Search Results (1,590)

This study examines the effects of nitrogen-planting density interactions on stalk lodging resistance mechanisms and yield formation in spring maize (Zea mays L.), aiming to establish a theoretical framework for optimizing planting configurations to achieve high and stable yields in Shanxi Province. Using the maize variety Qiangsheng 192 as the experimental material, a split-plot field experiment was conducted from 2023 to 2024. Planting density served as the main plot, with three levels: 60,000 plants ha⁻¹ (M1, 6 plants m⁻², control), 75,000 plants ha⁻¹ (M2, 7.5 plants m⁻²), and 90,000 plants ha⁻¹ (M3, 9 plants m⁻²), each replicated three times. Nitrogen application rate was the subplot, with four treatments: N0 (0 kg ha⁻¹), N1 (90 kg ha⁻¹), N2 (180 kg ha⁻¹), and N3 (270 kg ha⁻¹). At the tasseling stage, agronomic traits and mechanical properties of the stalks were investigated. The activities of Phenylalanine Ammonia-Lyase (PAL), Tyrosine Ammonia-Lyase (TAL), and Cinnamyl Alcohol Dehydrogenase (CAD) in the stalks were measured at the big trumpet stage, tasseling stage, filling stage, and maturity stages, and yield was determined. The results showed that the M2 treatment achieved the highest yield, followed by M3, while M1 (control) had the lowest yield. Under the M2N2 configuration, the yield reached 13.55 Mg ha⁻¹, the highest recorded. As planting density increased, maize growth exhibited variations: the basal internodes elongated, mechanical properties declined, and the activities of PAL, TAL, and CAD enzymes decreased. Increased nitrogen application improved basal internode quality. Correlation analysis revealed that stalk mechanical properties were positively correlated with PAL, TAL, and CAD enzyme activities, which could both reflect the quality of the stalk. In conclusion, the M2N2 configuration is an optimal combination for enhancing maize yield, improving stalk mechanical properties, and increasing enzyme activity, making it suitable for large-scale application in the dryland spring maize areas of Shanxi Province. Full article

Calcium is essential for legume symbiotic nitrogen fixation, acting as both a nutrient and a signal. Yet, how varying calcium levels—from deficiency to toxicity—affect the soybean ‘root-nodule-stem’ balance has not been fully elucidated. To investigate this mechanism, a two-year sand culture experiment was conducted with three treatments: low calcium (0.1 mmol/L), moderate calcium (1 mmol/L), and high calcium (10 mmol/L), to systematically analyze their effects on soybean plant growth, nitrogenase activity, and nitrogen fixation capacity. The results indicated that the moderate calcium treatment supported the best root growth and nodule development, with both leghemoglobin (Lb) content and specific nitrogenase activity (SNA) reaching their peak levels. Low calcium stress significantly inhibited root elongation, while poor nodule development accompanied by a decrease in Lb content, thereby suppressing nitrogen fixation potential. In contrast to the low calcium treatment, although high calcium treatment inhibited root growth, it significantly increased the allocation of total plant dry matter to the root system. Under high calcium treatment, the ureide content in nodules increased significantly, whereas the ureide content in stems decreased substantially. This distributional imbalance suggests that high calcium obstructed the long-distance transport of nitrogen fixation products, subsequently leading to a significant decline in nitrogenase activity through a negative metabolic feedback mechanism. Calcium deficiency primarily resulted in structural impairments in nodule development, whereas high calcium induced functional inhibition by blocking ureide transport. Maintaining calcium homeostasis is important for ensuring efficient nitrogen fixation and source-sink balance in soybeans. Full article

