Magnesium sulfate paste

Several studies have demonstrated, both in vitro and in animal models, the anti-tumor efficacy of high-dose ascorbate treatment against a variety of tumor entities, including glioblastoma, the most common and aggressive primary malignant brain tumor. The aim of this study was to investigate the effects of high-dose ascorbate as well as dehydroascorbic acid on human glioblastoma cell lines and to evaluate different treatment conditions for the combined administration of ascorbate with magnesium (Mg2+) and iron (Fe3+). Intracellular levels of reactive oxygen species and the induction of cell death following ascorbate treatment were also investigated. We demonstrated high cytotoxicity and antiproliferative efficacy of high-dose ascorbate in human glioblastoma cells, whereas much weaker effects were observed for dehydroascorbic acid. Ascorbate-induced cell death was independent of apoptosis. Both the reduction in cell viability and the ascorbate-induced generation of intracellular reactive oxygen species could be significantly increased by incubating the cells with Fe3+ before ascorbate treatment. This work demonstrates, for the first time, an increase in ascorbate-induced intracellular ROS formation and cytotoxicity in human glioblastoma cells by pre-treatment of the tumor cells with ferric iron, as well as caspase-3 independence of cell death induced by high-dose ascorbate. Instead, the cell death mechanism caused by high-dose ascorbate in glioblastoma cells shows evidence of ferroptosis. The results of the present work provide insights into the efficacy and mode of action of pharmacological ascorbate for the therapy of glioblastoma, as well as indications for possible approaches to increase the effectiveness of ascorbate treatment.

Abstract licence: CC BY

Nitrogen fertilization in broccoli is very important for plant growth and productivity. However, it is known that the nitrogen source of the nitrogen fertilizer is also effective on quality parameters. In this study we investigated the effects of different nitrogen sources (ammonium sulphate and calcium nitrate) on bioactive compounds and leaf nutrients of broccoli cultivars (Monet, Italian and Karadede). The highest total phenolic content was 0.24 mg g− 1 fw in cultivar Monet. Nitrate-based fertilizer treatments provided higher total phenolic (0.28 mg g− 1 fw) and flavonoid (0.56 mg g1 fw) contents and FRAP (0.24 mmol g− 1 fw) values compared to ammonium-based fertilizer treatments. On the other hand, DPPH (0.77 mmol g− 1 fw) values were higher in the ammonium nitrogen treatments. Among the cultivars, Monet had the highest total phenolics, flavonoids and FRAP values. When leaf nutrient concentrations were analyzed, ammonium sulfate application resulted in higher sulfur (0.86%), zinc (20.72 mg kg− 1) and manganese (28.80 mg kg− 1) concentrations compared to calcium nitrate. Calcium nitrate treatment provided the highest calcium (2.09%) and iron (37.50 mg kg− 1) concentration in Monet cultivar. Phosphorus (0.31–0.35%) and magnesium (0.073–0.084%) concentrations differed among cultivars. In conclusion, the choice of nitrogen source and cultivar in broccoli cultivation plays an important role in the bioactive compound profile and nutrient composition of the broccoli crop. The results provide useful information for the improvement of broccoli quality.

Abstract licence: CC BY-NC-ND

The assembly of rhizosphere microbial communities is essential for maintaining plant health, yet it is influenced by a wide range of biotic and abiotic factors. The key drivers shaping the composition of these communities, however, remain poorly understood. In this study, we analyzed 108 plant samples and evaluated root traits, plant growth characteristics, soil enzyme activities, rhizosphere metabolites, and soil chemical properties to identify the primary determinants of rhizosphere community assembly. Across 36 soil samples, we obtained 969,634 high-quality sequences, clustering into 6,284 ASVs predominantly classified into Proteobacteria (57.99%), Actinobacteria (30%), and Bacteroidetes (5.13%). Our findings revealed that rhizosphere metabolites accounted for more variance in microbial community composition compared to chemical properties (ANOVA, F = 1.53, p = 0.04), enzyme activities, or root traits (ANOVA, F = 1.04, p = 0.001). Seven small molecule metabolites, including glycerol, sorbitol, phytol, and alpha-ketoglutaric acid, were significantly correlated with βNTI, underscoring their role as critical drivers of microbial community assembly. The genus Rhizobium, significantly associated with βNTI (R = 0.25, p = 0.009), emerged as a keystone taxon shaping community structure. Soil culture experiments further validated that small molecule metabolites can modulate microbial community assembly. The ST treatment, enriched with these metabolites, produced 1,032,205 high-quality sequences and exhibited significant shifts in community composition (Adonis, p = 0.001, R = 0.463), with Rhizobium showing higher abundance compared to the control (CK). Variable selection (βNTI >2) drove phylogenetic turnover in ST, while stochastic processes (|βNTI| < 2) dominated in CK. This study provides quantitative insights into the role of rhizosphere metabolites in shaping microbial community assembly and highlights their potential for targeted modulation of rhizosphere microbiomes.

