Cover crops terminated with roller-crimper to manage Cynodon dactylon and other weeds in vineyards.

BACKGROUND: Using cover crops in organic vineyards can provide many advantages, including weed suppression. However, their effectiveness may depend on the weed community, the cover crop species and the termination method. The most common practice for cover crop termination is shredding, but rapid residue decomposition can allow noxious species like Cynodon dactylon to proliferate during summer and compete with the vines. The use of roller-crimpers as an alternative method can be effective in some cropping systems, but no studies have focused on their use in the inter-row of vineyards. The objective of this study was to evaluate the effectiveness of seven cover crops (spontaneous, Avena strigosa, Hordeum vulgare, Lolium multiflorum, Phacelia tanacetifolia, Sinapis alba and X Triticosecale) and two termination methods (shredding or roller-crimper) in managing C. dactylon during summer. RESULTS: In 2020, rolled A. strigosa, P. tanacetifolia and the spontaneous flora limited the coverage of C. dactylon more than shredding (increases of 3% and 18% in C. dactylon cover from July to September in rolled and shredded cover crops, respectively), while in 2021, rolling was better than shredding for all cover crop species in September (5% and 18% increases, respectively). CONCLUSION: Roller-crimping cover crops was an effective method to control C. dactylon in vineyard inter-rows but it did not consistently work for all cover crops in both years. Our study is one of the first to test the efficacy of roller-crimpers to manage summer weeds in vineyards. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Potential Risk of Residues From Neonicotinoid-Treated Sugar Beet Flowering Weeds to Honey Bees (Apis mellifera L.).

In 2018 the European Union (EU) banned the three neonicotinoid insecticides imidacloprid, clothianidin (CLO), and thiamethoxam (TMX), but they can still be used if an EU Member State issues an emergency approval. Such an approval went into effect in 2021 for TMX-coated sugar beet seeds in Germany. Usually, this crop is harvested before flowering without exposing non-target organisms to the active ingredient or its metabolites. In addition to the approval, strict mitigation measures were imposed by the EU and the German federal states. One of the measures was to monitor the drilling of sugar beet and its impact on the environment. Hence we took residue samples from different bee and plant matrices and at different dates to fully map beet growth in the German states of Lower Saxony, Bavaria, and Baden-Württemberg. A total of four treated and three untreated plots were surveyed, resulting in 189 samples. Residue data were evaluated using the US Environmental Protection Agency BeeREX model to assess acute and chronic risk to honey bees from the samples, because oral toxicity data are widely available for both TMX and CLO. Within treated plots, we found no residues either in pools of nectar and honey crop samples (n = 24) or dead bee samples (n = 21). Although 13% of beebread and pollen samples and 88% of weed and sugar beet shoot samples were positive, the BeeREX model found no evidence of acute or chronic risk. We also detected neonicotinoid residues in the nesting material of the solitary bee Osmia bicornis, probably from contaminated soil of a treated plot. All control plots were free of residues. Currently, there are insufficient data on wild bee species to allow for an individual risk assessment. In terms of the future use of these highly potent insecticides, therefore, it must be ensured that all regulatory requirements are complied with to mitigate any unintentional exposure. Environ Toxicol Chem 2023;42:1167-1177. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Invasive Wetland Weeds Derived Biochar Properties Affecting Soil Carbon Dynamics of South Indian Tropical Ultisol.

