Search Results (1,343)

Root phenology significantly influences ecosystem processes yet remains poorly characterized across biomes. This study synthesized data from 59 studies spanning Arctic to tropical ecosystems to identify woody plants root phenological patterns and their environmental drivers. The analysis revealed distinct climate-specific patterns. Arctic regions had a short growing season with remarkably low temperature threshold for initiation of root growth (0.5–1 °C). Temperate forests displayed pronounced spring-summer growth patterns with root growth initiation occurring at 1–9 °C. Mediterranean ecosystems showed bimodal patterns optimized around moisture availability, and tropical regions demonstrate seasonality primarily driven by precipitation. Root-shoot coordination varies predictably across biomes, with humid continental ecosystems showing the highest synchronous above- and belowground activity (57%), temperate regions exhibiting leaf-before-root emergence (55%), and Mediterranean regions consistently showing root-before-leaf patterns (100%). Winter root growth is more widespread than previously recognized (35% of studies), primarily in tropical and Mediterranean regions. Temperature thresholds for phenological transitions vary with climate region, suggesting adaptations to environmental conditions. These findings provide a critical, region-specific framework for improving models of terrestrial ecosystem responses to climate change. While our synthesis clarifies distinct phenological strategies, its conclusions are drawn from data focused primarily on Northern Hemisphere woody plants, highlighting significant geographic gaps in our current understanding. Bridging these knowledge gaps is essential for accurately forecasting how belowground dynamics will influence global carbon sequestration, nutrient cycling, and ecosystem resilience under changing climatic regimes. Full article

This study analyzed the heavy metal tolerance and chromium reduction and the potential of plant growth to promote Rhizobium sp. OS-1. By genetic makeup, the Rhizobium strain is nitrogen-fixing and phosphate-solubilizing in metal-contaminated agricultural soil. Among the Rhizobium group, bacterial strain OS-1 showed a significant tolerance to heavy metals, particularly chromium (900 µg/mL), zinc (700 µg/mL), and copper. In the initial investigation, the bacteria strains were morphologically short-rod, Gram-negative, appeared as light pink colonies on media plates, and were biochemically positive for catalase reaction and the ability to ferment glucose, sucrose, and mannitol. Further, bacterial genomic DNA was isolated and amplified with the 16SrRNA gene and sequencing; the obtained 16S rRNA sequence achieved accession no. HE663761.1 from the NCBI GenBank, and it was confirmed that the strain belongs to the Rhizobium genus by phylogenetic analysis. The strain’s performance was best for high hexavalent chromium [Cr(VI)] reduction at 7–8 pH and a temperature of 30 °C, resulting in a total decrease in 96 h. Additionally, the adsorption isotherm Freundlich and Langmuir models fit best for this study, revealing a large biosorption capacity, with Cr(VI) having the highest affinity. Further bacterial chromium reduction was confirmed by an enzymatic test of nitro reductase and chromate reductase activity in bacterial extract. Further, from the metal biosorption study, an Artificial Neural Network (ANN) model was built to assess the metal reduction capability, considering the variables of pH, temperature, incubation duration, and initial metal concentration. The model attained an excellent expected accuracy (R² > 0.90). With these features, this bacterial strain is excellent for bioremediation and use for industrial purposes and agricultural sustainability in metal-contaminated agricultural fields. Full article