Copper–aluminum layered composites offer a promising combination of high conductivity, light weight, and cost-effectiveness, making them attractive for applications in electric vehicles, electronics, and power transmission. However, achieving reliable interfacial bonding while avoiding excessive work hardening and brittle intermetallic formation remains a significant challenge. In this study, a Cu18150/Al1060/Cu18150 trilayer composite was fabricated through a three-stage high-temperature oxygen-free rolling process. Subsequently, the produced composite was subjected to annealing treatments to systematically investigate the effects of rolling passes, annealing temperature/time on interfacial evolution and mechanical behavior. Results indicate that rolling passes primarily influence interfacial topography and defect distribution. Fewer passes lead to wavy, mechanically bonded interfaces, while more passes improve flatness but reduce intermetallic continuity. Annealing temperature critically governs diffusion kinetics; temperatures up to 400 °C promote the formation of a uniform Al₂Cu layer, whereas 450 °C accelerates the growth of brittle Al₄Cu₉, thickening the intermetallic layer to 18 μm and compromising toughness. Annealing duration further modulates diffusion mechanisms, with short-term (0.5 h) treatments favoring defect-assisted diffusion, resulting in a porous, rapidly thickened layer. In contrast, longer annealing (≥1 h) shifts toward lattice diffusion, which densifies the interface but risks excessive brittle phase formation if prolonged. Mechanical performance evolves accordingly; as-rolled strength increases with the number of rolling passes, but at the expense of ductility. Annealing transforms bonding from a mechanical to a metallurgical condition, shifting fracture from delamination to collaborative failure. The identified optimal process, single-pass rolling followed by annealing at 420 °C for 1 h, yields a balanced interfacial structure of Al₂Cu, AlCu, and Al₄Cu₉ phases, achieving a tensile strength of 258.9 MPa and an elongation of 28.2%, thereby satisfying the target performance criteria (≥220 MPa and ≥20%). Full article

Background: The hairy ear (Eh) mutation in heterozygous mice (Eh/+) results in elongated and additional ear hairs, along with altered pinna morphology compared to wild-type (+/+) mice. Previous studies suggest that disruption of the Hoxc gene cluster caused by the Eh inversion influences the hair growth cycle. Methods: To elucidate the molecular basis of this phenotype, we performed RNA-seq analysis on ear tissues from four-week-old Eh/+ and +/+ mice and compared their transcriptomic profiles. Results: Differential expression analysis identified 2092 genes, and subsequent Gene Ontology (GO) and overrepresentation analysis revealed significant alterations in hair growth-related processes, including the hair cycle and canonical keratinization in Eh/+ ears. Notably, numerous hair keratin and keratin-associated protein (Krtap) genes were markedly upregulated in Eh/+ mice. Validation by quantitative real-time PCR confirmed increased expression of randomly selected keratin genes (Krt34, Krt39, Krt71, Krt81, Krt84) and keratin-associated proteins (Krtap4-16 and Krtap22-2). In contrast, epithelial keratin genes such as Krt2 and Krt14 were downregulated in Eh/+ ears. In addition, genes associated with hair follicle growth, Car6 and Gprc5d, showed elevated expression, while Dab2, a telogen–anagen transition marker linked to hair follicle stem cell activation, was slightly increased at the telogen stage in Eh/+ compared with +/+ mice. Conclusions: These findings provide new insights into the role of Hoxc cluster genes in orchestrating the expression of hair keratin and Krtap genes and highlight potential regulatory mechanisms underlying the hairy ear phenotype. Full article

The microstructure evolution law and the changes in mechanical properties of 442 ferritic stainless steel after annealing treatment at different temperatures are systematically investigated. The results show that, as the annealing temperature increases, the cold-rolled 442 ferritic stainless steel successively undergoes the process of recovery, recrystallization and grain growth, with the microstructure gradually changing from a fibrous to recrystallized structure, and the secondary phases, such as the Nb(C, N) phase, σ phase and Laves phase, precipitate. In terms of mechanical properties, the tensile strength, yield strength and Vickers hardness gradually decrease, while the elongation after fracture gradually increases. When the annealing temperature reaches 800 °C, the material exhibits the optimal comprehensive mechanical properties. The yield strength, tensile strength and elongation reach 371 MPa, 534 MPa and 31%, respectively, and the hardness is 175 HV. The fracture mode of the sample is mainly ductile fracture. EBSD analysis indicates that the strong Brass {110}<112> texture existing in the cold-rolled state gradually weakens with the annealing process, and the {111}<110> texture strengthens, thereby reducing the influence of unfavorable textures. The research results provide theoretical basis and data support for microstructure regulation and performance optimization of 442 ferritic stainless steel. Full article

