Evidence that Ophiostomatoid Fungal Symbionts of Mountain Pine Beetle Do Not Play a Role in Overcoming Lodgepole Pine Defenses During Mass Attack.

Mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a devastating forest insect pest that has killed millions of hectares of pines in western North America over the past two decades. Like other bark beetles, MPB vectors ophiostomatoid fungal species, some of which are pathogenic to host pine species. The phytopathogenicity of these fungal symbionts has sparked considerable debate regarding their role in facilitating MPB attack success. We tested the hypothesis that MPB ophiostomatoid fungal associates like Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield contribute to overwhelming host defenses during MPB mass attack. We compared responses of mature lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees growing in natural stands that were mass attacked by MPB with those inoculated with G. clavigera by examining host defense hormones, secondary metabolites, and gene expression profiles. The jasmonate and ethylene signatures of necrotrophic pathogen-triggered response were identified in G. clavigera-inoculated trees, but only the jasmonate signature of a herbivore-triggered response was measured in MPB-attacked trees. Several G. clavigera-induced changes in pine phenolic metabolite profiles and phenolic biosynthesis gene expression patterns were absent in MPB-attacked pines. These findings indicate that ophiostomatoid fungi like G. clavigera are not a major factor in overwhelming host defenses during MPB mass attack. Instead, fungal pathogenicity likely is more important in aiding MPB colonization and development within the host tree. Phenolics appear to play a larger role in the host response to G. clavigera than to MPB, although phenolics may also influence MPB feeding and behavior. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Rhytidome- and cork-type barks of holm oak, cork oak and their hybrids highlight processes leading to cork formation.

BACKGROUND: The periderm is basic for land plants due to its protective role during radial growth, which is achieved by the polymers deposited in the cell walls. In most trees, like holm oak, the first periderm is frequently replaced by subsequent internal periderms yielding a heterogeneous outer bark made of a mixture of periderms and phloem tissues, known as rhytidome. Exceptionally, cork oak forms a persistent or long-lived periderm which results in a homogeneous outer bark of thick phellem cell layers known as cork. Cork oak and holm oak distribution ranges overlap to a great extent, and they often share stands, where they can hybridize and produce offspring showing a rhytidome-type bark. RESULTS: Here we use the outer bark of cork oak, holm oak, and their natural hybrids to analyse the chemical composition, the anatomy and the transcriptome, and further understand the mechanisms underlying periderm development. We also include a unique natural hybrid individual corresponding to a backcross with cork oak that, interestingly, shows a cork-type bark. The inclusion of hybrid samples showing rhytidome-type and cork-type barks is valuable to approach cork and rhytidome development, allowing an accurate identification of candidate genes and processes. The present study underscores that abiotic stress and cell death are enhanced in rhytidome-type barks whereas lipid metabolism and cell cycle are enriched in cork-type barks. Development-related DEGs showing the highest expression, highlight cell division, cell expansion, and cell differentiation as key processes leading to cork or rhytidome-type barks. CONCLUSION: Transcriptome results, in agreement with anatomical and chemical analyses, show that rhytidome and cork-type barks are active in periderm development, and suberin and lignin deposition. Development and cell wall-related DEGs suggest that cell division and expansion are upregulated in cork-type barks whereas cell differentiation is enhanced in rhytidome-type barks.

Bark structure is coordinated with xylem hydraulic properties in branches of five Cupressaceae species.

The properties of bark and xylem contribute to tree growth and survival under drought and other types of stress conditions. However, little is known about the functional coordination of the xylem and bark despite the influence of selection on both structures in response to drought. To this end, we examined relationships between proportions of bark components (i.e. thicknesses of tissues outside the vascular cambium) and xylem transport properties in juvenile branches of five Cupressaceae species, focusing on transport efficiency and safety from hydraulic failure via drought-induced embolism. Both xylem efficiency and safety were correlated with multiple bark traits, suggesting that xylem transport and bark properties are coordinated. Specifically, xylem transport efficiency was greater in species with thicker secondary phloem, greater phloem-to-xylem thickness ratio and phloem-to-xylem cell number ratio. In contrast, species with thicker bark, living cortex and dead bark tissues were more resistant to embolism. Thicker phellem layers were associated with lower embolism resistance. Results of this study point to an important connection between xylem transport efficiency and phloem characteristics, which are shaped by the activity of vascular cambium. The link between bark and embolism resistance affirms the importance of both tissues to drought tolerance.

