Real-World Study of Ragweed Sublingual Immunotherapy in Hungary.

BACKGROUND: Ragweed (Ambrosia elatior) has become invasive in Europe, causing significant respiratory issues. Subcutaneous allergen immunotherapy (SCIT) has long been used to manage pollen allergies, but sublingual immunotherapy (SLIT) has gained interest. OBJECTIVE: This study aimed to evaluate the clinical benefits of ragweed SLIT under real-world in a cohort of Hungarian patients allergic to ragweed pollen. METHODS: We retrospectively reviewed the clinical records of 57 patients during the 2015 and 2016 ragweed pollen seasons. Patients were divided into two groups: Group 1 (n = 29), who had not received immunotherapy, and Group 2 (n = 28), who had previously undergone immunotherapy with another sublingual preparation. All patients were treated with Oraltek® ragweed for 4-6 months, initiating 2-4 months before the pollen season and rest of the period was 2 months of the 2016 pollen season. Symptom score (SS), medication score (MS), and combined symptom and medication score (CSMS) were evaluated intra- and intergroup. RESULTS: Pollen counts were consistent between 2015 and 2016. All patients showed significant improvement in SS, MS, and CSMS, with a large effect size (>0.8). Group 2 had significantly lower SS and CSMS in 2015 because of prior immunotherapy. By 2016, both groups exhibited marked improvements, with Group 1 showing a 75% improvement in CSMS. No local or systemic reactions were recorded, indicating a high safety profile. CONCLUSIONS: Ragweed SLIT significantly improved symptoms and reduced use of medication in patients allergic to ragweed pollen. The treatment was effective even in patients with previous immunotherapy, with a high benefit-risk ratio demonstrated by the absence of adverse reactions. These findings support the use of Oraltek SLIT for managing ragweed pollen allergy.

Combatting the antigenicity of common ragweed pollen and its primary allergen Amb a 1 with cold atmospheric pressure air plasma.

Airborne allergens, especially those originating from various types of pollen, significantly compromise the health and well-being of individuals on a global scale. Here, cold atmospheric pressure plasma (CAP) created in ambient air was used to treat highly allergenic and invasive Ambrosia artemisiifolia pollen. Immunoassays were used to evaluate the impact of CAP on the principal A. artemisiifolia allergen Amb a 1, demonstrating that > 90 % reduction in antigenicity could be achieved. Chemical analyses using Fourier Transform infrared revealed that CAP induced significant alterations to proteins on the surface of pollen grains, resulting in a 43 % increase in the amide I peak area and a 57 % increase in the amide II peak area. These findings were corroborated by Raman and X-ray photoelectron spectroscopy, which indicated that the protein modifications induced by CAP were due to carbonylation and nitration/nitrosylation processes. Beyond protein transformations, CAP also induced notable oxidation and modification of lipid-like compounds, polysaccharides and sporopollenin. Evident transformations at the chemical level translated into morphological changes at the grain surface, manifesting as increased roughness via significant outer-layer etching. These findings underscore the potential of CAP technology as a viable approach for mitigating against the allergenicity of pollen, providing a deeper understanding into the underlying chemical mechanisms.

The Impact of High-Fructose Diet and Co-Sensitization to House Dust Mites and Ragweed Pollen on the Modulation of Airway Reactivity and Serum Biomarkers in Rats.

The topic of ragweed pollen (RW) versus house dust mites (HDMs) has often been deliberated, but the increasing incidence of co-sensitization between them has been scarcely addressed. Utilizing Sprague Dawley rats, we explored the effects of co-sensitization with the combination of HDMs and RW pollen extracts in correlation with high-fructose diet (HFrD) by in vitro tracheal reactivity analysis in isolated organ bath and biological explorations. Our findings unveiled interrelated connections between allergic asthma, dyslipidemia, and HFrD-induced obesity, shedding light on their compounding role through inflammation. The increased CRP values and airway hyperresponsiveness to the methacholine challenge suggest a synergistic effect of obesity on amplifying the existing inflammation induced by asthma. One of the major outcomes is that the co-sensitization to HDMs and RW pollen led to the development of a severe allergic asthma phenotype in rats, especially in those with HFrD. Therefore, the co-sensitization to these allergens as well as the HFrD may play a crucial role in the modulation of systemic inflammation, obesity, and airway reactivity.

