Composition and biocidal properties of essential oil from pre-domesticated Spanish Satureja Montana
The aim of this study was to develop a chemically stable plant following a pre-domestication process and the valorization of its essential oil for the production of biopesticides. This study was conducted during four growing seasons to give a pre-domesticated population (SAMO-0). The resulting pre-domesticated population increased the hydrodistilled oil yield (average 0.45%) and maintained a stable yield of dry material (44.5%). The plant material was submitted to pilot plant scale steam distillation under three pressures (0.5, 1.0 and 1.5 bar) with lower yield (average 0.15%). The essential oil showed a carvacrol / p-cymene chemotype. The pre-domestication process increased β-myrcene, α- and γ-terpinene, p-cymene, thymol and β-bisabolene; and decreased α-thujene and carvacrol. The steam distillation increased the oil content in α-thujene, α-pinene, α-terpinene, p-cymene and trans-caryophyllene, and decreased borneol, thymoquinone thymol and β-bisabolene. Pressure increased α-terpinene, thymol and carvacrol Additionally, the study of the biocidal effects (against the insect pests Spodoptera littoralis, Myzus persicae and Leptinotarsa decemlineata and the phytopathogenic nematode Meloydogine javanica) of the EOs showed that overall, the most active oils were the hydrodistilled (to all insect species), followed by the steam distilled oils with higher carvacrol and thymol content (pressures of 1.5 and 1.0 bar). Carvacrol and thymol were responsible for the activity of these oils on M. persicae, and L. decemlineata but only partially on S. littoralis. The steam distilled oils showed strong nematicidal activity against M. javanica that could be partially explained by their content in active carvacrol and thymol.
Navarro-Rocha, Juliana; Andrés, María Fe; Díaz, Carmen E.; Burillo, Jesús; González-Coloma, Azucena
Dispersal Reduction: Causes, Genomic Mechanisms, and Evolutionary Consequences
Recent biological analyses suggest that reductions in dispersal ability have beenkey drivers of diversification across numerous lineages. We synthesise emergingdata to highlight similarities regarding the causes and consequences of dispersalreduction across taxa and ecosystems, as well as the diverse genomic mechanismsunderpinning these shifts. Natural selection has acted on standing genetic variationwithin taxa to drive often rapid–and in some cases parallel–losses of dispersal,and ultimately speciation. Such shifts can thus represent an important nexus be-tween adaptive and neutral diversification processes, with substantial evolutionaryconsequences. Recognition of the links between these concepts that are emergingfrom differentfields, taxa and ecosystems is transforming our understanding of thefascinating role of dispersal reduction in the formation of biodiversity.
Waters, J.M.; Emerson, Brent C.; Arribas, Paula; McCulloch, G. A.
Rapid changes of dust geochemistry in the Saharan Air Layer linked to sources and meteorology
Based at Izaña Observatory (~2400 m a.s.l. in Tenerife), we performed 1-h resolution measurements of elemental composition of dust in the Saharan Air Layer (SAL) and studied the variability of the ratios of these elements to aluminium (elemental ratios). In a period (~1 week) of continuous dust presence (50–200 μg/m3), we observed rapid variations of dust composition; some elemental ratios changed by a factor 2 in a few (5–8) hours. The lowest variability (Normalized Variability Range, %) was found for Si/Al (9%) and Fe/Al (9%), followed by the ratios of K, Ti, Mg, Mn, Ca and Sr to Al (20–80%), and the highest for S/Al, Na/Al and Cl/Al (110–160%) and a number of trace metals (Cr, Cu, Ni, Zn, Zr) and Br (>200%). This variability was induced by the alternating impacts of three of the large North African dust sources: NE Algeria (rich in evaporite minerals bearing Ca, S, Sr, K and Mg and in illite mineral), Western Sahara to Bechar region (containing Na, S and Cl rich Yermosol soils) and SW Sahara – Western Sahel (rich in illite and hematite). We traced the variability in large-scale meteorology using the so-called North African Dipole Intensity (NAFDI: strength of the subtropical Saharan high -Morocco-to the monsoon tropical low -Nigeria-). The mobilization of dust from the different sources was associated with westward propagating Harmattan pulses linked to the change of phase of NAFDI (- to +), the associated westward shifts of the Saharan Heat Low and convective monsoon inflow. We found a correlation between dust composition in the SAL and NAFDI: moderate NAFDI values (0 to +2.5) were associated with Ca, K, Na, Mg and S rich dust linked to dust sources in NE Algeria, whereas higher NAFDI values (+2.5 to +4) were linked to Fe rich dust (Ca, Na and S depleted) linked to dust sources in SW Sahara – Western Sahel. The results of this study also show that some trace elements (Br, Cr, Ni, Zn and Zr) are influenced by industrial emissions into North Africa.