Ecosystem services at risk from disturbance in Europe's forests.

Global change impacts on disturbances can strongly compromise the capacity of forests to provide ecosystem services to society. In addition, many ecosystem services in Europe are simultaneously provided by forests, emphasizing the importance of multifunctionality in forest ecosystem assessments. To address disturbances in forest ecosystem policies and management, spatially explicit risk analyses that consider multiple disturbances and ecosystem services are needed. However, we do not yet know which ecosystem services are most at risk from disturbances in Europe, where the respective risk hotspots are, nor which of the main disturbance agents are most detrimental to the provisioning of multiple ecosystem services from Europe's forests. Here, we quantify the risk of losing important ecosystem services (timber supply, carbon storage, soil erosion control and outdoor recreation) to forest disturbances (windthrows, bark beetle outbreaks and wildfires) in Europe on a continental scale. We find that up to 12% of Europe's ecosystem service supply is at risk from current disturbances. Soil erosion control is the ecosystem service at the highest risk, and windthrow is the disturbance agent posing the highest risk. Disturbances challenge forest multifunctionality by threatening multiple ecosystem services simultaneously on 19.8 Mha (9.7%) of Europe's forests. Our results highlight priority areas for risk management aiming to safeguard the sustainable provisioning of forest ecosystem services.

Unraveling the multifaceted effects of climatic factors on mountain pine beetle and its interaction with fungal symbionts.

Mountain pine beetles (MPBs) pose a substantial threat to North American pine forests, causing extensive tree mortality over large areas. Their tree-killing ability is closely linked to mass aggregation on host trees triggered via pheromones and dependence on their symbiotic fungi. However, the influence of a changing climate on the biology of MPBs and their co-evolved interactions with their fungal symbionts remains uncertain. To investigate this, male and female pairs of beetles were introduced into freshly cut logs from lodgepole pine trees and placed in controlled climate chambers with manipulated environmental conditions, including two levels of CO2 (ambient vs. 1000 ppm), O3 (ambient vs. 100 ppb) and humidity (33% vs. 65%). The beetle-infested logs were left in these chambers for 1 month and then returned to ambient conditions until brood emergence. Emerging broods were collected for further analysis. Additionally, three species of fungal symbionts (Grosmannia clavigera, Ophiostoma montium and Leptographium longiclavatum) were subjected to the same CO2 , O3 and humidity conditions for 5 days. Lower humidity promoted MPB reproduction and fungal growth. Elevated CO2 accelerated larval growth and emergence while improving brood pheromone production. Elevated O3 had a negative impact on MPB reproduction and brood fitness while improving its immune responses to an entomopathogenic fungus (Beauveria bassiana). It also inhibited fungal growth and reproduction, whereas elevated CO2 had varied (positive or negative) effects on fungal growth and ergosterol (proxy to fungal mass) production depending on the fungal species. Together, these findings suggest that climate change can potentially alter the interactions between MPBs and their fungal symbionts, highlighting the importance of understanding how climate change affects forest pests and their symbiotic relationships to develop effective management strategies in the future.

Exosome-like nanoparticles from Mulberry bark prevent DSS-induced colitis via the AhR/COPS8 pathway.

