Search Results (446)

[Background] Marigold (Tagetes erecta L.) is the main source of the natural pigment lutein. [Methods] In this study, Marigold served as the experimental material for systematic observation of floral organ development. Based on floral morphology and lutein content, the full-flowering stage was identified as the optimal harvesting period. [Results] Under different light intensity gradients (30–1500 μmol·m⁻²·s⁻¹), the highest lutein content in petals occurred at ≈500 μmol·m⁻²·s⁻¹. Increased light intensities promoted flowering and enlarged flower diameter while significantly shortening the growth cycle. Transcriptome analysis revealed that light intensity variation markedly influenced the expression of genes related to metabolic pathways, plant hormone signal transduction, and carotenoid biosynthesis, and enriched transcription factor families including bHLH, MYB, NAC, and WRKY. Metabolomic profiling identified lutein esters, such as lutein dimyristate and lutein dipalmitate, as the dominant accumulated forms, with their contents positively correlated with light intensity; under high light, intermediate metabolites, including α-cryptoxanthin and zeaxanthin, were significantly up-regulated. [Conclusions] This study clarifies the molecular mechanism by which light intensity precisely regulates lutein accumulation through coordinated synthesis, esterification, and degradation pathways, offering a theoretical foundation for light-regulated cultivation of T. erecta L. and efficient lutein production. Full article

Lycopene, a natural carotenoid with antioxidant and health-promoting properties, has attracted attention as a valuable compound for the food, pharmaceutical, and cosmetic industries. Conventional production methods based on plant extraction or chemical synthesis are limited by low yields, high costs, and environmental concerns. In this study, the oleaginous yeast Yarrowia lipolytica was engineered as an alternative microbial cell factory for sustainable lycopene biosynthesis using short-chain fatty acids (SCFAs)—such as acetate, butyrate, and propionate—as inexpensive, renewable carbon sources. Four heterologous genes from Pantoea agglomerans (crtI, crtB, crtE, and idi) were codon-optimized and integrated into the Y. lipolytica genome using different expression systems, including the Golden Gate Assembly strategy. Among the tested strains, PS05/4lyc/GGA, characterized by enhanced phospholipid biosynthesis, demonstrated the highest lycopene yield of 462.9 mg/g dry cell weight and a titer of 3.41 g/L on butyrate medium—values comparable to or exceeding those reported for bioreactor-scale fermentations. The results indicate that co-activation of phospholipid and carotenoid biosynthesis pathways creates favorable intracellular conditions for hydrophobic pigment accumulation. Moreover, the use of SCFAs improved acetyl-CoA availability and redirected carbon flux through the mevalonate pathway, enhancing productivity. Strains with elevated membrane lipid biosynthesis also exhibited higher metabolic stability and stress tolerance. Full article

Arsenic (As) contamination poses a major challenge to sustainable crop production, particularly in legumes such as peanut (Arachis hypogaea L.), where it disrupts growth, nodulation, and redox homeostasis. This study evaluated the potential of circular-economy-based amendments derived from spent mushroom substrate (SMS) of Pleurotus djamor and plant growth-promoting bacteria (PGPB) to mitigate As stress in peanut plants. Six growth conditions were tested under 20 µM arsenate, including single and combined inoculations with P. djamor and Pseudomonas fluorescens, as well as a residue-only benchmark (E). Results showed that the unamended control (AP) exhibited the highest As accumulation, oxidative stress (H₂O₂, TBARs), and biomass loss, whereas SMS-based amendments attenuated these effects. Treatments HB (SMS + P. djamor + PGPB) and B (SMS + PGPB) combined low As translocation with enhanced antioxidant performance (SOD, CAT), maintaining growth and pigment stability. Amendment H (SMS + P. djamor) preferentially activated phytochelatin-related genes (PCS2, CAD1), while E minimized As uptake but lacked circular applicability. Overall, SMS-PGPB interactions promoted As retention in roots and strengthened ROS-scavenging defenses. These findings highlight SMS-based amendments as viable, sustainable strategies to enhance peanut quality and resilience under As stress, supporting their integration into circular agronomic systems. Full article