Rodríguez, Sergio; Calzola, Giulia; Chiari, Massimo; Nava, Silvia; Isabel García, M.; López-Solano, Javier; Marrero, Carlos; López-Darias, Jessica; Cuevas, Emilio; Alonso-Pérez, Silvia; Prats, Natalia; Amato, Fulvio ; Lucarelli, Franco; Querol, Xavier
Unrest signals after 46 years of quiescence at Cumbre Vieja, La Palma, Canary Islands
Monogenetic eruptions are the most common volcanic activity in the world. However, unrest monitoring data are scarce due to the long intervening quiescence periods. This study analyzes unrest signals recorded in one of the largest monogenetic fields in the Canary Islands, Cumbre Vieja (La Palma). Two seismic swarms were registered in October 2017 and February 2018 with b-values of 1.6 ± 0.1 and 2.3 ± 0.2 respectively suggesting an intense magmatic fluids contribution, gas and/or magma. Both swarms were linked to changes in gas emissions. Increases in hydrogen concentration, and (R/R) up to 7.52 ± 0.05, were recorded before the first swarm, at the sampling point closest to where seismicity was located, indicating a deep gas input. After the second swarm, increases in (R/R) and thoron soil concentration were recorded at two locations. This dataset is compatible with a stalled magmatic intrusion at ca. 25 km depth, with an estimated volume between 5.5·10 km and 3·10 km.
Torres-González, Pedro A.; Luengo-Oroz, Natividad; Lamolda, Héctor; D'Alessandro, Walter; Albert, Helena; Iribarren, Ilazkiñe; Moure-García, David; Soler, Vicente
Climate drives community-wide divergence within species over a limited spatial scale: evidence from an oceanic island
Geographic isolation substantially contributes to species endemism on oceanic islands when speciation involves the colonisation of a new island. However, less is understood about the drivers of speciation within islands. What is lacking is a general understanding of the geographic scale of gene flow limitation within islands, and thus the spatial scale and drivers of geographical speciation within insular contexts. Using a community of beetle species, we show that when dispersal ability and climate tolerance are restricted, microclimatic variation over distances of only a few kilometres can maintain strong geographic isolation extending back several millions of years. Further to this, we demonstrate congruent diversification with gene flow across species, mediated by Quaternary climate oscillations that have facilitated a dynamic of isolation and secondary contact. The unprecedented scale of parallel species responses to a common environmental driver for evolutionary change has profound consequences for understanding past and future species responses to climate variation.
Salces-Castellano, Antonia; Patiño, Jairo; Alvarez, Nadir; Andújar, Carmelo; Arribas, Paula; Braojos-Ruiz, Juan José; del Arco-Aguilar, Marcelino; García-Olivares, Víctor; Karger, Dirk N.; López, Heriberto; Manolopoulou, Ioanna; Oromí, Pedro; Pérez-Delgado, Antonio J.; Peterman, William E.; Rijsdijk, Kenneth F.; Emerson, Brent C.