Cross-Reactivity of Ragweed Pollen Calcium-Binding Proteins and IgE Sensitization in a Ragweed-Allergic Population from Western Romania.

Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as calcium-binding proteins (polcalcins) and progression to more severe symptoms. We aimed to detect IgE sensitization to recombinant Amb a 9 and Amb a 10 in a Romanian population, to assess their potential clinical relevance and cross-reactivity, as well as to investigate the relation with clinical symptoms. rAmb a 9 and rAmb a 10 produced in Escherichia coli were used to detect specific IgE in sera from 87 clinically characterized ragweed-allergic patients in ELISA, for basophil activation experiments and rabbit immunization. Rabbit rAmb a 9- and rAmb a 10-specific sera were used to detect possible cross-reactivity with rArt v 5 and reactivity towards ragweed and mugwort pollen extracts. The results showed an IgE reactivity of 25% to rAmb a 9 and 35% to rAmb a 10. rAmb a 10 induced basophil degranulation in three out of four patients tested. Moreover, polcalcin-negative patients reported significantly more skin symptoms, whereas polcalcin-positive patients tended to report more respiratory symptoms. Furthermore, both rabbit antisera showed low reactivity towards extracts and showed high reactivity to rArt v 5, suggesting strong cross-reactivity. Our study indicated that recombinant ragweed polcalcins might be considered for molecular diagnosis.

Non-Specific Lipid Transfer Protein Amb a 6 Is a Source-Specific Important Allergenic Molecule in Ragweed Pollen.

Pollen from common ragweed is an important allergen source worldwide and especially in western and southern Romania. More than 100 million patients suffer from symptoms of respiratory allergy (e.g., rhinitis, asthma) to ragweed pollen. Among the eleven characterized allergens, Amb a 6 is a non-specific lipid transfer protein (nsLTP). nsLTPs are structurally stable proteins in pollen and food from different unrelated plants capable of inducing severe reactions. The goal of this study was to produce Amb a 6 as a recombinant and structurally folded protein (rAmb a 6) and to characterize its physicochemical and immunological features. rAmb a 6 was expressed in Spodoptera frugiperda Sf9 cells as a secreted protein and characterized by mass spectrometry and circular dichroism (CD) spectroscopy regarding molecular mass and fold, respectively. The IgE-binding frequency towards the purified protein was evaluated using sera from 150 clinically well-characterized ragweed-allergic patients. The allergenic activities of rAmb a 6 and the nsLTP from the weed Parietaria judaica (Par j 2) were evaluated in basophil activation assays. rAmb a 6-specific IgE reactivity was associated with clinical features. Pure rAmb a 6 was obtained by insect cell expression. Its deduced molecular weight corresponded to that determined by mass spectrometry (i.e., 10,963 Da). rAmb a 6 formed oligomers as determined by SDS-PAGE under non-reducing conditions. According to multiple sequence comparisons, Amb a 6 was a distinct nsLTP with less than 40% sequence identity to currently known plant nsLTP allergens, except for nsLTP from Helianthus (i.e., 52%). rAmb a 6 is an important ragweed allergen recognized by 30% of ragweed pollen allergic patients. For certain patients, rAmb a 6-specific IgE levels were higher than those specific for the major ragweed allergen Amb a 1 and analysis also showed a higher allergenic activity in the basophil activation test. rAmb a 6-positive patients suffered mainly from respiratory symptoms. The assumption that Amb a 6 is a source-specific ragweed allergen is supported by the finding that none of the patients showing rAmb a 6-induced basophil activation reacted with Par j 2 and only one rAmb a 6-sensitized patient had a history of plant food allergy. Immunization of rabbits with rAmb a 6 induced IgG antibodies which strongly inhibited IgE binding to rAmb a 6. Our results demonstrate that Amb a 6 is an important source-specific ragweed pollen allergen that should be considered for diagnosis and allergen-specific immunotherapy of ragweed pollen allergy.

Heterogenous Induction of Blocking Antibodies against Ragweed Allergen Molecules by Allergen Extract-Based Immunotherapy Vaccines.