This research investigates the biosynthesis optimization of the red pigment prodigiosin produced by Serratia marcescens 11E through submerged fermentation utilizing an alternative cheese whey-based medium, focusing on process parameters and antimicrobial properties. Four types of whey sourced from a local dairy industry were characterized, and the fermentation conditions were optimized using Plackett–Burman and central composite design methodologies, yielding up to 1.43 g/L of prodigiosin under optimal conditions, 25 °C, 200 rpm, pH 7, and 48 h of dark incubation, with whey serving as the sole carbon source. Normalization to biomass yielded 110 mg of prodigiosin per gram of dried cell weight (post-optimization), enabling meaningful comparison with prior studies. Pigment extraction was performed with acidic methanol, and identity was confirmed by UV–Vis spectrophotometry and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity of the purified pigment was also evaluated. Although cheese whey has significant nutritional value, nearly half of the global production is discarded due to high treatment costs. This study demonstrates that whey can be repurposed as a sustainable and economical fermentation medium for pigment production, which is compatible with dairy plants. This makes it a promising solution to address the underutilization of whey by cheese local producers in Mexico. Prodigiosin has diverse industrial applications, including antimicrobial, insecticidal, and antioxidant properties. These findings highlight the potential for dairy waste valorization in a circular bioeconomy, reducing environmental impacts and promoting the creation of valuable bioproducts. Full article

The expanding development of graphene-based materials (GBMs) requires immediate and balanced environmental assessment balancing two key areas: investigating the risk of graphene oxide toxicity to ecosystems and evaluating GBMs’ potential to act as solutions for challenges like heavy metal stress mitigation. This study analyzed the effects of reduced graphene oxide (rGO) on copper (Cu) and nickel (Ni) toxicity in Lemna minor. Our findings reveal that rGO’s protective effects are metal-specific. L. minor demonstrated significant sensitivity to nickel, but rGO offered no mitigation; growth parameters, pigment content, and nickel accumulation showed no significant improvements with rGO co-exposure compared to Ni-plants. This suggests that rGO does not enhance L. minor’s ability to tolerate or absorb nickel, especially after 14 days (T14). In contrast, rGO showed a partially protective effect against copper toxicity. At T14, the presence of rGO significantly improved plant performance under copper stress, resulting in a 17% increase in biomass, a 19% increase in relative growth rate, and enhanced pigment content, including a 40% increase in chlorophyll when compared to Cu-plants. The protective effect of rGO was directly tied to a 37% reduction in copper accumulation, providing strong evidence that rGO reduces copper’s bioavailability, thereby limiting plant uptake. The divergent effects on Cu and Ni uptake suggest differing affinities of these metals for rGO. Future research, including large-scale experiments with various GBMs and Lemna clones, is crucial to fully assessing their phytoremediation potential. Full article

Drought stress during the reproductive phase substantially reduces seed yield and quality, posing a major challenge to sustainable crop production under climate change. This study investigated the effects of drought stress at the flowering stage on selected biochemical and physiological parameters in 18 carrot accessions. To describe the long-term consequences of drought comprehensively, we examined seed quality parameters. Our analyses revealed that stress responses are highly dependent on the genotype and the parameter examined. Regarding antioxidant responses and potential tissue damage caused by drought, ‘Dolanka’, DC97, DC265, DC359, DC522, DC701, DC704, and DC720 exhibited the highest tolerance. The photosynthetic apparatus and pigments were maintained under stress in DC233, DC522, DC717, and DC728. Germination parameters served as reliable indicators of stress tolerance in DC97, DC359, DC432, DC522, DC701, and DC722 accessions. Based on these findings and detailed discussion of the results, we conclude that tolerance/sensitivity assessment of carrot genotypes should consider the holistic response of the plant rather than individual parameters. Through overall assessment, we recommended DC522 accession as the most drought-tolerant, given its enhanced ROS (Reactive Oxygen Species) scavenging mechanisms, increased chloroplast pigments accumulation, and superior germination parameters under drought conditions. Conversely, DC295 should not be cultivated under water-deficient conditions due to its impaired ability to detoxify ROS, altered photosynthetic activity, and disrupted seed germination under such conditions. These results collectively highlight the potential for selecting drought-tolerant carrot genotypes in breeding programs targeting improved seed performance under water-limited conditions, thereby supporting the development of resilient cultivars adapted to future climate challenges. Full article