Melastoma dodecandrum is primarily propagated through stem cuttings, which limits genetic variation and constrains breeding efforts. To overcome this limitation and facilitate molecular breeding, the establishment of a reliable and efficient regeneration system is essential. This study investigated the effects of plant growth regulators (PGRs) and culture media on the in vitro regeneration system of M. dodecandrum. The highest rate of callus induction (96.67%) was achieved when sterile leaf explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 2.00 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.50 mg·L⁻¹ 6-benzylaminopurine (6-BA). For callus differentiation, the optimal formulation of MS + 2.0 mg·L⁻¹ 6-BA + 0.5 mg·L⁻¹ naphthylacetic acid (NAA) resulted in a differentiation frequency of 83.33%. The optimal PGR combinations for shoot proliferation were 1.5 mg·L⁻¹ 6-BA + 0.1 mg·L⁻¹ NAA and 0.5 mg·L⁻¹ 6-BA + 0.2 mg·L⁻¹ NAA. The optimal rooting media were MS medium supplemented with 0.1, 0.2, or 0.5 mg·L⁻¹ indole-3-butyric acid (IBA) or 1/2MS medium supplemented with 0.1 mg·L⁻¹ IBA. Additionally, this study investigated the dynamic changes in endogenous hormones during the regeneration process. The levels and ratios of hormones, including gibberellin (GA₃), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (ZT), collectively regulated the regeneration process. Elevated levels of ABA and GA₃ may promote callus initiation as well as the growth and development of adventitious roots during the early induction stage. Reduced levels of ABA and IAA favored callus differentiation into shoots, whereas elevated GA₃ levels facilitated proliferation of adventitious shoots. Throughout the regeneration process, fluctuations in ZT levels remained relatively stable. This study successfully established an in vitro regeneration system for M. dodecandrum using leaf explants, providing theoretical guidance and technical support for further molecular breeding efforts, genetic transformation, and industrial development. Full article

Silver nanoparticles (AgNPs), iron oxide nanoparticles (Fe₂O₄NPs), and multiwalled carbon nanotubes (MWCNTs) are widely used in various applications, such as biomedicine, environmental remediation, and agriculture. In addition, these nanomaterials can affect the production of bioactive compounds in plants that have pharmacological activities. In the current study, the in vitro plant cultures of Chinese lobelia (Lobelia chinensis Lour.) were established in MS medium and treated with 0, 12.5, 25, 37.5, and 50 mg L⁻¹ AgNPs or Fe₂O₄NPs, or MWCNTs. Initially, plants were grown for four weeks without any elicitors, and after that, the cultures were treated with nano-elicitors for one week. After five weeks, the effects of nano-elicitors were estimated on growth, total phenolic, flavonoids, polyacetylenes, and ABTS/DPPH/FRAP antioxidant activity was investigated. The results showed that lower levels of AgNPs (25 mg L⁻¹), Fe₂O₄NPs (25 mg L⁻¹), and MWCNTs (12.5 mg L⁻¹) favored the accumulation of fresh and dry biomass. Whereas, 37.5 mg L⁻¹ AgNPs, 25 mg L⁻¹ Fe₂O₄NPs, and 37.5 mg L⁻¹ MWCNTs enhanced the accumulation of total phenolics, flavonoids, specific phenolic compounds including chlorogenic acid, catechin, phloretic acid, coumaric acid, salicylic acid, naringin, myricetin, linarin, and polyacetylenes viz. lobetylonin and lobetyolin in higher concentrations. The plant extracts elicited by nanomaterials also depicted very good antioxidant activities according to ABTS, DPPH, and FRAP assays. These results suggest that specific nanomaterials, and at specific levels, could be used for the production of bioactive compounds from shoot cultures of Chinese lobelia. Full article

Strawberry planting requires different amounts of soil water-holding capacity and fertilizer at different growth stages. Determining the stages of strawberry growth has important guiding significance for irrigation, fertilization, and picking. Quick and accurate identification of strawberry plants at different stages can provide important information for automated strawberry planting management. We propose an improved multistage identification model for strawberry based on the YOLOv9 algorithm—the ASHM-YOLOv9 model. The original YOLOv9 showed limitations in detecting strawberries at different growth stages, particularly lower precision in identifying occluded fruits and immature stages. We enhanced the YOLOv9 model by introducing the Alterable Kernel Convolution (AKConv) to improve the recognition efficiency while ensuring precision. The squeeze-and-excitation (SE) network was added to increase the network’s capacity for characteristic derivation and its ability to fuse features. Haar wavelet downsampling (HWD) was applied to optimize the Adaptive Downsampling module (Adown) of the initial model, thereby increasing the precision of object detection. Finally, the CIoU function was replaced by the Minimum Point Distance based IoU (MPDIoU) loss function to effectively solve the problem of low precision in identifying bounding boxes. The experimental results demonstrate that, under identical conditions, the improved model achieves a precision of 97.7%, a recall of 97.2%, mAP50 of 99.1%, and mAP50-95 of 90.7%, which are 0.6%, 3.0%, 0.7%, and 7.4% greater than those of the original model, respectively. The parameters, model size, and floating-point calculations were reduced by 3.7%, 5.6% and 3.8%, respectively, which significantly boosted the performance of the original model and outperformed that of the other models. Experiments revealed that the model could provide technical support for the multistage identification of strawberry planting. Full article

