Pigment Levels Research Articles

Drought Stress and the Modulation of Physiochemical Parameters and Antioxidant Enzymes in Grapevine Rootstocks: Insights into the Protective Role of Methyl Jasmonate

The present study scrutinized the influence of foliar application of methyl jasmonate on the physiochemical characteristics and antioxidant enzymes of two grapevine rootstocks, ‘SO4’ (high drought tolerance) and ‘101-14’ (low drought tolerance), under drought conditions. The grapevine seedlings were sprayed with methyl jasmonate at 100 µM at 3-day intervals throughout the 28-day drought stress period. The results showed that treating both rootstocks with methyl jasmonate greatly minimized the adverse effects of reactive oxygen species caused by drought. Specifically, methyl jasmonate substantially reduced levels of malondialdehyde, hydrogen peroxide, and ion leakage while increasing photosynthetic pigment levels, soluble carbohydrates, proline, protein, and total phenols content. Additionally, applying methyl jasmonate improved the action of antioxidant enzymes like superoxide dismutase, ascorbate peroxidase, and catalase. This made the membranes of leaves more solid during drought conditions. Methyl jasmonate treatment reduced oxidative damage and improved mineral element (P, K, Mg, Ca, Fe, and Zn) accumulation in the green leaves of treated plants as opposed to the drought-untreated plants. These results were more noticeable in ‘SO4’ compared to ‘101-14’ rootstocks. Based on these results, applying methyl jasmonate at 100 µM to the leaves of grapevines may be considered a novel strategy for mitigating water scarcity in the grapevine production system.

Do Different Wheat Ploidy Levels Respond Differently Against Stripe Rust Infection: Interplay between Reactive Oxygen Species (ROS) and the Antioxidant Defense System?

Wheat stripe rust (Puccinia striiformis f. sp. tritici, Pst) is the most damaging wheat disease, causing substantial losses in global wheat production and productivity. Our study aimed to unravel the complex reciprocity between reactive oxygen species and the antioxidant defense system as a source of resistance against stripe rust in diploid, tetraploid and hexaploid wheat genotypes. The significant genetic variability for stripe rust in the materials under study was evident as the genotypes showed contrasting responses during both the adult and seedling stages. Our thorough perspective on the biochemical responses of wheat genotypes to stripe rust infection revealed distinct patterns in oxidative damage, antioxidant enzymes and photosynthetic pigments. Principal component analysis revealed inverse correlations between antioxidants and ROS, underscoring their key function in maintaining the cellular redox balance and protecting plants against oxidative damage. Diploid (Ae. tauschii) wild wheat exhibited a better biochemical defense system and greater resistance to stripe rust than the tetraploid (T. durum) and hexaploid (Triticum aestivum) wheat genotypes. The antioxidant enzyme activity of durum wheat was moderate compared to diploid and hexaploid wheat genotypes. The hexaploid wheat genotypes exhibited increased ROS production, reduced antioxidant enzyme activity and decreased photosynthetic pigment levels. This study enhances understanding of the antioxidant defense system across different wheat ploidies facing stripe rust, serving as a valuable strategy for improving crop disease resistance. This study validated the biochemical response of stripe rust-resistant and susceptible candidate genotypes, which will be used to develop genetic resources for discovering stripe rust resistance genes in wheat.

Investigation into the mechanisms of photosynthetic regulation and adaptation under salt stress in lavender.

Salinity stress is a major threat to agricultural productivity and sustainability, often causing irreversible damage to photosynthesis. Lavender, a valuable aromatic plant, experiences growth impacts under salt stress. However, the regulatory mechanisms of photosynthesis related to its adaptation to salt stress remain unclear. In this study, lavender was exposed to 0, 100, 200, and 300mM NaCl for 28 days. It was observed that lavender effectively maintained chlorophyll stability when salt concentrations were below 200mM and stress duration was under 21 days. The most effective model for lavender under salt stress was identified as a right-angled hyperbolic modified model. Under moderate salt stress (100mM, 200mM), genes such as LaPSB28, LaPSBS, and LaPSBR contributed to PSII core stability, enhanced photosynthetic pigment levels, and sustained high electron transfer rates to improve salt-tolerance. Additionally, LaLHCB4-1 and LaPSAK-1 regulated stomatal size, thereby facilitating gas exchange and supporting the photosynthetic process. Conversely, under high salt stress (300mM), LaPSBW-1, -2, and LaPSAB were found to reduce photosynthetic pigment levels and inhibit photosynthetic activity. However, genes such as LaCHLG-2, LaGLG-3, LaBAM1-1 and -3, and LaCHLP-3 aided in starch synthesis by increasing pigment content, thus promoting energy balance and enhancing salt tolerance. This regulation involved photosynthesis-antenna proteins and pathways related to starch, sucrose, and chlorophyll metabolism. These findings may support the cultivation of salt-tolerant lavender varieties and maximize saline soil usage.

