Oceanic Island Bats as Flower visitors and pollinators

Oceanic islands are relatively poor in insects compared to mainland areas. Therefore, insect-eating island birds and lizards may include other food sources into their diet, e.g. nectar and pollen. Here, we explore if insect-eating island bats face a similar problem and accordingly join the birds and lizards and incorporate plant resources into their diet. Thus, a priory, we assume flower visitation by bats to be more common on oceanic islands than elsewhere. To test this, we reviewed the literature to obtain information on the geographic distribution and diet of all 1,399 species of bats in the world and found that 49%, 21%, and 31% of species have a mainland, mixed mainland-island, and island distribution, respectively. Diets are known for only 65% (905 species) of the bats in the world, and 70%, 22%, and 8% of these, respectively, rely on insects, fruit, and floral resources as their major diet component. Twenty-seven species are even obligate flower visitors. This study confirms that flower-visiting bats, especially Pteropodidae, are significantly more frequent on oceanic islands, while insect eaters are more frequent on mainland and continental islands. Consequently, we argue that flower visitation and pollination by insect-eating island bats require more attention in future island ecology studies. For a start, we list known examples in the literature and report a case study from the Canary Islands. In the latter, we examined the foreheads of 34 museum specimens of the seven Canarian bat species. Half of them carried pollen from ≥ 9 taxa, but only three bat species had larger amounts. Pollen was not identified, but many Canarian and exotic plant species are candidates. Thus, flower visitation by bats may be an oceanic island phenomenon, but requires more focused research, especially night-time flower observations and examination of bats for pollen.

Valido, Alfredo; Olesen, Jens M.

Journal of Pollination Ecology, 35(14): 239-251 (2023)
DOIDigital.CSIC

Antiproliferative effect of natural and semisynthetic polyethers from Laurencia viridis

Squalene-derived polyethers are a unique class of compounds that display a great diversity of structures and a broad array of bioactivities, among which its notable antiproliferative activity stands out against various types of cancer cell lines. In this study, eighteen triterpene squalene-derived polyethers, including twelve natural products and six synthetic derivatives, obtained from the red alga Laurencia viridis Gil-Rodríguez & Haroun were screened for their antiproliferative activity against six cancer cell lines: A549, HBL-100, HeLa, SW1573, T-47D, and WiDr; and a structure-activity relationship (SAR) study was established.

Santiago-Beníteza, Adrián J.; Puerta, Adrián; Padrón, José M.; Norte, Manuel; Fernández, José J.; Hernández Daranas, Antonio; Cen-Pacheco, Francisco.

Natural Product Research: 1-8 (2023)
DOIDigital.CSIC

Quantized compression of SAR data: Bounds on signal fidelity, InSAR PS candidates identification and surface motion accuracy

Satellite radar imaging has been used as a remote sensing tool for studying Earth’s surface. High spatial resolution achieved by Synthetic Aperture Radar (SAR) allows to classify landcover and, using radar interferometry, to measure topography and surface deformation at millimeter scale. However, the handling of voluminous SAR data has presented a significant challenge over the past decade, leading to a technological barrier for researchers to study regional and global scale problems. A possible solution will be to explore data compression algorithms. Despite of the importance of SAR data compression, limited research has focused on downsizing user-level SAR images, and none of the existing studies have explicitly explored the impact of compression on interferometric (InSAR) processing. This study investigates compression algorithms to downsize Sentinel-1 single-look complex (SLC) images by a factor of 2–4 within signal noise levels. The performance of the compressed images was evaluated in the context of PS-InSAR processing, specifically on persistent scatterer (PS) candidate selection and displacement time-series estimation. We observe that even when images were compressed by a factor of 4, more than 98 % of the PS candidates were identical to those selected from the original uncompressed images. In terms of linear velocity, the discrepancy is <2.5 mm/yr at a 99 % confidence interval for the identical PS set. This work provides evidence that, in the context of PS-InSAR processing, Sentinel-1 radar data can be compressed by a factor of 4, leading to possible wider participation in InSAR research and applications.

Yip, Man Wai; Webb, A. Alexander G.; González, Pablo J.