Oncidium has an important market value, with important high-grade cut orchids and potted flowers on the flower market. In the Oncidium cut flowers production industry, there is a common phenomenon that the development of vegetative buds disrupts the normal generation cycle of the inflorescence induction, so-called “bud jumping”. In this study, vegetative bud differentiation and flower bud differentiation were divided into three stages, namely, the initial stage of differentiation, the leaf primordial/flower primordial differentiation stage, and the late stage of leaf bud/flower bud differentiation, as observed by paraffin sectioning. Secondly, we analyzed the differences between the vegetative buds of “bud jumping” plants and the flower buds of normal flowering plants by transcriptome sequencing. The transcriptome analysis results revealed significant differences among plant signaling pathways, particularly in gibberellins, auxins, and cytokinins, which play important roles in this phenomenon’s formation. In conjunction with the transcriptome analysis, the researchers conducted field experiments by applying plant growth regulators on the newborn pseudobulb of young Oncidium plants measuring approximately 49 mm in length. The results showed that the treatment groups of 100 mg/L of gibberellic acid (GA₃) and 100 mg/L GA₃ + 10 mg/L 6-Benziladenine (6-BA) exhibited the highest rate of flower bud differentiation instead of the least “bud jumping” phenomenon, and the “bud jumping” phenomenon was significantly reduced under 25 mg/L, 50 mg/L, and 75 mg/L 3-indoleacetic acid (IAA) treatments. The application of exogenous gibberellins, cytokinins, and auxins can effectively reduce the occurrence of “bud jumping”. Full article

Amomum villosum Lour., a perennial medicinal plant in the Zingiber genus, usually requires approximately 3–4 years of vegetative growth from seed germination to first fruiting, resulting in high initial investment costs and a prolonged revenue cycle, which pose significant challenges to the industry’s sustainable development. Our research team observed a distinct premature fruiting phenomenon in A. villosum. We investigated the regulatory mechanisms underlying premature fruiting in A. villosum by identifying the key differentially expressed genes (DEGs) and metabolic pathways governing the premature fruiting (Precocious) and typical plants (CK) of the ‘Yunsha No.8’ cultivar. Transcriptomic sequencing (RNA-seq) and bioinformatic analyses were performed using the DNBSEQ^TM platform. The sequencing generated 29.0 gigabases (Gb) of clean data, and 115,965 unigenes were identified, with an average length of 1368 bp. Based on the sequencing results, 1545 DEGs were identified. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were annotated for these DEGs. This study identifies phytohormone signaling, carbohydrate and lipid metabolism, and polysaccharide degradation as critical pathways controlling premature fruiting in A. villosum. Six randomly selected DEGs were validated using real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and the results corroborated the transcriptome data, confirming their reliability. This study lays the foundation for the elucidation of the molecular mechanisms and metabolic pathways driving premature fruiting in A. villosum. Full article

The advance of the soil desertification process and water salinisation hinders reforestation actions in the Brazilian semiarid region due to the negative effects on the initial establishment of seedlings. Knowledge of potential species for overcoming the problems of soil and water salinity is of broad interest. This study evaluated the growth of seedlings of the species Handroanthus impetiginosus and Handroanthus spongiosus subjected to the combined stresses of salinity and water deficit. The species were subjected to three water depths (WDs): WD1—50%, WD2—75% and WD3—100% of reference evapotranspiration, and four salinity levels (SL): SL1—0.27 dS m⁻¹, SL2—2.52 dS m⁻¹, SL3—6.35 dS m⁻¹ and SL4—7.38 dS m⁻¹. Biometric data, including plant height, number of leaves, collar diameter and biomass, was obtained. The results showed that H. impetiginosus was more tolerant of the conditions analysed. The species showed greater sensitivity to salt stress, which reduced growth and dry biomass accumulation by up to 98%. Increased water deficit reduced height, collar diameter, number of leaves, root biomass and total biomass. We propose that the optimal water depth for both species is 100% of the reference evapotranspiration. Full article

