Search Results (212)

Cucumbers (Cucumis sativus L.) are highly sensitive to cold, but grafting onto cold-tolerant rootstocks can enhance their low-temperature resilience. This study investigates the physiological and molecular mechanisms by which exogenous vitamin C (Vc) mitigates cold stress in grafted cucumber seedlings. Using cucumber ‘Chiyu 505’ as the scion and pumpkin ‘Chuangfan No.1’ as the rootstock, seedlings were grafted using the whip grafting method. In the third true leaf expansion stage, seedlings were foliar sprayed with Vc at concentrations of 50, 100, 150, and 200 mg L⁻¹. Three days after initial spraying, seedlings were subjected to cold stress (8 °C) for 3 days, with continued spraying. After that, morphological and physiological parameters were assessed. Results showed that 150 mg L⁻¹ Vc treatment was most impactive, significantly reducing the cold damage index while increasing the root-to-shoot ratio, root vitality, chlorophyll content, and activities of antioxidant enzymes (SOD, POD, CAT). Moreover, this treatment enhanced levels of soluble sugars, soluble proteins, and proline compared to control. However, 200 mg L⁻¹ treatment elevated malondialdehyde (MDA) content, indicating potential oxidative stress. For transcriptomic analysis, leaves from the 150 mg L⁻¹ Vc and CK treatments were sampled at 0, 1, 2, and 3 days of cold stress. Differential gene expression revealed that genes associated with photosynthesis (LHCA1), stress signal transduction (MYC2-1, MYC2-2, WRKY22, WRKY2), and antioxidant defense (SOD-1, SOD-2) were initially up-regulated and subsequently down-regulated, as validated by qRT-PCR. Overall, we found that the application of 150 mg L⁻¹ Vc enhanced cold tolerance in grafted cucumber seedlings by modulating gene expression networks related to photosynthesis, stress response, and the antioxidant defense system. This study provides a way for developing Vc biostimulants to enhance cold tolerance in grafted cucumbers, improving sustainable cultivation in low-temperature regions. Full article

Soil phosphorus (P) availability is an important determinant of productivity in Pinus massoniana (Masson pine) forests. The mechanistic bases governing the physiological and growth responses of Masson pine to varying soil P conditions remain insufficiently characterized. This study aims to decipher the adaptive strategies of Masson pine to different soil P levels, focusing on root morphological–architectural plasticity and the allocation dynamics of nutrient elements and photosynthetic assimilates. One-year-old potted Masson pine seedlings were exposed to four P addition treatments for one year: P0 (0 mg kg⁻¹), P1 (25 mg kg⁻¹), P2 (50 mg·kg⁻¹), and P3 (100 mg kg⁻¹). In July and December, measurements were conducted on seedling organ biomass, root morphological indices [root length (RL), root surface area (RSA), root diameter (RD), specific root length (SRL), and root length ratio (RLR) for each diameter grade], root architectural indices [number of root tips (RTs), fractal dimension (FD), root branching angle (RBA), and root topological index (TI)], as well as the content of nitrogen (N), phosphorus (P), carbon (C), and non-structural carbohydrates (NSCs) in roots, stems, and leaves. Compared with the P0 treatment, P2 and P3 significantly increased root biomass, root–shoot ratio, RL, RSA, RTs, RLR of finer roots (diameter ≤ 0.4 mm), nutrient accumulation ratio in roots, and starch (ST) content in roots, stems and leaves. Meanwhile, they decreased soluble sugar (SS) content, SS/ST ratio, C and N content, and N/P and C/P ratios in stems and leaves, as well as nutrient accumulation ratio in leaves. The P3 treatment significantly reduced RBA and increased FD and SRL. Our results indicated that Masson pine adapts to low P by developing shallower roots with a reduced branching intensity and promoting the conversion of ST to SS. P’s addition effectively alleviates growth limitations imposed by low P, stimulating root growth, branching, and gravitropism. Although a sole P addition promotes short-term growth and P uptake, it triggers a substantial consumption of N, C, and SS, leading to significant decreases in N/P and C/P ratios and exacerbating N’s limitation, which is detrimental to long-term growth. Under high-P conditions, Masson pine strategically prioritizes allocating limited N and SS to roots, facilitating the formation of thinner roots with low C costs. Full article