Bark protects the tree against environmental insults. Here, we analyzed whether this defensive strategy could be utilized to broadly enhance protection against colitis. As a proof of concept, we show that exosome-like nanoparticles (MBELNs) derived from edible mulberry bark confer protection against colitis in a mouse model by promoting heat shock protein family A (Hsp70) member 8 (HSPA8)-mediated activation of the AhR signaling pathway. Activation of this pathway in intestinal epithelial cells leads to the induction of COP9 Constitutive Photomorphogenic Homolog Subunit 8 (COPS8). Utilizing a gut epithelium-specific knockout of COPS8, we demonstrate that COPS8 acts downstream of the AhR pathway and is required for the protective effect of MBELNs by inducing an array of anti-microbial peptides. Our results indicate that MBELNs represent an undescribed mode of inter-kingdom communication in the mammalian intestine through an AhR-COPS8-mediated anti-inflammatory pathway. These data suggest that inflammatory pathways in a microbiota-enriched intestinal environment are regulated by COPS8 and that edible plant-derived ELNs may hold the potential as new agents for the prevention and treatment of gut-related inflammatory disease.

Optimal allocation of resources among general and species-specific tools for plant pest biosecurity surveillance.

This paper proposes a surveillance model for plant pests that can optimally allocate resources among survey tools with varying properties. While some survey tools are highly specific for the detection of a single pest species, others are more generalized. There is considerable variation in the cost and sensitivity of these tools, but there are no guidelines or frameworks for identifying which tools are most cost-effective when used in surveillance programs that target the detection of newly invaded populations. To address this gap, we applied our model to design a trapping surveillance program in New Zealand for bark- and wood-boring insects, some of the most serious forest pests worldwide. Our findings show that exclusively utilizing generalized traps (GTs) proves to be highly cost-effective across a wide range of scenarios, particularly when they are capable of capturing all pest species. Implementing surveillance programs that only employ specialized traps (ST) is cost-effective only when these traps can detect highly damaging pests. However, even in such cases, they significantly lag in cost-effectiveness compared to GT-only programs due to their restricted coverage. When both GTs and STs are used in an integrated surveillance program, the total expected cost (TEC) generally diminishes when compared to programs relying on a single type of trap. However, this relative reduction in TEC is only marginally larger than that achieved with GT-only programs, as long as highly damaging species can be detected by GTs. The proportion of STs among the optimal required traps fluctuates based on several factors, including the relative pricing of GTs and STs, pest arrival rates, potential damage, and, more prominently, the coverage capacity of GTs. Our analysis suggests that deploying GTs extensively across landscapes appears to be more cost-effective in areas with either very high or very low levels of relative risk density, potential damage, and arrival rate. Finally, STs are less likely to be required when the pests that are detected by those tools have a higher likelihood of successful eradication because delaying detection becomes less costly for these species.

Comparison of trace elements in tissue of beaver (Castor canadensis) and local vegetation from a rural region of southern Ontario, Canada.

Beavers have been analyzed in several studies examining trace elements (TEs) in wildlife; however, most of these studies were undertaken in areas with known environmental pollutants. To understand and quantify natural enrichments of TEs in beaver tissue, samples of kidney, liver, muscle from 28 animals were compared with bark from 40 species of trees and shrubs, from the same, uncontaminated watershed. Pearson correlation and factor analysis show that conservative, lithophile elements such as Al, Ga, Th, and Y, all surrogates for mineral dust particles, explain 61% of the variation in the bark data. In contrast, Cd, Co, Cu, Mn, Mo, Ni, Rb, Se, Sr, and Tl in bark are independent of Al, and therefore most likely occur in non-mineral forms. Comparing tissue concentrations of beaver and bark, the organs are enriched in micronutrients such as Cu, Fe, Mo, Se, and Zn, but also non-essential, benign elements such as Cs and Rb, and potentially toxic elements such as Cd and Tl. Thus, the elements most enriched in beaver organs are those that apparently occur in biological form in the plant tissue. The elements enriched in these animals, relative to bark, appear to offer the most promise for monitoring environmental contamination by TEs using beavers. The majority of TEs of environmental relevance are most abundant in beaver kidney. However, monitoring studies must consider the variation in TE concentrations in beaver tissue, including those due to sex and age. Also, due consideration must be given to background concentrations of TEs in the vegetation composing the diet of the animals. The natural enrichment in the case of elements such as Cd, in beaver tissue relative to bark, is profound. These data establish critical baseline values for TEs in beavers in an unpolluted environment, thereby allowing for their use as model organisms in tracking how heavy metal pollutants may affect wildlife.

