The Science of Nature最新文献

Since tea is an economically valuable medicinal plant, pollen germination and pollen tube elongation are important for seed yield and quality. Therefore, strategies to increase pollen tube elongation for tea production are developing and especially the use of beneficial microorganisms is gaining importance. We aimed to investigate the potential activities of Streptomyces albidoflavus, Streptomyces indigoferus, Streptomyces nanhaiensis, Pseudomonas fluorescens, Paenibacillus xylanilyticus, and Paenibacillus alginolyticus on pollen germination and pollen tube length of Camellia sinensis. The amount of reducing sugars was determined by DNS method, and heat map analyses were performed to evaluate pollen germination, pollen tube length, and RS content. The tested bacteria were grown on pollen germination medium for 3, 6, and 24 h, after which the aforementioned parameters were analyzed. No statistically significant effect of treatments with tested bacteria was found in terms of pollen germination. However, especially in pollen samples treated with P. alginolyticus at 6 and 24 h, pollen tube length was found to be the most effective with an increase of 28.6 and 13.87%. Reducing sugar content was found to be the highest in S. indigoferus + pollen and P. alginolyticus + pollen groups at 24 h. According to heat map analyses, P. alginolyticus maintained consistently high values for pollen germination, tube elongation, RS content and showed the strongest positive effect. In conclusion, P. alginolyticus significantly increased pollen tube elongation and RS levels, suggesting its potential role in plant development and pollination. These findings indicate that such rhizosphere bacteria may act as biostimulants to enhance fertilization and support sustainable tea cultivation.

Nowadays, the fabrication of silver nanoparticles (Ag NPs) is receiving considerable attention due to their wide range of applications in various domains. The green approach to synthesizing Ag NPs is cost-effective and ecologically safe, as it does not involve any sophisticated instruments or hazardous chemicals. Cajanus cajan (CC, Pigeon pea) is a plant belonging to the family Fabaceae. So far, only pigeon pea leaves and seeds have been used in the synthesis of NPs. After the removal of edible seeds, pods are fed to cattle as fodder. The pods contain different flavonoids, iridoids, and other miscellaneous compounds. The present research focuses on the use of C. cajan pods in the fabrication of Ag NPs and the evaluation of their cytotoxicity against normal and breast cancer cells. On characterization, Ag NPs were found to be oval in shape, crystalline in nature, and capped with phytochemicals present in CC. The results of the MTT assay revealed that Ag NPs are cytotoxic to breast cancer cells. It can be concluded that phytochemicals present in C. cajan pods reduced the precursor into Ag NPs, which were significantly biologically active.

Three new species of Mesypochrysa Martynov, 1927: Mesypochrysa paucinervis sp. nov., Mesypochrysa angusta sp. nov. and Mesypochrysa paradoxica sp. nov., are described from the Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. The three species are assigned to Mesypochrysa based on the following characters: costal crossveins simple; two gradate series of crossveins present; MA and MP distally bifurcated; CuA with three to five pectinate branches; CuP distally bifurcated. Mesypochrysa paucinervis sp. nov. can be distinguished from other species of Mesypochrysa by nine RP branches and simple A1. Mesypochrysa angusta sp. nov. can be distinguished from other species by 16 RP branches and five CuA branches. Mesypochrysa paradoxica sp. nov. can be distinguished from other species by the distal position of 2m-cu. In addition, the position of 2m-cu in forewings of Limaiinae and distinguish characters of Mesypochrysa are discussed. The discovery of new fossil species enriches the species diversity of this taxon in the Jurassic, while also providing new evidence for the early evolution of chrysopids.