Anchote (Coccinia abyssinica) is a neglected high-potential food and nutrition security tuber crop in Ethiopia. Phenotyping core germplasm collections using agro-morphological and physiological markers is essential for effective crop improvement and utilization. A total of 282 anchote germplasms were profiled using six qualitative and twenty-six quantitative agro-morphological and physiological traits. Augmented Block Design was used for the experiment at the Debre Zeit Agricultural Research Center. The chi-square test and Shannon diversity index indicated the presence of substantial phenotypic variation and diversity among the accessions based on the predominant qualitative traits studied. The quantitative agro-morphological and physiological traits showed wider variability and ranges for the accessions. The broad-sense heritability and genetic advance as a percentage of the mean were notably high for quantitative traits such as root yield, vine length, and leaf area index. A significantly positive correlation was observed among agronomically important traits such as root yield and root diameter as well as root yield and leaf area. The principal component analysis for qualitative and quantitative traits found that ten components explained 72.2% of the variation for qualitative traits, whereas nine components accounted for 69.96% of the variation in quantitative traits. The primary contributors to the variations are traits such as root (shape, flesh color, and yield), leaf (color, length, diameter, area) and fruit (length, diameter, and weight). Further, the accessions were grouped into two and three clusters based on qualitative and quantitative traits, respectively, indicating that quantitative characters better differentiated among the accessions. Similarly, the tanglegram showed little similarity between the qualitative and quantitative agro-morphological and physiological traits in clustering the accessions. These findings indicate the presence of sizable trait variation among the accessions that can be exploited as a selection marker to design and facilitate conservation and breeding strategies of anchote. Full article

The tea tree root system is an important tissue for nutrient uptake, accumulation, and transport, and pH is an important environmental factor regulating the growth of tea tree (Camellia sinensis). However, the physiological and molecular mechanisms of how the tea tree root system responds to pH are unclear. In this study, Tieguanyin tea tree was used as the research object, and treated with different pH values to determine the morphological indexes of the tea plant root system and systematically study the physiological and molecular mechanisms of the effect of pH on the growth of the tea plant root system using transcriptomics in combination with metabolomics. The results showed that total root length, root surface area, root volume, total root tips, root fork number, and root crossing number of root crosses of the tea plant root system increased significantly (p < 0.05) with increasing pH. Transcriptome analysis showed that a total of 2654 characteristic genes were obtained in response to pH regulation in the root system of the tea plant, which were mainly enriched in six metabolic pathways. Metabolomics analysis showed that the metabolites with the highest contribution in differentiating tea plant responses to different pH regulations were mainly heterocyclic compounds, amino acids and derivatives, alkaloids, and flavonoids. Interaction network analysis showed that pH positively regulated the metabolic intensity of the MAPK signaling pathway (plant, plant hormone signal transduction, and RNA degradation pathway), positively regulated the content of the heterocyclic compound, amino acids and derivatives, and alkaloids, and positively regulated tea plant root growth. However, it negatively regulated ribosome, protein processing in the endoplasmic reticulum, and phenylpropanoid biosynthesis pathway intensity, and negatively regulated the flavonoid content. This study reveals the physiological and molecular mechanisms of the tea plant root system in response to pH changes and provides an important theoretical basis for the cultivation and management of tea plants in acidified tea plantations. Full article