Currently, allergen-specific immunotherapy (AIT) for ragweed allergy is still based on natural allergen extracts. This study aimed to analyse the ability of four commercially available AIT vaccines (CLUSTOID, TYRO-SIT, POLLINEX Quattro Plus and Diater Depot) regarding their ability to induce IgG antibodies against ragweed pollen allergens in rabbits. Accordingly, the IgG reactivity of AIT-induced rabbit sera was tested for ten different ragweed pollen allergens (Amb a 1, 3, 4, 5, 6, 8, 9, 10, 11 and 12) by an ELISA. Furthermore, the ability of rabbit AIT-specific sera to block allergic patients' IgE binding to relevant ragweed allergens (Amb a 1, 4, 6, 8 and 11) and to inhibit allergen-induced basophil activation was evaluated by an IgE inhibition ELISA and a mediator release assay. Only two AIT vaccines (Diater Depot > CLUSTOID) induced relevant IgG antibody levels to the major ragweed allergen Amb a 1. The IgG responses induced by the AIT vaccines against the other ragweed allergens were low and highly heterogeneous. Interestingly, the kinetics of IgG responses were different among the AIT vaccines and even within one AIT vaccine (Diater Depot) for Amb a 1 (long-lasting) versus Amb a 8 and Amb a 11 (short-lived). This could be due to variations in allergen contents, the immunogenicity of the allergens, and different immunization protocols. The IgE inhibition experiments showed that rabbit AIT-specific sera containing high allergen-specific IgG levels were able to inhibit patients' IgE binding and prevent the mediator release with Diater Depot. The high levels of allergen-specific IgG levels were associated with their ability to prevent the recognition of allergens by patients' IgE and allergen-induced basophil activation, indicating that the measurement of allergen-induced IgG could be a useful surrogate marker for the immunological efficacy of vaccines. Accordingly, the results of our study may be helpful for the selection of personalized AIT vaccination strategies for ragweed-allergic patients.

Insect Cell-Expressed Major Ragweed Allergen Amb a 1.01 Exhibits Similar Allergenic Properties to Its Natural Counterpart from Common Ragweed Pollen.

Common ragweed pollen allergy has become a health burden worldwide. One of the major allergens in ragweed allergy is Amb a 1, which is responsible for over 90% of the IgE response in ragweed-allergic patients. The major allergen isoform Amb a 1.01 is the most allergenic isoform in ragweed pollen. So far, no recombinant Amb a 1.01 with similar allergenic properties to its natural counterpart (nAmb a 1.01) has been produced. Hence, this study aimed to produce a recombinant Amb a 1.01 with similar properties to the natural isoform for improved ragweed allergy management. Amb a 1.01 was expressed in insect cells using a codon-optimized DNA construct with a removable N-terminal His-Tag (rAmb a 1.01). The recombinant protein was purified by affinity chromatography and physicochemically characterized. The rAmb a 1.01 was compared to nAmb a 1.01 in terms of the IgE binding (enzyme-linked immunosorbent assay (ELISA), immunoblot) and allergenic activity (mediator release assay) in well-characterized ragweed-allergic patients. The rAmb a 1.01 exhibited similar IgE reactivity to nAmb a 1.01 in different IgE-binding assays (i.e., IgE immunoblot, ELISA, quantitative ImmunoCAP inhibition measurements). Furthermore, the rAmb a 1.01 showed comparable dose-dependent allergenic activity to nAmb a 1.01 regarding basophil activation. Overall, the results showed the successful expression of an rAmb a 1.01 with comparable characteristics to the corresponding natural isoform. Our findings provide the basis for an improvement in ragweed allergy research, diagnosis, and immunotherapy.

Environmental impacts on intraspecific variation in Ambrosia artemisiifolia genome size in Slovakia, Central Europe.

