Search Results (4,874)

In constructed wetlands (CWs) with multiple plant communities, population structure may change over time and these variations may ultimately influence water quality. However, in CWs with multiple plant communities, it is still unclear how population structure may change over time and how these variations ultimately influence water quality. Here, we established a CW featuring multiple plant species within a polder to investigate the variation in plant population structure and wastewater treatment effect for drainage water over the course of one year. Our results showed that the total species decreased from 52 to 36; however, 20 established species with different ecological types (emerged or submerged) remained with the same functional assembly for nutrient absorption, accounting for 94.69% of relative richness at the initial stage and 91.37% at the last state. The Shannon index showed no significant differences among the initial, middle, and last states. Meanwhile, regarding nutrient content, the total phosphorus (TP) concentration decreased by 57.66% at the middle stage and by 56.76% at the last state. Total nitrogen (TN) decreased by 50.86% and 49.30%, respectively. Chemical oxygen demand (COD) decreased by 36.83% and 38.47%, while chlorophyll a (Chla) decreased by 72.36% and 78.54%, respectively. Redundancy analysis (RDA) results indicated that none of the selected environmental variables significantly affected the species community except for conductivity. Our findings suggest that when utilizing multiple species for CWs, it is essential to focus on the well-established species within the plant community. By maintaining these well-established species, water purification in CWs can be sustained. Full article

Interest among consumers in the availability of organically produced fruits and vegetables is increasing. Seafood demand is increasingly being met by fish raised using aquaculture methods that provide fish excretory products that can meet organic standards for nutrient sources for organic vegetables. We conducted an experiment in a glass greenhouse to evaluate fish biosolids as a substrate amendment for organic tomato transplant production. We compared the fish biosolids treatment to several different organic fertilizers, along with a commonly used inorganic slow-release fertilizer (Osmocote). All treatments used a target N concentration of 400 mg/L incorporated into the substrate and we also included fish biosolids treatments of 200 and 800 mg N/L. Plant performance was monitored for 4 weeks starting with commercially available 2-week-old seedlings. The results showed that the 800 mg N/L fish biosolids treatment compared very favorably with the conventional Osmocote treatment at the conclusion of the trial. The 800 mg N/L fish biosolids treatment exceeded the Osmocote treatment for chlorophyll content and for leaf number for the first 3 weeks of the 4-week trial. Grower management protocols could further improve seedling performance by providing additional top dressings of fish biosolids or fish effluent waters as plants age. Full article

Drought stress significantly affects maize (Zea mays L.) growth by disrupting vital physiological and biochemical processes. This study investigates the potential of proline supplementation to alleviate drought-induced stress in maize plants. The results show that proline supplementation enhanced shoot and root growth under normal conditions and alleviated drought-induced reductions in growth parameters. Under drought stress, proline increased shoot length by 40%, root length by 36%, shoot fresh weight by 97%, root fresh weight by 247%, shoot dry weight by 77%, and root dry weight by 154% compared to the untreated plants. While drought stress induced electrolyte leakage and reduced the relative water content (RWC) and leaf area, proline treatment mitigated these effects by improving membrane stability, water retention, and chlorophyll content. Moreover, proline supplementation reduced hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) levels by 38% and 67%, respectively, in the drought-stressed plants compared to the untreated controls. It also enhanced catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities by 14%, 69%, and 144%, respectively, under drought stress, indicating a strengthened antioxidative defense. Proline also increased the protein content and improved N, P, and K retention by 30%, 40%, and 28%, respectively, in the drought-stressed plants, supporting metabolic and osmotic balance. Additionally, proline improved endogenous proline and sugar levels, facilitating osmotic adjustment and providing energy reserves. These findings suggest that proline supplementation effectively enhances maize resilience under drought stress, improving growth, reducing oxidative stress, and enhancing osmoprotection. Full article