Effectiveness of cork and pine bark powders as biosorbents for potentially toxic elements present in aqueous solution.

Cork oak and pine bark, two of the most prolific byproducts of the European forestry sector, were assessed as biosorbents for eliminating potentially toxic elements (PTEs) from water-based solutions. Our research suggests that bioadsorption stands out as a viable and environmental eco-friendly technology, presenting a sustainable method for the extraction of PTEs from polluted water sources. This study aimed to evaluate and compare the efficiency of cork powder and pine bark powder as biosorbents. Specifically, the adsorption of Fe, Cu, Zn, Cd, Ni, Pb and Sn at equilibrium were studied through batch experiments by varying PTEs concentrations, pH, and ionic strength. Results from adsorption-desorption experiments demonstrate the remarkable capacity of both materials to retain the studied PTE. Cork powder and pine bark powder exhibited the maximum retention capacity for Fe and Cd, while they performed poorly for Pb and Sn, respectively. Nevertheless, pine bark showed a slightly lower retention capacity than cork. Increasing the pH resulted in cork showing the highest adsorption for Zn and the lowest for Sn, while for pine bark, Cd was the most adsorbed, and Sn was the least adsorbed, respectively. The highest adsorption of both materials occurred at pH 3.5-5, depending on the PTE tested. The ionic strength also influenced the adsorption of the various PTEs for both materials, with decreased adsorption as ionic strength increased. The findings suggest that both materials could be effective for capturing and eliminating the examined PTEs, albeit with different efficiencies. Remarkably, pine bark demonstrated superior adsorption capabilities, which were observed to vary based on the specific element and the experimental conditions. These findings contribute to elucidating the bio-adsorption potential of these natural materials, specifically their suitability in mitigating PTEs pollution, and favoring the recycling and revalorization of byproducts that might otherwise be considered residue.

Antimicrobial and biocompatibility nature of methanol extract of Lannea coromandelica bark and edible coating film preparation for fruit preservation.

This research was performed to evaluate the antimicrobial activity of methanol extract of Lannea coromandelica bark against fruit damage causing microbes such as fungi: Alternaria sp., Aspergillus sp., Botrytis sp., Cladosporium sp., Fusarium sp., Penicillium sp., Phytophthora sp., and Trichoderma sp. The bacteria: such as Chromobacter sp., Enterobacter sp., Erwinia sp., Flavobacterium sp., Lactobacillus sp., Pseudomonas sp., and Xanthomonas sp. was investigated. Furthermore, their biocompatibility nature was determined through animal (rat) model study and their fruit preserving potential was determined by edible coating preparation with chitosan and other substances. Interestingly, the extract showed dose dependent (1000 µg mL-1) activity against these microbes in the following order: Enterobacter sp. (26.4 ± 1.5) > Chromobacter sp. (25.4 ± 1.6) > Pseudomonas sp. (24.5 ± 1.3) > Flavobacterium sp. (24.3 ± 1.4) > Xanthomonas sp. (23.6 ± 1.6) > Erwinia sp. (23.6 ± 1.6) > Lactobacillus sp. (19.6 ± 1.3). Similarly, the antifungal activity was found as Penicillium sp. (32.6 ± 1.3) > Cladosporium sp. (32.6 ± 1.5) > Alternaria sp. (30.3 ± 1.2) > Aspergillus sp. (29.9 ± 1.8) > Botrytis sp. (29.8 ± 1.2) > Fusarium sp. (28.6 ± 1.5) > Trichoderma sp. (19.8 ± 1.4) > Phytophthora sp. (16.2 ± 1.1). The acute toxicity and histopathological study results revealed that the extract possesses biocompatible in nature. The illumination transmittance and active functional groups involved in interaction among test methanol extract and chitosan investigated by UV-vis and Fourier-transform infrared spectroscopy (FTIR) analyses and found average light transmittance and few vital functional groups accountable for optimistic interaction to creak edible coating. Approximately four (set I-IV) treatment sets were prepared, and it was discovered that all of the coated Citrus maxima fruit quality characteristics including total soluble solids (TSS), weight loss (%), pH of fruit pulp juice, and decay percentage were significantly (p>0.05) better than uncoated fruit.