The quantity of DNA in angiosperms exhibits variation attributed to many external influences, such as environmental factors, geographical features, or stress factors, which exert constant selection pressure on organisms. Since invasive species possess adaptive capabilities to acclimate to novel environmental conditions, ragweed (Ambrosia artemisiifolia L.) was chosen as a subject for investigating their influence on genome size variation. Slovakia has diverse climatic conditions, suitable for testing the hypothesis that air temperature and precipitation, the main limiting factors of ragweed occurrence, would also have an impact on its genome size. Our results using flow cytometry confirmed this hypothesis and also found a significant association with geographical features such as latitude, altitude, and longitude. We can conclude that plants growing in colder environments farther from oceanic influences exhibit smaller DNA amounts, while optimal growth conditions result in a greater variability in genome size, reflecting the diminished effect of selection pressure.

The Essential Oil Compositions of Ambrosia acanthicarpa Hook., Artemisia ludoviciana Nutt., and Gutierrezia sarothrae (Pursh) Britton & Rusby (Asteraceae) from the Owyhee Mountains of Idaho.

As part of our interest in the volatile phytoconstituents of aromatic plants of the Great Basin, we have obtained essential oils of Ambrosia acanthicarpa (three samples), Artemisia ludoviciana (12 samples), and Gutierrezia sarothrae (six samples) from the Owyhee Mountains of southwestern Idaho. Gas chromatographic analyses (GC-MS, GC-FID, and chiral GC-MS) were carried out on each essential oil sample. The essential oils of A. acanthicarpa were dominated by monoterpene hydrocarbons, including α-pinene (36.7-45.1%), myrcene (21.6-25.5%), and ß-phellandrene (4.9-7.0%). Monoterpene hydrocarbons also dominated the essential oils of G. sarothrae, with ß-pinene (0.5-18.4%), α-phellandrene (2.2-11.8%), limonene (1.4-25.4%), and (Z)-ß-ocimene (18.8-39.4%) as major components. The essential oils of A. ludoviciana showed wide variation in composition, but the relatively abundant compounds were camphor (0.1-61.9%, average 14.1%), 1,8-cineole (0.1-50.8%, average 11.1%), (E)-nerolidol (0.0-41.0%, average 6.8%), and artemisia ketone (0.0-46.1%, average 5.1%). This is the first report on the essential oil composition of A. acanthicarpa and the first report on the enantiomeric distribution in an Ambrosia species. The essential oil compositions of A. ludoviciana and G. sarothrae showed wide variation in composition in this study and compared with previous studies, likely due to subspecies variation.

Ambrosia grayi as a new alien causal species in Israel: plant biology and chemical management.

BACKGROUND: Ambrosia grayi is a perennial weed native to northern Mexico, which can also be found in the Great Plains of the US. Outside the Americas, A. grayi has only been documented in Israel, where it is currently categorized as a casual species at advanced eradication stages. Here, we studied the plant biology and chemical weed management options of A. grayi. RESULTS: Only large achenes of A. grayi (~5% of all achenes) contain seeds; moreover, the viability of seeds extracted from large achenes was ~25%. Examination of plant anatomy revealed that underground vegetative segments show an anatomical structure of stems (rhizomes) with anomalous secondary growth. The optimal (night/day) temperature for the emergence of A. grayi rhizomes was 20/30 °C, and the emergence rate increased under elevated temperatures. Emergence may occur at different soil moisture content (25-60%); rhizomes were able to emerge even after 1 month of drought conditions (20%, 25% and 30%). Herbicide combinations, such as fluroxypyr + glufosinate, fluroxypyr + glyphosate, and glyphosate + saflufenacil + surfactant, were tested under quarantine conditions and showed high efficacy for the control of A. grayi. However, the efficiency of these treatments was highly correlated with plant growth stage. CONCLUSION: In Israel, the spread of A. grayi occurs mainly via rhizomes that can emerge under a wide range of temperatures and soil moisture conditions. Data regarding herbicide efficacy will aid in improving the eradication efforts taken by Israel's Plant Protection and Inspection Services. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sublingual Tablet Immunotherapy Improves Quality of Life in Adults With Allergic Rhinoconjunctivitis.