Abstract licence: CC BY

Siderophores, specialized iron-chelating molecules produced by Bacillus amyloliquefaciens D5, were investigated for their role in enhancing plant defense mechanisms against Cercospora canescens in mung bean (Vigna radiata L.). Siderophores were extracted and purified using Amberlite XAD-4 and applied to plants at concentrations of 5, 10, and 15 µg/mL, followed by pathogen inoculation. The treatments significantly influenced enzymatic activities and defense-related gene expression. On Day 6, peroxidase (POD) activity reached its highest value of 0.563 in the SP15 (siderophore + pathogen at 15 µg/mL) treatment, with S15 (siderophore-only at 15 µg/mL) showing a lower but significant increase of 0.453, while control groups remained unchanged. Polyphenol oxidase (PPO) activity peaked in SP15 (0.10 U/mL), followed by S15 (0.08 U/mL), highlighting the role of these treatments in enhancing stress responses. Chitinase activity was significantly elevated in SP15 on Day 6, with a sustained response through Day 8, while no significant change was observed in the control group. Total phenolic content was highest in SP15 (100 µg/mL), showing a a ramified immune response whereas S15 recorded 80 µg/mL, significantly above the control. Gene expression analysis further demonstrated the effectiveness of siderophore and siderophore + pathogen treatments. Catalase expression was upregulated by 21.1-fold in siderophore-only treatment and amplified to 25.9-fold in SP15. Epoxide hydrolase (EH) gene expression increased by 77.3-fold in S15 and further synergized to over 90-fold in SP15. Similarly, PR10 expression showed moderate upregulation in S15 and significantly higher levels in SP15, reflecting enhanced pathogen defense. Calmodulin (CAL) gene expression was moderately regulated in S15 but significantly amplified in SP15. These findings underscore the dual role of siderophores in nutrient acquisition and as potent elicitors of plant defenses, highlighting their potential as bio-stimulants. Field trials are essential to validate these results under natural conditions and optimize their use in agriculture.

Abstract licence: CC BY

Polyphosphate (polyP) is found in plankton of diverse aquatic ecosystems and is important for plankton ecology and biogeochemical cycling. However, our knowledge of polyP in aquatic environments is hindered by a lack of data due to the limitations of quantification methods. The estimate of polyP in model organisms using phenol-chloroform extraction followed by enzymatic hydrolysis is complicated and fails for environmental samples. The commonly used 4',6-diamidino-2-phenylindole (DAPI) fluorescence method for environmental studies, on the contrary, severely overestimates polyP due to interference. In this paper, we develop a plankton lysis buffer to extract polyP and a quantification method using a novel polyP-specific fluorescence dye JC-D7. We test the methods using cultured algae and bacteria, as well as natural samples from marine and freshwater environments. We show that our plankton lysis extracts polyP with high recovery while requiring substantially less time and effort. Subsequent polyP quantification using JC-D7 fluorescence overcomes the interference encountered by the DAPI method and provides an accurate measurement of polyP down to -1. This novel method enables more accurate quantification of polyP in aquatic environments and will profoundly enhance our knowledge of polyP, plankton ecology, and biogeochemistry.

Abstract licence: CC BY-NC-ND

This study evaluated the effects of ZnO and green-synthesized ZnO nanoparticles (ZnO-NPs) from Sargassum ilicifolium extract on the biochemical interactions between tomato leaves and the destructive pest Tuta absoluta. The average size and stability of ZnO-NPs were characterized using DLS, X-RD, and FE-SEM. Peaks in the FT-IR spectrum of the extract of the algae and ZnO-NPs, indicated the presence of carboxyl groups, amines, alkynes and alcohols. Treated tomato leaves exhibited increased total chlorophyll and anthocyanin contents, particularly at 100 and 50 ppm, compared to the control. A significant increase in total flavonoid content was observed at 100 ppm, while total phenolic content was also enhanced at 50 ppm. In T. absoluta larvae, exposure to 50 and 100 ppm ZnO-NPs led to a reduction in α-amylase, total protease, total protein, and TAG levels, alongside increased catalase activity. Additionally, G6PD and ALT activities decreased at 50 ppm compared to the control. Lactate, MDA, and the RSSR/RSH increased at 100 ppm. Furthermore, ZnO-NPs at 50 and 100 ppm elevated larval aldolase activity, while AST and γ-GT activities declined. These findings indicate that ZnO-NPs enhance tomato defense mechanisms and mitigate larval damage, supporting their potential use in integrated pest management strategies against T. absoluta.

Abstract licence: CC BY-NC-ND