This study extends our previous work showing that a process-based (PB) model, the DIMONA PB model, could accurately simulate peatland soil water dynamics when driven by water table depth, d_WT, or by near surface soil water contents, θ. Here, we explore the model’s ability to simulate the peatland canopy photosynthesis, growth, biomass, height, and gross primary productivity (GPP) of vascular plants and bryophytes—thus ecosystem GPP—using either of these drivers. The DIMONA PB model is embedded into the DIMONA online modelling platform, a web application capable of ingesting data from the Internet and performing machine learning (ML) modelling and Internet of Things (IoT) modelling complementary to PB modelling. We test whether the DIMONA PB model, driven by d_WT (Hypothesis 1) and by near-surface θ (Hypothesis 2), can successfully simulate peatland ecosystem GPP at the Mer Bleue bog (Ontario, Canada). Two model runs were generated, one driven by d_WT and another by near-surface θ. Both model runs performed with similar accuracy. Data fit for simulated on observed GPP reached 0.72 for R², 1.7 umol CO₂ m⁻² s⁻¹ for RMSE, and 0.88 for Willmott’s index of agreement at an hourly time step and 0.91, 0.8 g C m⁻² d⁻¹, and 0.92, respectively, at a daily time step. We use the output from the two model runs to examine whether the model’s modifiers (i.e., equations) for water control can capture the specifics of contrasting hydrological conditions on peatland GPP (Hypothesis 3). Both model runs closely simulated the observed GPP to contrasting peatland hydrological conditions under similar meteorological forcing. We illustrate the ability of the DIMONA platform to facilitate the parameterization of DIMONA models for any geographic location, as well as its ability to perform IoT modelling of real-time photosynthesis at two site locations and ML modelling for ecosystem GPP as a complementary tool to PB modelling. Full article

This study investigates the anatomical adaptations of leaves from two halophyte species, Nitraria retusa (Forsskal) Asch. and Atriplex halimus L., in response to pollutants from a cement factory and human activities. In industrial areas, these plants absorb pollutants through their leaf surfaces, including Cu, Zn, and Pb. The two species were examined for anatomical changes under air pollution, and key factors including leaf blade thickness, palisade parenchyma cell height, spongy parenchyma cell diameter, epidermal characteristics, and stomatal traits were assessed. Under pollution, the leaves displayed smaller and denser stomata and idioblasts in the palisade and spongy parenchyma. These anatomical responses suggest that N. retusa and A. halimus could be effective bioindicators for detecting cement dust pollutants. Their leaf relative water content (RWC) exhibited a range of values: 70.1% and 87% for N. retusa and 64.8% to 74.2% for A. halimus on the highly polluted site (S1) and the control site (S4), respectively. Notably, a statistically significant site effect was observed (p > 0.01), confirming previous studies, and indicating reduced leaf relative water content (RWC) values in plants exposed to heavy metals like Cd and Pb. Heavy metals can lead to mineralization by binding to cell walls, altering their physicochemical properties and plasticity. Furthermore, significant correlations between specific heavy metals and histological parameters in A. halimus leaves indicated potential interactions between metal composition and leaf structure, highlighting their role in modulating anatomical adaptations. The correlation of leaf thickness, upper epidermal thickness, and stomatal density with Zn and Pb levels underlines the importance of these anatomical features in heavy metal accumulation and retention in plant tissues. Full article