BACKGROUND: Allergic rhinitis with or without conjunctivitis can negatively impact many aspects of quality of life (QoL). The efficacy and safety of standardized quality (SQ) sublingual immunotherapy (SLIT) tablets have been confirmed across large clinical trials in adults with grass, tree, ragweed, and house dust mite (HDM) allergic rhinitis with or without conjunctivitis. OBJECTIVE: This pooled analysis investigates whether the reduction in symptom burden found across the clinical trials is supported by improvements in QoL. METHODS: A total of 11 phase II/III randomized placebo-controlled trials across the SQ grass, tree, ragweed, and HDM SLIT tablets (grass: N = 3179; ragweed: N = 767; tree: N = 634; HDM: N = 2221) were included. QoL was assessed using the standardized Rhinitis Quality of Life Questionnaire (RQLQ), with the exception of 3 grass trials, which used the nonstandardized version. The overall RQLQ scores were expressed as a mean of 7 domains. In the pooled analysis, treatment was used as fixed effect; and the trial, and the interaction between region/country and trial as random effects. RESULTS: The pooled analysis showed consistent and statistically significant improvements in overall RQLQ scores across all 4 SQ SLIT tablets versus placebo (pooled estimate [95% CI], P value-grass: -0.20 [-0.28 to -0.12], P < .001; tree: -0.42 [-0.58 to -0.26], P < .001; ragweed: -0.36 [-0.55 to -0.17], P < .001; HDM: -0.28 [-0.39 to -0.17], P < .001). Furthermore, significant improvements versus placebo for all 4 SQ SLIT tablets were seen across the 7 individual domains. CONCLUSIONS: The proven efficacy of SQ SLIT tablets to reduce symptoms across 4 of the most common respiratory allergens is supported by concurrent significant improvements in RQLQ scores overall and for all 7 domains.

Radiation-Detoxified Form of Endotoxin Effectively Activates Th1 Responses and Attenuates Ragweed-Induced Th2-Type Airway Inflammation in Mice.

Urbanization with reduced microbial exposure is associated with an increased burden of asthma and atopic symptoms. Conversely, environmental exposure to endotoxins in childhood can protect against the development of allergies. Our study aimed to investigate whether the renaturation of the indoor environment with aerosolized radiation-detoxified lipopolysaccharide (RD-LPS) has a preventative effect against the development of ragweed-induced Th2-type airway inflammation. To explore this, cages of six-week-old BALB/c mice were treated daily with aerosolized native LPS (N-LPS) or RD-LPS. After a 10-week treatment period, mice were sensitized and challenged with ragweed pollen extract, and inflammatory cell infiltration into the airways was observed. As dendritic cells (DCs) play a crucial role in the polarization of T-cell responses, in our in vitro experiments, the effects of N-LPS and RD-LPS were compared on human monocyte-derived DCs (moDCs). Mice in RD-LPS-rich milieu developed significantly less allergic airway inflammation than mice in N-LPS-rich or common environments. The results of our in vitro experiments demonstrate that RD-LPS-exposed moDCs have a higher Th1-polarizing capacity than moDCs exposed to N-LPS. Consequently, we suppose that the aerosolized, non-toxic RD-LPS applied in early life for the renaturation of urban indoors may be suitable for the prevention of Th2-mediated allergies in childhood.

Artificial light at night reduces earthworm activity but increases growth of invasive ragweed.

BACKGROUND: Artificial light at night, also referred to as light pollution (LP), has been shown to affect many organisms. However, little is known about the extent to which ecological interactions between earthworms and plants are altered by LP. We investigated the effects of LP on anecic earthworms (Lumbricus terrestris) that come to the surface at night to forage and mate, and on the germination and growth of the invasive and allergenic ragweed (Ambrosia artemisiifolia). In a full factorial pot experiment in the greenhouse, we tested four factors and their interactions: LP (5 lux vs. 0 lux at night), earthworms (two individuals vs. none), plant species (seeding of ragweed only vs. mixed with Phacelia seeds) and sowing depth (seed placed at the surface vs. in 5 cm depth). Data were analysed using Generalized Linear (Mixed) Models and multifactorial ANOVAs with soil parameters as covariates. RESULTS: Light pollution reduced earthworm surface activity by 76% as measured by casting activity and toothpick index; 85% of mating earthworms were observed in the absence of LP. Light pollution in interaction with earthworms reduced ragweed germination by 33%. However, LP increased ragweed height growth by 104%. Earthworms reduced ragweed germination especially when seeds were placed on the soil surface, suggesting seed consumption by earthworms. CONCLUSIONS: Our data suggest that anecic earthworms are negatively affected by LP because reduced surface activity limits their ability to forage and mate. The extent to which earthworm-induced ecosystem services or community interactions are also affected by LP remains to be investigated. If the increased height growth of ragweed leads to increased pollen and seed production, it is likely that the competition of ragweed with field crops and the risks to human health will also increase under LP.