Wood trait preferences of Neotropical xylophagous beetles (Coleoptera: Cerambycidae).

Tree life history strategies are correlated with functional plant traits, such as wood density, moisture content, bark thickness, and nitrogen content; these traits affect the nutrients available to xylophagous insects. Cerambycid beetles feed on substrates that vary in these traits, but little is known about how they affect community composition. The goal of this project is to explore the community composition of two cerambycid subfamilies (Cerambycinae and Lamiinae) according to the wood traits in the wood they eat. In a salvage project conducted adjacent to the Panama Canal, trees were felled and exposed to Cerambycidae for oviposition. Disks from branches of differing thickness from the same plant individuals were used to calculate wood density, moisture content, and bark thickness in the field; nitrogen data were acquired offsite. Thick and thin branches tended to differ in wood trait values; therefore, data were analyzed separately in subsequent analyses. In thin branches, cerambycid abundance and species richness were higher in samples with less dense, moister wood, and thicker bark. Thick branches showed similar trends, but the wood traits accounted for little variability in beetle abundance or species richness. There were no significant regressions between beetle data and nitrogen. Cerambycines emerged more slowly, and from denser, drier wood, than lamiines. Cerambycines might be more drought-tolerant than lamiines, and therefore more resistant to the longer, more severe dry seasons that are predicted to occur due to climate change.

La historia de vida de los árboles se correlaciona con los rasgos funcionales de la planta, como la densidad de la madera, el contenido de humedad, el grosor de la corteza, y el contenido de nitrógeno; estos rasgos afectan los nutrientes disponibles para los insectos xilófagos. Los escarabajos cerambícidos se alimentan de sustratos que varían en estos rasgos, pero se sabe poco sobre cómo afectan la composición de la comunidad. El objetivo de este proyecto es explorarla composición comunitaria de dos subfamilias de cerambícidos (Cerambycinae y Lamiinae) según las características de la madera que consumen. En un proyecto de salvamento realizado junto al Canal de Panamá, se talaron árboles y se expusieron a Cerambycidae para la oviposición. Se usaron discos de ramas de diferente grosor de las mismas plantas para calcular la densidad de la madera, el contenido de humedad y el grosor de la corteza en el campo; los datos de nitrógeno fueron adquiridos fuera del sitio. Las ramas gruesas y delgadas tendieron a diferir en los valores de las características de la madera; por lo tanto, los datos se analizaron por separado en análisis posteriores. En ramas delgadas, la abundancia de cerambícidos y la riqueza de especies fueron mayores en muestras con madera menos densa, más húmeda y con corteza más gruesa. Las ramas gruesas mostraron tendencias similares, pero las características de la madera explicaron poca variabilidad en la abundancia de escarabajos o la riqueza de especies. No hubo regresión significativas entre los datos del escarabajo y el nitrógeno. Cerambycines surgieron más lentamente y de maderas más densas y secas que los lamiines. Cerambycines podrían ser más tolerantes a la sequía que lamiines y, por lo tanto, más resistentes a las estaciones secas más largas y severas que se prevé que ocurran debido al cambio climático.

Enzyme Inhibitory Activities, Phenolic Profile, and in Silico Studies of Sorbus torminalis Tree Bark Methanol Extract.

