. Collectively, we show that while mother knows best may not fit FAW-Soybean interaction, muffled volatile emission in reproductive stages can have positive consequences for host success. The results from this study will enhance our understanding of FAW behavior across different phenological stages of host plants, that can be used to develop alternative and sustainable management strategies. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Urban Greening and Pollen Allergy: Balancing Health and Environmental Sustainability.

Urban living requires a careful balance between human health and environmental sustainability when selecting urban vegetation. Public gardens and green roofs offer significant environmental benefits, including air filtration, exposure to health-associated microbiota, and mitigation of the urban heat island effect. However, prioritizing allergy-friendly species is crucial to prevent the exacerbation of pollen allergies. This review highlights three primary criteria for selecting vegetation that supports these ecosystem services while minimizing allergy risks. Firstly, reducing the use of many wind-pollinated plants, such as birch trees and grasses, is crucial due to their high pollen production and cross-reactivity with other species, which can exacerbate allergies. In contrast, insect-pollinated plants are generally safer for allergy sufferers. Secondly, cultivating multispecies plant communities with minimal maintenance supports habitats for microbiota and invertebrates, further providing ecosystem services. Lastly, balancing plant gender ratios in urban spaces can help control pollen levels. Together these criteria provide a framework for urban planners to create green spaces that are both environmentally beneficial and allergy friendly. Although this review focuses on European data, the principles discussed have global relevance, reinforcing the need to integrate environmental sustainability with public health considerations in urban planning. Future studies should also investigate the health impacts of plant volatile emissions, explore heat-resistant plant varieties, and assess the ecological risks of invasive species to support sustainable, allergy-friendly urban environments.