Anaphylaxis in Clinical Trials of Sublingual Immunotherapy Tablets.

BACKGROUND: There is no consensus method to identify anaphylaxis in sublingual immunotherapy (SLIT) trials. Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries (SMQs) are standardized groupings of MedDRA terms used in drug safety monitoring. OBJECTIVE: To develop a method to identify potential anaphylaxis in SLIT-tablet trials using SMQ searches and case definitions of anaphylaxis adopted from the National Institute of Allergy and Infectious Disease. METHODS: The SMQ search tool contained 2 criteria including treatment-emergent adverse events (AEs): (1) narrow MedDRA terms related to anaphylaxis and (2) all AEs with broad MedDRA terms from at least 2 of 3 categories (respiratory/skin/cardiovascular) occurring on the same day. Criteria were applied to a pooled data set of all subjects from 48 timothy grass, ragweed, house dust mite, and tree SLIT-tablet trials (SLIT-tablet, N = 8200; placebo, N = 7033). Additional search strategies were any treatment-emergent AE with MedDRA preferred term "hypersensitivity" and epinephrine administrations. Identified potential cases underwent blinded independent medical expert review. Nonanaphylaxis cases were designated local AEs or mild to moderate systemic reactions. RESULTS: Using the SMQ search tool and after subsequent medical review, 8 anaphylaxis cases were identified; 3 were considered treatment-related, resulting in a proportion of anaphylaxis cases/subject of 0.02% (2 of 8200) with SLIT-tablet and 0.01% (1 of 7033) with placebo. One additional anaphylaxis case related to SLIT-tablet was identified by the preferred term "hypersensitivity." The 3 anaphylaxis cases associated with SLIT-tablet treatment were not life-threatening. The epinephrine administration rate was 17 of 8200 (0.2%) with SLIT-tablet treatment and 2 of 7033 (0.03%) with placebo. CONCLUSIONS: SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.

Population genetic differentiation and phenotypic plasticity of Ambrosia artemisiifolia under different nitrogen levels.

Rapid adaptive evolution and phenotypic plasticity are two mechanisms that often underlie invasiveness of alien plant species, but whether they can co-occur within invasive plant populations under altered environmental conditions such as nitrogen (N) enrichment has seldom been explored. Latitudinal clines in plant trait responses to variation in environmental factors may provide evidence of local adaptation. Here, we inferred the relative contributions of phenotypic plasticity and local adaptation to the performance of the invasive plant Ambrosia artemisiifolia under different soil N levels, using a common garden approach. We grew A. artemisiifolia individuals raised from seeds that were sampled from six invasive populations along a wide latitudinal cline in China (23°42' N to 45°43' N) under three N (0, 5, and 10 g N m-2 ) levels in a common garden. Results show significant interpopulation genetic differentiation in plant height, number of branches, total biomass, and transpiration rate of the invader A. artemisiifolia across the N treatments. The populations also expressed genetic differentiation in basal diameter, growth rate, leaf area, seed width, root biomass, aboveground biomass, stomatal conductance, and intercellular CO2 concentration regardless of N treatments. Moreover, plants from different populations of the invader displayed plastic responses in time to first flower, hundred-grain weight, net photosynthetic rate, and relative biomass allocation to roots and shoots and seed length under different N treatments. Additionally, individuals of A. artemisiifolia from higher latitudes grew shorter and allocated less biomass to the roots regardless of N treatment, while latitudinal cline (or lack thereof) in other traits depended on the level of N in which the plants were grown. Overall, these results suggest that rapid adaptive evolution and phenotypic plasticity in the various traits that we quantified may jointly contribute to invasiveness of A. artemisiifolia under different levels of N availability. More broadly, the results support the idea that phenotypic plasticity and rapid adaptive evolution can jointly enable invasive plants to colonize a wide range of environmental conditions.

