Levels Of Soluble Sugars Research Articles

Heating alters the nutritional and antioxidant characteristics of lotus root

To investigate the impact of heating on the nutritional and antioxidant properties of lotus root, a comparative analysis was conducted between its heated and unheated whole powders. The whole powder of heated lotus root (HLRWP) exhibited a higher level of total soluble sugars but a lower level of free phenolic compounds compared to the whole powder of fresh lotus root (FLRWP). Meanwhile, they showed significant differences in metabolite composition encompassing phenolic compounds, flavonoids, amino acids, vitamins and lipids. The replacement of sugar and corn in the medium with 25% HLRWP effectively enhanced the activities of antioxidant enzymes (total superoxide dismutase and catalase), while reducing malonaldehyde content in Drosophila melanogaster males. The average, median and maximum lifespans of the fruit flies were extended by 35.90%, 23.49% and 24.00% respectively, accompanied by an improvement in climbing ability. Additionally, their resistance to oxidative stress induced by hydrogen peroxide or paraquat was enhanced. The antioxidant capacity of HLRWP in vivo was found to be obviously stronger compared to FLRWP, which may have a crucial association with the regulation of L-arginine and adenosine monophosphate levels. The results indicate that heating can enhance the nutritional quality of lotus root products by strengthening their antioxidant capacity.

Biochar Increases Rice Yield in Soda Saline-Alkali Paddy Fields by Improving Saline-Alkali Stress and Phosphorus Use Efficiency

Soda saline-alkali significantly hinders rice growth, phosphorus utilization efficiency, and yield formation. The application of biochar can alleviate the adverse effects of saline-alkali stress on crops. However, there is limited research on the interaction between biochar and phosphorus fertilizer concerning ionic accumulation, phosphorus utilization efficiency, and rice yield in soda saline-alkali soils. A two-year field experiment was conducted to study the combined effects of biochar and phosphate fertilizer on ionic accumulation, physiological status, phosphorus utilization efficiency, and rice yield in soda saline-alkali soil. Four treatments were established for the study: NK (225 kg N, 75 kg K ha−1 year−1), NPK (225 kg N, 70 kg P, 75 kg K ha−1 year−1), NK + B [225 kg N, 75 kg K ha−1 year−1, 1.5% biochar (w/w)], and NPK + B [225 kg N, 70 kg P, 75 kg K ha−1 year−1, 1.5% biochar (w/w)]. The findings indicated that the combined application of biochar and phosphorus fertilizer (NPK + B) significantly reduced the Na+ concentration, Na+/K+ ratio, malondialdehyde (MDA), superoxide anion (O2−), and hydrogen peroxide (H2O2) levels in rice plants. Furthermore, it resulted in a significant increase in K+ concentration and elevated the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), proline (Pro), soluble protein (SP), soluble sugar (SS), and acid phosphatase (ACP). The NPK + B treatment exhibited a significant difference compared to the other treatments (p < 0.05). Compared with NK, phosphorus accumulation and phosphorus utilization efficiency under NPK + B were significantly increased (p < 0.05). The average of biomass yield, grain yield, and harvest index of NPK + B, NK + B, and NPK significantly surpassed those of NK by 6.28–12.25%, 19.80–42.13%, and 11.59–24.64%, respectively. Moreover, a significant difference was observed between NPK + B and the other treatments (p < 0.05). Principal component analysis of the two-year mean data revealed a strong positive correlation of 89.5% for PC1 and a minor negative correlation of 4.4% for PC2. Our research findings demonstrate that the combination of biochar and phosphorus fertilizer effectively enhances salt and alkali tolerance in rice plants, resulting in increased yield through improved ionic balance and physiological status.