This study aimed to: (i) investigate the agronomic properties of biochars derived from selected invasive wetland weeds and (ii) examine the effect of biochar on soil organic carbon (SOC) dynamics and stability of tropical Ultisol soil. The biochars were analyzed for proximate properties, surface characteristics, elemental composition, functional groups, and thermal and carbon stability. Plant growth studies supplemented with biochar under greenhouse conditions for 1 year were conducted. The SOC, its fractions, and its dynamics were studied. The biochar incorporation significantly increased the SOC and its stable fractions like mineral Organic Carbon (MOC), fine-particulate organic carbon (fPOC), and Non-labile Carbon (NLC) by 24.54-7.82, 5.79-2.0, and 9.50-2.16 g kg-1 than control. The labile carbon fractions like Dissolved Organic Carbon (DOC), and coarse-Particulate Organic Carbon (cPOC) showed a substantial reduction by 0.72-0.26 and 2.92-1.29 g kg-1 respectively. However, the easily oxidizable carbon (EOC) and microbial biomass carbon (MBC) content increased by 2.10-4.87 g kg-1 and 28.33-158.55 mg kg-1 respectively. The addition of biochars resulted in the stabilization of soil aggregates. Likewise, substantial CO2 emission reduction (75.24-46.60%) has been achieved during the trials. The carbon pool management index (CPMI) values recorded a substantial increase of 40-7.2% between the trials. The findings imply that the inherent nature of weed biomasses determines the characteristics of the resulting biochar, and their application significantly influenced the carbon dynamics of the tropical Ultisol soil.

Pyrrolizidine-producing weeds in tea gardens as an indicator of alkaloids in tea.

Pyrrolizidine alkaloids (PAs) can be transferred between plants via soil. Indicators of PAs in tea products are useful for tea garden management. In the present work a total of 37 weed species, 37 weed rhizospheric soils and 24 fresh tea leaf samples were collected from tea gardens, in which PAs were detected in 35 weeds species, 21 soil samples and 10 fresh tea leaves samples. In Shexian tea garden, 12.9 µg/kg of intermedine (Im) in one bud plus three leaves, 1.40 and 14.6 µg/kg of intermedine-N-oxide (ImNO) in one bud plus two leaves and one bud plus three leaves were detected, which were transferred from the PA-producing weeds via soil. However, no PAs were detected in fresh tea leaves collected from Langxi tea garden. The results indicated that synthesis of PAs in weeds and their transfer through the weed-soil-fresh tea leaf route varied with soil environments in different tea gardens.

Impact of post-emergent imazethapyr on morpho-physiological and biochemical responses in lentil (Lens culinaris Medik.).

Yield reduction in lentil crop due to weed infestation is a key hindrance to its growth due to poor weed-crop competition. Imazethapyr (IM), a selective herbicide, target acetolactate synthase (ALS) which catalyzes the first reaction in biosynthesis of branched chain amino acids, required for plant growth and development. The objective of the present study was to investigate the impact of IM treatment on weeds, ALS enzyme activity, antioxidant capacity, osmolyte accumulation, growth and yield related parameters in lentil genotypes. Two IM tolerant (LL1397 and LL1612) and two susceptible (FLIP2004-7L and PL07) lentil genotypes were cultivated under weed free, weedy check and IM treatments. Weed control efficiency reached its peak at 21 days after spray (DAS). Imazethapyr treatment decreased chlorophyll and carotenoid content up to 28 DAS with higher reduction in susceptible genotypes. FLIP2004-7L and PL07 had reduced plant height and lower number of pods under IM treatment which resulted in decreased seed yield. Higher ALS activity in LL1397 and LL1612 at 21 DAS, higher antioxidant capacity and glycine betaine content both at 21 and 28 DAS and lower decrease in relative leaf water content might be mediating herbicide tolerance in these genotypes that led to higher seed yield. The identified IM tolerance mechanism can be used to impart herbicide resistance in lentil. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01244-x.

The Allelopathic Activity of Extracts and Isolated from Spirulina platensis.

We determined the allelopathic effects of crude organic (hexane, ethyl acetate, and methanol) extracts of the cyanobacterial Spirulina platensis on barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and Chinese amaranth (Amaranthus tricolor L.). The crude ethyl acetate extract showed the highest inhibitory activity and was subsequently fractionated by column chromatography into 23 fractions based on thin-layer chromatography band pattern similarities. Four concentrations (2000, 1000, 500, and 250 ppm) of each fraction were tested for their allelopathic activity. Fractions E6 and E13 exhibited the most significant inhibitory effects against Chinese amaranth. The constituents of the highly active E6F3-E6F5 fractions determined by GC-MS, chromatography, and spectroscopy included the fatty acids, γ-linolenic acid 15, oleic acid 12, and predominantly palmitic acid 7; minor constituents included 2-ethyl-3-methylmaleimide 9 and C11 norisoprenoids (dihydroactinidiolide 10 and 4-oxo-ß-ionone 13). Isolation of E13 fraction by column chromatography revealed four C13 norisoprenoids: 3-hydroxy-ß-ionone 17, 3-hydroxy-5α,6α-epoxy-ß-ionone 18, 3-hydroxy-5ß,6ß-epoxy-ß-ionone 19, and loliolide 20. Their structures were elucidated by NMR spectroscopy. All six isolated norisoprenoids inhibited seed germination and seedling growth of Chinese amaranth at concentrations of 250-1000 ppm. Allelochemicals from S. platensis could be utilized in the development of novel bioactive herbicides.

