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.

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 β-phellandrene (4.9-7.0%). Monoterpene hydrocarbons also dominated the essential oils of G. sarothrae, with β-pinene (0.5-18.4%), α-phellandrene (2.2-11.8%), limonene (1.4-25.4%), and (Z)-β-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.

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.
CONCLUSIONS: 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.

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.

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.

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.
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.
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.
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.
SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.

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.
目的：了解北京地区变应性鼻炎（allergic rhinitis，AR）和（或）过敏性哮喘患者豚草花粉致敏特点，为豚草花粉致敏患者的防治提供依据。 方法：回顾性分析2017年1月—2019年12月就诊于北京世纪坛医院变态反应科门诊AR和（或）哮喘的患者，采用豚草花粉过敏原试剂进行皮肤点刺试验（skin prick test，SPT），比较不同年龄、性别和呼吸道疾病患者中豚草花粉致敏情况，观察豚草花粉致敏的人群分布特征。采用SAS 9.4软件进行统计学分析。 结果：纳入9 727例患者，豚草花粉SPT总阳性率达45.50%（4 426/9 727），其中13～17岁阳性率最高（65.54%）；AR合并哮喘患者豚草花粉SPT阳性率最高（49.79%），其次为AR（46.46%），单一过敏性哮喘患者最低（19.42%）。豚草花粉致敏和非豚草花粉致敏2组患者均为女性多于男性（P<0.05），30～39岁高于其他年龄段（P<0.05）。AR组豚草花粉致敏高于非豚草花粉致敏（98.49% vs 94.76%，P<0.05）。豚草花粉SPT阳性患者合并其他夏秋花粉过敏原中，排名前3位的是灰藜花粉、葎草花粉和大籽蒿花粉，阳性率分别为90.42%、89.63%和85.40%。豚草合并其他花粉致敏者占99.57%（4 407/4 426）。无论是单一豚草花粉或合并其他花粉致敏的患者均以AR为主，但2组差异无统计学意义（94.97% vs 98.50%，P>0.05）。 结论：北京地区豚草花粉致敏性较高，单一豚草致敏少见，常合并多重花粉致敏，且以AR为主。.

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.

Determining whether the climatic ecological niche of an invasive alien plant is similar to that of the niche occupied by its native population (ecological niche conservatism) is essential for predicting the plant invasion process. Ragweed (Ambrosia artemisiifolia L.) usually poses serious threats to human health, agriculture, and ecosystems within its newly occupied range. We calculated the overlap, stability, unfilling, and expansion of ragweed\'s climatic ecological niche using principal component analysis and performed ecological niche hypothesis testing. The current and potential distribution of A. artemisiifolia was mapped by ecological niche models to identify areas in China with the highest potential risk of A. artemisiifolia invasion. The high ecological niche stability indicates that A. artemisiifolia is ecologically conservative during the invasion. Ecological niche expansion (expansion = 0.407) occurred only in South America. In addition, the difference between the climatic and native niches of the invasive populations is mainly the result of unpopulated niches. The ecological niche model suggests that southwest China, which has not been invaded by A. artemisiifolia, faces an elevated risk of invasion. Although A. artemisiifolia occupies a climatic niche distinct from native populations, the climatic niche of the invasive population is only a subset of the native niche. The difference in climatic conditions is the main factor leading to the ecological niche expansion of A. artemisiifolia during the invasion. Additionally, human activities play a substantial role in the expansion of A. artemisiifolia. Alterations in the A. artemisiifolia niche would help explain why this species is so invasive in China.

Ragweed is an invasive plant in Europe, causing hay fever and asthma in allergic patients. Climate change is predicted to increase expansion and allergenicity. Elevated NO2 induced upregulation of a new allergen in ragweed pollen, an enolase, Amb a 12.
of this study was producing ragweed enolase as a recombinant protein and characterizing its physicochemical and immunological features.
Amb a 12 was designed for E. coli and insect cell expression. Physicochemical features were determined by mass spectrometry, circular dichroism measurements and enzymatic activity assay. Immunological characteristics were determined in ELISA, in a mediator release assay and by investigation of association with clinical symptoms. Common allergen sources were screened for similar proteins.
Ragweed enolase was produced as a 48 kDa protein forming oligomers in both expression systems, showing differences in secondary structure content and enzymatic activity depending on expression system. IgE frequency and allergenicity were low regardless of expression system. Enolase-specific serum bound to similar sized molecules in mugwort, timothy grass and birch pollen, as well as food allergen sources, while highest IgE inhibition was achieved with peach pulp extract.
Amb a 12 had high sequence similarity and comparable IgE frequency to enolase allergens from different sources. 50 kDa proteins were found in other pollen and food allergen sources, suggesting that enolases might be pan-allergens in pollen and plant foods.