Influence of Combined Supplemental Lighting and Nutrient Solution Concentration on Fruit Production and Quality of Cherry Tomato

We conducted an analysis on the combined effects of two light conditions (L1: greenhouse natural lighting; L2: greenhouse natural lighting plus supplemental lighting (SL)) and three nutrient solution concentrations (EC, NS1: 3.2 dS/m; NS2: 3.7 dS/m; NS3: 4.2 dS/m) on the growth, fruit production, and quality of two cherry tomato cultivars with different fruit coloring (‘Baiyu’ and ‘Qianxi’). The plants subjected to NS2 exhibited enhanced growth, photosynthetic parameters, and fruit production. The utilization of SL further enhanced stem diameter, leaf number, and single fruit weight, resulting in higher fruit weight per plant in ‘Baiyu’, which was not observed in ‘Qianxi’. The growth, fruit size, and fruit weight of both cultivars cultivated under NS3 conditions were suppressed, while these fruits exhibited elevated levels of total soluble solids (TSS), soluble sugars, vitamin C, polyphenols, fructose, glucose, sucrose, citric acid, and carotenoids. These levels were further enhanced by SL treatment. The improvement of fruit quality through the application of SL was found to be cultivar and EC dependent. In ‘Baiyu’, SL at NS1 significantly enhanced the accumulation of fruit water, minerals (N, P, K, Ca, and Mg), TSS, vitamin C, fructose, sucrose, and carotenoids. However, this effect was not observed in ‘Qianxi’. The combination of SL and EC 4.2 dS/m (NS3) generally contributes to the enhancement of fruit quality, while SL and EC 3.7 dS/m can ensure consistent fruit production. The yellowish-white fruit cultivar exhibited higher levels of soluble sugars, vitamin C, and polyphenols under L2NS3 conditions compared to the red fruit cultivar, whereas the carotenoid content showed an opposite trend. The findings are anticipated to establish a theoretical foundation for the consistent annual cultivation of cherry tomatoes in protected horticultural settings.

Time of Application of Desiccant Herbicides Affects Photosynthetic Pigments, Physiological Indicators, and the Quality of Cowpea Seeds.

Chemical desiccation is widely used in agriculture to anticipate harvest and mitigate the effects of adverse environmental conditions. It is applied to both grains and seeds. Although this practice is widely used, there are still significant gaps in understanding the effects of different herbicide application times on seed quality and plant physiological responses. The objective of this study was to evaluate the effects of different herbicide application times on cowpea, focusing on seed quality, physiological responses, and biochemical composition, including chlorophylls, carotenoids, sugars, and proline, under nocturnal desiccation. In the first experiment, eight herbicides and two mixtures were applied at night: diquat, flumioxazin, diquat + flumioxazin, glufosinate ammonium, saflufenacil, carfentrazone, diquat + carfentrazone, atrazine, and glyphosate. All of the tested herbicides caused a reduction in normal seedling formation, with the diquat + carfentrazone combination resulting in 100% abnormal seedlings. A significant decrease in chlorophyll levels (chlorophyll a: 63.5%, chlorophyll b: 50.2%) was observed using diquat, which indicates damage to photosynthetic processes, while the carotenoid content increased. Total soluble sugars and proline were also negatively impacted, reflecting physiological stress and metabolic changes in seedlings. In the second experiment, three application times were tested with diquat, diquat + flumioxazin, and diquat + carfentrazone. Nocturnal application showed the most significant reduction in chlorophyll levels and increased carotenoid levels. Application at noon and late afternoon also significantly changed the soluble sugar and proline levels. These results indicate that the herbicide application time directly influences the seeds' physiological quality.

Dynamic Changes of Active Components and Volatile Organic Compounds in Rosa roxburghii Fruit during the Process of Maturity.