The paradoxical effects of beneficial bacteria on Solanum lycopersicum under Cd stress.

This study investigated the complex interactions between a novel consortium and tomato seedlings under cadmium (Cd) stress. The consortium consists of two bacteria, Pseudomonas sp. HS4 and Paenarthrobacter sp. AS8, both with proven plant growth-promoting (PGP) properties, isolated from Cd hyperaccumulators. Our research highlights the paradoxical effects of these bacteria, revealing their dual role in reducing Cd uptake while simultaneously inducing oxidative stress in plants. Hydroponic experiments showed that the consortium reduced Cd accumulation in tomato shoots by 52% compared to uninoculated controls. However, this reduction was accompanied by decreased plant biomass and increased oxidative stress, with malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels up to 80% and 160% higher, respectively, in inoculated plants. Root H₂O₂ production increased by 38% under 50μM Cd without a corresponding rise in catalase (CAT) activity. Despite Cd exposure, the consortium promoted chlorophyll and carotenoid synthesis, restoring pigment levels to those of unstressed controls. Gene expression analysis revealed a complex impact on stress responses, with inoculation suppressing Sl1 gene expression in roots and upregulating the oxidative stress-related GR-1 gene in shoots. These findings highlight the complex and multifaceted relationship between beneficial bacteria and plant fitness under heavy metal stress, with significant implications for sustainable agriculture. The study raises new questions regarding the broader physiological and ecological impacts of applying hyperaccumulator-associated bacteria in crop management, emphasizing the necessity for deeper mechanistic insights into these interactions to fully harness their potential in improving crop resilience and productivity.

Antagonist Action of Endophytic Metarhizium anisopliae Isolates on Development, Reproduction, and Host Selection of Grass Bug in Bermudagrass.

To understand the interactions of entomopathogenic fungi with forage plants and their influence on associated herbivorous, we evaluated the influence of endophytic colonization with three isolates (CEPAF_ENT 25, CEPAF_ENT 27, and IBCB 425) of Metarhizium anisopliae on Cynodon dactylon, regarding the biological and behavioral aspects of Collaria scenica, an emerging sucking pest in pastoral systems in Brazil. The application of suspensions at the base of plant (drench) was effective in promoting endophytic colonization, especially in the roots, with emphasis on isolates CEPAF_ENT25 and CEPAF_ENT27. Despite the significant reduction in damage caused by C. scenica observed in plants colonized with isolate CEPAF_ENT 27 in a choice test, our results indicated a limited influence of the isolates tested on the host selection behavior and in C. scenica development, including parameters of the fertility life table. The cluster analysis, however, indicated a significant difference between all isolates tested in terms of the chemical-bromatological composition and the levels of photosynthetic pigments in inoculated plants. The biplot analysis indicated that isolate CEPAF-ENT27 (most promising) showed a positive correlation with nitrogen, potassium, calcium, boron, copper, and zinc levels, as well as with chlorophyll a and b levels. Additionally, foliar magnesium levels were significantly higher in all isolates tested. Improvements in plant nutrition may increase tolerance in infested plants through compensation mechanisms, contributing to more resilient pastoral systems.

Effects of Serendipita indica on the Morphological and Physiological Characteristics of Agrostis stolonifera L. Under Drought Stress