Insulin-loaded mucoadhesive nanoparticles based on mucin-chitosan complexes for oral delivery and diabetes treatment
In this study, insulin-loaded nanoparticles (NPs) were prepared via self-gelation method using chitosan and aqueous soluble snail mucin as natural polymers. Herein, mucins were ionically interacted with chitosan at different concentrations to obtained insulin-loaded NPs, labelled as A1 (1:1) (i.e., chitosan 2 % w/v + mucin 2 % w/v) and A2 (2:1) (chitosan 4 % w/v + mucin 2 % w/v), using poloxamer and poly vinyl alcohol as solid surfactant. Such formulation was selected to provide the necessary dynamics for the formation of the nanoparticles while maintaining the surface properties that will favor the encapsulation of insulin. Each system was characterized in terms of their particle size distribution, morphology, zeta potential, and polydispersity index. In vitro release of insulin was evaluated in acidic solution (pH 1.2) and phosphate buffer solution (pH 7.4), and the hypoglycaemic activity was evaluated in diabetes rats. The prepared insulin-loaded NPs displayed particles with relatively smooth surfaces and an average particle size of 479.6 and 504.1 nm for A1 and A2, respectively. Zeta potential and polydispersity index, ranged from 22.1 to 31.2 mV and 0.155–0.185, respectively. The encapsulating efficiency for the systems A1 and A2 were 88.6 and 92.5, respectively, and a self-sustained release of encapsulated insulin was observed for over a period of 8 h. In vivo studies revealed a pronounced hypoglycaemic effect in diabetic rats after peroral administration of the insulin-loaded NPs compared to the effect caused by free oral insulin solution. In addition, both the pharmacokinetic and toxicity results showed low plasma clearance of insulin and no signs of toxicity on the liver enzyme and cell viability, which suggested good biocompatibility of the NPs formulations. Overall, the formation of NPs of insulin with chitosan and snail mucin represents a potentially safe and promising approach to protect insulin and enhance its peroral delivery.
Mumuni, Momoh A.; Kenechukwu, Franklin C.; Ofokansi, Kenneth C.; Attama, Anthony A.; Díaz Díaz, David
A validated workflow for rapid taxonomic assignment and monitoring of a national fauna of bees (Apiformes) using high throughput DNA barcoding
Improved taxonomic methods are needed to quantify declining populations of insect pollinators. This study devises a high-throughput DNA barcoding protocol for a regional fauna (United Kingdom) of bees (Apiformes), consisting of reference library construction, a proof-of-concept monitoring scheme, and the deep barcoding of individuals to assess potential artefacts and organismal associations. A reference database of cytochrome oxidase c subunit 1 (cox1) sequences including 92.4% of 278 bee species known from the UK showed high congruence with morphological taxon concepts, but molecular species delimitations resulted in numerous split and (fewer) lumped entities within the Linnaean species. Double tagging permitted deep Illumina sequencing of 762 separate individuals of bees from a UK-wide survey. Extracting the target barcode from the amplicon mix required a new protocol employing read abundance and phylogenetic position, which revealed 180 molecular entities of Apiformes identifiable to species. An additional 72 entities were ascribed to nuclear pseudogenes based on patterns of read abundance and phylogenetic relatedness to the reference set. Clustering of reads revealed a range of secondary operational taxonomic units (OTUs) in almost all samples, resulting from traces of insect species caught in the same traps, organisms associated with the insects including a known mite parasite of bees, and the common detection of human DNA, besides evidence for low-level cross-contamination in pan traps and laboratory procedures. Custom scripts were generated to conduct critical steps of the bioinformatics protocol. The resources built here will greatly aid DNA-based monitoring to inform management and conservation policies for the protection of pollinators.
Creedy, Thomas J.; Norman, Hannah; Tang, Cuong Q.; Qing Chin, Kai; Andujar, Carmelo; Arribas, Paula; O'Connor, Rory S.; Carvell, Claire; Notton, David G.; Vogler, Alfred P.
The phylogeny of leaf beetles (Chrysomelidae) inferred from mitochondrial genomes
The high-level classification of Chrysomelidae (leaf beetles) currently recognizes 12 or 13 well-established subfamilies, but the phylogenetic relationships among them remain ambiguous. Full mitochondrial genomes were newly generated for 27 taxa and combined with existing GenBank data to provide a dataset of 108 mitochondrial genomes covering all subfamilies. Phylogenetic analysis under maximum likelihood and Bayesian inference recovered the monophyly of all subfamilies, except that Timarcha was split from Chrysomelinae in some analyses. Three previously recognized major clades of Chrysomelidae were broadly supported: the ‘chrysomeline’ clade consisting of (Chrysomelinae (Galerucinae + Alticinae)); the ‘sagrine’ clade with internal relationships of ((Bruchinae + Sagrinae) + (Criocerinae + Donaciinae)), and the ‘eumolpine’ clade comprising (Spilopyrinae (Cassidinae (Eumolpinae (Cryptocephalinae + Lamprosomatinae)))). Relationships among these clades differed between data treatments and phylogenetic algorithms, and were complicated by two additional deep lineages, Timarcha and Synetinae. Various topological tests favoured the PhyloBayes software as the preferred inference method, resulting in the arrangement of (chrysomelines (eumolpines + sagrines)), with Timarcha placed as sister to the chrysomeline clade and Synetinae as a deep lineage splitting near the base. Whereas mitogenomes provide a solid framework for the phylogeny of Chrysomelidae, the basal relationships do not agree with the topology of existing molecular studies and remain one of the most difficult problems of Chrysomelidae phylogenetics.