Nitrogen (N) critically regulates wheat growth and grain quality, yet the molecular mechanisms underlying foliar nitrogen application remain unclear. This study evaluated the effects of foliar nitrogen application (12.25 kg ha⁻¹) on the growth, grain yield, and quality of spring wheat, as well as its molecular mechanisms. The results indicated that N was absorbed within 3 h post-application, with leaf nitrogen concentration peaking at 12 h. The N treatment increased whole-plant dry matter accumulation and grain protein content by 11.34% and 6.8%, respectively. Amino acid content peaked 24 h post-application, increasing by 25.3% compared to the control. RNA-sequencing analysis identified 4559 and 3455 differentially expressed genes at 3 h and 24 h after urea treatment, respectively, these DEGs being primarily involved in nitrogen metabolism, photosynthetic carbon fixation, amino acid biosynthesis, antioxidant systems, and nucleotide biosynthesis. Notably, the plastidic glutamine synthetase gene (GS2) is crucial in the initial phase of urea application (3 h post-treatment). The pronounced downregulation of GS2 initiates a reconfiguration of nitrogen assimilation pathways. This downregulation impedes glutamine synthesis, resulting in a transient accumulation of free ammonia. In response to ammonia toxicity, the leaves promptly activate the GDH (glutamate dehydrogenase) pathway to facilitate the temporary translocation of ammonium. This compensatory mechanism suggests that GS2 downregulation may be a key switch that redirects nitrogen metabolism from the GS/GOGAT cycle to the GDH bypass. Additionally, the upregulation of the purine and pyrimidine metabolic routes channels nitrogen resources towards nucleic acid synthesis, and thereby supporting growth. Amino acids are then transported to the seeds, culminating in enhanced seed protein content. This research elucidates the molecular mechanisms underlying the foliar response to urea application, offering significant insights for further investigation. Full article

The SCARECROW (SCR) transcription factor governs cell-type patterning in plant roots and Kranz anatomy of leaves, serving as a master regulator of root and shoot morphogenesis. Foxtail millet (Setaria italica), characterized by a compact genome, self-pollination, and a short growth cycle, has emerged as a C₄ model plant. Here, we revealed two SCR paralogs in foxtail millet—SiSCR1 and SiSCR2—which exhibit high sequence conservation with ZmSCR1/1h (Zea mays), OsSCR1/2 (Oryza sativa), and AtSCR (Arabidopsis thaliana), particularly within the C-terminal GRAS domain. Both SiSCR genes exhibited nearly identical secondary structures and physicochemical profiles, with promoter analyses revealing five conserved cis-regulatory elements. Robust phylogenetic reconstruction resolved SCR orthologs into monocot- and dicot-specific clades, with SiSCR genes forming a sister branch to SvSCR from its progenitor species Setaria viridis. Spatiotemporal expression profiling demonstrated ubiquitous SiSCR gene transcription across developmental stages, with notable enrichment in germinated seeds, plants at the one-tip-two-leaf stage, leaf 1 (two days after heading), and roots during the seedling stage. Co-expression network analysis revealed that there is a correlation between SiSCR genes and other functional genes. Abscisic acid (ABA) treatment led to a significant downregulation of the expression level of SiSCR genes in Yugu1 roots, and the expression of the SiSCR genes in the roots of An04 is more sensitive to PEG6000 treatment. Drought treatment significantly upregulated SiSCR2 expression in leaves, demonstrating its pivotal role in plant adaptation to abiotic stress. Analysis of heterologous expression under the control of the 35S promoter revealed that SiSCR genes were expressed in root cortical/endodermal initial cells, endodermal cells, cortical cells, and leaf stomatal complexes. Strikingly, ectopic expression of SiSCR genes in Arabidopsis led to hypersensitivity to ABA, and ABA treatment resulted in a significant reduction in the length of the meristematic zone. These data delineate the functional divergence and evolutionary conservation of SiSCR genes, providing critical insights into their roles in root/shoot development and abiotic stress signaling in foxtail millet. Full article