Vegetation indices (VIs) are a widely adopted and straightforward tool for non-contact estimation of chlorophyll and carotenoid content in plant leaves. However, VI-based method accuracy depends critically on instrument configuration and calibration procedures. This study aimed to evaluate the sensitivity of VI-based pigment assessment to variations in spectral channel parameters (central wavelength and bandwidth) as well as to changes in calibration details defined by the specific VI formula. Pigment content was measured in leaves of Lactuca sativa L. and Cucumis sativus L. at contrasting developmental stages using VI-based reflection spectroscopy across the 450–950 nm spectral range with various protocols and spectrophotometry as the reference method. VI values were calculated with varying central wavelength and widths of spectral bands, and across different VI formulas. Comparative analysis of the obtained measurements revealed that even minor shifts in central wavelengths of less than 20 nm or the use of an alternative index formula could lead to relative errors of 42–77% in the estimation of chlorophylls and carotenoids content, while changes in bandwidth had a much smaller impact, resulting in only 2–5% relative errors. Even with identical parameters of spectral channels, the choice of an appropriate VI and its regression model could introduce significant errors, ranging from 36% to 86%. These findings highlight the critical role of instrument specifications and calibration models in the VIs-based method accuracy and stability, as measurement errors can lead to suboptimal agronomic decisions. Moreover, our study underscores that comparing results from different sensors or platforms can be unreliable unless the channel parameters and calibration details are clearly specified. Therefore, standardization and transparency in VIs assignment is vital to ensure reproducibility and cross-compatibility in non-destructive pigment monitoring by using various devices. Full article

The photochemical reflectance index (PRI) based on reflectance at 531 and 570 nm and its modifications with shifted measuring wavelengths are well-known indicators of stress changes in photosynthetic processes which can be induced in plants under the action of numerous adverse factors (e.g., drought). However, the relationships between photosynthetic characteristics and the PRI are varied in different works; this means that photosynthetic responses are not the only reason for PRI changes. In the current work, we analyzed the influence of the light scattering of leaf surfaces and mesophyll layers and concentrations of leaf pigments on typical and modified PRIs. The analytical model of light reflectance and transmittance in the leaves of dicot plants, which had been previously developed in our work, and experimental measurements were used to analyze this influence. It was shown that increasing the light scattering of the leaf surface and the anthocyanin concentration and decreasing the light scattering of the spongy mesophyll increased PRIs with short measuring wavelengths and decreased PRIs with long measuring wavelengths. The action of drought induced similar changes in typical and modified PRIs, which were accompanied by an increased light scattering of the leaf surface and anthocyanin concentration and a decreased light scattering of the spongy mesophyll. The results show that changes in the light scattering of the leaf surface and spongy mesophyll and in the anthocyanin concentration can be the important mechanisms of slow changes in typical and modified PRIs, including drought-induced ones. Full article

Light quality affects the visual and morphological traits of ornamental species, and its effects on plant quality can be quantitatively assessed using image analysis combined with machine-learning classifiers. The objective was to characterize the morphological, reproductive, and color-related traits of Viola cornuta L. cv. Sorbeth^® Coconut^® Swirl^® grown under red, black, green, and blue shade nets in open-field conditions in Montecillo, Mexico, based on the combined use of traditional measurements and image-based analysis. Measurements were taken 69 days after transplanting. Image analysis with a multiclass Naive Bayes classifier (98.9% accuracy) quantified flower area and the three color classes (yellow, cream, and purple). Leaf area and ground cover were measured through color-based segmentation and adaptative thresholding. Open-field plants showed the largest ground cover, with flowers (19.4%), compact canopy (37% smaller than under the black net), and the highest number of flowers (33 flowers/plant). The yellow floral area was also the largest (0.3 cm²/flower). Black, green, and blue nets promoted larger leaf areas (10 to 11 cm²/leaf), while the black net produced the largest flowers (18.6 cm²). Blue and red nets reduced cream (4.3 cm²) and purple (7.3 cm²) areas, respectively. Photoselective nets differentially modulated viola morphology and pigmentation, while open-field conditions yielded compact plants with large flower areas of the highest visual quality. Full article

This work focuses on research into innovative lead-free perovskite materials to be employed as a sensitive layer for a new generation of solar cells, exploiting their potential applications in covering greenhouses to move toward an eco-friendly environment. Two types of lead-free perovskites—yellow and orange double-cation Cs₂AgBiBr₆, synthesized with an innovative method without chemical thinners—have been used, for the first time, as a cover for greenhouses in indoor experiments by analyzing the incident electromagnetic radiation. Two plant species, Solanum lycopersicum L. and Artemisia annua L., were cultivated indoors under controlled light, temperature, and humidity, covering the greenhouses with yellow (PY+) and orange (PO+) panels for comparison with control plants (P−) roofed by a glass panel. The growth and development parameters of all plants were investigated, referring to the aerial and root parts. Significant differences were found in terms of the plant growth parameters and photosynthetic pigments of both PY+ and PO+ compared to P− and also between them, with the yellow panel being less invasive. These results, dealing with two different plant species, confirm the feasibility of using perovskite-based panels for indoor cultivation and pave the way for outdoor application in greenhouses under sunlight. Full article