Rosa roxburghii (R. roxburghii), native to the southwest provinces of China, is a fruit crop of important economic value in Guizhou Province. However, the changes in fruit quality and flavor during R. roxburghii fruit ripening have remained unknown. Here, this study investigated the changes of seven active components and volatile organic compounds (VOCs) during the ripening of the R. roxburghii fruit at five different ripening stages including 45, 65, 75, 90, and 105 days after anthesis. The results indicated that during the ripening process, the levels of total acid, vitamin C, and soluble sugar significantly increased (p < 0.05), while the levels of total flavonoids, superoxide dismutase (SOD), and soluble tannin significantly decreased (p < 0.05). Additionally, the content of total phenol exhibited a trend of first decreasing significantly and then increasing significantly (p < 0.05). A total of 145 VOCs were detected by HS-SPME-GC-MS at five mature stages, primarily consisting of aldehydes, alcohols, esters, and alkenes. As R. roxburghii matured, both the diversity and total quantity of VOCs in the fruit increased, with a notable rise in the contents of acids, ketones, and alkenes. By calculating the ROAV values of these VOCs, 53 key substances were identified, which included aromas such as fruit, citrus, green, caramel, grass, flower, sweet, soap, wood, and fat notes. The aromas of citrus, caramel, sweet, and wood were predominantly concentrated in the later stages of R. roxburghii fruit ripening. Cluster heatmap analysis revealed distinct distribution patterns of VOCs across five different maturity stages, serving as characteristic chemical fingerprints for each stage. Notably, stages IV and V were primarily characterized by a dominance of alkenes. OPLS-DA analysis categorized the ripening process of R. roxburghii fruit into three segments: the first segment encompassed the initial three stages (I, II, and III), the second segment corresponded to the fourth stage (IV), and the third segment pertained to the fifth stage (V). Following the variable importance in projection (VIP) > 1 criterion, a total of 30 key differential VOCs were identified across the five stages, predominantly comprising ester compounds, which significantly influenced the aroma profiles of R. roxburghii fruit. By integrating the VIP > 1 and ROAV > 1 criteria, 21 differential VOCs were further identified as key contributors to the aroma changes in R. roxburghii fruit during the ripening process. This study provided data on the changes in quality and aroma of R. roxburghii fruit during ripening and laid the foundation for the investigation of the mechanism of compound accumulation during ripening.

The Efficiency of Seed Priming with Dead Sea Water for Improving Germination and Early Seedling Growth of Wheat (Triticum aestivum L.) under Salinity

&lt;p&gt;Salinity is considered the most critical environmental factor which negatively affects the germination and growth of plants. In this study, the potential of using Dead Sea water (DS) as a seed priming agent for the mitigation of the adverse effects of salinity on seed germination and growth performance of wheat (&lt;em&gt;Triticum aestivum&lt;/em&gt; L.) was investigated. Germination of wheat seeds primed with different doses of DS; 0%, 5%, 10%, 15%, and 20% were evaluated under different saline conditions (0, 100, 200, and 300 mM NaCl). High salinity (300 mM NaCl) remarkably inhibited germination attributes and reduced seedling length. However, seeds primed with DS exhibited improved germination parameters and seedling growth. Among the different DS concentrations used, the 10% DS priming achieved the highest increase in final germination percentage tolerance, germination index, relative germination salt tolerance, and seedling length. The increased tolerance to salinity was associated with improved water imbibition, α-amylase activity, antioxidant capacity and osmotic homeostasis correlated with high proline and soluble sugar levels. In addition, DS priming increased the membrane stability index, and reduced malondialdehyde content and K&lt;sup&gt;+&lt;/sup&gt; leakage besides lowering Na&lt;sup&gt;+&lt;/sup&gt;/K&lt;sup&gt;+&lt;/sup&gt; ratio. Overall, priming with DS could be a promising strategy for minimizing the damaging effects of salinity in wheat.&lt;/p&gt;

Effects of cadmium stress on the growth, physiology, mineral uptake, cadmium accumulation and fruit quality of 'Sharpblue' blueberry

Cadmium (Cd) contamination is becoming a widespread environmental problem, and Cd toxicity risk is increasing in blueberries, typical acidophilous plants. However, studies on the physiological mechanisms of Cd toxicity affecting the growth of blueberry plants and fruits remain limited. Herein, a pot experiment involving four treatments, CK (0 mg·kg−1), Cd1 (2.5 mg·kg−1), Cd2 (15 mg·kg−1) and Cd3 (50 mg·kg−1), was conducted to investigate the effects of Cd stress on the growth, fruit quality, physiological characteristics, mineral composition and Cd uptake of 'Sharpblue' blueberry cuttings, and relationships between physicochemical indices and phenotypic data under Cd stress were analyzed via principal component analysis and Mantel's test. Compared with CK, Cd treatment led to chlorosis (decrease in SPAD and N content) in 'Sharpblue' leaves and inhibited increases in plant height, basal stem, crown width and biomass (dry weight), with the most significant changes in the 50 mg·kg−1 Cd treatment. The size and thickness of the upper epidermal cells, as well as the thickness of the palisade mesophyll and spongy tissues of 'Sharpblue' were significantly reduced at Cd > 15 mg·kg−1, while the density of stomata was significantly increased. Moreover, Cd stress reduced the yield (decrease in size and single-fruit weight) and quality (decrease in anthocyanin, flavonoid and total phenol content and increase in titratable acid content) of 'Sharpblue' fruits, and Cd content in fruit exceeded the Chinese food safety threshold of 0.05 mg·kg−1 when Cd > 15 mg·kg−1. The Cd enrichment capacity of different organs of 'Sharpblue' plants was in the following order: root > shoot > leaf > fruit, and the 50 mg·kg−1 Cd treatment significantly inhibited the uptake of Fe, Mn, Cu, and Zn. Additionally, 'Sharpblue' plants responded to H2O2 and malondialdehyde accumulation in different organs under Cd stress by regulating levels of osmoregulatory substances (soluble protein (SP), soluble sugar, and proline) and altering the activities of catalase, superoxide dismutase, ascorbic acid, and glutathione in the antioxidant system. Finally, correlation analysis revealed that Mg, Fe, Mn, Cu, Cd, H2O2, SP, SPAD, N, anthocyanin, titratable acid, flavonoids, and total phenols were strongly correlated with 'Sharpblue' growth, leaf and fruit phenotype under Cd stress. These findings provide theoretical information for soil safety management and the breeding of Cd-tolerant cultivars during blueberry cultivation, as well as for the study of Cd stress response mechanisms in acidophilous plants.