A previous exposure to drought priming (DP) or salt priming (SP) could significantly improve future tolerance to both the same and different abiotic stresses, which is an effective mitigation strategy for plants to adapt to changing environmental conditions. If the type of stress priming is different from subsequent abiotic stress, this indicates that plants are trained to acquire cross tolerance. The objective of this study was to explore DP-regulated cross tolerance to salt stress and SP-induced cross tolerance to drought associated with changes in growth, antioxidant defense, proline metabolism, and the expression of the dehydration-responsive gene Dehydrin b involved in the stabilization of membrane systems, cryoprotection of intracellular proteins, and enhancement in water retention capacity in white clover (Trifolium repens). Plants were pretreated by initial DP or SP and then subjected to subsequent salt stress or drought stress for 10 days, respectively. The results demonstrated that DP significantly increased number of roots during subsequent salt stress, whereas SP significantly improved stem length, root length, and number of roots under drought stress, which indicated that the SP exhibited more pronounced and positive effects on mitigating subsequent drought-induced growth retardant. Both salt stress and drought resulted in significant increases in electrolyte leakage and contents of superoxide anion, hydrogen peroxide, and malonaldehyde due to reduced superoxide dismutase, peroxide, and catalase, as well as key enzyme activities in the ascorbate–glutathione cycle. SP or DP could significantly enhance these enzyme activities to alleviate subsequent drought- or salt-induced oxidative damage. SP or DP also significantly improved the accumulation of proline contributing to better water homeostasis by promoting biosynthetic enzyme activities (Δ¹-pyrroline-5-carboxylate synthetase and aminotransferase) and restricting proline dehydrogenase activity for proline degradation under drought or salt stress, respectively. In addition, SP significantly up-regulated the expression of dehydrin b under drought stress, but DP failed to induce the expression of dehydrin b in response to subsequent salt stress. The current findings proved that the pre-exposure of white clover plants to DP or SP could effectively mitigate the negative effects of subsequent salt stress or drought related to some common and different pathways. Plants pretreated by initial DP or SP exhibited better adaption to subsequent different stress by regulating growth, physiological, metabolic, and transcriptional changes. Full article

White clover (Trifolium repens) is an excellent perennial cold-season ground-cover plant for municipal landscaping and urban greening. It is, therefore, widely distributed and utilized throughout the world. However, poor salt tolerance greatly limits its promotion and application. This study aims to investigate the difference in the mechanism of salt tolerance in relation to osmotic adjustment, enzymatic and nonenzymatic antioxidant defenses, and organic metabolites remodeling between salt-tolerant PI237292 (Trp004) and salt-sensitive Korla (KL). Results demonstrated that salt stress significantly induced chlorophyll loss, water imbalance, and accumulations of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and superoxide anion (O₂^.−), resulting in reduced cell membrane stability in two types of white clovers. However, Trp004 maintained significantly higher leaf relative water content and chlorophyll content as well as lower osmotic potential and oxidative damage, compared with KL under salt stress. Although Trp004 exhibited significantly lower activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, monodehydroasorbate reductase, dehydroascorbate reductase, and glutathione reductase than KL in response to salt stress, significantly higher ascorbic acid (ASA), dehydroascorbic acid (DHA), glutathione (GSH), glutathione disulfide (GSSG), ASA/DHA, and GSH/GSSG were detected in Trp004. These findings indicated a trade-off relationship between antioxidant enzymes and nonenzymatic antioxidants in different white clover genotypes adapting to salt stress. In addition, Trp004 accumulated more organic acids (glycolic acid, succinic acid, fumaric acid, malic acid, linolenic acid, and cis-sinapic acid), amino acids (serine, l-allothreonine, and 4-aminobutyric acid), sugars (tagatose, fructose, glucoheptose, cellobiose, and melezitose), and other metabolites (myo-inositol, arabitol, galactinol, cellobiotol, and stigmasterol) than KL when they suffered from the same salt concentration and duration of stress. These organic metabolites helped to maintain osmotic adjustment, energy supply, reactive oxygen species homeostasis, and cellular metabolic homeostasis with regard to salt stress. Trp004 can be used as a potential resource for cultivating in salinized soils. Full article

The growing interest in a plant-based diet leads to the search for new sources of protein in the human diet as an alternative to animal proteins. Plant materials that can supplement protein as additives in food products are being studied. Watermelon seeds (Citrillus lanatus L.) are rich in proteins and waste from the food industry; however, their extraction is not completely cost-free, and the flour production process may involve additional costs related to their extraction and processing. The studies showed that watermelon seed protein concentrate, obtained using the alkaline extraction method, contained 82.52 g/100 g of protein and 1.51 g/100 g of fat. The polyphenol content in the protein preparation from defatted watermelon seeds was 1.9 mg gallic acid/g, and the antioxidant activity of the concentrate was 29.26 µmol Trolox/g (by the ABTS+). The obtained watermelon seed protein concentrate was characterised by solubility of more than 80% (at pH = 10), water absorption at the level of 2.46 (g water/g) and oil absorption equal to 2.1 (ml oil/g), showed poor foaming properties (1.51%), and was characterised by low emulsification. Full article