Porphyra umbilicalis is a red macroalga belonging to the genus Porphyra and the family Bangiaceae. Porphyra umbilicalis distinguishes itself among macroalgae due to its remarkable biochemical composition and nutritional value. It contains a broad spectrum of bioactive compounds, including macronutrients and micronutrients. Among the macronutrients, carbohydrates, proteins, and essential fatty acids are particularly abundant, with protein levels reaching up to 40% dw (dry weight). Its high protein content makes Porphyra umbilicalis a promising alternative and sustainable protein source, particularly for plant-based diets. Its micronutrients, including vitamins (C, E, and B-group), pigments, and mineral components, contribute to antioxidant protection, metabolic regulation, and maintenance of overall nutritional balance. What makes P. umbilicalis particularly distinctive is its content of unique bioactives such as porphyran, phycobiliproteins, and mycosporine-like amino acids. Preliminary evidence from animal and in vitro studies indicates that these unique bioactive compounds contribute to the anticancer, anti-inflammatory, and antioxidant effects of P. umbilicalis. However, more systematic research into its chemical composition is needed due to variability related to harvest location, environmental factors, and inconsistencies in the existing literature. Detailed data on the full chemical profile and bioavailability of specific compounds remain limited, underscoring the need for further investigation. Evidence on the health benefits of P. umbilicalis remains limited, as current studies are restricted to preclinical models and have not been validated through human trials, emphasizing the need for rigorous research to clarify its role in functional foods. Full article

Australian plants of the family Haemodoraceae have been a reliable source of new secondary metabolites, particularly those of the ‘phenylphenalenone’ class, and related chromenes and xanthones. Some of these compounds demonstrate anti-microbial properties against both Gram-negative and Gram-positive bacteria. Chemical profiling of thirty individual ethanolic extracts from six separate species of Australian plants belonging to the family Haemodoraceae was conducted using an HPLC-MS approach reinforced by HRLC(ESI)-MS. Six of the extracts were further explored by employing HRLC(ESI)-MS and the compounds present were characterised and confirmed based on a comparison to the original data. All thirty extracts were assessed for biological activity against the parasitic nematode Haemonchus contortus in vitro. The chemical profiling methodology adopted resulted in the identification of thirty-four previously reported compounds, identifying on average 64% of the previously reported secondary metabolites across the species Haemodorum simulans, Haemodorum spicatum, Haemodorum brevisepalum and Macropidia fuliginosa. Furthermore, compounds from the phenylbenzoisoquinolindone class were detected in the bulbs of Haemodorum simulans and Haemodorum coccineum, representing the first report of the structure class in extracts of the genus Haemodorum. Extracts of the H. simulans stems, M. fuliginosa bulbs and H. distichophyllum roots and bulbs exhibited anthelmintic activity in vitro. The chemical profiling HPLC-MS methodology adopted was successful in the rapid identification of most of the previously reported secondary metabolites across the Haemodoracae species, indicating that the analytical approach was robust. This study demonstrates the effectiveness of dereplication via HPLC-MS-based chemical profiling across six Australian Haemodoraceae species, identifying numerous known and putatively novel secondary metabolites. It also reports, for the first time, anthelmintic activity in selected species and marks the first detailed phytochemical investigation of H. distichophyllum since its initial pigment analysis over 50 years ago. Full article

Background: Tyrosinase is a copper-dependent oxyreductase capable of catalyzing the oxidation of mono- and diphenols. Its activity is crucial in the biosynthetic pathway of melanin, the pigment responsible for the pigmentation of mammalian skin and fur, and protecting their skin from harmful UV radiation. Overproduction of this pigment leads to numerous pathological conditions, including the most severe form of skin cancer—malignant melanoma. Furthermore, tyrosinase produced in plant tissues leads to the browning of damaged vegetables and fruits. Therefore, the search for compounds that effectively and efficiently control tyrosinase activity is desirable for both pharmaceutical and food applications. Methods: A group of six boronate derivatives of thiosemicarbazones was synthesized, and their inhibitory properties against tyrosinase were determined. Furthermore, their ability to inhibit melanogenesis and proliferation in SK-MEL-3 and Hs294T cells was investigated. Docking simulations were performed to determine the nature of the inhibitor–protein interactions. Results: The tested inhibitors exhibited half-maximal inhibitory concentrations (IC₅₀) in the micromolar range. The best inhibitor, compound 6, had an IC₅₀ of 1.4 µM. The tested compounds exhibited poor selectivity for cell lines capable of high and low tyrosinase overexpression, with inhibitor 4 proving to be the most selective compound among those tested. Molecular modeling results indicate that the compounds with the highest activity against tyrosinase interact with the active cavity and the copper ions present within it via a boron moiety substituted on the aromatic ring of the thiosemicarbazones. Cell-based experiments indicated limited antiproliferative effects up to 100 µM across the tested lines. The compounds demonstrated weak antiproliferative effects in SK-MEL-3 and Hs-294T up to 100 µM. Conclusions: Our results show that the introduction of a boronic acid moiety is an alternative to carboxylic acid derivatives, improving the inhibitory activity of boron analogs (by fourfold) against fungal tyrosinase. Full article

