Background: Salinity is a major abiotic stress, and the use of saline water in the agricultural sector will incur greater demand under the current and future climate changing scenarios. The objective of this study was to develop a dual-functional nanofertilizer capable of releasing a micronutrient that nourishes plant growth while enhancing salt stress resilience in faba bean (Vicia faba L.). Results: Moringa oleifera leaf extract was used to synthesize sulfur nanoparticles (SNPs), which were applied as a foliar spray at different concentrations (0, 25, 50, and 100 mg/l) to mitigate the negative effects of salt stress (150 mM NaCl) on faba bean plants. The SNPs were characterized and found to be spherical in shape with an average size of 10.98 ± 2.91 nm. The results showed that salt stress had detrimental effects on the growth and photosynthetic performance (Fv/Fm) of faba bean compared with control, while foliar spraying with SNPs improved these parameters under salinity stress. SNPs application also increased the levels of osmolytes (soluble sugars, amino acids, proline, and glycine betaine) and nonenzymatic antioxidants, while reducing the levels of oxidative stress biomarkers (MDA and H₂O₂). Moreover, SNPs treatment under salinity stress stimulated the activity of antioxidant enzymes (ascorbate peroxidase (APX), and peroxidase (POD), polyphenol oxidase (PPO)) and upregulated the expression of stress-responsive genes: chlorophyll a-b binding protein of LHCII type 1-like (Lhcb1), ribulose bisphosphate carboxylase large chain-like (RbcL), cell wall invertase I (CWINV1), ornithine aminotransferase (OAT), and ethylene-responsive transcription factor 1 (ERF1), with the greatest upregulation observed at 50 mg/l SNPs. Conclusion: Overall, foliar application of sulfur nanofertilizers in agriculture could improve productivity while minimizing the deleterious effects of salt stress on plants. Therefore, this study provides a strong foundation for future research focused on evaluating the replacement of conventional sulfur-containing fertilizers with their nanoforms to reduce the harmful effects of salinity stress and enhance the productivity of faba beans.

Zinc oxide nanoparticles (ZnO NPs) can be considered as nanofertilizer providing zinc as an essential micronutrient for plant growth and production at specific safe dose, however, above this dose; ZnO NPs induce oxidative stress. The present research aimed to evaluate some physiological and molecular effects of ZnO NPs on Trigonella foenum-graecum (fenugreek) plant. The ZnO NPs were applied at five different concentrations (10, 20, 30, 40, and 50 mg/l) via soaking fenugreek seeds for 24 h. Fenugreek seedlings were harvested after 14 days for biomass and biochemical analyses. The results revealed that increasing ZnO NPs concentration led to a significant increase in all measured parameters until peaked at 30 mg/l; after that, a decline trend was detected. However, malondialdehyde (MDA) increased significantly just at higher concentrations of ZnO NPs (40 and 50 mg/l). In addition, genetic variation measure using start codon targeted (SCoT) markers revealed that ZnO NP treatments exhibited limited genetic variation. Results showed that treatment with ZnO NPs at 30 mg/l can improve biomass, bioactive compounds, and antioxidant activity of fenugreek seedlings, besides being safe for DNA. So, this concentration could be a decent nanofertilizer for fenugreek plant.

Salinity stress poses a significant threat to crop productivity worldwide, necessitating effective mitigation strategies. This study investigated the phytochemical composition and potential of grape seed extract (GSE) to mitigate salinity stress effects on faba bean plants. GC–MS analysis revealed several bioactive components in GSE, predominantly fatty acids. GSE was rich in essential nutrients and possessed a high antioxidant capacity. After 14 days of germination, GSE was applied as a foliar spray at different concentrations (0, 2, 4, 6, and 8 g/L) to mitigate the negative effects of salt stress (150 mM NaCl) on faba bean plants. Foliar application of 2–8 g/L GSE significantly enhanced growth parameters such as shoot length, root length, fresh weight, and dry weight of salt-stressed bean plants compared to the control. The Fv/Fm ratio, indicating photosynthetic activity, also improved with GSE treatment under salinity stress compared to the control. GSE effectively alleviated the oxidative stress induced by salinity, reducing malondialdehyde, hydrogen peroxide, praline, and glycine betaine levels. Total soluble proteins, amino acids, and sugars were enhanced in GSE-treated, salt-stressed plants. GSE treatment under salinity stress modulated the total antioxidant capacity, antioxidant responses, and enzyme activities such as peroxidase, ascorbate peroxidase, and polyphenol oxidase compared to salt-stressed plants. Gene expression analysis revealed GSE (6 g/L) upregulated photosynthesis (chlorophyll a/b-binding protein of LHCII type 1-like (Lhcb1) and ribulose bisphosphate carboxylase large chain-like (RbcL)) and carbohydrate metabolism (cell wall invertase I (CWINV1) genes) while downregulating stress response genes (ornithine aminotransferase (OAT) and ethylene-responsive transcription factor 1 (ERF1)) in salt-stressed bean plants. The study demonstrates GSE’s usefulness in mitigating salinity stress effects on bean plants by modulating growth, physiology, and gene expression patterns, highlighting its potential as a natural approach to enhance salt tolerance.

