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This study investigates the enhanced production of key therapeutic metabolites (ellagic acid, serotonin, and chlorogenic acid) in response to abiotic stress in in vitro cultures of Quercus suber somatic embryos. Findings indicate significant increases in metabolite levels under various stress conditions, highlighting the potential for commercial-scale production of these compounds, known for their antioxidant, anticancer, and anti-COVID-19 properties. Under osmotic/saline stress, ellagic acid production significantly increased, representing an 80% increase compared to control conditions. In embryos exposed to different stressors, serotonin accumulation showed a six-fold increase under osmotic/saline stress. Although the elicitors used did not increase chlorogenic acid levels, exploring alternative stress types may enhance its production. This research paves the way for sustainable, large-scale production of health-beneficial metabolites, addressing global health challenges and promoting resource sustainability.

This study presents a novel green synthesis method for aluminum phosphate (AlPO4) nanoplates using extracts from Quercus suber somatic embryos. Traditionally, metallic nanoparticles are synthesized using harmful chemical reagents and solvents, but our approach leverages bioactive compounds, such as phytic acid (IP6) from plant extracts, offering a more sustainable alternative. We observed a high phosphate content of 23.6 μMol PO43−/mg dry weight (DW) in the extracts, which is significantly higher than in other Quercus species. Characterization through UV–VIS spectroscopy and XRD confirmed the formation of complex crystal nanoplates, where anisotropic aluminum phosphate with a triclinic crystal structure coexists with monoclinic structures, both forms of aluminum phosphate tridymite. Electron microscopy (TEM and SEM) revealed the hierarchical organization of these nanoplates, distinguishing them from the more commonly observed spherical nanoparticles. Fourier-transform infrared (FTIR) spectroscopy further validated the incorporation of phytic acid into the nanoplate structure. This innovative method not only advances sustainable nanomaterial synthesis but also demonstrates the potential for unique optical and structural properties in aluminum phosphate nanoplates, paving the way for future applications in specialized fields.

Nanopriming, a technique that involves treating seeds with nanoparticles, is gaining attention for enhancing seed germination and seedling growth. This study explored the effects of silver nanoparticles (AgNPs), synthesized using Ascorbic acid, Caffeic acid, and Gallic acid, on cucumber seedling development. The nanoparticles, characterized by spherical morphology and distinct optical properties, showed varying effects based on the type and concentration of the reducing agents used. AgNP treatments generally led to higher germination rates and improved shoot and root growth compared to controls. Biochemical analyses revealed that these treatments influenced plant physiology, affecting reactive oxygen species (ROS) production, oxidative stress markers, and the content of amino acids, phenolic compounds, flavonoids, and soluble sugars. Specifically, certain AgNP treatments reduced oxidative stress, while others increased oxidative damage. Additionally, variations in free amino acids and phenolic and flavonoid contents were noted, suggesting complex interactions between nanoparticles and plant biochemical pathways. These findings highlight the potential of nanopriming in agriculture and underscore the need for further research to optimize nanoparticle formulations for different plant species.

This study aims to evaluate the biocontrol potential of Meyerozyma guilliermondii (CECT13190), an endophytic yeast, and its role in mitigating the adverse effects of abiotic and biotic stress in cucumber plants. The relevance of this study lies in addressing the threat of Fusarium wilt, a major fungal disease that impacts cucumber crop productivity, as well as the exacerbation of food scarcity caused by climate change-induced abiotic stress factors such as high temperatures and drought. The study was conducted in a greenhouse environment where Cucumis sativus seedlings were exposed to biotic (F. oxysporum inoculation) and abiotic stress conditions (heat and water deficit). The impact of M. guilliermondii on treated plants’ physiology, growth, development, and flowering was assessed. The study confirmed the biocontrol activity of M. guilliermondii against F. oxysporum and highlighted its positive effects as a plant growth promoter. It enhanced overall plant health, activated natural defense mechanisms against F. oxysporum, and alleviated the detrimental impacts of abiotic stress. Notably, M. guilliermondii also induced early flowering in cucumber plants. This research underscores the potential of M. guilliermondii as a biocontrol agent for managing Fusarium wilt, enhancing stress tolerance, promoting early flowering, and offering promising prospects for sustainable crop production amidst fungal diseases and climate change-induced stressors. The findings emphasize the importance of utilizing M. guilliermondii to improve cucumber crop productivity and address food scarcity challenges.