The genus Ziziphus includes numerous species, both cultivated and wild, offering significant genetic variability and economic potential that are often overlooked. Due to their high variability and ecological plasticity, jujube species and genotypes can be utilized in marginal areas and on land where few plants could be efficiently exploited. This study investigated variations in morphological characteristics (qualitative and quantitative), bioactive content (e.g., DPPH radicals), and antioxidant capacity in fruits, leaves, and stones of cultivated Z. jujuba genotypes (‘Hu Ping Zao’ and ‘Jun Zao’) and wild genotypes (Z. acido-jujuba and ‘Jurilovca’), using different solvents (water, ethanol, and methanol). The mass and dimensions of the fruits as well as their parameters (fresh and dry weight, length, width, and pulp-to-stone ratio) and the antioxidant potential of different plant organ types (leaves, fruit pulps, and stones) were determined. The results showed that the cultivated genotypes produced larger and heavier fruits with a higher pulp percentage than the wild forms of the same species. However, the wild forms exhibited higher antioxidant capacities than the cultivated genotypes, depending on the type of plant organ analyzed and the solvent used for extraction. Full article

Argania spinosa (L.) Skeels is a unique endemic species in Morocco, renowned for its ecological characteristics and socio-economic importance. In Morocco, recent years have seen an exacerbation of the harmful effects of climate change, leading to an alarming decline in the natural regeneration of this species in its original habitats. It seems that the only viable solution lies in the domestication of this genetic heritage. This study marks the first in-depth investigation of the impact of various climatic and edaphic factors on the morphological and physiological traits of Argania spinosa young plants, assessed in six separate orchards and observed over four seasons (March 2022 (Winter), June 2022 (Summer), November 2022 (Autumn), and March 2023 (Winter)). A climatic assessment was carried out at each site, including measurements of rainfall, maximum and minimum temperatures, mean temperature, air temperature, and wind speed. The soil was analyzed for the pH, electrical conductivity (EC), water content, limestone (CaCO₃), Kjeldahl nitrogen (N), available phosphorus (P₂O₅), organic matter (OM), and carbon/nitrogen ratio (C/N). To gain a better understanding of the morphophysiological characteristics of young argan seedlings, we carried out various observations, such as measuring the height and diameter of aerial parts, and the water content of leaves (WCL) and branches (WCB), quantifying chlorophyll (mg/m²) and leaf area. The results revealed a significant impact of edaphic and climatic factors on the morphophysiological parameters of young argan trees. Results revealed significant correlations of young argan plants between edaphic and climatic factors and morphophysiological parameters. The Tamjloujt site, characterized by protective vegetation cover, showed optimal growth conditions with the highest leaf and branch water content (46.89 ± 4.06% and 37.76 ± 3.51%, respectively), maximum height growth (91.33 ± 28.68 mm), trunk diameter (24.85 ± 3.78 mm), and leaf surface area (69.33 ± 19.28 mm²) during Summer 2022. The Saharan zone of Laqsabi exhibited peak chlorophyll concentrations (506.9 ± 92.25 mg/m²) during Autumn 2022, due to high temperatures. The mountainous environment of Imoulass negatively impacted plant growth (mean height: 52.61 ± 12.37 mm; diameter: 6.46 ± 1.57 mm) due to harsh climatic and edaphic conditions. This research provides vital knowledge regarding the environmental factors influencing the establishment of young argan plants within the Argan Biosphere Reserve. This contributes to the development of more effective domestication strategies and the restoration of agroecosystems. The aim is to use this knowledge to promote the rehabilitation and sustainability of argan agroecosystems. Full article