In wildlife seizure proceedings, it is essential to accurately identify and differentiate between seized Asian and African elephant ivory and their carved products. This differentiation is necessary for effectively tracking the ivory trade, which will assist in combating illegal ivory trafficking. However, distinguishing similar types of samples from closely related species poses a challenging task, as they share similar chemical compositions. Therefore, the present study aimed to differentiate Asian and African elephant ivory samples, collected from ten individuals of each species. To achieve this objective, a rapid and cost-effective ATR-FTIR spectroscopy combined with chemometrics was employed. The spectra of the ivory samples were visually compared and subsequently subjected to chemometric analysis. The PCA model differentiated Asian and African elephant ivory samples into two distinct clusters, achieving an accuracy of 95%. Furthermore, the PLS-DA model successfully classified the ivory samples into two distinct categories with 100% accuracy. To validate the performance of the developed PLS-DA model, both cross-validation and external validation were conducted, yielding a classification accuracy of 100%. A blind test was also conducted to assess the prediction accuracy of the PLS-DA model, which also achieved 100% prediction accuracy. Additionally, the PLS-DA model effectively differentiated ivory from bone samples. The findings of this study highlighted the effectiveness of employing ATR-FTIR spectroscopy combined with PLS-DA tool to differentiate ivory samples sourced from Asian and African elephants. The present approach is effective even for the samples that have lost their morphological characteristics or consist of powdered ivory traces recovered from crime scenes.

The objective of the study is to establish an extraction method of exosomes (Exos) from neural stem cells (NSCs) and to explore the effect of exosomes on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, MPTP). In this study, neural stem cell-derived exosomes (NSC-Exos) were extracted for treatment; a mouse model of PD induced by MPTP was established. After the treatment with NSC-Exos, the behavioral ability of mice in the EXO group was significantly improved compared to that in the MPTP group. The biochemical index test results showed that compared with that in the MPTP group, the activity of SOD and the content of GSH in the serum of mice in the EXO group increased (P < 0.01), while the content of MDA decreased (P < 0.05). Hematoxylin–eosin staining (HE) was used to observe the histopathological morphological changes in the brain of PD mice. Western blot results showed that compared with that in the MPTP group, after the treatment with NSC-Exos, the expression level of α-syn protein in the brain tissue of mice in the EXO group decreased, while that of TH protein increased (P < 0.05); compared with those in the MPTP group, the expression levels of I-κB, NF-κB, IL-6, IL-1β, and TNF-α proteins increased (P < 0.01). The 16S rDNA sequencing results of mouse gut microbiota showed that compared with that in the MPTP group, the abundance of Firmicutes decreased (P < 0.05), while the abundance of Bacteroidetes and Actinobacteria increased (P < 0.05) in the EXO group. The results of this study indicate that NSC-Exos have a certain therapeutic effect on the MPTP-induced PD in mice.

Malvastrum coromandelianum (L.) Garcke (Malvaceae) is a widely distributed herbaceous species known for its ecological adaptability and invasive behavior in tropical and subtropical ecosystems. In plantation forests, such invasive understory species can alter community composition, affect regeneration, and influence ecosystem functioning. Understanding their trait plasticity across contrasting tree plantation environments is critical for managing understory biodiversity and assessing the ecological consequences of afforestation practices. This study examined the phenotypic and functional responses of M. coromandelianum across different tree plantations in Pakistan, focusing on how canopy-driven microclimatic variation and soil physicochemical conditions influence its morphological, physiological, and anatomical traits. Results revealed that functional trait responses were highly variable and plantation-specific. Plant height, shoot length, and glycine betaine accumulation were highest under Morus nigra, corresponding with elevated soil phosphorus and calcium, while the longest roots and highest proline levels occurred under Melia azedarach, where soil calcium and magnesium were also enriched. The smallest individuals were observed under Tecomella undulata, where higher sodium and lower nutrient availability may have constrained growth. Ion concentrations in plant tissues varied significantly across plantation types, generally aligning with soil ion availability—for instance, elevated shoot and root sodium under Melia azedarach corresponded with higher soil salinity, while calcium accumulation was greatest in soils with higher calcium. Leaf anatomical traits, including thicker mesophyll and midrib tissues under Morus nigra, suggested resource-acquisitive strategies, while root epidermis and stem sclerenchyma thickening under Conocarpus lancifolius reflected stress-tolerant adaptations. Structural traits varied along the Leaf–Stem–Root Economics Spectrum (LSRES), indicating a balance between conservative and acquisitive strategies depending on resource availability. These findings highlight the species considerable plasticity in response to integrated canopy and soil factors. However, given its invasive nature, M. coromandelianum should not be promoted for use in ecological restoration without careful consideration of its ecological impacts. Instead, its consistent trait responses make it a potentially valuable bioindicator for assessing understory microhabitat conditions, especially in semi-arid plantations.