Comprehensive Assessment of Herbicide Toxicity on Navicula sp. Algae: Effects on Growth, Chlorophyll Content, Antioxidant System, and Lipid Metabolism.

This study investigated the effects of herbicide exposure on Navicula sp. (MASCC-0035) algae, focusing on growth density, chlorophyll content, antioxidant system, and lipid metabolism. Navicula cultures were exposed to different concentrations of atrazine (ATZ), glyphosate (Gly), and acetochlor (ACT) for 96 h. Results showed a significant decrease in cell numbers, with higher herbicide concentrations having the most noticeable impacts. For instance, Gly-G2 had reduced cell populations by 21.00% at 96 h. Chlorophyll content varied, with Gly having a greater impact on chlorophyll a compared to ATZ and ACT. Herbicide exposure also affected the antioxidant system, altering levels of soluble sugar, soluble protein, and reactive oxygen species (ROS). Higher herbicide rates increased soluble sugar content (e.g., ATZ, Gly, and ACT-G2 had increased by 14.03%, 19.88%, and 19.83%, respectively, at 72 h) but decreased soluble protein content, notably in Gly-G2 by 11.40%, indicating cellular stress. Lipid metabolism analysis revealed complex responses, with changes in free proline, fatty acids, and lipase content, each herbicide exerting distinct effects. These findings highlight the multifaceted impacts of herbicide exposure on Navicula algae, emphasizing the need for further research to understand ecological implications and develop mitigation strategies for aquatic ecosystems.

Impact of Maize Nutrient Composition on the Developmental Defects of Spodoptera frugiperda

Spodoptera frugiperda (J.E. Smith) is a crucial agricultural pest owing to its global impact on &gt;300 crops. Among these, the corn strain of S. frugiperda causes significant damage to maize (Zea mays L.). However, limited research exists on the influence of maize nutrients on the metamorphosis of S. frugiperda and the underlying mechanisms. In this study, the effects of different growth stages of maize leaves, namely, tender leaves (tender) and mature leaves (mature), on various aspects of larval development, including body weight, body length, developmental age, pupation rate, and eclosion rate, were investigated. Additionally, we measured the levels of 20-hydroxyecdysone (20E) and three types of juvenile hormone (JH; i.e., JH I–III) in S. frugiperda larvae fed on tender or mature. The results revealed that larvae fed on Tender exhibited significantly prolonged instar duration, reduced body weight and length, and decreased pupation and eclosion rates, with the emergence of abnormal adults. Analysis of nutritional components in maize leaves revealed significantly higher levels of amino acids, soluble sugars, and sterols in mature than in tender. Hormone analysis in S. frugiperda larvae revealed higher 20E titers in individuals feeding on mature during prepupal and pupal stages. We demonstrated the crucial role of sterols in regulating the level of 20E and pupation rate of S. frugiperda. Based on these findings, we propose that isoleucine, arginine, glutamic acid, sucrose, campesterol, and β-sitosterol serve as key nutrients influencing the development of S. frugiperda. Moreover, β-sitosterol is a significant factor influencing the interaction between maize leaves and S. frugiperda. Our research results provide a reference for the control strategy of S. frugiperda based on breeding insect-resistant varieties by altering host nutrition.