International Journal of Applied Earth Observation and Geoinformation, 125, 103548: 1-10 (2023)
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A radiation of Psylliodes flea beetles on Brassicaceae is associated with the evolution of specific detoxification enzymes

Flea beetles of the genus Psylliodes have evolved specialized interactions with plant species belonging to several distantly related families, mainly Brassicaceae, Solanaceae, and Fagaceae. This diverse host use indicates that Psylliodes flea beetles are able to cope with different chemical defense metabolites, including glucosinolates, the characteristic defense metabolites of Brassicaceae. Here we investigated the evolution of host use and the emergence of a glucosinolate-specific detoxification mechanism in Psylliodes flea beetles. In phylogenetic analyses, Psylliodes species clustered into four major clades, three of which contained mainly species specialized on either Brassicaceae, Solanaceae, or Fagaceae. Most members of the fourth clade have broader host use, including Brassicaceae and Poaceae as major host plant families. Ancestral state reconstructions suggest that Psylliodes flea beetles were initially associated with Brassicaceae and then either shifted to Solanaceae or Fagaceae, or expanded their host repertoire to Poaceae. Despite a putative ancestral association with Brassicaceae, we found evidence that the evolution of glucosinolate-specific detoxification enzymes coincides with the radiation of Psylliodes on Brassicaceae, suggesting that these are not required for using Brassicaceae as hosts but could improve the efficiency of host use by specialized Psylliodes species.

Gikonyo, Matilda W; Ahn, Seung-Joon; Biondi, Maurizio; Fritzlar, Frank; Okamura, Yu; Vogel, Heiko; Köllner, Tobias G.; Şen, İsmail; Hernández-Teixidor, David; Lee, Chi-Feng; Letsch, Harald; Beran, Franziska.

Evolution, 78(1): 1-19 (2023)
DOIDigital.CSIC

The Development of METAL-WRF Regional Model for the Description of Dust Mineralogy in the Atmosphere

The mineralogical composition of airborne dust particles is an important but often neglected parameter for several physiochemical processes, such as atmospheric radiative transfer and ocean biochemistry. We present the development of the METAL-WRF module for the simulation of the composition of desert dust minerals in atmospheric aerosols. The new development is based on the GOCART-AFWA dust module of WRF-Chem. A new wet deposition scheme has been implemented in the dust module alongside the existing dry deposition scheme. The new model includes separate prognostic fields for nine (9) minerals: illite, kaolinite, smectite, calcite, quartz, feldspar, hematite, gypsum, and phosphorus, derived from the GMINER30 database and also iron derived from the FERRUM30 database. Two regional model sensitivity studies are presented for dust events that occurred in August and December 2017, which include a comparison of the model versus elemental dust composition measurements performed in the North Atlantic (at Izaña Observatory, Tenerife Island) and in the eastern Mediterranean (at Agia Marina Xyliatos station, Cyprus Island). The results indicate the important role of dust minerals, as dominant aerosols, for the greater region of North Africa, South Europe, the North Atlantic, and the Middle East, including the dry and wet depositions away from desert sources. Overall, METAL-WRF was found to be capable of reproducing the relative abundances of the different dust minerals in the atmosphere. In particular, the concentration of iron (Fe), which is an important element for ocean biochemistry and solar absorption, was modeled in good agreement with the corresponding measurements at Izaña Observatory (22% overestimation) and at Agia Marina Xyliatos site (4% overestimation). Further model developments, including the implementation of newer surface mineralogical datasets, e.g., from the NASA-EMIT satellite mission, can be implemented in the model to improve its accuracy.

Solomos, Stavros; Spyrou, Christos; Barreto, África; Rodríguez, Sergio; González, Yenny; Neophytou, Marina K. A.; Mouzourides, Petros; Bartsotas, Nikolaos S.; Kalogeri, Christina; Nickovic, Slobodan; Vukovic Vimic, Ana; Vujadinovic Mandic, Mirjam; Pejanovic, Goran; Cvetkovic, Bojan; Amiridis, Vassilis; Sykioti, Olga; Gkikas, Antonis; Zerefos, Christos.