Insecticidal Effect of Weeds Extract in the Poultry Pest Alphitobius diaperinus.

<b>Background and Objective:</b> <i>Alphitobius diaperinus</i> (Coleoptera: Tenebrionidae) is the major pest in chicken farms. The control of pests using synthetic insecticides is not recommended. Besides its expensive, synthetic insecticides are proved harmful to poultry health, farmworkers and polluting the environment. To explore the sources of bioinsecticides that are cheap and eco-friendly, this study was conducted to evaluate the insecticidal effect of weeds extracts (<i>Chromolaena odorata</i>, <i>Ageratum conyzoides</i> and <i>Tithonia diversifolia</i>) against post-embryonic survival of <i>A. diaperinus</i>. <b>Materials and Methods:</b> The experimental study using a completely randomized design of 2 factors, i.e., 3 types of weeds extract and 6 levels of concentration. The insecticidal effect was observed based on the post-embryonic survival. The post-embryonic survival of larvae was evaluated for 4 weeks by measuring the number of Larvae Released (LR) from the eggs, as well as the number of Adults Emergence (AE). Data were analyzed using Variance Analysis (ANOVA) and continued with the least significant different tests (α<u><</u>0.5). <b>Results:</b> The statistical analysis showed that the differences in extract concentration contributed significant influence (α<u><</u>0.05) on the total number of larvae released and adult emergence. The lowest LR and AE occurred at the 40% concentration level, i.e., on the extract of <i>T. diversifolia</i>, while the highest LR and AE were found in the treatment of <i>C. odorata</i> extract. <b>Conclusion:</b> In this study, all types of extracts have an insecticidal effect on the post-embryonic survival of <i>A. diaperinus</i> but the strongest effect was found in the extract of <i>T. diversifolia</i> in 40% concentration. At last, these findings inform people that the weeds extract, especially <i>T. diversifolia</i> is possible to be developed as bioinsecticides for <i>A. diaperinus</i>.

Impact of Weed Management Practices on Soil Microflora and Dehydrogenase Enzyme Activity Under Varying Levels of Nitrogen in Winter Season Onion (Allium cepa L.).

The study was conducted to evaluate the suitability of different weed management practices under influence of varying levels of N doses to test their effects on the various soil microflora and dehydrogenase enzyme activity in the winter onion field during 2016-2017 and 2017-2018. There were a total of twenty eight treatments replicated three times under the split-plot design (SPD). The treatments associated with weed management practices were applied to the main plots and the different N doses were given in each subplot. Microbial population and dehydrogenase enzyme activity in soil and crop weed competition index were determined. The two-hand weeding (HW) at 20 and 40 days after transplanting (DAT) of onion seedlings as well as preplant application of oxyfluorfen along with one HW at 40 DAT, exhibited a significant increase in dehydrogenase activity and microbial population in the soil when the N was applied at 100 kg ha-1. The study suggests that suitable weed management practices for the winter onion exerts a transient impact on soil microbial population, maintained good soil health and reduced crop-weed competition (CWC) with relatively less environmental hazards.

