Search Results (265)

To determine optimal light conditions for Hopea hainanensis Merr. & Chun seedling growth, this study examined growth and physiological parameters under four shading treatments (0%, 30%, 60%, and 90% irradiance reduction) over 12 months. Shading significantly affected the growth adaptability of seedlings. As shading increased, height, leaf traits (area, length, width), and light saturation point all initially increased, peaked at 30% shading, and then decreased. Conversely, basal diameter, leaf thickness, the maximum net photosynthetic rate, net photosynthetic rate, photosynthetic quantum efficiency, transpiration rate, and stomatal conductance progressively declined as shading increased. Biomass accumulation (in stems and roots), dark respiration rate, and light compensation point exhibited a U-shaped response to shading, being minimized under low or moderate shading. All shading treatments significantly reduced biomass and photosynthetic performance compared to controls. Multivariate analysis identified 0%–30% shading as optimal for cultivation, with 30% shading enhancing photomorphogenic responses while maintaining photosynthetic efficiency. The study findings suggest a novel seedling cultivation protocol for nursery use, in which initial establishment occurs under 30% shading to maximize vertical elongation, followed by the progressive reduction in shading to stimulate radial growth and optimal biomass partitioning. This approach mimics natural canopy gap dynamics, effectively mimicking natural regeneration in tropical rainforest ecosystems. Full article

The biomass allocation patterns between aboveground and belowground are an essential functional trait for plant survival under a changing environment. The effects of arbuscular mycorrhizal fungi (AMF) communities on plant biomass allocation, particularly in degraded Festuca ovina grasslands in ecologically fragile karst areas, remain unclear. Therefore, we conducted a field investigation combined with a greenhouse experiment to explore the importance of AMF compared to bacteria and fungi for plant biomass allocation. The results showed that plant biomass in degraded grasslands exhibited allometric biomass allocation, contrasting with isometric partitioning in non-degraded grasslands. AMF, not bacteria or fungi, were the primary microbial mediators of grassland degradation effects on plant biomass allocation based on structural equation modeling. The greenhouse experiment demonstrated that the selected AMF keystone species from the field study performed according to ecological network analysis, particularly multi-species combinations, enhanced the belowground biomass allocation of F. ovina under rocky desertification stress compared to single-species inoculations, through decreasing soil pH, enhancing alkaline phosphatase (ALP) activity, and increasing the expression level of AMF-inducible phosphate transporter (PT4). This study highlights the critical role of the AMF community, rather than individual species, in mediating plant survival strategies under rocky desertification stress. Full article

Subtropical plateau lakes, which are distinguished by their elevated altitudes and subtropical climates, display distinct ecological dynamics. Nevertheless, the spatial and seasonal variations in the plankton community structure, as well as their interactions with environmental factors, remain inadequately understood. This study investigated the alterations in the phytoplankton and zooplankton community structure across different geographical regions (southern, central, and northern) and seasonal periods (rainy and dry) in Erhai lake, located in a subtropical plateau in China. The results indicated that the average values of total nitrogen (TN), total phosphorus (TP), chlorophyll-a (Chla), pH, and conductivity are significantly higher during the rainy season in comparison to the dry season. Furthermore, during the rainy season, there were significant differences in the concentrations of TN, TP, and Chla among the three designated water areas. Notable differences were also observed in the distribution of Microcystis, the density of Cladocera and copepods, and the biomass of copepods across the three regions during this season. Conversely, in the dry season, only the biomass of Cladocera exhibited significant variation among the three water areas. The redundancy analysis (RDA) and variance partitioning analysis demonstrated that the distribution of plankton groups (Cyanophyta, Cryptophyta, and Cladocera) is significantly associated with TN, Secchi depth (SD), and Chla during the rainy season, whereas it is significantly correlated with TP and SD during the dry season. These findings underscore the critical influence of environmental factors, shaped by rainfall patterns, in driving these ecological changes. In the context of the early stages of eutrophication in Lake Erhai, it is essential to ascertain the spatial distribution of water quality parameters, as well as phytoplankton and zooplankton density and biomass, during both the rainy and dry seasons. Full article