Macrophytes are important components of aquatic ecosystems performing essential ecological functions. Their species composition and density reflect the ecological status of water bodies. The optimal ratio of morphological types of macrophytes is an important condition for preventing eutrophication. The aim of the study is to analyse the species composition, distribution, and density of macrophytes in the Vyzhyvka River (Ukraine) in a seasonal aspect (2023–2024) under constant physical and chemical characteristics of water. To assess the seasonal dynamics of water quality, changes in indicators in three representative areas were analysed. The MIR method of environmental indexation of watercourses was used to assess the ecological state of the river. The water quality in the Vyzhyvka River at all test sites corresponds to the second class of the “good” category with the trophic status of “mesotrophic”. This is confirmed by the identified species diversity, which includes 64 species of higher aquatic and riparian plants. Among the various morphological types of macrophytes, submerged rooted forms account for only 10.56% of the total species composition. To ensure a functional balance between submerged and other forms of macrophytes, a scientifically based approach is proposed, which involves the use of mineral raw materials of local origin, in particular, mining and quarrying wastes rich in silicon, calcium and other mineral components. The results obtained are of practical value for water management, environmental protection, and ecological reclamation and can be used to develop effective measures to restore river ecosystems. Full article

This study investigates the potential role of Acrocalymma dark septate endophytic (DSE) fungi in promoting the growth of Solanum lycopersicum (tomato). Recognized as important symbionts that enhance plant growth and resilience under stress, particularly Acrocalymma species, DSE fungi were the focus of this investigation. Specifically, four stains isolated from gramineous plant roots (Acrocalymma sp. E00677, Acrocalymma vagum E00690, Acrocalymma chuxiongense E01299A, and Acrocalymma chuxiongense E01299B) were examined. Morphological characteristics were observed using three different media, confirming typical DSE traits such as dark pigmentation and septate hyphae. Phylogenetic analysis using six genetic markers (ITS, LSU, SSU, tef1, rpb2, and tub2) placed the strains within the Acrocalymma genus. Co-culture test and physiological index measurements showed that all strains significantly enhanced root development, as evidenced by an increased root-to-shoot ratio and a higher number of lateral roots. Additionally, the Acrocalymma DSE strains elevated chlorophyll a, chlorophyll b, and total chlorophyll content, suggesting improved photosynthetic efficiency. Anthocyanin levels were also increased in the tomato leaves, indicating enhanced antioxidative defense mechanisms. Among these strains, Acrocalymma vagum E00690 exhibited the most substantial effect on root activity. The widespread presence of 325 Acrocalymma isolates from 25 countries underscores its broad ecological adaptability. These findings suggest that Acrocalymma DSE fungi positively influence tomato growth, with potential implications for improving plant resilience under environmental stress. This study highlights the importance of further exploring DSEs, particularly Acrocalymma fungi, to better understand their ecological roles in agricultural practices, particularly in tomato cultivation. Full article

Root-knot nematodes, Meloidogyne spp., are widespread phytoparasites that cause a significant reduction in the yield of tomato Solanum lycopersicum. In the Russian Federation, where the use of chemical nematicides is limited due to environmental and toxicological risks, the cultivation of resistant varieties and hybrids remains the most effective and environmentally safe method to control Meloidogyne. In the course of this study, the resistance screening of 20 tomato varieties/hybrids and 21 mutant lines from the collection of the FSBSI FRCBPP to M. hapla was carried out using a comprehensive approach that included morphological and biochemical analysis methods. Resistance was assessed by calculating the gall formation index, the degree of root system damage, and biochemical parameters of fruits—vitamin C content and titratable acidity. In addition, molecular screening was carried out using the SCAR marker Mi23 to identify the Mi-1.2 gene, known as a key factor in resistance to a number of Meloidogyne spp. Although Mi-1.2 is not typically associated with resistance to M. hapla, all genotypes carrying this gene showed phenotypic resistance. This unexpected correlation suggests the possible involvement of Mi-associated or parallel mechanisms and highlights the need for further investigation into noncanonical resistance pathways. It was found that when susceptible genotypes were infected with M. hapla, there was a tendency for the vitamin C content to decrease, while resistant lines retained values close to the control. The presence of the Mi-1.2 gene was confirmed in 9.5% of samples. However, the phenotypic resistance of some lines, such as Volgogradets, which do not contain a marker for the Mi-1.2 gene, indicates a polygenic nature of resistance, alternative genetic mechanisms, or the possible influence of epigenetic mechanisms. The obtained data highlight the potential of using the identified resistant genotypes in breeding programs and the need for further studies of the molecular mechanisms of resistance, including the search for new markers specific to M. hapla, to develop effective strategies for tomato protection in sustainable agriculture. Full article