Invasive alien plants and weeds in South Africa: A review of their applications in traditional medicine and potential pharmaceutical properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional pharmacopoeias are constantly evolving and adapting, hence the assimilation of alien plants and weeds into traditional systems of healing. Invasive plants are detrimental to the ecosystem, however they are also potential sources of secondary metabolites with useful biological activities. AIM OF THE REVIEW: The aim of this review was to investigate published reports of traditional use and biological activity of declared invasive alien plants and other weeds in South Africa. MATERIALS AND METHODS: Information was retrieved from scientific databases including Scopus, Web of Science, ScienceDirect, Google Scholar, PubMed, Chemical Abstracts Services and books, theses, dissertations and technical reports. Keywords used for the search engines were "South Africa" or "southern Africa" in conjunction with "(native weeds OR alien invasive)" AND "medicinal". Separate searches were conducted on the individual invasive plant species recorded as having been used in ethnobotanical surveys to determine their known biological activities and chemical components. RESULTS: A total of 89 plant species regarded as invasive species or weeds in South Africa were identified as being used in traditional medicine. The most commonly mentioned plant family was the Asteraceae with a total of 15 species followed by the Fabaceae and Solanaceae with 6 species each. Of the 89 species recorded, 68% were reported to have traditional usage with both phytochemical and biological data available. A history of traditional usage coupled with biological data was available for 12% of species. Records of traditional usage alone were linked to 11% of species. Invasive alien species comprised 61% of recorded species, while native and non-invasive alien weeds formed the remaining 39%. CONCLUSIONS: The exploration of alternative uses for weeds and particularly invasive plants, whether native or alien, as medicines for possible commercialisation may lead to innovative mechanisms for putting such species to good use.

Three Active Phytotoxic Compounds from the Leaves of Albizia richardiana (Voigt.) King and Prain for the Development of Bioherbicides to Control Weeds.

The global population is increasing day by day. To meet the food demand for such a huge number of people, crop production must increase without damaging the environment, and to prevent synthetic chemical herbicides from polluting the environment, controlling weeds using bioherbicides is essential. Accordingly, using phytotoxic substances obtained from plants for biological weed management has attracted attention. The plant Albizia richardiana possesses phytotoxic compounds that have been previously recorded. Hence, we have conducted this research to characterize more phytotoxic compounds in Albizia richardiana. Aqueous methanolic extracts of Albizia richardiana plant significantly restricted the growth of the examined plants lettuce and Italian ryegrass in a species- and concentration-dependent manner. Three active phytotoxic compounds were isolated through various chromatographic methods and identified as compound 1, 2, and 3. Compound 3 exhibited stronger phytotoxic potentials than the other two compounds and significantly suppressed the growth of Lepidium sativum (cress). The concentration of the compounds required for 50% growth reduction (I50 value) of the Lepidium sativum seedlings ranged between 0.0827 to 0.4133 mg/mL. The results suggest that these three phytotoxic compounds might contribute to the allelopathic potential of Albizia richardiana.

Biological Ingredient Analysis of Traditional Herbal Patent Medicine Fuke Desheng Wan Using the Shotgun Metabarcoding Approach.

With the widespread use of traditional medicine around the world, the safety and efficacy of traditional herbal patent medicine have become an increasing concern to the public. However, it is difficult to supervise the authenticity of herbal materials in mixed herbal products according to the current quality standards, especially for traditional herbal patent medicine, with a distinct variance in the dosage of herbal materials. This study utilized the shotgun metabarcoding approach to analyze the biological ingredients of Fuke Desheng Wan (FKDSW), which is an effective traditional herbal product for the treatment of dysmenorrhea. Six herbal materials were collected, and a lab-made mock FKDSW sample was produced to establish a method for the authentication assessment of biological ingredients in traditional herbal patent medicine based on shotgun metabarcoding. Furthermore, four commercial FKDSW samples were collected to verify the practicality of the shotgun metabarcoding approach. Then, a total of 52.16 Gb raw data for 174 million paired-end reads was generated using the Illumina NovaSeq sequencing platform. Meanwhile, 228, 23, and 14 operational taxonomic units (OTUs) were obtained for the ITS2, matK, and rbcL regions, respectively, after bioinformatic analysis. Moreover, no differences were evident between the assembly sequences obtained via shotgun metabarcoding and their corresponding reference sequences of the same species obtained via Sanger sequencing, except for part of the ITS2 and matK assembly sequences of Paeonia lactiflora Pall., Saussurea costus (Falc.) Lipsch. and Bupleurum chinense DC. with 1-6 different bases. The identification results showed that all six prescribed ingredients were successfully detected and that the non-authentic ingredient of Bupleuri Radix (Chaihu, Bupleurum chinense DC. or Bupleurum scorzonerifolium Willd.) was found in all the commercial samples, namely Bupleurum falcatum L. Here, 25 weed species representing 16 genera of ten families were detected. Moreover, 26 fungal genera belonging to 17 families were found in both lab-made and commercial FKDSW samples. This study demonstrated that the shotgun metabarcoding approach could overcome the biased PCR amplification and authenticate the biological ingredients of traditional herbal patent medicine with a distinct variance in the dosage of the herbal materials. Therefore, this provides an appropriate evaluation method for improving the safety and efficacy of traditional herbal patent medicine.