Cadmium (Cd) is a toxic heavy metal that impairs plant growth and induces oxidative stress. In this study, we compared the physiological, biochemical, and molecular responses of two durum wheat (Triticum turgidum ssp. durum) cultivars, Razek and Chili, to Cd stress. Seedlings were exposed to 0, 5, and 50 µM Cd (Cd²⁺; supplied as CdCl₂) under controlled hydroponic and Petri assay conditions. Cd reduced radicle elongation, biomass accumulation, and water uptake in both cultivars, but the relative inhibition of growth was lower in Razek than in Chili, indicating a better capacity to maintain growth under Cd stress. This was accompanied by milder oxidative stress symptoms and more stable antioxidant enzyme activity, particularly for catalase (CAT) and ascorbate peroxidase (APX). Gene expression analyses revealed that Razek maintained a higher expression of antioxidant and stress-related genes under acute Cd stress, while Chili exhibited pronounced downregulation. Histochemical analyses showed increased H₂O₂ accumulation and lignin deposition in Chili roots, suggesting a stronger stress response. Notably, Chili also showed a sharp depletion of reduced glutathione (GSH) under high Cd concentrations, with limited upregulation of GSH synthesis and phytochelatin-related genes. Together, these findings indicate that Razek activates more efficient detoxification, redox regulation, and hormonal signaling pathways under Cd stress, indicating its potential suitability for cultivation in slightly Cd-contaminated soils. Full article

Water and nitrogen supply are key factors limiting the establishment of alpine plant seedlings and the efficiency of ecological restoration on the Tibetan Plateau. As an endemic shrub to Tibet, the morphological and physiological response mechanisms of Piptanthus nepalensis (Hook.) D. Don to coupled water and nitrogen stress remain poorly understood. This study employed a pot experiment with a completely randomized two-factor design, incorporating five water gradients (0–100% field capacity, FC) and five nitrogen levels (0–4 g·plant⁻¹ urea). The aim was to elucidate the regulatory mechanisms of water/nitrogen coupling on Piptanthus nepalensis growth, physiology, and morphogenesis. The results indicated the following: (1) A significant water/nitrogen coupling effect was observed, with optimal water/nitrogen combinations producing pronounced synergistic effects. Principal component analysis (PCA) revealed that the first two axes cumulatively explained 99.32% of the morphological variation. The W3N3 treatment (40–60% FC water + 2 g·plant⁻¹ nitrogen) exhibited optimal growth traits and maximum leaf elongation, establishing the optimal water and fertilizer management threshold for this species. (2) Confronted with two starkly contrasting stresses—drought (W4, W5) and waterlogging (W1)—plants adopted convergent “conservative” morphological adaptation strategies (significantly reduced leaf length and width) to lower metabolic expenditure. (3) Photosynthetic physiological analysis revealed that under extreme water deficiency (W5) or waterlogging (W1) stress, intercellular CO₂ concentration (Ci) paradoxically increased, indicating a shift in photosynthetic suppression mechanisms from stomatal limitation to non-stomatal limitation (metabolic injury). (4) The Mantel Test confirmed that photosynthetic physiological traits significantly drove morphological trait variation (p < 0.001), establishing a close feedback loop between “physiological function and morphological structure”. Conclusions: Moderate water deficit (40–60% FC) combined with moderate nitrogen fertilization (2 g·plant⁻¹) effectively alleviates non-stomatal limitation and releases morphological constraints, thereby promoting rapid growth in Piptanthus nepalensis. This study reveals the phenotypic plasticity and convergent adaptation mechanisms of Piptanthus nepalensis under water/nitrogen co-stress, providing precise water and fertilizer management guidelines for vegetation restoration in degraded ecosystems of Tibet. Full article