The different parts of Sorbus torminalis (L.) Crantz are used in traditional medicine for various conditions such as cardiac diseases, cough, and diabetes, indicating its significant medicinal potential. Therefore, the current investigation aimed to reveal the phenolic composition of the poorly studied S. torminalis methanol extract of the bark, as well as its capacity to inhibit enzymes relevant to cardiovascular, neurodegenerative, and metabolic diseases. A total of 28 phenolic components, including 20 procyanidins aglycones (A- and B-type), four procyanidin glycosides, catechin and its glycoside, and two (epi)catechin derivatives, were detected using LC-MS. The contents of total polyphenols (6.22%), total tannins (3.04%), condensed tannins (0.70%), and total flavonoids (0.24 %) were determined spectrophotometrically, highlighting the considerable phenolic richness of the examined plant material. The concentration-dependent ability to inhibit α-amylase (IC50=130 µg/mL), α-glucosidase (IC50=312.13 µg/mL), acetylcholinesterase (IC50=156.46 µg/mL), butyrylcholinesterase (IC50=217.68 µg/mL), and angiotensin-converting enzyme (IC50=36.77 µg/mL) was demonstrated. The in silico approach showed that catechin, procyanidin B2 and C1, S. torminalis bark constituents, can form stable complexes with the target enzymes but with different binding affinity. The results supported the medicinal potential of S. torminalis bark and significantly expanded our knowledge of its chemistry, justifying further research.

Chemical Profile, Antibacterial Activity and Antioxidant Activity of Bark Volatile Oil of Terminalia arjuna.

Terminalia arjuna is an evergreen medicinal plant that belongs to the Combretaceae family of flowering plants. The bark of the plant exhibits antiviral, anticancer, hypocholesterolemic, antioxidant and antimicrobial properties. In this study, composition antibacterial activity, antioxidant activity and cytotoxicity of bark oil of Terminalia Arjuna (Roxb.) were reported. Oils were extracted by microwave assisted hydrodistillation where an oil yield of 0.18% was obtained followed by the identification of 35 compounds by gas chromatography mass spectrometry. The most abundant volatiles were furfural (11.11%), isoeugenol (9.99%), p-ethylguaiacol (9.97%), α-cadinol (9.57%), and estragole (9.47%). The oil was further evaluated against ten different drug resistant strains where oil showed significant activity against all pathogens and the highest activity was found against Acinetobacter baumannii (22mm), Klebsiella pneumoniae (22mm) and Staphylococcus aureus (22mm) in a concentration-dependent manner. Antioxidant activity evaluation demonstrated 68% radical scavenging activity by the volatile oil as compared to 81% of the standard, ascorbic acid at a concentration of 1000 µg. Cytotoxicity studies were conducted to see the effect of sample on the expression level of a housekeeping gene, Glyceraldehyde 3-phosphate dehydrogenase where it did not affect the normal transcription of the gene.

Fungal Species Causing Canker and Wilt of Ficus carica and Evidence of Their Association by Bark Beetles in Italy.

Field surveys conducted during 2021 and 2022 in Western Sicily, Italy, revealed the presence of common fig trees severely affected by trunk and crown root canker and bark cracking. Moreover, in conjunction with the symptomatic tissues, the same surveyed plants showed the presence of bark beetle holes and internal wood galleries. The predominant beetle Criphalus dilutus was previously reported attacking figs in Sicily. Phylogenetic analyses based on multilocus DNA data showed the presence of different fungal taxa associated with disease symptoms, including Botryosphaeria dothidea, Ceratocystis ficicola, Diaporthe foeniculina, Neocosmospora bostrycoides, N. perseae, and Neofusicoccum luteum. Pathogenicity tests conducted on potted fig plants showed that all the species were pathogenic to fig, with C. ficicola and Neocosmospora spp. as the most aggressive fungal species. Moreover, isolations conducted from the bodies of emerging adult insects recovered from disease samples confirmed the presence of C. ficicola and Neocosmospora spp., suggesting the potential involvement of C. dilutus in their dissemination.

A facile-treated sago bark (Metroxylon sagu) as a biosorbent for Cd(II) ions removal in aqueous solution by using the batch method.