Urban green spaces play a crucial role in protecting insect biodiversity against habitat loss. However, chemical pollution poses a potential threat to these ecosystems, making ecological risk assessment essential. In the city of San Luis Potosí, a former copper smelter operated for several decades, releasing arsenic into the environment. Despite this, its ecological impact has received no attention, which is important given the presence of nearby green spaces that provide habitat for urban insects. This study assessed arsenic levels in soil, plants, and insects near this former copper smelter to determine whether this pollutant poses risks to local insects. The study sites included green spaces near the smelter (smelter-impacted zone) and reference green spaces (reference zone), both ubicated within the same city. The study sites harbor more than 50 insect families with different ecological roles. Arsenic levels in soil, plants, and insects in the smelter-impacted zone were 4, 2, and 20 times higher compared to the reference zone, respectively. The analysis of exposure routes indicates that soil is a direct route for plants and insects, plants transfer the arsenic to several herbivores, decomposers reincorporate arsenic into the trophic chain, and predators are also exposed. Moreover, Cotinis mutabilis (Coleoptera: Scarabaeidae: Cetoniinae) was identified as a bioindicator of arsenic pollution, showing a positive correlation between its tissue concentrations and arsenic levels in soil. In conclusion, this study demonstrates that arsenic pollution threatens insects in the smelter-impacted zone, highlighting the need for further research to assess the potential ecological risks.

The house fly, Musca domestica L., plays a crucial role as a mechanical vector for a variety of pathogens that impact both humans and animals, highlighting the need for effective control measures. Conventional approaches, including sanitation and waste management, exhibit certain constraints, resulting in a dependence on synthetic insecticides that carry potential risks of toxicity and the development of resistance. This research examined the lethal and behavioral effects of Cinnamomum verum (cinnamon) extracts on house flies, employing an age-stage two-sex life table methodology to evaluate life table parameters. The analysis utilizing gas chromatography-mass spectrometry (GC–MS) revealed significant phytochemicals present in cinnamon bark, such as cinnamaldehyde and eugenol, which are recognized for their insecticidal and behavioral effects in insects. Acute toxicity assessments demonstrated lethal concentrations (LC₅, LC₂₅, and control) of cinnamon extracts, significantly affecting developmental and reproductive parameters. Interestingly, lower concentrations (LC₅) promoted fecundity and intrinsic growth rates compared to higher concentrations (LC₂₅), suggesting a biphasic response that aligns with the concept of pesticide-induced hormesis. Furthermore, oviposition preference trials confirmed a concentration-dependent deterrent effect of cinnamon extracts, with higher doses significantly reducing egg-laying behavior in gravid females. This research has included traditional GC–MS-based phytochemical screening by incorporating comprehensive biological and molecular assessments, offering a more integrated approach for biopesticide identification. The identification of phytochemicals like cinnamaldehyde and α-muurolene establishes a robust basis for the screening of additional bioactive compounds and exploring novel insecticidal agents.

Cecropia obtusa is a Neotropical myrmecophyte (i.e., plant sheltering ant colonies in hollow structures in exchange for protection against different enemies) that, in French Guiana, is associated with the dolichoderine ants Azteca alfari or A. ovaticeps that nest in this tree’s internodes and are provided food, mostly food bodies called Müllerian bodies. We show that the workers of the ectatommine ant Ectatomma tuberculatum are able to select small C. obtusa individuals (i.e., they were never noted on trees more than 3 m tall) to ambush the Azteca workers exiting the entrance holes to the internodes on these trees. Their presence is more frequent diurnally when the Azteca must leave their nest to harvest Müllerian bodies, whose production requires sunlight, than at night. We witnessed 36 E. tuberculatum foragers ambushing Azteca workers, then seizing and stinging them. Exceptionally, they captured three Azteca workers successively. In all cases, they retrieved them by carrying them between their mandibles. These results confirm that E. tuberculatum foragers, which nest at the base of different tree species, are well adapted to ambushing insect prey, including social insects exiting their nests.