Cotton is an important cash crop globally. Cotton fiber is the main economic product of cotton plants. Phosphorus, as one of the essential nutrients, plays an important role in plant growth and development. However, few studies focus on phosphorus regulating fiber elongation. In this study, we used the cotton ovule culture system in vitro to explore the effects of various phosphorus levels on fiber and ovule growth, and screened for phosphorus-responsive factor, as well as revealed its action mechanism. The results indicated that fiber elongation was more sensitive than ovule growth to phosphorus deficiency. GhPHR1, a homolog of phosphate starvation response 1 (PHR1) in upland cotton, was significantly upregulated in fibers and ovules under phosphorus-deficient conditions. GhPHR1 directly binds to the promoter of the glucosylceramide synthase gene in cotton (GhGCS1) and positively regulates its expression. Overexpressing GhGCS1 enhanced phosphorus uptake and transport in cotton, increased phosphorus content in fiber cells, and promoted fiber cell elongation. Conversely, downregulating GhGCS1 reduced phosphorus content in fiber cells and suppressed fiber elongation. These findings demonstrate the importance of the GhPHR1-GhGCS1 molecular module in regulating fiber cell elongation and elucidate the molecular mechanism by which phosphorus influences fiber elongation. Full article

Traditional homogeneous copper foils suffer from a trade-off between strength and ductility, while gradient or heterogeneous structures are mostly based on deformation processing, making it difficult to achieve controllable construction within a thickness of ≤10 μm. This study aims to directly construct a layered structure with a “fine–coarse–fine” (A-B-A) gradient grain distribution, denoted as 3L-ABA in an 8 μm copper foil via direct current electrodeposition, which utilizes composite additives to regulate electrochemical polarization and nucleation modes. Through systematic characterization and mechanical testing, it was found that the 3L-ABA copper foil exhibits a tensile strength of 604 ± 18 MPa, an elongation of 3.6 ± 0.25%, and low surface roughness Rz of 0.46 μm. Microscopic mechanism analysis demonstrates that the gradient structure achieves synergistic strengthening and toughening through surface fine-grain strengthening, intermediate coarse-grain coordinated plastic deformation, combined with dislocation density and twin strengthening. Electrochemical tests confirm that Additive A (containing collagen, bis-(3-sulfopropyl)-disulfide (SPS), thiourea and 2-mercapto-5-benzimidazolesulfonic acid sodium salt (2M5S)) induces strong cathodic polarization, promoting instantaneous nucleation and grain refinement, whereas Additive B (containing collagen and bis-(3-sulfopropyl)-disulfide (SPS) shows weaker polarization and promotes grain growth. This research provides a scalable electrodeposition solution for the microstructural design and performance regulation of ultra-thin copper foils. Full article

Flammulina filiformis is the key industrial edible fungus that requires elevated CO₂ to promote the growth of long stipe and small pileus fruiting bodies. Heat shock transcription factors (HSFs) play vital roles in stress response and development regulation; yet the HSF gene family and its expression dynamics during fruiting body development in F. filiformis remain uncharacterized. This study aims to identify and characterize the HSF gene family in F. filiformis and to investigate their expression patterns during fruiting body development and in response to CO₂ treatments. In this study, 7 FfHSFs were identified, and their structures, sequence features, and phylogenetics were further analyzed. Expression patterns under CO₂ regulation were examined via qRT-PCR. The FfHSFs exhibited CDS lengths of 618–2298 bp, encoding 301–765 hydrophilic amino acids, with molecular weights ranging from 23.4 to 83.8 kDa and theoretical pI values between 4.75 and 9.15. All were predicted to be nuclear-localized. Cis-element analysis revealed motifs associated with growth regulation and stress responses such as low temperature, drought, and hypoxia. Phylogenetically, fungal HSFs were grouped into five clusters, with FfHSFs distributed across four. In this study, we examined the expression levels at four time points (0 h, 2 h, 12 h, and 36 h), under three different carbon dioxide concentrations (0.1%, 5%, and 20%) and in two types of tissues (pileus and stipe) for each six biological replicates. CO₂ treatments showed that 5% CO₂ significantly suppressed pileus expansion but not stipe elongation, while 20% CO₂ inhibited both. Under 20% CO₂ treatment, the pileus diameter decreased by approximately 40%, and simultaneously, the expression level of FfHSF1 decreased by about 70%. qRT-PCR indicated that FfHSF1 decreased with pileus expansion, whereas FfHSF4 increased. All FfHSFs were highly expressed in the stipe elongation zone. Elevated CO₂ down-regulated FfHSF1 in pileus and FfHSF6 in stipes. Based on these findings, it could be proposed that FfHSF1 and FfHSF6 might be candidate regulators in CO₂-mediated morphogenesis, providing insights into hormonal and environmental control of fruiting body development in F. filiformis. Full article