Bioactive Diterpenes from the Brazilian Native Plant (Moquiniastrum pulchrum) and Their Application in Weed Control.

Even today, weeds continue to be a considerable problem for agriculture. The application of synthetic herbicides produces serious environmental consequences, and crops suffer loss of their activity due to the appearance of new resistant weed biotypes. Our aim is to develop new effective natural herbicides that improve the problem of resistance and do not harm the environment. This work is focused on a bioassay-guided isolation and the characterization of natural products present in Moquiniastrum pulchrum leaves with phytotoxic activity and its preliminary application in weeds. Moquiniastrum pulchrum was selected for two reasons: it is an abundant species in the Cerrado region (the second most important ecosystem in Brazil, after the Amazon)-the explanation behind its being a dominant species is a major focus of interest-and it has traditional employment in folk medicine. Six major compounds were isolated in this plant: one flavone and five diterpenes, two of which are described for the first time in the literature. Four of the six compounds exhibited phytotoxic activity in the bioassays performed. The results confirmed the phytotoxic potential of this plant, which had not been investigated until now.

Invasive Plant Species Biomass-Evaluation of Functional Value.

Invasive plant species (IAS), with their numerous negative ecological, health, and economic impacts, represent one of the greatest conservation challenges in the world. Reducing the negative impacts and potentially exploiting the biomass of these plant species can significantly contribute to sustainable management, protect biodiversity, and create a healthy environment. Therefore, the main objective of this study was to evaluate the nutritional potential, phytochemical status, and antioxidant capacity of nine alien invasive plant species: Abutilon theophrasti, Amaranthus retroflexus, Ambrosia artemisiifolia, Datura stramonium, Erigeron annuus, Galinsoga ciliata, Reynoutria japonica, Solidago gigantea, and Sorghum halepense. Multivariate statistical methods such as cluster and PCA were performed to determine possible connections and correlations among selected IAS depending on the phytochemical content. According to the obtained results, R. japonica was notable with the highest content of vitamin C (38.46 mg/100 g FW); while E. annuus (1365.92 mg GAE/100 g FW) showed the highest values of total polyphenolic compounds. A. retroflexus was characterized by the highest content of total chlorophylls (0.26 mg/g) and antioxidant capacity (2221.97 µmol TE/kg). Therefore, it can be concluded that the selected IAS represent nutrient-rich plant material with significant potential for the recovering of bioactive compounds.

Living with exotic annual grasses in the sagebrush ecosystem.

Exotic annual grasses dominate millions of hectares and increase fire frequency in the sagebrush ecosystem of North America. This devastating invasion is so costly and challenging to revegetate with perennial vegetation that restoration efforts need to be prioritized and strategically implemented. Management needs to break the annual grass-fire cycle and prevent invasion of new areas, while research is needed to improve restoration success. Under current land management and climate regimes, extensive areas will remain annual grasslands, because of their expansiveness and the low probability of transition to perennial dominance. We propose referring to these communities as Intermountain West Annual Grasslands, recognizing that they are a stable state and require different management goals and objectives than perennial-dominated systems. We need to learn to live with annual grasslands, reducing their costs and increasing benefits derived from them, at the same time maintaining landscape-level plant diversity that could allow transition to perennial dominance under future scenarios. To accomplish this task, we propose a framework and research to improve our ability to live with exotic annual grasses in the sagebrush biome.