This study investigates the effect of Serendipita indica inoculation on the growth, structural characteristics of leaf epidermis, photosynthetic parameters, and antioxidant and osmoregulation capacities of Agrostis stolonifera L. under different drought stresses (normal moisture management: at 70–75% of the field capacity, low drought: at 55–60% field capacity, moderate drought: at 40–45% of the field capacity, and severe drought: at 25–30% of the field capacity). The results showed that inoculation with S. indica significantly enhanced the growth potential of A. stolonifera compared to uninoculated controls, and then under drought stress conditions, inoculation with S. indica significantly alleviated the inhibition of the growth and development of A. stolonifera, especially under mild and moderate drought stresses. These improvements were evident in both aboveground and underground parts, leaf relative water content, total root length, and root surface area after 25 days of drought treatments. Inoculated plants also exhibited higher levels of photosynthetic pigments, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) under drought conditions. Additionally, S. indica inoculation significantly increased the activities of catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), as well as the soluble sugar, soluble protein, and proline levels under drought-stressed and non-stressed conditions. In addition, the increases in the malondialdehyde (MDA) content and relative conductivity (RC) of leaves were significantly lower in the inoculated group compared to the control group. In conclusion, the symbiosis with S. indica promotes the growth of A. stolonifera under drought stress, likely by enhancing photosynthesis, osmoregulatory substances, and antioxidant enzyme activities.

Comparative Efficacy of Melatonin and Brassinolide in Mitigating the Adverse Effects of Cadmium on Wolffia arrhiza.

Melatonin (MT) and brassinolide (BL) are phytohormones that regulate various physiological processes in plants. This study investigates their effects on Wolffia arrhiza when exposed to cadmium (Cd). Plant hormones were quantified using liquid chromatography-mass spectrometry, while photosynthetic pigments and phytochelatins (PCs) were analyzed through high-performance liquid chromatography. Protein, monosaccharide levels, and antioxidant activities were also spectrophotometrically measured. The findings reveal that MT and BL treatment decreased Cd accumulation in W. arrhiza compared to plants only exposed to Cd. MT was particularly effective in reversing Cd-induced growth inhibition and reducing stress markers more significantly than BL. It also enhanced antioxidant activity and maintained higher levels of photosynthetic pigments, proteins, and sugars. Although BL was less effective in these aspects, it promoted greater synthesis of glutathione and PCs in Cd-exposed duckweed. Overall, both MT and BL alleviate the negative impact of Cd on W. arrhiza, confirming their crucial role in supporting plant health under metal stress conditions.

Foliar spraying with zinc oxide nanoparticles enhances the anti-osteoporotic efficacy of the fruit extracts of Silybum marianum L. by stimulating silybin production.

Silybum marianum is a medicinal plant that produces silymarin, which has been demonstrated to possess antiviral, anti-neurodegenerative, and anticancer activities. Silybin (A+B) are two major hepatoprotective flavonolignans produced predominantly in S. marianum fruits. Several attempts have been made to increase the synthesis of silymarin, or its primary components, silybin (A+B). Zinc oxide nanoparticles (ZnO-NPs) are considered a highly efficient Zn source widely used to promote crop development and productivity. In this study, we aimed to investigate the effects of the foliar application of ZnO-NPs on the growth, yield, photosynthetic pigment content, silybin (A+B) content, and the expression of the chalcone synthase (CHS) gene in S. marianum plants. Different concentrations of ZnO-NPs were administered as foliar sprays to S. marianum plants growing in greenhouse conditions. Furthermore, we evaluated the anti-osteoporotic efficacy of the corresponding fruit extract against dexamethasone (Dex)-induced osteoporosis. Foliar treatment at all ZnO-NP concentrations increased the amounts of bioactive components of silybin (A+B), which enhanced the growth and yield of S. marianum plants while increasing the levels of N, P, K, and Zn in their leaves, roots, and fruits; the levels of photosynthetic pigments in their leaves; and silybin (A+B) content in their fruits, thereby increasing the medicinal value of S. marianum. The highest gains were observed in plants sprayed with the highest ZnO-NP concentration (20.0 mg/L). In addition, gene expression studies revealed that ZnO-NPs stimulated silybin (A+B) production by activating CHS genes. The administration of S. marianum extracts to Dex-administered rats increased osteoblast and bone formation while inhibiting osteoclast and bone resorption, thereby protecting the animals against Dex-induced osteoporosis.

Estimation of Tyrosinase-Related Protein 1 (TRP-1) Gene Expression in Human Gingiva and Its Correlation With Gingival Melanin Hyperpigmentation: A Pilot Study.