Seed treatments with insecticides are important tools for managing corn stunting disease complex (CSDC) transmitted by Dalbulus maidis (Hemiptera: Cicadellidae) by reducing the initial leafhoppers’ population and, consequently, the risk of pathogen transmission. We evaluated the effect of insecticides used in seed treatment on both healthy and spiroplasma-infected leafhoppers, the persistence of the seed treatment effect on disease symptom severity, and its impact on corn productivity. At the V2 stage, imidacloprid/thiodicarb was the most effective, resulting in 100% mortality of healthy leafhoppers and 85.7% mortality of infective ones, thus preventing spiroplasma transmission. Thiamethoxam and methomyl + fipronil/thiamethoxam showed a high total mortality after 72 h, but only for the infective leafhoppers, with a total mortality of healthy leafhoppers around 40%, reducing the number of plants with symptoms by 80% and 90%, respectively. Our results prove that there is a difference between the chemical molecules and that the infected leafhoppers are more susceptible. Insecticide seed treatment was effective until the V2 growth stage, and imidacloprid/thiodicarb was the most effective product tested. Infective leafhoppers were more susceptible to insecticide seed treatments, and the infestation by the corn leafhopper carrying spiroplasma in the early stages of plant development heavily reduced corn yield. Full article

Greenhouses are crucial for maintaining an ideal temperature and humidity level for plant growth; however, attaining ideal levels remains a challenge. Energy-efficient and sustainable alternatives are needed because traditional temperature/humidity control practices and vapor compression air conditioning systems depend on climate conditions and harmful refrigerants. Advanced alternative technologies like evaporative cooling and desiccant dehumidification have emerged that maintain the ideal greenhouse temperature and humidity while using the least amount of energy. This study reviews direct evaporative cooling, indirect evaporative cooling, and Maisotsenko-cycle evaporative cooling (MEC) systems and solid and liquid desiccant dehumidification systems. In addition, integrated desiccant and evaporative cooling systems and hybrid systems are reviewed in this study. The results show that the MEC system effectively reduces the ambient temperature up to the ideal range while maintaining the humidity ratio, and both dehumidification systems effectively reduce the humidity level and improve evaporative cooling efficiency. The integrated systems and hybrid systems have the ability to increase energy efficiency and controlled climatic stability in greenhouses. Regular maintenance, initial system cost, economic feasibility, and system scalability are significant challenges to implement these advanced temperature and humidity control systems for greenhouses. These findings will assist agricultural practitioners, engineers, and researchers in seeking alternate efficient cooling methods for greenhouse applications. Future research directions are suggested to manufacture high-efficiency, low-energy consumption, and efficient greenhouse temperature control systems while considering the present challenges. Full article

The focus of this study was on young populations of Kandelia obovata within a constructed coastal wetland in Haicang Bay, Xiamen, Southeast China. The objective was to systematically examine their allometric growth characteristics and carbon sequestration potential over an 8-year monitoring period (2016–2024). Allometric equations were developed to estimate biomass, and the spatiotemporal variation in both plant and soil carbon stocks was estimated. There was a significant increase in total biomass per tree, from 120 ± 17 g at initial planting to 4.37 ± 0.59 kg after 8 years (p < 0.001), with aboveground biomass accounting for the largest part (72.2% ± 7.3%). The power law equation with D²H as an independent variable yielded the highest predictive accuracy for total biomass (R² = 0.957). Vegetation carbon storage exhibited an annual growth rate of 4.2 ± 0.8 Mg C·ha⁻¹·yr⁻¹. In contrast, sediment carbon stocks did not show a significant increase throughout the experimental period, although long-term accumulation was observed. The restoration of mangroves in urban coastal constructed wetlands is an effective measure to sequester carbon, achieving a carbon accumulation rate of 21.8 Mg CO₂eq·ha⁻¹·yr⁻¹. This rate surpasses that of traditional restoration methods, underscoring the pivotal role of interventions in augmenting blue carbon sinks. This study provides essential parameters for allometric modeling and carbon accounting in urban mangrove afforestation strategies, facilitating optimized restoration management and low-carbon strategies. Full article