This study presents the development and evaluation of an automated ultraviolet-C irradiation system for maize seed treatment, emphasizing disinfection performance, environmental control, and vision-based monitoring. The system features dual 8-watt ultraviolet-C lamps, sensors for temperature and humidity, and an air extraction unit to regulate the microclimate of the chamber. Without air extraction, radiation stabilized within one minute, with internal temperatures increasing by 5.1 °C and humidity decreasing by 13.26% over 10 min. When activated, the extractor reduced heat build-up by 1.4 °C, minimized humidity fluctuations (4.6%), and removed odors, although it also attenuated the intensity of ultraviolet-C by up to 19.59%. A 10 min ultraviolet-C treatment significantly reduced the fungal infestation in maize seeds by 23.5–26.25% under both extraction conditions. Thermal imaging confirmed localized heating on seed surfaces, which stressed the importance of temperature regulation during exposure. Notable color changes ($\Delta E>2.3$) in treated seeds suggested radiation-induced pigment degradation. Ultraviolet-C intensity mapping revealed spatial non-uniformity, with measurements limited to a central axis, indicating the need for comprehensive spatial analysis. The integrated computer vision system successfully detected seed contours and color changes under high-contrast conditions, but underperformed under low-light or uneven illumination. These limitations highlight the need for improved image processing and consistent lighting to ensure accurate monitoring. Overall, the chamber shows strong potential as a non-chemical seed disinfection tool. Future research will focus on improving radiation uniformity, assessing effects on germination and plant growth, and advancing system calibration, safety mechanisms, and remote control capabilities. Full article

Drought stress is one of the primary abiotic factors negatively affecting garlic growth, development, and yield formation. The application of plant growth-promoting bacteria (PGPB) could enhance plant tolerance to drought stress. The aim of this study was to explore the regulatory effect of the PGPB Pseudomonas sp. UW4 on growth and physiological indexes of garlic under drought stress. The results revealed that drought stresses significantly reduced total root length, total root surface area, root projection area and total root volume, chlorophyll content, antioxidant enzyme activity and osmolyte content (proline and soluble proteins), and increased relative electrical conductivity and malondialdehyde (MDA) content, all of which could be significantly improved by inoculating the roots with strain UW4. Under drought stress, an increase in total surface area of roots of 87.06% and an increase in root projected area of 40.71% were observed upon inoculation with strain UW4. The a, b, and total content of chlorophyll were increased significantly by 83.63%, 217.33% and 100.02%, respectively. The osmolyte content in leaves significantly increased, and decreased significantly in roots. The content of antioxidants also significantly increased. Moreover, the relative electrical conductivity in leaves and roots was decreased by 23.18% and 41.20%, respectively, upon strain UW4 inoculation. The content of malondialdehyde (MDA) was decreased by 25.23% and 54.08%, respectively, in the presence of strain UW4. The result of principal component analysis (PCA) revealed that the key factors influencing drought tolerance in garlic inoculated with Pseudomonas sp. UW4 could be summarized into two categories: photosynthetic pigments and root growth-related factors, and leaf osmotic adjustment and root antioxidant enzyme-related factors. Based on the result of the Mantel test, it can be inferred that there was a connection between the osmoregulation and antioxidant enzyme systems in the roots and leaves. Based on the D values, the comprehensive evaluation result of drought resistance was that the drought resistance of the garlic inoculated with strain UW4 under drought stress was lower than that of the garlic inoculated with UW4 under normal treatment and higher than that of the garlic under normal treatment. Therefore, Pseudomonas sp. UW4 enhanced the drought resistance of garlic seedlings by improving root phenotype and antioxidant enzyme activity, and increasing the content of shoot chlorophyll. Full article