Background Melanin synthesis in humans relies on the activity of the tyrosinase enzyme, along with tyrosinase-related proteins 1 and 2 (TRP-1 and TRP-2). TRP-1 functions as a 5,6-dihydroxyindole-2-carboxylic acid oxidase and plays a crucial role in activating and stabilizing tyrosinase, as well as in melanosome synthesis. However, TRP-1 gene expression in human gingiva has not been explored. Therefore, this study aimed to estimate TRP-1 gene expression in human gingiva. Aim The aim of the study was to estimate TRP-1 gene expression in human gingiva and examine its correlation with the degree of gingival melanin hyperpigmentation. Materials and methods Gingival tissue samples were collected from individuals undergoing gingival depigmentation surgery due to concerns about blackish-looking gums. The gingival epithelial tissue was excised under local anesthesia using a surgical scalpel blade. The excised tissue, including a thin layer of underlying connective tissue, was sent to the laboratory for TRP-1 gene expression analysis using the RT-PCR technique. Results The levels of TRP-1 gene expression in human gingiva ranged from 0.459 to 0.973. TRP-1 gene expression in the gingival tissues showed a correlation with the degree of gingival melanin hyperpigmentation, with lower expression levels observed at sites with mild to moderate pigmentation and higher levels at sites with severe pigmentation. Conclusions TRP-1 gene expression in human gingiva was positively correlated with the degree of gingival melanin hyperpigmentation, suggesting its potential role in the regulation of gingival melanin pigmentation.

Spectral unmixing of hyperspectral images revealed pine wilt disease sensitive endmembers.

Throughout the entire cycle of leaf phenological events, leaf colour undergoes changes that are influenced by either abiotic stress or biotic infection. These changes in colouration are closely linked to the quantity and quality of photosynthetic pigments, which directly impact the primary productivity of plants. Therefore, monitoring and quantifying leaf colouration changes are crucial for distinguishing damage caused by pine wilt nematodes from natural tree senescence. In this study, a hyperspectral camera sensor was employed for the non-invasive and non-destructive evaluation of needle colour changes in coniferous trees grown in field tests. Three distinct needle colour variations of six coniferous tree species were selected and monitored using a hyperspectral sensor: those displaying seasonal autumn colours, undergoing nematode-infected necrosis processes, and experiencing natural death. To mitigate the inherently mixed spectral properties of hyperspectral data, endmembers were extracted from individual images using the Purity Pixel Index algorithm under the assumption of linear mixing of endmembers. From a total of 1,321 endmembers extracted from 378 hyperspectral images of six pine species, eight endmembers were ultimately chosen to reconstruct hyperspectral images and generate abundance maps. Among these eight endmembers, four represent varying levels of photosynthetic pigment contents-ranging from very low to high. Consequently, these coniferous endmembers hold promise for assessing seasonal leaf phenology and the extent of damage in pine trees infected by pine wilt nematodes. This comprehensive approach underscores the effectiveness of spectral unmixing of hyperspectral images in advancing precision forestry through meticulous coniferous needle trait analysis.

Gibberellin-Dependent Pulp Pigmentation in CPPU-Induced Parthenocarpic Melon Fruit: Insights from Metabolome and Transcriptome Analysis

The plant growth regulator N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) is applied to induce parthenocarpic fruit setting in melon (Cucumis melo L.) production. However, CPPU-induced fruits frequently exhibit a decline in quality attributes, such as sucrose, aroma, and pigmentation, the mechanisms underlying these changes remain largely unclear. This research assessed the effects of CPPU application on carotenoid biosynthesis in the pulp during melon fruit development, aiming to elucidate the underlying mechanisms. Transcriptome and metabolome analyses were employed to examine changes in pigment and hormone levels in melon fruit at various developmental stages following CPPU treatment. The results indicated that CPPU application for fruit setting significantly reduced β-carotene content in the fruit pulp compared to fruits resulting from artificial pollination. Transcriptome analysis revealed a decrease in the expression of carotenoid biosynthesis genes (e.g., PSY1/2, Z-ISO, and LYCB), while the expression of catabolic enzyme genes (e.g., NCED5/6, NXS, and CCD4) were up-regulated following CPPU application. Metabolome analysis showed a decrease in gibberellin production during the development of CPPU-induced fruits compared to pollinated samples. Furthermore, exogenous gibberellin application recovered the pigment defects in the CPPU-induced parthenocarpic fruits. This study provides novel insights into how CPPU-induced parthenocarpy affects melon pulp pigmentation during development, offering valuable theoretical foundations for improving fruit set management in melon cultivation.

Lignin-based cryogels for advancing sustainable crop production via enhanced nutrient accessibility and growth efficiency.