Ajowan (Trachyspermum ammi) is an important spice in the food industry, as a well as a medicinal plant with remarkable antioxidant properties. In this study, its essential oil content, chemical composition, flavonoid content, phenolic content, and antioxidant capacity were evaluated under three irrigation regimes (50, 70, and 90% field capacity) and different amounts of nano silicon (0, 1.5, and 3 mM) in ten populations of ajowan. Based on the GC–MS analysis, thymol, carvacrol, p-cymene, and γ-terpinene were determined as the main components of the oil. The thymol content ranged from 34.16% in the Ardabil population (irrigation at 50% and nano silicon at 1.5 mM) to 65.71% in the Khorbir population (without nano silicon and irrigation at 50%). The highest phenolic content was in Khormo with irrigation at 90% and without nano silicon (172.3 mg TAE/g DW), while the lowest was found in Hamedan (irrigation at 50% and without nano silicon (7.2 mg TAE/g DW)). Irrigation at 50% and no nano silicon treatment led to an increase in total flavonoids in Ardabil (46.786 mg QUE/g DW). The antioxidant activity of ajowan was evaluated using the DPPH assay. Accordingly, the highest antioxidant capacity was observed in Khormo (irrigation at 90% without nano silicon; 4126 µg/mL). Moreover, the highest thymol content was observed in the Khorbir population with irrigation at 50% and without nano silicon treatment. Furthermore, correlation and principal component analysis (PCA) provide new insights into the production of ajowan from their substrates under nano silicon treatment and water deficit conditions. Finally, the results revealed information on how to improve the desired essential oil profile and antioxidant capacity of extracts for industrial producers. Full article

Late embryonic developmental abundant (LEA) genes play a crucial role in the response to abiotic stress and are important target genes for research on plant stress tolerance mechanisms. Acer truncatum Bunge is a promising candidate tree species for investigating the tolerance mechanism of woody plants against abiotic stress. In our previous study, AtruLEA1 was identified as being associated with seed drought tolerance. In this study, LEA1 was cloned from A. truncatum Bunge and functionally characterized. AtruLEA1 encodes an LEA protein and is located in the nucleus. Phylogenetic tree analysis revealed a recent affinity of the AtruLEA1 protein to AT3G15760.1. Overexpression of AtruLEA1 resulted in enhanced tolerance of Arabidopsis thaliana to drought and salt stress and heightened the ABA sensitivity. Compared to wild-type (WT) plants, plants with overexpressed AtruLEA1 exhibited increased activities of antioxidant enzymes under drought stress. Meanwhile, the ROS level of transgenic Arabidopsis was significantly less than that of the WT. Additionally, the stoma density and stoma openness of AtruLEA1 Arabidopsis were higher compared to those in the WT Arabidopsis under salt and drought stress conditions, which ensures that the biomass and relative water content of transgenic Arabidopsis are significantly better than those of the WT. These results indicated that AtruLEA1 was involved in salt and drought stress tolerances by maintaining ROS homeostasis, and its expression was positively regulated by abiotic stress. These results indicate a positive role of AtruLEA1 in drought and salt stress and provide theoretical evidence in the direction of cultivating resistant plants. Full article

Plant growth and development require water, but excessive water hinders growth. Sesame (Sesamum indicum L.) is an important oil crop; it is drought-tolerant but sensitive to waterlogging, and its drought tolerance has been extensively studied. However, the waterlogging tolerance of sesame still has relatively few studies. In this study, two kinds of sesame, R (waterlogging-tolerant) and S (waterlogging-intolerant), were used as materials, and they were treated with waterlogging stress for 0, 24, 72, and 120 h. Physiological analysis showed that after waterlogging, sesame plants responded to stress by increasing the contents of ascorbate peroxidase (APX), glutathione (GSH), and some other antioxidants. The results of the multi-omics analysis of sesame under waterlogging stress revealed 15,652 (R) and 12,156 (S) differentially expressed genes (DEGs), 41 (R) and 47 (S) differentially expressed miRNAs (DEMis), and 896 (R) and 1036 (S) differentially accumulated metabolites (DAMs). The combined DEMi-DEG analysis that 24 DEMis regulated 114 DEGs in response to waterlogging stress. In addition, 13 hub genes and three key pathways of plant hormone signal transduction, glutathione metabolism, and glyoxylate and dicarboxylate metabolism were identified by multi-omics analysis under waterlogging stress. The results showed that sesame regulated the content of hormones and antioxidants and promoted energy conversion in the plant through the above pathways to adapt to waterlogging stress. In summary, this study further analyzed the response mechanism of sesame to waterlogging stress and provides helpful information for the breeding of plants for waterlogging tolerance and genetic improvement. Full article