Argania spinosa L. Skeels is an ecological pillar of the arid zones of South-West Morocco, currently threatened by the drastic climate change. This study investigates the effect of the combined application of compost (C) and subsurface water retention technology (SWRT) on field performances of one-(1Y) and two-year-old (2Y) argan seedlings. A randomized field trial was performed with four treatments: Control, C, SWRT, and C + SWRT. We evaluated soil properties, growth, and physiology, alongside biochemical parameters including stress markers, compatible solutes, antioxidant enzyme activities, and secondary metabolites. The results reveal the significant effect of C and/or SWRT on argan seedlings performances, particularly in 1Y subjects. The C + SWRT strongly stimulated stem elongation (246% vs. 163%), stomatal conductance (75% vs. 99%), photosynthetic efficiency (18% vs. 11%), and chlorophyll a content (80% vs. 65%) in 1Y and 2Y seedlings, respectively, compared to their corresponding controls. Under the same treatment, malondialdehyde levels were significantly reduced by 37% in 1Y seedlings and 23% in 2Y seedlings. In addition, catalase activity and soluble sugar, protein, and polyphenol content increased by 38, 43, 26, and 21%, respectively, in the younger seedlings and by 53, 51, 18, and 19%, respectively, in the elder seedlings. In terms of soil health, C + SWRT significantly enhanced total organic carbon and matter, available phosphorus, and reduced electrical conductivity. In summary, the C + SWRT application significantly improved argan plant performances, with a particularly marked effect on 1Y seedlings, which makes this combination an alternative solution to enhance the resilience of the argan tree in the era of climate change and promote the success of the reforestation program. Full article

Clonal propagation often must incorporate heaters to warm stock plants and stabilize growth. This study investigates the impact that different temperature regimes for stock plants have on the rooting capacity of mini-cuttings derived therefrom. Experiments were conducted in growth chambers using two clones of Eucalyptus dunnii Maiden, with clone A’s rooting being moderately better that that of clone B in commercial production. Root primordia differentiation and elongation were faster in clone A than clone B. Stock plants were maintained for one month under two temperature conditions: Δ0 (26/26 °C day/night) and Δ10 (26/16 °C). The main results indicate that rooting significantly decreased with the reduction in nocturnal temperature. Clone A exhibited a 38% reduction in rooting, whereas clone B showed a more pronounced decrease of 65%. In cold nights, soluble carbohydrates at the cutting bases dropped by approximately 25% considering both clones, and overall foliar nutrients also decreased. Cutting base transcript profiles revealed that cold nights decreased the expression of efflux auxin transporter PIN1, increased expression of auxin catabolism-related enzyme DAO, and that expression of auxin nuclear receptor TIR1 remained stable. Fine management of clonal gardens by adjusting thermal conditions can optimize the physiological status of donor plants and enhance the rooting potential and establishment of the derived cuttings. Full article