Background: Secondary metabolites are distinct compounds with significant medicinal value, yet their production and chemical synthesis present considerable challenges. This necessitates the development of innovative strategies to improve their yield. This study investigated the potential of biosynthesized sulfur nanoparticles (SNPs) as an eco-friendly elicitor to enhance the synthesis of antioxidant secondary metabolites in Lotus arabicus L. callus cultures. Results: After seven weeks, induced calli of L. arabicus L were transferred to MS media supplemented with SNPs at different concentrations (0, 25, 50, 100, and 200 mg/l). The results indicated that SNPs (100 mg/l) induced significantly higher profiles for biomass and secondary metabolite compared to the control treatments. Enzyme activities related to secondary metabolite biosynthesis, specifically phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were enhanced in a dose-dependent manner, with the greatest increases observed at 100 mg/l SNPs. The SNPs also modulated oxidative stress markers (MDA and H₂O₂), generally improving callus growth conditions by reducing oxidative stress, except at the highest concentration of 200 mg/l. Additionally, the application of SNPs at 100 mg/l markedly upregulated the expression levels of six crucial genes in the biosynthesis pathway of secondary metabolites (chalcone synthase (CHS), phenylalanine ammonia lyase (PAL), flavonol synthase (FLS), chalcone isomerase (CHI), hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase (HQT), and deoxyxylulose phosphate reductoisomerase (DXR)). Quantitative HPLC profiling of 16 phenolic and flavonoid compounds revealed that supplementation with SNPs resulted in noticeable boots in the majority of the measured compounds with SNP supplementation. Conclusion: Overall, the supplementation of SNPs in the culture media of L. arabicus L callus positively influenced secondary metabolite production at the molecular and physiological levels, increasing its potential for medicinal use.

Background: Plants are considered the primary source of many principal bioactive compounds that have been utilized in a wide range of applications including the pharmaceutical and biotechnological industries. Therefore, there is an imperative need to modulate the production of natural bioactive components. The present study aimed to determine the importance of dried and pulverized date palm seeds (DPS) as a natural elicitor for the synthesis of secondary metabolites in Lotus arabicus L. Results: The presence of various antioxidant compounds, simple sugars, amino acids, fatty acids and reasonable mineral contents was distinct in the phytochemical characterization of DPS. The major components detected in DPS analysis were the 5-(hydroxymethyl) furfural and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyranone. The induced callus of L. arabicus (seven weeks old) was supplemented with DPS at different concentrations (0, 2, 4, 8 and 10 g/l) in culture media. Treatment with 8 g/l DPS induced the highest antioxidant capacity, ascorbic acid content and secondary metabolites (total phenolics and flavonoids) in the produced callus. Stress biomarkers (hydrogen peroxide and malondialdehyde) were found in the control ranges except at 10 g/l DPS. The expression patterns of key genes involoved in secondary metabolism modulation, such as phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavonol synthase (FLS) and deoxyxylulose phosphate reductoisomerase (DXR), were triggered after DPS treatments. Moreover, the quantitative profiling of phenolic and flavonoid compounds showed that supplementation with DPS, especially at 8 g/l, led to pronounced increases in most of the measured compounds. Conclusion: The marked upregulation of eliciting-responsive genes and overproduction of secondary metabolites provide molecular-based evidence for intensifying the principal pathways of phenylpropanoid, flavonoid and terpenoid biosynthesis. Overall, the present in vitro study highlights the stimulating capacity of DPS utilization to improve the bioactive components of L. arabicus at the physiological and molecular levels, enhancing its potential as a medicinal herb.

Plant callus cultures are a sustainable alternative for producing bioactive secondary metabolites, but their low yields limit industrial applications. Carob (Ceratonia siliqua L.) is rich in medicinally valuable compounds, yet conventional cultivation faces challenges. To address this, we use biofortified calcium phosphate nanoparticles, which refer to CaP-NPs that have been enriched with bioactive compounds via green synthesis using Jania rubens extract, thereby enhancing their functional properties as elicitors in carob callus. CaP-NPs were green-synthesized using Jania rubens extract and applied to 7-week-old callus cultures at 0, 25, 50, and 75 mg/L concentrations. At the optimal concentration (50 mg/L), CaP-NPs increased callus fresh weight by 23.9% and dry weight by 35.1%. At 50 mg/L CaP-NPs, phenolic content increased by 95.7%, flavonoids by 34.4%, tannins by 131.8%, and terpenoids by 211.9% compared to controls. Total antioxidant capacity rose by 76.2%, while oxidative stress markers malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) decreased by 34.8% and 14.1%, respectively. Gene expression analysis revealed upregulation of PAL (4-fold), CHI (3.15-fold), FLS (1.16-fold), MVK (8.3-fold), and TA (3.24-fold) at 50 mg/L CaP-NPs. Higher doses (75 mg/L) induced oxidative damage, demonstrating a hormetic threshold. These findings indicate that CaP-NPs effectively enhance secondary metabolite production in carob callus by modulating biosynthetic pathways and redox balance, offering a scalable, eco-friendly approach for pharmaceutical and nutraceutical applications.