Sustainable lignin-based materials are becoming increasingly valuable in agriculture, where climate change and nutrient deficiencies threaten crop productivity. We developed lignin-derived cryogels using waste biomass to improve soil nutrients, seed germination, water retention, and photosynthetic pigment levels. These cryogels were synthesized with gum Arabic (GA), keratin (K), and N-vinylpyrrolidone at lignin concentrations of 0.02wt% (LbC1), and 0.1wt% (LbC2), along with a control (NLC), through low-temperature polymerization at -20°C. The cryogels exhibited high thermal stability and water retention, exceeding 170%, due to their network structure. Functional groups like carboxyl and hydroxyl enhanced nutrient assimilation, accelerating germination and plant growth, with keratin providing bioavailable amino acids through microbial degradation. After 5days, the cryogel treatments significantly improved early germination rates (100%, 100%, and 99% for wheat, maize, and rapeseed, respectively), while boosting chlorophyll (a, b, and total), sugar, and soluble protein levels. Treated plants showed increased leaf numbers, plant height, and root length, with a 98.4% improvement in water uptake compared to controls, mitigating the effect of soil salinity. LbC1 and LbC2 also notably increased chlorophyll pigments, soluble sugars, and total protein across all crops compared to the NLC. Additionally, the cryogel exhibited a 33% biodegradation rate after 130days in soil, confirming their environmental compatibility. In conclusion, the developed lignin-based cryogels represent a sustainable, effective solution to enhance nutrient availability and resilience in agriculture, repurposing industrial lignin waste to address climate-driven challenges in crop production.

The Ameliorative Effect of Coumarin on Copper Toxicity in Citrus sinensis: Insights from Growth, Nutrient Uptake, Oxidative Damage, and Photosynthetic Performance.

Excessive copper (Cu) has become a common physiological disorder restricting the sustainable production of citrus. Coumarin (COU) is a hydroxycinnamic acid that can protect plants from heavy metal toxicity. No data to date are available on the ameliorative effect of COU on plant Cu toxicity. 'Xuegan' (Citrus sinensis (L.) Osbeck) seedlings were treated for 24 weeks with nutrient solution containing two Cu levels (0.5 (Cu0.5) and 400 (Cu400) μM CuCl2) × four COU levels (0 (COU0), 10 (COU10), 50 (COU50), and 100 (COU100) μM COU). There were eight treatments in total. COU supply alleviated Cu400-induced increase in Cu absorption and oxidative injury in roots and leaves, decrease in growth, nutrient uptake, and leaf pigment concentrations and CO2 assimilation (ACO2), and photo-inhibitory impairment to the whole photosynthetic electron transport chain (PETC) in leaves, as revealed by chlorophyll a fluorescence (OJIP) transient. Further analysis suggested that the COU-mediated improvement of nutrient status (decreased competition of Cu2+ with Mg2+ and Fe2+, increased uptake of nutrients, and elevated ability to maintain nutrient balance) and mitigation of oxidative damage (decreased formation of reactive oxygen species and efficient detoxification system in leaves and roots) might lower the damage of Cu400 to roots and leaves (chloroplast ultrastructure and PETC), thereby improving the leaf pigment levels, ACO2, and growth of Cu400-treated seedlings.

Quantification of growth and physiological characteristics in tolerant and sensitive watermelon lines under cold treatment

AbstractBiochemical and physiological processes serve as key indicators for assessing the adverse effects of biotic and abiotic stressors in plants. Due to the limited and incomplete information on the growth, root morphology, and physiology of watermelon lines under cold stress in Korea, this study aimed to evaluate selected cold-tolerant lines (PI254744, SW20, and SW66) and cold-sensitive lines (PI525233 and SW54). The evaluation was based on root and shoot weight, root and shoot length, root morphology, photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids), and levels of proline, malondialdehyde (MDA), and soluble sugars in root and leaf samples collected at various time points. Two treatments were conducted: one at 28 °C as a control and one at 10 °C to simulate cold stress. The results revealed a decline in growth variables under cold stress compared to the control across all lines. However, the disintegration of root cellular structures and reduction in growth variables were less severe in the tolerant watermelon lines than in the sensitive ones. Under cold stress, proline, MDA, and soluble sugar levels increased in all watermelon lines relative to the control. Notably, the tolerant lines displayed elevated proline and soluble sugar levels, while the sensitive lines had higher MDA content. Furthermore, photosynthetic pigment levels were generally lower in all lines during cold treatment compared to the control, though the reduction was less pronounced in the tolerant lines than in the sensitive ones. A significant positive correlation was found between the percentage reduction in total chlorophyll content and the percentage reduction in growth variables. The lesser reduction in photosynthetic pigments, combined with higher levels of osmoprotectants (proline and soluble sugars) and lower MDA levels in the tolerant lines during cold stress, may suggest underlying mechanisms that warrant further biochemical and molecular studies to better understand cold resistance.