The performance of sago bark for Cd(II) ions removal in the aqueous solution has been investigated using the batch method. The sago bark was facile-treated using HNO3 0.01 M and its ability on Cd(II) removal was evaluated under specific parameters such as pH, contact time, agitation speed, temperature, initial concentration, and adsorbent mass. The adsorption capacity of sago bark was found to be 2.473 mg/g. The Langmuir isotherm model corresponding to the monolayer adsorption process described the adsorption data well. The kinetic and thermodynamic evaluation confirmed that the Cd(II) ion sorption followed a pseudo-second-order model and endothermic. The adsorption capacity decreased after three times adsorption-desorption cycles. This result showed that the treated sago bark could be a good candidate as an adsorbent for Cd(II) removal.

Pretreatment of Melanoma Cells with Aqueous Ethanol Extract from Madhuca longifolia Bark Strongly Potentiates the Activity of a Low Dose of Dacarbazine.

Madhuca longifolia is an evergreen tree distributed in India, Nepal, and Sri Lanka. This tree is commonly known as Mahua and is used in traditional medicine. It was demonstrated that ethanol extract from the bark of M. longifolia possessed potent cytotoxic activity towards two melanoma cell lines, in contrast to aqueous extract that exhibited no activity. Apart from being selectively cytotoxic to cancer cells (with no activity towards non-cancerous fibroblasts), the studied extract induced apoptosis and increased reactive oxygen species generation in melanoma cells. Additionally, the use of the extract together with dacarbazine (both in non-toxic concentrations) resulted in the enhancement of their anticancer activity. Moreover, the pretreatment of melanoma cells with M. longifolia extract potentiated the activity of a low dose of dacarbazine to an even higher extent. It was concluded that ethanol extract of M. longifolia sensitized human melanoma cells to chemotherapeutic drugs. It can therefore be interesting as a promising source of compounds for prospective combination therapy.

Mapping the natural disturbance risk to protective forests across the European Alps.

Mountain forests play an essential role in protecting people and infrastructure from natural hazards. However, forests are currently experiencing an increasing rate of natural disturbances (including windthrows, bark beetle outbreaks and forest fires) that may jeopardize their capacity to provide this ecosystem service in the future. Here, we mapped the risk to forests' protective service across the European Alps by integrating the risk components of hazard (in this case, the probability of a disturbance occurring), exposure (the proportion of forests that protect people or infrastructure), and vulnerability (the probability that the forests lose their protective structure after a disturbance). We combined satellite-based data on forest disturbances from 1986 to 2020 with data on key forest structural characteristics (cover and height) from spaceborne lidar (GEDI), and used ensemble models to predict disturbance probabilities and post-disturbance forest structure based on topographic and climatic predictors. Wind and bark beetles are dominant natural disturbance agents in the Alps, with a mean annual probability of occurrence of 0.05%, while forest fires were less likely (mean annual probability <0.01%), except in the south-western Alps. After a disturbance, over 40% of forests maintained their protective structure, highlighting the important role of residual living or dead trees. Within 30 years after wind and bark beetle disturbance, 61% of forests were likely to either maintain or recover their protective structure. Vulnerability to fires was higher, with 51% of forest still lacking sufficient protective structure 30 years after fire. Fire vulnerability was especially pronounced at dry sites, which also had a high fire hazard. Combining hazard and vulnerability with the exposure of protective forests we identified 186 Alpine municipalities with a high risk to protective forests due to wind and bark beetles, and 117 with a high fire risk. Mapping the disturbance risk to ecosystem services can help identify priority areas for increasing preparedness and managing forests towards lower susceptibility under an intensifying disturbance regime.

Antioxidant and Cytotoxic Properties of Berberis vulgaris (L.) Stem Bark Dry Extract.