Analysis of lettuce transcriptome reveals the mechanism of different light/dark cycle in promoting the growth and quality.

Light/dark (L/D) cycle plays a crucial role in controlling the production and quality of vegetables. However, the mechanism of L/D cycle on vegetable growth and quality is scarce studied. To investigate the impact of L/D cycle on lettuce growth and quality, we designed three diel scenarios, including 16 hours of light and 8 hours of darkness (L16/D8), 12 hours of light and 6 hours of darkness (L12/D6), and 8 hours of light and 4 hours of darkness (L8/D4). By phenotypic analysis, we found that lettuce grew taller under the L8/D4 scenario than under L16/D8 light cycle scenarios. The physiological indexes showed that the lettuce leaves grown in the L8/D4 scenario exhibited greater enhancements in the levels of soluble protein, soluble sugar, and carotenoid content compared to the other scenarios. By comparing the expression levels under different diel scenarios (L16/D8 vs L12/D6, L16/D8 vs L8/D4, and L12/D6 vs L8/D4), we identified 7,209 differentially expressed genes (DEGs). Additionally, 3 gene modules that were closely related to L/D cycle of lettuce were selected by WGCNA analysis. The eigengenes of three gene modules were enriched in plant hormone signal transduction, sphingolipid metabolism, and nucleocytoplasmic transport pathways. Through network analysis, we identified six hub genes (CIP1, SCL34, ROPGEF1, ACD6, CcmB, and Rps4) in the three gene modules, which were dominant in plant circadian rhythms and greatly affected lettuce growth. qRT-PCR analysis confirmed the diurnal response patterns of the 6 hub genes in different treatments were significant. This study intensively enhanced our comprehension of the L/D cycle in the growth morphology, nutritional quality, and metabolic pathways of lettuce.

Microplastics in soil affect the growth and physiological characteristics of Chinese fir and Phoebe bournei seedlings

Pot experiments were conducted using Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Phoebe bournei (Hemsl.) Yang) to investigate whether soil microplastics adversely affect the nurturing and renewal of plantations. Microplastics composed of polyethylene and polypropylene with a size of 48 μm were used. The treatments included a control group (without microplastics) and groups treated with microplastic concentrations of 1% and 2% (w/w). The effects of microplastics on the growth, photosynthetic pigments in leaves, antioxidant systems, and osmotic regulation substances of the seedlings were analysed by measuring the seedling height, ground-line diameter growth, chlorophyll (chlorophyll a, chlorophyll b, and total chlorophyll) contents, antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities, and malondialdehyde, soluble sugar, and soluble protein levels. The results indicated that treatment with 1% polyethylene microplastics increased the chlorophyll a, total chlorophyll, and soluble protein contents in the leaves of both types of seedlings while inhibiting superoxide dismutase and peroxidase activities in P. bournei seedlings. Treatment with 2% polyethylene or polypropylene microplastics suppressed the chlorophyll a, chlorophyll b, and total chlorophyll contents; superoxide dismutase, peroxidase, and catalase activities; and soluble sugar and soluble protein levels in the leaves of both types of seedlings, resulting in reduced growth in terms of height and ground-line diameter. The physiological effects of polyethylene microplastics were more evident than those of polypropylene at the same concentration. The results demonstrated that microplastics can affect photosynthesis, the antioxidant system, and osmotic regulation in Chinese fir and P. bournei seedlings, thereby inhibiting their normal growth and development. Exposure to 1% (w/w) microplastics triggered stress responses in seedlings, whereas 2% (w/w) microplastics impeded seedling growth.