The promising field of low-temperature plasma treatment, known for its non-invasive and environmentally sustainable nature, is being actively investigated for its ability to enhance germination, emergence, yield, and overall plant development in a broad spectrum of crops. For gene bank requirements, low-temperature plasma technologies can also improve germination parameters and promote the development seeds suitable for long-term storage. Seeds from four selected cultivars of wheat, oats, flax, and rapeseed stored in the gene bank for 1, 10, and 20 years were subjected to plasma treatments for 20, 25, and 30 min. The study evaluated the mean root and shoot length, root–shoot ratio, and seedling vigour index. Additionally, the malondialdehyde level, total polyphenol content, total flavonoid content, and total antioxidant capacity were analysed. Plasma treatment displayed varying effects on the morphological characteristics and antioxidant activity of the tested cultivars, which were influenced by treatment duration and cultivar. A positive effect of plasma treatment on seedling length, seedling vigour index, and root–shoot ratio was observed in flax cultivar ‘N-9/62/K3/B’ in all periods and in variants T2 and T3. Conversely, the wheat cultivar ‘Granny’ showed variable results, and the oat cultivar ‘Risto’ showed variable negative results in regards to mean root length and mean shoot length after plasma treatment. The indicators of oxidative stress and antioxidant capacity were affected in all the cultivars studied. A positive effect of plasma treatment on these indicators was observed in the wheat cultivar ‘Granny’, while flax cultivar ‘N-9/62/K3/B’ exhibited inconsistent results. While in cereals, a decrease in malondialdehyde content after plasma treatment was associated with an increase in polyphenol and flavonoid content as the treatment duration increased, small-seeded species responded somewhat differently. The rapeseed cultivar ‘Skrivenskij’ and flax cultivar ‘N-9/62/K3/B’ showed an increase in polyphenol and flavonoid content following a decrease in malondialdehyde levels. This study highlights the potential of low-temperature plasma treatment for long-term-stored seeds and its applicability to plant genetic resources. The findings emphasize the need for the further optimization of low-temperature plasma treatment conditions for different plant species and cultivars. Full article

Soil salinization limits global agricultural sustainability, and extensive areas of saline–alkaline soils on the Qinghai–Tibet Plateau remain underutilized. Against this backdrop, this study evaluated the effects and ecological regulatory mechanisms of potassium fulvate (PF) application on oat (Avena sativa L.) growth, soil properties, and rhizosphere microbial communities in the saline–alkali soils of the Qaidam Basin. The results showed that PF significantly enhanced both aboveground and belowground biomass and improved root morphological traits, with the higher application rate (150 kg·hm⁻²) showing superior performance. PF also effectively improved soil nutrient conditions (organic matter, ammonium nitrogen, and potassium), reduced the integrated salinity–alkalinity index, significantly optimized the composition of rhizosphere soil cations (increased K⁺ and Ca²⁺; decreased Na⁺ and Mg²⁺), and induced a marked reshaping of the composition and structure of rhizosphere microbial communities. Notably, microbial β-diversity exhibited a significant regulatory effect on the comprehensive growth of oats. Structural equation modeling (SEM) revealed that PF primarily promoted oat growth indirectly by improving soil physicochemical properties (direct effect = 0.94), while the microbial community structure served as a synergistic ecological mediator. This study clarifies the regulatory mechanisms of PF in oat cultivation under alpine saline–alkali conditions, providing both theoretical and practical support for improving soil quality, enhancing forage productivity, and promoting sustainable agriculture in cold regions. Full article