Nie, Rui-e; Andújar, Carmelo ; Gómez-Rodríguez, Carola ; Bai, Ming; Xue, Huai-Jun; Tang, Min; Yang, Chen-Tao.; Tang, Pu; Yang, Xing-Ke; Vogler, Alfried P.
Characterization of Chemical Compounds and Antioxidant Activity of Centaurea solstitialis sp. schouwii (DC.) Q. et S. (Asteraceae)
Background: The antioxidant activity and the total phenolic and flavonoid contents of the derived extracts (chloroform, ethyl acetate and n-butanol) of the 70% hydroalcoholic extract of the aerial parts of Centaurea solstitialis growing in Algeria was assessed. The active extracts were selected for phytochemical investigations.
Methods: The antioxidant capabilities of the extracts were assessed using 1, 1-diphenyl-2- picrylhydrazyl radical (DPPH•) scavenging and Cupric Ion Reducing Antioxidant Capacity (CUPRAC) assays. Butylhydroxyanisole (BHA), butylhydroxytoluene (BHT) and α –tocopherol were used as positive controls. The total phenolic content and total flavonoid content of the extracts were determined as gallic acid equivalents and quercetin equivalents, respectively. Chromatographic methods were used to isolate the secondary metabolites and spectrometric and spectroscopic methods were used to determine their chemical structures.
Results: The ethyl acetate extract exhibited the highest antioxidant activities followed by the n-butanol extract. The highest phenolic and flavonoid contents were found in the n-butanol extract. Phytochemical study of the ethyl acetate and n-butanol extracts led to the isolation of an undescribed guaianolide named 3-(4-hydroxybenzoyl)-cynaratriol and a known sesquiterpene lactone along with three known flavonoid glycosides. Their structures were established by spectral analyzes mainly high resolution electrospray ionisation mass spectrometry (HR-ESIMS) and 1D and 2D nuclear magnetic resonance experiments.
Conclusion: The extracts of aerial parts of C. solstitialis showed significant antioxidant activities. An undescribed sesquiterpene lactone and four known secondary metabolites were isolated from the most active extracts.
Aliouche, Lamia; Mosset, Paul; León, Francisco; Brouard, Ignacio; Benayache, Samir; Djamel, Sarri; Benayache, Fadila
Behavioural complementarity among frugivorous birds and lizards can promote plant diversity in island ecosystems
The behavioural complementarity of fruit-eating animals is thought to exert a key role in plant community assembly. However, a mechanistic understanding of the causal links between the two processes is still lacking. This study assesses whether complementarity between dispersers in feeding and microhabitat-use behaviour enhances community-scale dispersal services, resulting in a more diverse community of seedlings. We used a Bayesian approach to connect a comprehensive database of seed dispersal effectiveness at a community scale with a transition probability model that accounts for behavioural complementarity. Our model system was the thermosclerophyllous shrubland of the Canary Islands. There, fleshy-fruited plants rely on two types of frugivores: lizards and birds. Lizards consumed all plant species and preferentially used open areas, whereas birds foraged for small single-seeded fruits and dispersed their seeds beneath plants. Through feeding on different sets of plants, they generated a rich seed-rain community. By diversifying the microhabitat of deposition, more species could find suitable recruitment sites. Distinct foraging and microhabitat-use choices led to complementary dispersal services. Lizards ensured that all plant species were present in the seedling community, while birds promoted a more even distribution of them. As a result, diversity in the community of seedlings was enhanced. Overall, our work underscores that behavioural complementarity promotes diversity in the early-regenerating plant communities. These enhanced dispersal services rely on the presence of all functional groups. Thus, in communities where frugivores display unique behaviours, preserving a diverse community of dispersers should be a conservation target. A free Plain Language Summary can be found within the Supporting Information of this article.
Morán-López, Teresa; González-Castro, Aarón; Morales, Juan Manuel; Nogales, Manuel