The distinctive leaf and twig heteromorphism in Euphrates poplar (Populus euphratica Oliv.) reflects its adaptive strategies to cope with arid environments across ontogenetic stages. In the key distribution area of P. euphratica forests in China, we sampled P. euphratica twigs (which grow in the current year) at different age classes (1-, 3-, 5-, 8-, and 11-year-old trees), then analyzed their morphological traits, biomass allocation, as well as allometric relationships. Results revealed significant ontogenetic shifts: seedlings prioritized vertical growth by lengthening stems (32.06 ± 10.28 cm in 1-year-olds) and increasing stem biomass allocation (0.36 ± 0.14 g), while subadult trees developed shorter stems (6.80 ± 2.42 cm in 11-year-olds) with increasesd petiole length (2.997 ± 0.63 cm) and lamina biomass (1.035 ± 0.406 g). Variance partitioning showed that 93%–99% of the trait variation originated from age and individual differences. Standardized major axis analysis demonstrated a consistent “diminishing returns” allometry in biomass allocation (lamina–stem slope = 0.737, lamina–petiole slope = 0.827), with age-modulated intercepts reflecting developmental adjustments. These patterns revealed an evolutionary trade-off strategy where subadult trees optimized photosynthetic efficiency through compact architecture and enhanced hydraulic safety, while seedlings prioritized vertical space occupation. Our findings revealed that heteromorphic twigs play a pivotal role in modular trait coordination, providing mechanistic insights into P. euphratica’s adaptation to extreme aridity throughout its lifespan. Full article

Seamounts are distributed globally across the oceans and are generally considered oases of biomass abundance as well as hotspots of species richness. Diverse microbial communities are essential for biogeochemical cycling, yet their functional partitioning among seamounts with geographic features remains poorly investigated. Through metagenomic sequencing and genome-resolved analysis, we revealed that Proteobacteria (33.18–40.35%) dominated the bacterial communities, while Thaumarchaeota (5.98–10.86%) were the predominant archaea. Metagenome-assembled genomes uncovered 117 medium-quality genomes, 81.91% of which lacked species-level annotation, highlighting uncultured diversity. In the Nazuna seamount, which is located in the Marcus-Wake seamount region, microbiomes exhibited heightened autotrophic potential via the 3-hydroxypropionate cycle and dissimilatory nitrate reduction, whereas in the Magellan seamounts regions, nitrification and organic nitrogen metabolism were prioritized. Sulfur oxidation genes dominated Nazuna seamount microbes, with 33 MAGs coupling denitrification to sulfur redox pathways. Metal resistance genes for tellurium, mercury, and copper were prevalent, alongside habitat-specific iron transport systems. Cross-feeding interactions mediated by manganese, reduced ferredoxin, and sulfur–metal integration suggested adaptive detoxification strategies. This study elucidates how deep-sea microbes partition metabolic roles and evolve metal resilience mechanisms across geographical niches. It also supports the view that microbial community structure and metabolic function across seamount regions are likely influenced by the geomorphological features of the seamounts. Full article

Zinc (Zn) fertilization is widely used in maize (Zea mays L.) production to alleviate Zn deficiency and improve biomass and grain yield. However, limited research exists on Zn management in maize cultivated in high-pH paddy soils following rice-based systems, where altered soil chemistry may affect Zn availability and plant uptake. This study aimed to evaluate the effects of Zn application rates on growth, yield, and Zn uptake in two hybrid maize varieties under such conditions. Field experiments were conducted during the 2019 and 2020 dry seasons in Phetchabun Province, Thailand, using a randomized complete block design with a 4 × 2 factorial arrangement and four replications. Treatments included four Zn rates (0, 5, 10, and 20.6 kg of Zn/ha), applied as Zn sulfate monohydrate (ZnSO₄·H₂O, 36% Zn) by soil banding at the V6 stage, and two hybrid varieties, Suwan 5731 (SW5731) and Suwan 5819 (SW5819). In 2019, significant Zn × variety interactions were observed for biomass, crop growth rate (CGR), and grain yield. SW5819 at 10 kg of Zn/ha produced the highest biomass (31.6 t/ha) and CGR (25.6 g/m²/day), increasing by 15.3% and 39.1%, respectively, compared to its own no Zn treatment. In contrast, 20.6 kg of Zn/ha reduced SW5819 biomass by 6.6% and 13.1% relative to SW5731 and its own no-Zn treatment, respectively. Grain yield in SW5819 peaked at 14.7 t/ha under 5 and 10 kg of Zn/ha, significantly higher than SW5731 under 0 and 5 kg of Zn/ha by 16.7%, while SW5731 showed no significant response. In SW5819, shoot and grain Zn uptake significantly increased under 5 and 10 kg of Zn/ha by up to 36.8% and 33.3%, respectively, compared to no Zn treatment. The lowest shoot Zn uptake was found in SW5819 under 20.6 kg of Zn/ha (264.1 ± 43.9 g/ha), which was lower than all its Zn treatments and all SW5731 treatments, showing a reduction of 19.4–43.6%. Zn application improved soil Zn availability, and Zn partitioning among plant organs varied with Zn rate and season. A moderate Zn rate (10 kg of Zn/ha) optimized maize performance under high-pH, rice-based conditions, emphasizing the need for variety-specific Zn management. Full article