Berberis vulgaris (L.) has remarkable ethnopharmacological properties and is widely used in traditional medicine. The present study investigated B. vulgaris stem bark (Berberidis cortex) by extraction with 50% ethanol. The main secondary metabolites were quantified, resulting in a polyphenols content of 17.6780 ± 3.9320 mg Eq tannic acid/100 g extract, phenolic acids amount of 3.3886 ± 0.3481 mg Eq chlorogenic acid/100 g extract and 78.95 µg/g berberine. The dried hydro-ethanolic extract (BVE) was thoroughly analyzed using Ultra-High-Performance Liquid Chromatography coupled with High-Resolution Mass Spectrometry (UHPLC-HRMS/MS) and HPLC, and 40 bioactive phenolic constituents were identified. Then, the antioxidant potential of BVE was evaluated using three methods. Our results could explain the protective effects of Berberidis cortex EC50FRAP = 0.1398 mg/mL, IC50ABTS = 0.0442 mg/mL, IC50DPPH = 0.2610 mg/mL compared to ascorbic acid (IC50 = 0.0165 mg/mL). Next, the acute toxicity and teratogenicity of BVE and berberine-berberine sulfate hydrate (BS)-investigated on Daphnia sp. revealed significant BS toxicity after 24 h, while BVE revealed considerable toxicity after 48 h and induced embryonic developmental delays. Finally, the anticancer effects of BVE and BS were evaluated in different tumor cell lines after 24 and 48 h of treatments. The MTS assay evidenced dose- and time-dependent antiproliferative activity, which was higher for BS than BVE. The strongest diminution of tumor cell viability was recorded in the breast (MDA-MB-231), colon (LoVo) cancer, and OSCC (PE/CA-PJ49) cell lines after 48 h of exposure (IC50 < 100 µg/mL). However, no cytotoxicity was reported in the normal epithelial cells (HUVEC) and hepatocellular carcinoma (HT-29) cell lines. Extensive data analysis supports our results, showing a significant correlation between the BVE concentration, phenolic compounds content, antioxidant activity, exposure time, and the viability rate of various normal cells and cancer cell lines.

Antimicrobial Activity of Bark from Four North American Tree Species.

INTRODUCTION: Although many backcountry first aid kits contain antibiotic ointment, the supply can be quickly exhausted if a patient has extensive wounds or if there are multiple patients. METHODS: We assessed the antibacterial properties of bark extract from four North American woody plant species known to native Missourians as medicinal plants (Quercus macrocarpa, Salix humilis, Pinus echinata, and Hamamelis vernalis). We tested their antimicrobial properties, with the disc diffusion technique, against four common pathogenic bacterial species: Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterobacter aerogenes (now known as Klebsiella aerogenes). RESULTS: We report evidence of antibacterial activity of bark extract from all four plant species. CONCLUSIONS: Our results confirm that traditional uses of these species may be useful in fighting infection and could be especially useful in a wilderness setting when modern antibiotics are exhausted.

Effective removal of chromium by adsorption using Delonix regia bark derived activated carbon from aqueous solution: a sustainable approach.

This study introduces a new biosorbent derived from Delonix regia bark-activated carbon to efficiently remove Chromium Cr(VI) metal ions from aqueous systems. The biosorbent was synthesized from the bark powder of the plant species and chemically activated with phosphoric acid. The biosorbent was characterized using FTIR, SEM, and BET to determine its functional properties and structural morphology. The batch adsorption experiments examined the optimal conditions for Cr(VI) metal ion adsorption, identifying that the highest removal efficiency occurred at pH levels of 2. The ideal adsorbent dosage was determined to be 2.5 g/L, with equilibrium achieved at a contact time of 60 min at the optimal temperature of about 303 K for a Cr(VI) metal ion concentration of 20 mg/L. Various isotherm models were applied to the adsorption equilibrium values, revealing that the adsorbent had a maximum removal capacity of approximately 224.8 mg/g for Cr(VI) metal ions. The adsorption process of Cr(VI) on the DAC biosorbent was best described by the Freundlich isotherm, indicating multilayer adsorption. The kinetic data fit well with the pseudo-second-order model. Thermodynamic parameters suggested that the adsorption process was spontaneous, exothermic, and feasible across different temperatures. Furthermore, the desorption studies showed that the DAC biosorbent can easily be rejuvenated and utilized several cycles with high adsorption capacity. These findings indicate that the developed adsorbent is environmentally friendly and effective for removing Cr(VI) from water systems.