Rice (Oryza sativa L.) root system plays a critical role in water and nutrient uptake, influencing overall plant growth and crop yield. In this study, we characterized the Osdrp2b mutant, which exhibits a short-root phenotype and was identified through map-based cloning. The Osdrp2b mutation was traced to the gene encoding a dynamin-related protein, and the mutant displayed reduced cell elongation and impaired cell division in the root tip. Further analysis revealed that ROS (reactive oxygen species) accumulation was elevated in the mutant roots, and treatment with ROS inhibitors restored root elongation in the Osdrp2b mutant, indicating that altered ROS homeostasis is associated with the phenotype. Transcriptomic analysis highlighted the differential expression of genes involved in cell wall organization and hydrogen peroxide catabolism. Agronomic evaluations of the Osdrp2b mutant demonstrated compromised shoot growth, reduced tiller number, and lower seed setting rates, indicating the impact of the mutation on rice yield. Overall, these results suggest that OsDRP2B is involved in regulating root growth, potentially through effects on ROS homeostasis and associated signaling networks. These findings provide a basis for future studies on improving rice root development and agronomic performance. Full article

DNA methylation regulates plant growth by modulating gene expression; however, its contribution to hormone responsiveness and photomorphogenesis remains only partially understood. We examined Arabidopsis thaliana DNA methylation mutants met1 and drm1, drm2, and cmt3 (ddc) under defined light regimes and following exogenous treatments with auxin, gibberellin, and the auxin transport inhibitor TIBA. Hypocotyl elongation and cotyledon expansion exhibited strong light dependency across all genotypes, with met1 seedlings developing a consistently reduced cotyledon area and ddc seedlings displaying impaired hypocotyl elongation under specific light qualities. Exogenous auxin inhibited growth in all genotypes, whereas GA₃ promoted elongation in hypocotyls and roots (by approximately 75–80% and 15–35%, respectively, in Col0 and met1), with ddc exhibiting delayed and non-linear dose-dependent sensitivity. Quantitative RT–PCR analysis revealed differential expression of genes involved in auxin transport (PIN1, PIN3, PIN7), auxin signalling (ARF7, IAA3, LAX3), circadian regulation (TOC1, LHY, CCA1), and light signalling (PIFs, HY5, HYH), supporting a link between DNA methylation status and coordinated regulation of hormone-, light-, and clock-controlled transcriptional networks. Together, these findings demonstrate that MET1- and DRM/CMT-dependent methylation pathways integrate epigenetic regulation with environmental and hormonal cues, modulating the intensity, timing, and organ specificity of growth responses, thereby fine-tuning growth plasticity during early Arabidopsis seedling development. Full article

Between 2022 and 2024, a severe branch dieback disease was observed affecting over 6% of sweet cherry trees of the ‘Tieton’ cultivar in commercial greenhouses in southern Liaoning Province, China. Symptoms primarily occurred at the top of young branches. At the early stage of disease onset, the lesions appeared as dark brown, irregularly shaped areas with a moist surface; as the disease progressed, these lesions turned dry and rotten, leading to tree decline symptoms in sweet cherry trees. Disease diagnosis was carried out in sweet cherry greenhouses across Liaoning Province, where 24 diseased samples were collected and 14 fungal isolates were obtained therefrom. Based on morphological traits, cultural characteristics, and multi-locus phylogenetic analyses of the internal transcribed spacer (ITS) region, beta-tubulin (TUB2) gene, and translation elongation factor 1-α (TEF1) gene, these isolates were identified as Botryosphaeria dothidea. Two representative isolates, namely zdcy-1 and zdcy-2, were selected for pathogenicity assays. Both mycelial plug and spore suspension inoculation methods confirmed the pathogenicity of the pathogen. The biological characteristic assays revealed that the optimal temperature range for the pathogen’s mycelial growth on PDA medium was 25–28 °C, and the optimal pH range was 6.0–8.0. This study improves the understanding of branch dieback disease in sweet cherry orchards in China, enriches the knowledge regarding the geographical distribution, host range, and infection sites of the pathogen, and provides novel insights for the management of sweet cherry diseases. Full article