The conflicting demands of urban trees and walkable surfaces result in significant financial burdens for municipal administrators who understand that urban residents want tree-lined walkable surfaces. This study investigates three methodologies for mitigating this tension: suspended grating systems, modular box systems, and structural soils. A Multi-Criteria Analysis (MCA) was conducted to evaluate their suitability in dense urban areas, employing criteria categorized into Environmental, Economical, and Other considerations. The comparison focused on critical aspects such as the impact on tree health (root growth, water availability), installation complexity, initial costs, and overall suitability for diverse urban contexts. The MCA indicates that, under the given weighting of criteria, suspended grating systems (especially those suited for existing trees) rank the highest, primarily due to their superior root protection and minimal disturbance to established root systems. In contrast, modular box systems and structural soils emerge as particularly strong contenders for new tree plantings. Structural soils may have application at sites with existing trees, but the costs of removing native soil are a consideration. Sensitivity analysis suggests that modular box systems may become the preferred option when greater emphasis is placed on stormwater management and new plantings, rather than on challenges for existing trees or underground infrastructure. Structural soils score well in cost-effectiveness and installation speed but require careful implementation to address their lower root protection performance and long-term maintenance concerns. Ultimately, the optimal solution depends on unique site-specific conditions and budgetary constraints, emphasizing the necessity of tailored approaches to balance urban infrastructure with tree health. Full article

In this work, we evaluated the silvicultural and ecological parameters of Populus bolleana Lauche trees growing in conditions of anthropogenic pollution, using the example of one of the largest megacities of the Donetsk ridge, the city of Donetsk. The objectives of this study included determining the level of anthropogenic load of the territory; conducting dendrological studies to assess morphometric and allometric parameters, age structure, and condition of P. bolleana stands under the influence of environmental factors; as well as completing biomechanical studies to assess and predict the mechanical stability of stands. A total of 1109 plants growing in areas with increased anthropogenic load and in the control areas were studied. The model territories of the study were located in the city of Donetsk on Fallen Communards Avenue (length of field routes: 2.6 km) and Ilyicha Avenue (length of field routes: 9.7 km). Control plantings grew on the territory of the Donetsk botanical garden and residential (dormitory) districts of the city. The age structure of P. bolleana plantations remained uniform throughout the city for 50–55 years due to the fact that the landscaping was under a single state program. In the steppe zone in the south of the East European Plain, with a high level of anthropogenic load and severe natural climatic factors, the critical age of P. bolleana (55 years) was determined. The condition of plantations and their morphometric indices correlate with the level of anthropogenic load of the city (H, Dbase, DBH). Under control conditions, the plants are in good condition with signs of weakening (2 points). Under conditions of increased anthropogenic load, the plants are in a severely weakened condition (3 points). A total of 25% of the plants in the sample are in critical condition (4–5 points). The main damages to the crowns and trunks of plants include core rot, mechanical damage to bark and tissues, the development of core rot through the affected skeletal branch, crown thinning, and drying. P. bolleana trees are valued for their crown area and ability to retain dust particles from the air. The analysis of experimentally obtained data on the crown area showed that in the initial phases of ontogenesis, the average deviation in the crown area of plants does not depend on the place of growth. Due to artificial narrowing and sanitary pruning of the crown, as well as skeletal branches dying along the busiest highways, the values do not exceed 22–23 m² on average, with an allometric coefficient of 0.35–0.37. When comparing this coefficient in the control areas, the crown area in areas with a high level of anthropogenic load is 36 ± 11% lower. For trees growing under the conditions of the anthropogenic load of an industrial city and having reached the critical age, mechanical resistance varied depending on the study area and load level. At sites with a high level of pollution of the territory, a significant decrease in indicators was revealed in comparison with the control (mcr—71%, EI—75%, RRB—43%). Having analyzed all the obtained data, we can conclude that, until the age of 50–55 years, P. bolleana retains good viability, mechanical resistance, and general allometric ratios, upon which the stability of the whole plant depends. Even with modern approaches and tendencies toward landscaping with exotic introductions, it is necessary to keep P. bolleana as the main species in dendrobanocenoses. Full article