Physiological and biochemical characterisation of split and healthy Daisy mandarin (Citrus reticulata Burm.) fruits

ABSTRACT Fruit splitting is a prevalent physiological disorder that has a significant impact on Daisy mandarin fruit production, posing challenges to farmers in terms of productivity and economic viability. Despite its impact, no prior research on fruit splitting in Daisy mandarin has been conducted. This study aimed to assess the effect of fruit splitting on quality, morphological characteristics, biochemical composition and nutrient content in Daisy mandarin. In 2022, a comprehensive analysis was conducted on both split and healthy Daisy mandarin fruits, budded on Rough lemon rootstock, to investigate their morphological characteristics, biochemical characteristics, mineral content and cell wall components. Additionally, the study examined the activity of cell wall-degrading enzymes, such as peroxidase (POD), cellulase (Cx) and polygalacturonase (PG). The Results indicated that split fruits exhibited larger fruit size and weight and increased water content in both the fruits and peel compared to healthy fruits. However, split fruits had thinner peel thickness and lower peel content. The peels of split fruits also contained higher level of total soluble sugars, amino acids, and proline content. Furthermore, the peels of split fruits displayed much higher activity of cell wall-degrading enzymes than those of healthy fruits. The nutrient analysis of the split fruits revealed a decrease in boron, calcium and potassium content in the peel compared to healthy fruits. The study provides crucial insights into the mechanisms underlying fruit splitting, identifying biochemical and physiological differences between split and healthy fruits. These findings offer valuable information for developing strategies to mitigate fruit splitting, enhancing fruit quality and reducing economic losses for citrus growers. Future research should explore the genetic and environmental factors contributing to fruit splitting and investigate potential interventions to improve nutrient management and fruit integrity in Daisy mandarin cultivation.

Studies on the Impact of Microplastics in Freshwater Systems: Biota Could Be Vital Indicators in Delta State, Nigeria

Microplastics have impacted freshwater system globally. Despite the global concern about microplastic pollution, only a little is evidenced in research on the occurrence and intensity of pollution in research. This study determined the effects of microplastics on aquatic water bodies was determined using plants as bio-indicator. The study was conducted bimonthly (June- August) to examine the occurrence of microplastics. Physicochemical parameters and biochemical parameters of plants were analyzed using standard methods. Hydrogen ion concentrations of the water sources were mildly acidic (5.6±0.15 and 5.49±0.19), and turbidity levels were notably high (71.00±4.20 NTU and 92.70 ±4.32 NTU) in lotic and lentic water bodies respectively. Dissolved oxygen and biological oxygen demand were significantly compared within aquatic systems (p&lt;0.05). Water hyacinth- Pontederia crassipes Mart (former Eichhornia crassipes) exhibited higher levels of soluble sugar at 110.34±3.32 mg/L in lotic water body compared to water leaf- Talinum triangulare (Jacq.) Willd, 70.44±4.78 mg/L in lentic water. Total chlorophyll levels and water retention capacity were lower in lotic water at 37.90±2.35 and 2.08±0.21 respectively. Ascorbic acid levels were higher in lotic water (308.00±12.34 mg/100g). Chironomus sp. and Nais sp. were commonly encountered. The vital role of Chironomus sp. and Nais sp. should not be underestimated as bioindicators in freshwater systems. Hence, they should be further investigated in different freshwater ecosystems.

Dynamic analysis of nutrients and phenolic compounds in different growth stages of Lanzhou lily bulbs

Lanzhou lily (Lilium davidii var. unicolor), a perennial herb stands as a crucial economic crop in northwest China. However, the influence of growth stages on its nutritional profile remains uncertain. Hence, this study aimed to shed light on the physicochemical characteristics of Lanzhou lily bulbs by harvesting them at different growth stages. Collectively, total dietary fiber (TDF) and reducing sugar exhibited the highest levels in the 4th year. Meanwhile, the levels of soluble sugar, phenolic compounds and child essential amino acids (CEAA) demonstrated the highest content in the 5th year. Dry matter (DM), total amino acids (TAA) and starch reached peak concentrations in the 6th year (Y6). Medical amino acids (MAA) constituted a significant portion of TAA (> 80 %) across all growth stages. Starch and sweet amino acids (SAA) exhibited a notably positive correlation (r = 0.87 and 0.89, respectively) with growth stages. Interestingly, soluble dietary fiber (SDF), TDF and soluble sugar displayed a negative correlation (r = −0.69, −0.64 and −0.58, respectively). Starch, soluble sugar, SDF and amino acids (AAs) were particularly sensitive to growth stage effects. Taken together, the results showed that Lanzhou lily bulbs cultivated over a 5-year period emerged as the top-tier choice, elevated levels of CEAA, MAA and phenolic compounds.

Biochemical analysis of three red grapevine varieties during three phenological periods grown under Mediterranean climate conditions.