The main antioxidants present in plant extracts—quercetin, β-carotene, gallic acid, ascorbic acid, hydroxybenzoic acid, caffeic acid, catechin and scopoletin—are able to synthesize silver nanoparticles when reacting with a Ag NO3 solution. The UV-visible absorption spectrum recorded with most of the antioxidants shows the characteristic surface plasmon resonance band of silver nanoparticles. Nanoparticles synthesised with ascorbic, hydroxybenzoic, caffeic, and gallic acids and scopoletin are spherical. Nanoparticles synthesised with quercetin are grouped together to form micellar structures. Nanoparticles synthesised by β-carotene, were triangular and polyhedral forms with truncated corners. Pentagonal nanoparticles were synthesized with catechin. We used Fourier-transform infrared spectroscopy to check that the biomolecules coat the synthesised silver nanoparticles. X-ray powder diffractograms showed the presence of silver, AgO, Ag2O, Ag3O4 and Ag2O3. Rod-like structures were obtained with quercetin and gallic acid and cookie-like structures in the nanoparticles obtained with scopoletin, as a consequence of their reactivity with cyanide. This analysis explained the role played by the various agents responsible for the bio-reduction triggered by nanoparticle synthesis in their shape, size and activity. This will facilitate targeted synthesis and the application of biotechnological techniques to optimise the green synthesis of nanoparticles.

This article emphasizes the crucial importance of yeast Meyerozyma guilliermondii (Patent CECT13190) as a biological control agent (BCA) in eliciting defensive responses in vine plants, and is supported by comprehensive physiological, proteomic, and transcriptomic analyses. The results demonstrate that the BCA M. guilliermondii can induce enhanced defensive responses, as reflected in the regulation of key proteins. Notably, the upregulated expression of calmodulin and pathogenesis-related protein 10 (PR-10) are indicative of a complex interplay between calcium signalling, salicylic acid accumulation, and the elicitation of plant defence responses against pathogens. Furthermore, changes in microtubule dynamics and proteins related to protein synthesis and folding are observed, confirming the elicitation of defence responses. The correspondence between proteomic and transcriptomic analyses for genes codifying pathogenesis-related proteins, such as Vcgns1, VviTL1, and Vcchit1b, reinforces the empirical robustness of our findings. Collectively, our research explores the modulation of plant defences by the BCA, opening promising avenues for innovative agricultural strategies that enhance crop resilience and productivity.

This research is concerned with the fungicidal properties of the phenolic extract from industrial residues of Aloe vera used for antifungal treatment of various plant pathogens (Fusarium oxysporum f. sp. radicis-lycopersici, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum, and Sporisorium scitamineum). Six phenolic compounds were identified in this extract from A. vera cortex: aloesin, α-barbaloin, chromone X, isoaloeresin D, β- barbaloin and aloeresin E. Phenolic extract was added to PDA medium at 20 concentrations from 0.32% to 10% and the growth of four different plant pathogenic fungi was tested. Fungal inhibition was calculated in order to evaluate the antifungal efficacy of phenolic extract against pathogens. Inhibition of Sporisorium scitamineum hyphal growth was observed after treatment with the phenolic extract at concentrations higher than 2.5% and a fungistatic effect with a 58.2% mycelia growth inhibition was detected at 3% extract concentration. Inhibition of P. chlamydospora and P. aleophilum hyphal growth was observed at concentrations higher than 4% and 3% respectively. A fungistatic effect with a 71.65% and a 19.87% mycelia growth inhibition was detected at 4.5% and 3.5% extract concentration respectively. About F. oxysporum f. sp. radicis-lycopersici, inhibition of hyphal growth was observed at concentrations higher than 2.5% and a fungistatic effect with a 32.07% mycelia growth inhibition was detected at 3% extract concentration. The results indicate that the tested extract possess antifungal activities against these pathogens at various concentration levels and could be used as a potential natural fungicide in order to control fungi pathogens providing a new use for the A. vera industrial residues.