Is intraspecific trait differentiation in Parthenium hysterophorus a consequence of hereditary factors and/or phenotypic plasticity?

Of the various strategies adopted by an invasive plant species for expanding its niche breadth, phenotypic differentiation (either due to plasticity and/or adaptive evolution) is proven to be the most successful. Lately, we studied the persistence of substantial morpho-functional variations within the individuals of alien invasive plant, Parthenium hysterophorus in Chandigarh, India, through field surveys. Based on observed differences, the individuals were categorized into two morphotypes, PA and PB. PA had higher leaf area, leaf biomass, and chlorophyll content as compared with PB. However, PB had a higher stem circumference, stem specific density, twig dry matter content, profuse branching, bigger canopy, and better reproductive output than PA. To substantiate the persistence of intraspecific variations in P. hysterophorus and to deduce the possible genesis of these variations, we propagated both the morphotypes under experimental conditions in winter and summer. Apart from the key morpho-functional differences observed during the field studies, protein and carbohydrate metabolism were studied in leaves and roots of the propagated plants. Differences in plant metabolism were observed only during the early growth period, whereas the morpho-functional traits varied in the mature flowering plants. The effect of growth season was highly significant on all the studied morpho-functional and biochemical parameters (p ≤ 0.05). Parent morphotypes (P) and interactions between morphotypes and seasons significantly affected several growth parameters (p ≤ 0.05). The analyses revealed that the contrasting growth conditions at the time of transplantation and early growth may regulate the phenotype of P. hysterophorus. The pattern of intraspecific variations observed during the study is justified to consider morphotype PA as winter biotype and morphotype PB as summer biotype of P. hysterophorus. The study points towards the role of plasticity or a combination of genetic and environmental (G × E) factors in producing the phenotypic variability observed in the population of P. hysterophorus.

Extracts and Residues of Common Ragweed (Ambrosia artemisiifolia L.) Cause Alterations in Root and Shoot Growth of Crops.

Following the novel weapon hypothesis, the invasiveness of non-native species, such as common ragweed (Ambrosia artemisiifolia L.) can result from a loss of natural competitors due to the production of chemical compounds, which negatively affect native communities. Particularly the genus Ambrosia produces several types of organic compounds, which have the potential to inhibit germination and growth of other plants. Subsequent to an assessment of the chemical content of three different ragweed extracts (aqueous shoot and root extracts, as well as essential oil), two different trials on the effects of different concentrations of these extracts, as well as ragweed residues, were conducted on two different mediums (Petri dish vs. soil). In addition, we investigated the impact on the infection potential of Bradyrhizobium japonicum on soybean roots in three different soil types (arable soil, potting soil, and sand). The results showed that the exposure to common ragweed extracts and residues induced changes in the biomass and root production of crops and ragweed itself. Even though crops and ragweed differed in their response behavior, the strongest negative impact on all crops and ragweed was observed with ragweed residues, leading to reductions in biomass and root growth of up to 90%. Furthermore, we found a decrease in the number of rhizobial nodules of up to 48% when soybean was exposed to ragweed root extract.

[Sensitization characteristics of ragweed pollen in Beijing area].

Objective:To investigate the sensitization characteristics of ragweed pollen in patients with allergic rhinitis（AR） and（or） allergic asthma in Beijing area, and to provide basis for the prevention and treatment of ragweed pollen sensitized population. Methods:Patients with allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were retrospectively analyzed in this study. Skin prick test（SPT） was performed with ragweed pollen allergen reagents to compare different ages, genders and respiratory diseases allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results:A total of 9 727 patients were enrolled in the end. The total positive rate of ragweed pollen SPT was 45.50%（4 426/9 727）, the highest positive rate was 65.54% in 13-17 years old group; The positive rate of ragweed pollen SPT was 49.79% in allergic rhinitis combined with asthma patients, followed by 46.46% in allergic rhinitis patients, and the lowest rate was 19.42% in single allergic asthma patients. There were more females than males in both ragweed pollen sensitized and non-ragweed pollen sensitized groups（P<0.05）, and the proportion was higher in 30-39 years old than in other age groups（P<0.05）. Ragweed pollen sensitization was higher than non-ragweed pollen sensitization in the allergic rhinitis group（98.49% vs 94.76%, P<0.05）. Ragweed pollen with other summer and autumn pollen allergens in patients with positive SPT, the top three were Chenopodium pollen, Humulus pollen and Artemisia grandis pollen, with positive rates of 90.42%, 89.63% and 85.40%, respectively. Ragweed combined with other pollen sensitization accounted for 99.57%（4 407/4 426）. Allergic rhinitis was the main disease in patients sensitized with ragweed pollen alone or combined with other pollens, and there was no significant difference between the two groups（94.97% vs 98.50%, P>0.05）. Conclusion:Ragweed pollen is highly sensitized in Beijing area, single ragweed pollen sensitization is rare, often combined with multiple pollen sensitization, and allergic rhinitis is the main disease.