To identify seedling traits closely associated with drought resistance and to screen for drought-tolerant germplasm, 202 cotton varieties (lines) were evaluated under controlled indoor conditions using a nutrient soil cultivation method. Seedling-stage traits measured included plant height, cotyledon node diameter, true leaf number, chlorophyll content, and fresh and dry biomass of both shoots and roots. Drought resistance was assessed using drought resistance coefficients for each trait, followed by descriptive statistics, principal component analysis (PCA), partial correlation analysis, and comprehensive evaluation via the entropy weight method. PCA and partial correlation analysis revealed that plant height, cotyledon node diameter, aboveground fresh weight, and underground fresh weight were strongly associated with drought resistance at the seedling stage. The comprehensive drought resistance index (D-value) classified the 202 cotton lines into four categories: highly drought-resistant, moderately drought-resistant, drought-sensitive, and highly drought-sensitive. Physiological assays indicated that malondialdehyde (MDA) content in drought-resistant lines first increased and then declined with prolonged drought stress, while it continued to increase in sensitive lines. In contrast, proline (Pro) content and superoxide dismutase (SOD) activity increased steadily in drought-resistant lines but showed negligible changes in sensitive lines. These four morphological traits and three physiological indicators represent reliable criteria for evaluating drought resistance in cotton seedlings. Four highly drought-resistant and thirteen moderately drought-resistant lines were identified, providing valuable germplasm for genetic improvement of drought tolerance in cotton. Full article

Maternal hyperglycemia during pregnancy poses significant health risks to both mother and fetus. Although gestational diabetes mellitus (GDM) is mainly characterized by insulin resistance, severe hyperglycemia may also result from impaired pancreatic function. This study evaluates the therapeutic potential of pandan (Pandanus amaryllifolius) root and teak (Tectona grandis) leaf extracts in managing streptozotocin (STZ)-induced maternal hyperglycemia in pregnant rats, compared to metformin. Methods: Pregnant rats were administered STZ (60 mg/kg) on gestation day 5. Treatments with metformin (300 mg/kg), pandan extract (low, medium, high doses), and teak extract (low, medium, high doses) were given from gestation day 7 to 21. The key parameters included the maternal blood glucose, insulin levels, pancreatic morphology, fetal and placental outcomes, and gas chromatography/mass spectrometry (GC/MS) phytochemical profiling. GC/MS analysis identified 2,3-butanediol and propanoic acid derivatives as major compounds in pandan, while teak contained catavic acid and methyl copalate. The high-dose pandan extract significantly reduced the maternal blood glucose (p < 0.05), improved the insulin levels and pancreatic mass index, and increased the number of live fetuses, with effects comparable to metformin. The teak extract showed milder improvements. The pandan extract demonstrated dose-dependent antidiabetic potential in this STZ-induced model. Future studies should evaluate these effects in insulin-resistance-based GDM models. Full article

This paper focuses on the coupling relationships between the optical constants (n: refractive index; k: extinction coefficient) and Mueller matrix elements, as well as between the morphological parameters (σ: root mean square roughness; τ: correlation length) and Mueller matrix elements, of randomly micro-rough surfaces. The electromagnetic response of randomly micro-rough surfaces was simulated by the finite-difference time-domain method, so that the rough surfaces’ reflection coefficients of incident light in the p and s directions could be obtained. According to the formula for the Jones-to-Mueller matrix conversion, we obtained a 4 × 4 Mueller matrix of rough surfaces. The simulation method was validated with experimental results measured by Mueller matrix spectroscopic ellipsometry. It was found that the Mueller matrix element m₁₂ has great potential to invert the optical constants of the rough surfaces, whose refractive indices, n, and extinction coefficients, k, are in the ranges of 0 ≤ n ≤ 4 and 0 ≤ k ≤ 10, respectively. The Mueller matrix element m₃₄ is proportional to the morphological parameters σ/λ (λ: incident wavelength) or σ/τ. Moreover, the expressions (S + β₂) ∝ σ/λ and (S + β₂) ∝ σ/τ can be applied to predict the morphologies of rough surfaces within morphological parameter ranges of 0.003 ≤ σ/λ ≤ 0.015 and 0.125 ≤ σ/τ ≤ 0.75. This research signifies a key step toward the ability to invert the morphological parameters or optical constants of micro-rough surfaces through a Mueller matrix. Full article