Evaluation of the Phytotoxicity of Urochloa humidicola Roots by Bioassays and Microscopic Analysis. Characterization of New Compounds.

Herbicides are a key element in agriculture but they do cause environmental problems and natural alternatives are being sought. In this context, invasive plants could provide an as yet unexplored source for the development of future herbicides. Urochloa humidicola has great invasive potential in Brazilian environments as it hampers the establishment of other plants. The phytotoxicity of U. humidicola root extracts has been evaluated, and the major components have been identified. The phytotoxicity of the extract was assessed in the wheat coleoptile assay on seeds of troublesome weeds and on Anadenanthera colubrina, a tree species used in ecological restoration programs. The ethyl acetate extract showed the highest activity, and the most affected weeds were E. crus-galli, M. maximus, and A. viridis with the latter weed more affected by the extract than by the herbicide Logran. Microscopic ultrastructural analysis of A. colubrina roots indicated possible signals of cell death. Seven compounds were identified in the ethyl acetate extract of which one diterpene and four saponins are new. Six of these compounds were tested in the wheat coleoptile bioassay. The most active were diterpene 1 and saponins 2, 3, and 6. The phytotoxic activity of U. humidicola explains the issues observed in ecological restoration with A. colubrina in the presence of Urochloa species, and its effect on weeds reinforces its potential use in agriculture.

Cynara cardunculus Crude Extract as a Powerful Natural Herbicide and Insight into the Mode of Action of Its Bioactive Molecules.

The use of chemical herbicides could not only potentially induce negative impacts on the environment, animals, and human health, but also increase the weed resistance to herbicides. In this context, the use of plant extracts could be an interesting and natural alternative to chemical products. It is important to understand the mode of action of their bioactive compounds. This is why we have studied the herbicidal effect of Cynara cardunculus crude extract in terms of inhibition of weeds' seedling growth and its impact on physiological parameters of treated plantlets, like conductivity, dry weight, and fluorescence, and biochemical parameters linked to oxidative stress. We have observed that C. cardunculus crude extract induces oxidative stress in the treated plants and consequently disturbs the physiological and biochemical functions of the plant cells. We have investigated the herbicidal activity of three bioactive compounds, naringenin, myricitrin, and quercetin, from the C. cardunculus crude extract. In both pre- and post-emergence trials, naringenin and myricitrin were significantly more phytotoxic than quercetin. We suggest that their differential initial interaction with the plant's plasma membrane could be one of the main signals for electrolyte leakage and production of high levels of phenoxyl radicals.

Percepción etnobotánica de los campesinos sobre la flora arvense en fincas de la agricultura suburbana en Santiago de Cuba, Cuba / Ethnobotanical perception of the farmers about the weed flora in farms of suburban agriculture in Santiago de Cuba, Cuba

Currently the weed species are a resource to conserve. The objective was to evaluate the ethnobotanical perception of the peasants about the weed flora in farms of suburban agriculture in Santiago de Cuba, Cuba. An ethnobotanical study was developed and the percentage of known species, percentage of species per management action and the percentage of weed species with potential utility was determined. The spectrum of use, the categories of use and the species richness by category were also taken into account. The weed species found in each of the farms were identified by at least 60% of the producers conferring more than 70% of this flora potential utilities such as medicinal, animal feed and agricultural. Although different forms of management for these species were identified, more than 40% are eliminated regardless of the potential benefits that productive systems can bring to this.

Actualmente las especies arvenses son un recurso a conservar. El objetivo fue evaluar la percepción etnobotánica de los campesinos sobre la flora arvense en fincas de la agricultura suburbana en Santiago de Cuba, Cuba. Se desarrolló un estudio etnobotánico y se determinó el porcentaje de especies conocidas, porcentaje de especies por acción de manejo y el porcentaje de especies arvenses con utilidad potencial. También se tuvo en cuenta el espectro de uso, las categorías de uso y la riqueza de especies por categoría. Las especies arvenses que se encuentran en cada una de las fincas fueron identificadas por al menos el 60% de los productores confiriéndoles a más del 70% de esta flora utilidades potenciales como medicinal, alimento animal y agrícola. Aunque se identificaron diferentes formas de manejo para estas especies, más del 40% resultan eliminadas independientemente de los beneficios potenciales que puedan aportar a estos sistemas productivos.