Atmosphere 14(11): 1615 (2023)
DOIDigital.CSIC

OSMAC Approach and Cocultivation for the Induction of Secondary Metabolism of the Fungus Pleotrichocladium opacum

The application of an OSMAC (One Strain–Many Compounds) approach on the fungus Pleotrichocladium opacum, isolated from a soil sample collected on the coast of Asturias (Spain), using different culture media, chemical elicitors, and cocultivation techniques resulted in the isolation and identification of nine new compounds (8, 9, 12, 15–18, 20, 21), along with 15 known ones (1–7, 10, 11, 14, 19, 22–25). Compounds 1–9 were detected in fungal extracts from JSA liquid fermentation, compounds 10–12 were isolated from a solid rice medium, whereas compounds 14 and 15 were isolated from a solid wheat medium. Addition of 5-azacytidine to the solid rice medium caused the accumulation of compounds 16–18, whereas adding N-acetyl-d-glucosamine triggered the production of two additional metabolites, 19 and 20. Finally, cocultivation of the fungus Pleotrichocladium opacum with Echinocatena sp. in a solid PDA medium led to the production of five additional natural products, 21–25. The structures of the new compounds were elucidated by HRESIMS and 1D and 2D NMR as well as by comparison with literature data. DP4+ and mix-J-DP4 computational methods were applied to determine the relative configurations of the novel compounds, and in some cases, the absolute configurations were assigned by a comparison of the optical rotations with those of related natural products.

Rodríguez Martín-Aragón, Víctor; Trigal Martínez, Mónica; Cuadrado, Cristina; Hernández Daranas, Antonio; Fernández Medarde, Antonio; Sánchez López, José M.

ACS Omega, 8(42): 39873–39885 (2023)
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Combining in-situ monitoring and remote sensing to detect spatial patterns of volcanic sulphur impact on pine needles

Volcanic eruptions have a strong environmental impact on surrounding forests. Trees are affected by mechanical damage, tephra deposition and volcanic gases. Oceanic islands are shaped by relatively frequent volcanic eruptions and thus offer the opportunity to study the effect of volcanic activity on biodiversity. We investigate the impact of volcanic gas emissions and tephra deposition during the 2021 Tajogaite eruption on the Canary Pine forests of the island of La Palma, Spain, characterized by monospecific stands of the endemic pine species Pinus canariensis C. Sm. ex D.C. Large quantities of volcanic sulphur dioxide caused chlorotic damage up to approximately 7 km around the crater, followed by widespread resprouting of P. canariensis. To detect the spatial pattern of impacts, we sampled P. canariensis needles from all over the island of La Palma and analyzed their sulphur (S), nitrogen (N) and carbon (C) content. We found a strong increase of S needle content close to the crater, while C decreased significantly. S levels were strongly related to distance to the crater, C and N were mostly influenced by S content. Trees affected by volcanic gases allocate resources to resprouting, leading to lower levels of C due to translocation of C as a building block. Surprisingly, we found higher N levels in needles with high levels of S and a less clear pattern compared to C, likely due to a multitude of environmental factors influencing N needle levels. We investigated how canopy damage patterns detected in Sentinel-2 remote sensing imagery after the eruption correlated to the in-situ needle contents. However, we did not find a clear correlation between in-situ needle values and spectral responses in remote sensing. While satellite images were well suited to analyse large scale patterns of canopy damage following the eruption, needle levels varied strongly on a local, tree-based level, which is not reflected in remote sensing imagery.

Weiser, Frank; Walentowitz, Anna; Baumann, Esther; Shatto, Christopher; Guerrero-Campos, María; Jentsch, Anke; Nogales, Manuel; Medina, Félix Manuel; Vetaas, Ole Reidar; Beierkuhnlein, Carl.