A water deficit can significantly limit the sustainable production of plants, resulting in reduced growth, development, and flowering. The use of biostimulants improves plant stability and promotes growth under low-irrigation conditions. This study evaluated the effects of biostimulators on the growth, development, and flowering of tuberose (Polianthes tuberosa L.) under water-deficit conditions. This experiment was conducted using a completely randomized design with three replications in pots and eight treatments: four irrigation regimes (100%, 80%, 60%, and 40%), and four biostimulant treatments (foliar application of seaweed extract (SE) at concentrations of 500, 1000, and 2000 ppm; humic acid (HA) application at concentrations of 150, 300, and 600 ppm; inoculation of the bed with mycorrhiza; a control treatment without biostimulators). We measured the length, diameter, and fresh and dry weight of the flower pedicel; the number of leaves per plant; the fresh and dry weight of the leaves, stem, and root of each plant; and the content of photosynthetic pigments, phenol, proline, carbohydrates, and flavonoids. The results of this study showed that the growth and development of tuberoses were positively affected by different irrigation levels and biostimulants. The highest morphological characteristics were observed in plants irrigated at 100% field capacity. In contrast, the irrigation regime treatment of 40% of the field capacity combined with 600 mg/l of HA had the most detrimental effect on plant growth indicators. Findings suggest that application of 2000 ppm of SE biostimulant contributes to the mitigation of the negative effects of water deficit in tuberose production under greenhouse conditions as an irrigation water conservation strategy that can be exploited to maintain high yields. Full article

Healthy plant material that is uniform and genetically pure is essential for the successful raspberries production since it guarantees quality and consistent yields. A 4-year study (2018–2021) focused on raspberry cultivars “Meeker” and “Willamette”, which were propagated by tissue culture (MpP) and root suckering (RsP) methods in three irrigation regimes (IR1-100% ETc, IR2-50% ETc, and IR3-25% ETc). “Meeker” had longer primocanes, higher productivity, sweetness, soluble solids, and sugar content in IR1. Micropropagated plants demonstrated initially longer primocanes (177.9 cm in 2018 and 203.5 cm in 2019) and slightly better productivity compared to root-suckered plants. Over time, the growth rates of plants obtained by two vegetative propagation methods became similar. The IR1 irrigation regime maximized yields per floricane and meter of trellis in 2019 and 2021 (619.8 and 501.9 g and 2.5 and 2.0 kg, respectively), providing sufficient water for raspberry plants. IR1 improved primocane height in 2018 and 2021 (181.3 and 238.3 cm), fruiting lateral length (31 cm), and number of flowers per fruiting lateral (10.7) in 2021. In all experimental years, “Meeker” showed a high sweetness index (8.53, 11.28, and 9.36) due to high sugar and low acid content, but it was sensitive to water deficit. “Willamette” maintained high total anthocyanins and stable sugar content, which emphasizes its adaptability to different conditions. Both cultivars showed high antioxidant activity with variability across study years. Antioxidant activity peaked in 2019 under all irrigation regimes and remained stable in 2021. The cultivar “Meeker” excelled in vegetative growth, productivity, and fruit taste, making it suitable for obtaining high yields in a 100% ETc irrigation level. In contrast, “Willamette” is better suited for obtaining high-quality fruit under water-limited conditions. Full article