Correlation of arbuscular mycorrhizal dosage with level of colonization, nutrient concentration, and photosynthesis pigment of Cavendish banana plant

The commercial development of Cavendish bananas still faces many obstacles, including the availability of seedlings/suckers at low prices, so technological substitution is needed to stimulate the growth of Cavendish banana suckers in the form of arbuscular mycorrhizal (AM) biological agents. The research aims to determine the correlation between AM doses and colonization levels, tissue nutrient concentrations, and photosynthetic pigments in Cavendish banana seedlings/suckers. It is also a novelty in this research study. The research was carried out in Parepare city at coordinates 3°59'30.204" S; 119°38'42.936" E using four AM doses as independent variables, namely 0 g, 5 g, 10 g, and 15 g pot-1. The variables observed (dependent variables) were the level of colonization, nutrient concentration in the tissue, and photosynthetic pigment content. Using Microsoft Excel software, statistical tests, regression, and correlation analyses were conducted to see the relationship between treatment (independent variable) and observed parameters (dependent variable). The research showed that AM dosage was positively correlated with the level of root colonization, the concentration of N, P, and K elements in the tissue, and the photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids). A dose AM of 15 g pot-1 gave a better effect on Cavendish banana suckers, which can be recommended for the development of Cavendish banana seedlings.

Treatment with Ascorbyl Glucoside-Arginine Complex Ameliorates Solar Lentigos.

Little is known about the anti-pigmenting effects of skin-whitening agents on solar lentigos (SLs). To characterize the anti-pigmenting effects of a newly designed derivative ascorbyl glucoside-arginine complex (AGAC) on SLs, lotions with or without 28% AGAC were applied twice daily for 24 weeks in a double-blind half-face study of 27 Japanese females with SLs. The pigmentation scores and skin colors of previously selected SLs on the right and left sides of the faces of the subjects were evaluated using a photo-scale, a color difference meter and a Mexameter. Treatment with the test lotion elicited a significant decrease in pigmentation scores at 24 weeks compared to week 0, with a significant decrease in pigmentation scores at 24 weeks compared to the placebo lotion. In the test lotion-treated SLs, the lightness (L) and melanin index (MI) values that reflect the pigmentation level significantly increased and decreased, respectively, at 12 and 24 weeks of treatment compared to week 0. Comparisons of increased L values or decreased MI values between the test and placebo lotion-treated SLs demonstrated that the test lotion-treated SLs had significantly higher increased L or decreased MI values than the placebo lotion-treated SLs both at 12 and 24 weeks of treatment. The sum of our results strongly indicates that AGAC is distinctly effective in ameliorating the hyperpigmentation levels of SLs at a level visibly recognizable by the subjects, without any hypo-pigmenting effects or skin problems.

Morpho-Physiological Responses of Shade-Loving Fern Polystichum spp. to Single and Combined Lead and Light Stress

The effects of lead (Pb) stress on plant growth and physiological processes may depend on other environmental stresses coinciding. Knowledge of the response of shade-loving plants to stresses, particularly the relationship between Pb stress and light stress, is lacking. The effects of single and combined Pb and light stress on the growth and physiological parameters of Polystichum setiferum and Polystichum setiferum ‘Proliferum’ ferns were evaluated under glasshouse conditions. Treatments comprised control (80% shade, ~111 μmol m−2 s−1 photosynthetic photon flux density, PPFD), light stress (100% full sunlight, ~525 μmol m−2 s−1 PPFD), 1000 mg dm−3 Pb solution applied to plants under shade and light stress conditions. Under full sunlight, plants had damaged leaves and reduced leaf biomass, and underground parts of the plants had levels of photosynthetic pigments, reducing sugars and total flavonoids. The Pb stress decreased plant growth, reducing sugars, and free amino acids content, and at the same time increased chlorophyll content in P. setiferum and total polyphenols and flavonoid content in P. setiferum ‘Proliferum’. The combined stress of Pb and full sunlight reduced plant growth and the accumulation of pigments, reducing sugars, and free amino acids without affecting the levels of secondary metabolites. P. setiferum plants accumulated more Pb than P. setiferum ‘Proliferum.’ The fern P. setiferum ‘Proliferum’ was more tolerant to abiotic stresses than the fern P. setiferum. This study provided new insights into the response of shade-loving ornamental plants to single and combined Pb and light stress.