Urban vulnerability creates structural imbalances, leading to unsafe conditions and urban decline. One of the key root causes of urban vulnerability is significant changes in urban layout morphology, which significantly influences the determination of accessibility potential, causing some areas to grow while others decline. This study aims to examine the morphological structural factors that influenced physical vulnerability, with a focus on commercial buildings, which were affected by the transformation of urban structure resulting from the layout and connectivity of the transportation network at the global, local, and community levels, depending on their location; these factors contribute to spatial vulnerability in varying degrees. This study applied an indicator-based quantitative research methodology, constructing a Physical Vulnerability Index (PVI) by using Principal Component Analysis (PCA) to create new factors or components and compare physical vulnerability levels across different areas. The research findings found that the most influential morphological structural factor on physical vulnerability was micro-level morphology, primarily due to the relationship between the configuration of space and the level of usage popularity. The second most influential factor is macro-level morphology, resulting from the relationship between the accessibility potential of urban-level and neighborhood-level transportation networks. Full article

Ammonium greatly influences nutrient partitioning and root architecture, particularly in the tuberous crops where assimilate translocation is critical for yield formation. However, relatively few studies have systematically delved into the physiological and molecular mechanisms of ammonium on assimilate translocation and root growth in sweetpotato (Ipomoea batatas Lam.). In this study, we investigated the morphological, physiological, and molecular effects of different concentrations of ammonium (0, 0.5, 1.0, 3.0, 5.0 mM) on the growth of the Sushu16 variety in the root-swelling stage. The plant weight and leaf area index of Sushu16 seedlings exhibited a progressive increase with elevated ammonium levels. However, the weight, volume, and number of storage roots (SRs) displayed a trend of a rapid rise and substantial decline, peaking at 1 mM ammonium. Similarly, the chlorophyll content, photosynthetic rate, and stomatal conductance were significantly increased with 1 mM ammonium treatment. Further, the contents of CK, ABA, and IAA increased first and then decreased, reaching a maximum at 1 mM ammonium. Notably, the “down then up” trend of sucrose content in leaves and stems contrasted with the fall–rise pattern of starch content in SRs at 1 mM ammonium. Furthermore, we screened 34 significant DEGs involved in photosynthesis, starch biosynthetic processes, and hormone signal pathway in SRs by RNA-Seq. All the results indicated that 1 mM ammonium had a promotive effect on source–sink conversion and SR production in Sushu16, which highlights potential targets for breeding or agronomic strategies to optimize yield formation in sweetpotato. Full article

Cowpea (Vigna unguiculata (L.) Walp.) is a vital legume crop recognized for its nutritional value and adaptability to various growing conditions. However, exposure of cowpea to drought stress during the early growth stages can significantly restrict growth and yield potential. Therefore, identifying cowpea genotypes tolerant to drought during early growth and development is essential for maintaining yield potential. This study characterized 15 diverse cowpea genotypes for various physiological, pigment, and morphological traits that may contribute to drought tolerance. At the V2 stage, the cowpea genotypes were subjected to two moisture regimes: control (100% irrigation) and drought (50% irrigation) for 22 days to assess trait responses and their relationship to drought tolerance. Drought-stressed plants decreased stomatal conductance by 79%, negatively correlating with a 2.9 °C increase in canopy temperature. Under drought, the photochemical reflectance index (PRI) was strongly associated with the quantum yield of PSII and electron transport rate. Shoot biomass decreased by 51% and root biomass by 32% under drought. Leaf area and shoot weight were correlated with root traits such as total length, surface area, and weight. Among all genotypes, 280785-11 and UCR 1004 demonstrated superior rooting vigor under drought, emphasizing their efficiency in resource utilization. These findings highlight the relevance of utilizing drought-adaptive traits to improve early-season drought tolerance. Full article