In Mediterranean regions, severe summers are becoming more common, leading to restrictions to vine productivity and yield quality, requiring sustainable practices to support this sector. We assessed the behaviour of three red grapevine varieties from the Douro Region to examine their tolerance to summer climate stress from the perspective that the less common varieties may have potential for increased use in a climate change scenario. Leaf and fruit biochemical profile, antioxidant activity and fruit colorimetric parameters were assessed at different phenological stages in Aragonez (AR), Tinto Cão (TC) and Touriga Nacional (TN) grape varieties. All three varieties exhibit significant variability in phenological timing, influenced by genetic and environmental factors. Photosynthetic pigment strategies differed among varieties. Chlorophyll content in AR was high to cope with high radiation, while TN displaying a balanced approach, and TC had lower pigment levels, with higher levels of phenolics, antioxidants, and soluble sugars, particularly during stress. The variations in berry biochemical profile highlight the distinct characteristics of the varieties. TC and TN show potential for coping with climate change, having elevated total acidity, while AR has larger and heavier berries with distinct coloration. These findings reinforce the need to study the behaviour of different varieties in each Terroir, to understand their diverse strategies to deal with summer climate stress. This will help in selecting the most suitable variety for these conditions under vineyard management in the Douro Region.

Salicylic Acid Priming Improves Cotton Seedling Heat Tolerance through Photosynthetic Pigment Preservation, Enhanced Antioxidant Activity, and Osmoprotectant Levels.

The escalating global temperatures associated with climate change are detrimental to plant growth and development, leading to significant reductions in crop yields worldwide. Our research demonstrates that salicylic acid (SA), a phytohormone known for its growth-promoting properties, is crucial in enhancing heat tolerance in cotton (Gossypium hirsutum). This enhancement is achieved through modifications in various biochemical, physiological, and growth parameters. Under heat stress, cotton plants typically show significant growth disturbances, including leaf wilting, stunted growth, and reduced biomass. However, priming cotton plants with 1 mM SA significantly mitigated these adverse effects, evidenced by increases in shoot dry mass, leaf-water content, and chlorophyll concentrations in the heat-stressed plants. Heat stress also prompted an increase in hydrogen peroxide levels-a key reactive oxygen species-resulting in heightened electrolyte leakage and elevated malondialdehyde concentrations, which indicate severe impacts on cellular membrane integrity and oxidative stress. Remarkably, SA treatment significantly reduced these oxidative stresses by enhancing the activities of critical antioxidant enzymes, such as catalase, glutathione S-transferase, and ascorbate peroxidase. Additionally, the elevated levels of total soluble sugars in SA-treated plants enhanced osmotic regulation under heat stress. Overall, our findings reveal that SA-triggered protective mechanisms not only preserve photosynthetic pigments but also ameliorate oxidative stress and boost plant resilience in the face of elevated temperatures. In conclusion, the application of 1 mM SA is highly effective in enhancing heat tolerance in cotton and is recommended for field trials before being commercially used to improve crop resilience under increasing global temperatures.

Effect of Polyethylene Glycol-Simulated Drought Stress on Stomatal Opening in "Modern" and "Ancient" Wheat Varieties.

Climate change is leading to an increase in the intensity, duration, and frequency of severe droughts, especially in southern and southeastern Europe, thus aggravating water scarcity problems. Water deficit stress harms the growth, physiology, and yield of crops like durum wheat. Hence, studying ancient wheat varieties' stress responses could help identify genetic traits to enhance crop tolerance to environmental stresses. In this background, this study aimed to investigate the effects of PEG 6000-stimulated drought stress in the ancient wheat variety Saragolla and the modern one Svevo by analyzing various biochemical and molecular parameters that can especially condition the stomatal movement. Our data revealed that drought stress caused a significant increase in the levels of total soluble sugars, ABA, and IAA in both selected cultivars to a greater extent in the Saragolla than in the Svevo. We demonstrated that, under water deficit stress, calcium dynamics as well as the expression of ERF109, MAPK3/6, MYB60, and TaTPC1, involved in the activation of drought-related calcium-sensitive pathways, display significant differences between the two varieties. Therefore, our study provided further evidence regarding the ability of the ancient wheat variety Saragolla to better cope with drought stress compared to the modern variety Svevo.