Enhancing Lettuce (Lactuca sativa) Productivity: Foliar Sprayed Fe-Alg-CaCO3 MPs as Fertilizers for Aquaponics Cultivation.

Aquaponics is an innovative agricultural method combining aquaculture and hydroponics. However, this balance can lead to the gradual depletion of essential micronutrients, particularly iron. Over time, decreasing iron levels can negatively impact plant health and productivity, making the monitoring and management of iron in aquaponic systems vital. This study investigates the use of Fe-Alg-CaCO3 microparticles (MPs) as foliar fertilizer on lettuce plants in an aquaponic system. The research investigated Lactuca sativa L. cv. Foglia di Quercia Verde plants as the experimental cultivar. Three iron concentrations (10, 50, and 250 ppm) were tested, with 15 plants per treatment group, plus a control group receiving only sterile double-distilled water. The Fe-Alg-CaCO3 MPs and ultrapure water were applied directly to the leaves using a specialized nebulizer. Foliar nebulization was chosen for its precision and minimal resource use, aligning with the sustainability goals of aquaponic cultivation. The research evaluated rosette diameter, root length, fresh weight, soluble solids concentration, levels of photosynthetic pigments, and phenolic and flavonoid content. The 250 ppm treatment produced the most notable enhancements in both biomass yield and quality, highlighting the potential of precision fertilizers to boost sustainability and efficiency in aquaponic systems. In fact, the most significant increases involved biomass production, particularly in the edible portions, along with photosynthetic pigment levels. Additionally, the analysis of secondary metabolite content, such as phenols and flavonoids, revealed no reduction compared to the control group, meaning that the proposed fertilizer did not negatively impact the biosynthetic pathways of these bioactive compounds. This study opens new possibilities in aquaponics cultivation, highlighting the potential of precision fertilizers to enhance sustainability and productivity in soilless agriculture.

Soil Salinity Differentiates Winter Triticale Genotypes in Physiological and Biochemical Characteristics of Seedlings and Consequently Their Yield.

The aim of this study was to test the hypothesis that both the winter triticale genotype and salinity treatment influence the photosynthesis efficiency and content of metabolites and proteins, including antioxidant enzymes, under field conditions, as well as that these parameters are correlated with yielding capacity. The research material involved four genotypes differing in their tolerance to stress in previous tests. Chlorophyll a fluorescence parameters and antioxidant activity were assessed in the seedlings. Specific antibodies were then used to verify the involvement of selected proteins. Simultaneously, Raman spectroscopy was employed to detect chlorophyll, carotenoids, phenolic compounds, and protein levels. The findings suggest that improved PSII performance, reduced catalase activity, increased pigment levels, and higher thioredoxin reductase abundance in the seedlings were associated with better yield potential in triticale genotypes grown under salt stress conditions. The Raman analysis revealed that salinity caused changes in the photosynthetic pigments, particularly carotenoids. The carbon isotope ratios indicate that the salinization generated different physiological stresses in the availability of water.

Foliar Application of Nettle and Japanese Knotweed Extracts on Vitis vinifera: Consequences for Plant Physiology, Biochemical Parameters, and Yield

Climate change is expected to affect grapevine physiology, berry quality, and yield in the Douro Demarcated Region (DDR). In this study, nettle (NE) and Japanese knotweed (JKE) extracts were tested to verify their biostimulant effect on the physiological and biochemical parameters of grapevine leaves and in vine yields. In fact, some parameters were improved after foliar application of the plant extracts, namely the photosynthetic activity and consequently, the levels of photosynthetic pigments (Clb), starch, and total soluble sugars. We also observed a reduction in lipid peroxidation, which could play a crucial role in protecting cell membranes from oxidative damage induced by the climatic conditions prevalent in this region. Therefore, we confirmed that the foliar application of plant extracts, along with the enhancement of secondary metabolites and the upregulation of plant defense genes, as previously reported, resulted in the enhancement of grapevine physiology, while also increasing the yield at harvest. In the future, these plant extracts could serve as a vital tool for winegrowers in mitigating the effects of expected changes in climatic conditions.