Forest Ecology and Management, 549(1), 121468: 1-17 (2023)
DOIDigital.CSIC

Conformational control enables boroxine-to-boronate cage metamorphosis

The discovery of molecular organic cages (MOCs) is inhibited by the limited organic-chemical space of the building blocks designed to fulfill strict geometric requirements for efficient assembly. Using intramolecular attractive or repulsive non-covalent interactions to control the conformation of flexible systems can effectively augment the variety of building blocks, ultimately facilitating the exploration of new MOCs. In this study, we introduce a set of boronic acid tripods that were designed using rational design principles. Conformational control was induced by extending the tripod's arms by a 2,3-dimethylbenzene unit, leading to the efficient formation of a tetrapodal nanometer-sized boroxine cage. The new building block's versatility was demonstrated by performing cage metamorphosis upon adding an aromatic tetraol. This led to a quantitative boroxine-to-boronate transformation and a topological shift from tetrahedral to trigonal bipyramidal.

Rondelli, Manuel; Delgado-Hernández, Samuel; Hernández Daranas, Antonio; Martín, Tomás.

Chemical Science: 1-8 (2023)
DOIDigital.CSIC

Optimization and bio-fabrication of phyto-mediated silver nanoparticles (Ag-NPs) for antibacterial potential

This report examines the bio-fabrication of silver nanoparticles (Ag-NPs) utilizing AgNO3 and leaf extract of Crataegus monogyna as the precursor material. In order to maximize the antibacterial efficacy against Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae and Pseudomonas aeruginosa, the reaction conditions for the green fabrication of Ag-NPs were optimized. A one factor at a time approach (volume concentration of extract, volume concentration of AgNO3, pH and temperature) was used to optimize the best condition, and results were assessed through UV-visible spectroscopy and particle size distribution. The results showed that 20 mL of plant extract, 80 mL of AgNO3, pH 08, 100 °C temperature were the optimum reaction conditions under which we obtained the smallest Ag-NPs (7 nm). The scanning electron microscopy and X-ray diffraction analysis confirmed the spherical and crystalline nature of Ag-NPs. The antibacterial activity assay demonstrated a high antibacterial effect of Ag-NPs against S. aureus, P. mirabilis, K. pneumoniae and P. aeruginosa, and that impact was greater with smaller-sized nanoparticles (7 nm). This study shows that leaf extract of C. monogyna is a possible medium for the green fabrication of Ag-NPs, and control over reaction factors can establish the characteristics and antibacterial effectiveness of Ag-NPs.

Mehmood, Ansar; Zahir, Sobia; Khan, Muhammad Abdul Rauf; Ahmad, Khawaja Shafique; Abasi, Fozia; Raffi, Muhammad; Proćków, Jarosław; Pérez de Lastra, José Manuel.

Journal of Biomolecular Structure and Dynamics: 1-11 (2023)
DOIDigital.CSIC

Induction of New Aromatic Polyketides from the Marine Actinobacterium Streptomyces griseorubiginosus through an OSMAC Approach

Using the OSMAC (One Strain Many Compounds) approach, the actinobacterium Streptomyces griseorubiginosus, derived from an unidentified cnidarian collected from a reef near Pointe de Bellevue in Réunion Island (France), was subjected to cultivation under diverse conditions. This endeavour yielded the isolation of a repertoire of 23 secondary metabolites (1–23), wherein five compounds were unprecedented as natural products (19–23). Specifically, compounds 19 and 20 showcased novel anthrone backbones, while compound 23 displayed a distinctive tetralone structure. Additionally, compounds 21 and 22 presented an unusual naphtho [2,3-c]furan-4(9H)-one chromophore. Interestingly, the detection of all these novel compounds (19–23) was exclusively achieved when the bacterium was cultured in FA-1 liquid medium supplemented with the epigenetic modifier γ-butyrolactone. The elucidation of the structural features of the newfound compounds was accomplished through a combination of HRESIMS, 1D and 2D NMR spectroscopy, as well as QM-NMR (Quantum Mechanical—Nuclear Magnetic Resonance) methods and by comparison with existing literature. Moreover, the determination of the relative configuration of compound 23 was facilitated by employing the mix-J-DP4 computational approach.

Rodríguez Martín-Aragón, Víctor; Romero Millán, Francisco; Cuadrado, Cristina; Hernández Daranas, Antonio; Fernández Medarde, Antonio; Sánchez López, José M.

Marine Drugs 21(10): 526 (2023)
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