The carbohydrate metabolism and expression of carbohydrate-active enzyme genes in Aspergillus luchuensis fermentation of tea leaves.

Carbohydrates, which make up 20 to 25% of tea beverages, are responsible for their flavor and bioactivity. Carbohydrates of pu-erh tea change during microbial fermentation and require further research. In this study, we examined the carbohydrate metabolism and expression of carbohydrate-active enzyme genes during the fermentation of tea leaves with Aspergillus luchuensis. Widely targeted metabolomics analysis, high-performance anion-exchange chromatography measurements, and transcriptomics were used in this study. After fermentation, the levels of soluble sugar, hemicellulose, lignin, eight monosaccharides, and seven sugar alcohols increased. Meanwhile, the relative contents of polysaccharides, D-sorbitol, D-glucose, and cellulose decreased. High expression of 40 genes encoding 16 carbohydrate enzymes was observed during fermentation (FPKM>10). These genes encode L-iditol 2-dehydrogenase, pectinesterase, polygalacturonase, α-amylase, glucoamylase, endoglucanase, β-glucosidase, β-galactosidase, α-galactosidase, α-glucosidase, and glucose-6-phosphate isomerase, among others. These enzymes are known to break down polysaccharides and cell wall cellulose, increasing the content of monosaccharides and soluble sugars.

Physiological and molecular mechanisms of melatonin to alleviate benzoic acid-induced autotoxicity stress in Prunus persica

Autotoxicity stress is well known as a critical factor in the replant problem that hinders the sustainable development of agriculture. Benzoic acid (BA) is identified as a major autotoxin in peach replant problem, and causes serious growth inhibition of peach plants. Melatonin is a multi-functional molecule that plays a key role in alleviating stress-induced damage in plants. However, the functions and the inherent molecular mechanisms of melatonin under autotoxicity stress remains largely elusive. Here, we found that application of melatonin significantly enhanced BA tolerance in peach seedlings. Exogenous melatonin mitigated the negative impact of BA stress on peach root growth. Melatonin pretreatment boosted flavonoid biosynthesis and increased soluble sugar content of peach plants under BA stress. In addition, melatonin also promoted the reactive oxygen species scavenging by enhancing the antioxidant capacity. Consistent with these alterations, transcriptome analysis demonstrated that up-regulations of flavonoid biosynthesis, starch and sucrose metabolism, and antioxidant-related genes were observed when melatonin applied under BA stress. Furthermore, we also observed that an induction in genes involved in xenobiotic transmembrane transport, cell wall organization or biogenesis, and α-linolenic acid metabolism, which might contribute to the melatonin-mediated BA tolerance. Collectively, our findings reveal that melatonin confers BA tolerance of peach seedlings, primarily attributed to increased flavonoid and soluble sugar levels, enhanced antioxidant capacities, and extensive transcriptome reprograming. This opens new avenues for utilizing melatonin to alleviate peach replant problem.

Methodological and Physiological Study during Seed Dormancy Release of Symplocos paniculata.

Symplocos paniculata are reported to exhibit seed dormancy, which impedes its cultivation and widespread adoption. In this study, a comprehensive method was established to overcome seed dormancy by subjecting seeds to scarification in 98% H2SO4 for 10 min, followed by 1000 mg·L-1 GA3 soaking for 48 h and stratification at 4 °C for 100 days. The seed germination percentage has increased significantly, to a peak of 42.67%, though the seeds could not germinate timely by NaOH scarification. Additionally, the dynamic changes of key stored substances (proteins, soluble sugars, starches, and fats), associated enzyme activities (amylases, peroxidase, and catalase), and endogenous hormones (abscisic acid, gibberellic acid, and indole-3-acetic acid) in seeds were investigated. The results demonstrated a continuous degradation of starch and fat in S. paniculata seeds, while the levels of protein and soluble sugar exhibited fluctuations, which probably facilitated seed dormancy breaking through energy supply and transformation. The enzymatic activities underwent rapid changes, accompanied by a gradual decrease in ABA content within the seeds with increasing stratification time. Notably, GA3, GA3/ABA, and (GA3 + IAA)/ABA showed significant increases, indicating their positive regulatory roles in seed germination. This study clarified the dormancy mechanism and established an effective method for the release dormancy of S. paniculata seeds.