Isolation of compounds from the roots of Ambrosia artemisiifolia and their effects on human cancer cell lines.

Common ragweed (Ambrosia artemisiifolia L.) is an invasive plant in Europe with spreading use in the contemporary folk medicine. The chemical composition of the above-ground parts is extensively studied, however, the metabolites of the roots are less discovered. By multiple chromatographic purification of the root extracts, we isolated thiophene A (1), n-dodecene (2), taraxerol-3-O-acetate (3), α-linoleic acid (4), (+)-pinoresinol (5), and thiophene E (7,10-epithio-7,9-tridecadiene-3,5,11-triyne-1,2-diol) (6). The 1H NMR data published earlier for 1 were supplemented together with the assignment of 13C NMR data. Thiophene E (6), which is reported for the first time from this species, exerted cytotoxic and antiproliferative effects on A-431 epidermoid skin cancer cells, whereas taraxerol-3-O-acetate (3) and α-linoleic acid (4) had slight antiproliferative effect on gynecological cancer cell lines. Thiophene E (6) and taraxerol-3-O-acetate (3) displayed antiproliferative and cytotoxic effects on MRC-5 fibroblast cells. Thiophene E (6) exerted weak antibacterial activity (MIC 25 µg/mL) on MRSA ATCC 43300, on Staphylococcus aureus ATCC 25923, Escherichia coli AG100 and E. coli ATCC 25922 both thiophenes were inactive. Although the isolated compounds exerted no remarkable cytotoxic or antiproliferative activities, the effects on MRC-5 fibroblast cells highlight the necessity of further studies to support the safety of ragweed root.

Distinctive foliar features and volatile profiles in three Ambrosia species (Asteraceae).

MAIN CONCLUSION: Ambrosia species differ both in their trichome types and in metabolic profiles of leaf volatiles. The current study provides tools for easier taxonomic identification of ragweed species. The genus Ambrosia (Asteraceae) includes some of the most noxious allergenic invasive weeds in the world. Due to high polymorphism in this genus, identification of species is often difficult. This study focuses on microscopic investigation of foliar features and GC-MS identification of the main leaf volatile components of three Ambrosia species currently found in Israel-invasive species Ambrosia confertiflora and A. tenuifolia, and transient A. grayi. A. confertiflora and A. tenuifolia have three trichome types: non-glandular trichomes, capitate glandular trichomes and linear glandular trichomes. Their non-glandular trichomes and capitate trichomes have distinct structures and can serve as taxonomic characters. A. grayi (the least successful invader) has only very dense covering trichomes. All three Ambrosia species have secretory structures in their leaf midrib. A. confertiflora, the most problematic invasive plant in Israel, had a ten times higher volatiles content than the other two species. In A. confertiflora, the most abundant volatiles were chrysanthenone (25.5%), borneol (18%), germacrene D and (E)-caryophyllene (both around 12%). In A. tenuifolia, the most abundant volatiles were ß-myrcene (32.9%), (2E)-hexenal (13%) and 1,8-cineole (11.7%). In A. grayi, the most abundant volatiles were ß-myrcene (17.9%), germacrene D (17.8%) and limonene (14%). The three examined species have distinct trichome types and metabolic profiles. Non-glandular trichomes show structural diversification between species and are a good descriptive character. Considering the anthropocentric significance of this highly problematic genus, the current study provides tools for easier identification of ragweed species.