Quantification of Strigolactones.

Strigolactones (SLs) are a family of natural products produced by the plants as shoot branching factors and responsible for the induction of hyphal branching in arbuscular mycorrhizal (AM) fungi. They have been also used by parasitic plant seeds as stimulators of their germination as a strategy to ensure the presence of a host in the environment. For all these bioactivities, SLs have kept the attention of the researchers in the last years, increasing the number of published papers, and have opened new areas of research in the multiple roles that they play in the rhizosphere and as plant hormones. However, the low amount of them produced by plants and their rapid degradability make it crucial to develop fast analytical methods with very low limits of quantification. Herein, it is described a protocol for the development of an LC-MS/MS method for the quantification of SLs, using GR24 as IS, in roots exudates and extracts.

Similar Allergenicity to Different Artemisia Species Is a Consequence of Highly Cross-Reactive Art v 1-Like Molecules.

Background and objectives: Pollens of weeds are relevant elicitors of type I allergies. While many Artemisia species occur worldwide, allergy research so far has only focused on Artemisia vulgaris. We aimed to characterize other prevalent Artemisia species regarding their allergen profiles. Materials and Methods: Aqueous extracts of pollen from seven Artemisia species were characterized by gel electrophoresis and ELISA using sera from mugwort pollen-allergic patients (n = 11). The cDNA sequences of defensin-proline-linked proteins (DPLPs) were obtained, and purified proteins were tested in a competition ELISA, in rat basophil mediator release assays, and for activation of Jurkat T cells transduced with an Art v 1-specific TCR. IgE cross-reactivity to other allergens was evaluated using ImmunoCAP and ISAC. Results: The protein patterns of Artemisia spp. pollen extracts were similar in gel electrophoresis, with a major band at 24 kDa corresponding to DPLPs, like the previously identified Art v 1. Natural Art v 1 potently inhibited IgE binding to immobilized pollen extracts. Six novel Art v 1 homologs with high sequence identity and equivalent IgE reactivity were identified and termed Art ab 1, Art an 1, Art c 1, Art f 1, Art l 1, and Art t 1. All proteins triggered mediator release and cross-reacted at the T cell level. The Artemisia extracts contained additional IgE cross-reactive molecules from the nonspecific lipid transfer protein, pectate lyase, profilin, and polcalcin family. Conclusions: Our findings demonstrate that DPLPs in various Artemisia species have high allergenic potential. Therefore, related Artemisia species need to be considered to be allergen elicitors, especially due to the consideration of potential geographic expansion due to climatic changes.

Narrow pollen diets are associated with declining Midwestern bumble bee species.

Many species of bumble bee (Bombus) have declined in range and abundance across Europe, the Americas, and Asia, whereas other species have persisted and remain common and widespread. One explanation as to why some species have declined, based primarily on studies of the European bumble bee fauna, is that declining species have relatively narrow pollen-foraging niches and are less able to use alternative host plants in the absence of their preferred hosts. Though extensively explored in Europe, this hypothesis has not been investigated in North America, in part due to incomplete information on the foraging niche of many species. We selected 12 bumble bee species found in Michigan and quantified their pollen diets using museum specimens. We also extensively resurveyed the state to understand their contemporary status and distribution. Compared to a pre-2000 baseline, six species remain relatively common and widespread, whereas six species show range contractions of over 50%. There was a significant relationship between dietary breadth and distributional range change, with declined or declining species collecting around one-third fewer pollen types than stable species. Though there were significant compositional differences, we found no differences in the number of pollen types collected by species with differing tongue lengths. Overall, these results support the hypothesis that species with narrower dietary niches are at greater risk of decline. However, it is not clear if narrow dietary niches are a cause of declines, or if both are driven by an underlying factor such as proximity to the edge of climatic niches. Further research is needed to improve our understanding of dietary niche in bumble bees, and how it interacts with other factors to influence population trajectories of stable and at-risk species.