Salvia miltiorrhiza is a traditional herbal remedy for cardiovascular diseases and is in high demand in the market. Excessive chemical fertilizer application, resulting from unscientific fertilization practices, reduced the tanshinone content in S. miltiorrhiza roots. This study investigated how different fertilization types alter the endophytic microbial community composition of S. miltiorrhiza through field experiments, aiming to understand how fertilization affects its medicinal quality. The results showed that root fertilizers (F1) significantly increased root biomass and tanshinone I content, whereas foliar fertilizers (F2) increased tanshinone IIA content. High-throughput sequencing further revealed that F2 treatment significantly decreased the Shannon index of endophytic bacteria while significantly increasing the Shannon index of endophytic fungi. Co-occurrence network analysis revealed that fertilization significantly altered fungal community complexity and modularity, with F1 increasing network nodes and edges. Variance partitioning analysis indicated fungal diversity more strongly influenced medicinal compound levels under F2 and a combination of both (F3) than bacterial diversity. Septoria and Gibberella were positively correlated with tanshinone I and cryptotanshinone content under F2 treatment, respectively. Notably, the unique strains were isolated from different fertilization treatments for subsequent bacterial fertilizer development. These findings elucidate microbial responses to fertilization, guiding optimized cultivation for improved S. miltiorrhiza quality. Full article

Background/Objective: Ganoderma spp. have long been studied for their bioactive pharmacological properties, and their biomass and extracts have been obtained from various sources. This study adopts a novel approach: enriching a liquid culture of Ganoderma mexicanum with a vineyard pruning waste extract to identify bioactive compounds with antiproliferative activity through enriched chromatographic fractions. Methods: The ethanolic extract from a mycelial culture was separated following a partitioning process, and the hexane fraction was subsequently separated in a chromatographic column. The fractions were evaluated for their antiproliferative properties against cancer cell lines. The interactions of the molecules identified with peroxisome proliferator-activated receptor gamma (PPAR-γ) were analyzed via molecular docking. Results: Three chromatographic fractions (FH11–FH13) exhibited antiproliferative activity which was significantly more effective against non-small lung cancer cells (A549). The cells treated with the crude extract and fractions presented a balloon-like morphology. A chemical analysis of the active fractions allowed us to identify four compounds: one fatty acid (9-Hydroxy-10E,12Z-octadecadienoic acid) and three triterpenes (ganoderic acids DM, TQ, and X). These compounds showed interactions with the PPAR-γ receptor through molecular docking. Conclusions: Ganoderma mexicanum is a promising source of compounds with antiproliferative activity that could serve as natural ligands for PPAR-γ and has possible applications in lung cancer therapy. Full article

The high demands of corn (Zea mays L.) grain production coupled with water quality goals and phosphorus (P) conservation pose a great challenge to farmers and society and necessitate improved P utilization efficiency (PUtE: grain yield per mass total P (TP) content). The objective of this study was to evaluate PUtE among six Pioneer corn hybrids released over a span of 75 years. Corn was grown in a sand culture hydroponics system that eliminated confounding plant–soil interactions and root architecture and allowed for precise control of nutrient availability. Four P concentration levels (4, 7, 10, and 12 mg P L⁻¹) were applied to hybrids released in 1936, 1942, 1946, 1952, 2008, and 2011. Nutrients other than P were applied at sufficient levels. Shoots and roots were harvested at maturity (R6) and biomass and P concentration determined. Results showed that total biomass did not differ among hybrids, but partitioning of biomass varied with hybrid. Grain yield varied between hybrids, but there was no trend with the year of release. Grain P content was negatively correlated with stem P content (R² = 0.89). PUtE differed between the most recently released hybrids (2008 and 2011) whereas older hybrids had intermediate and similar PUtE. Grain yield was not solely determined by TP in the plant, but was strongly influenced by biomass and P partitioning, which was manifested as relative differences in PUtE between hybrids. While the PUtE did not necessarily change as a function of the breeding period, there were differences between hybrids. The findings highlight the critical role of the source–sink relationship in determining PUtE and grain yield. Full article

Vegetation restoration is critical for improving soil quality and microbial community dynamics in degraded mining areas. This study explored the effects of different vegetation types (grassland, shrubland, and mixed grass–shrub areas) on soil physicochemical properties, organic carbon fractions, and abundant versus scarce microbial taxa assemblies in a Loess Plateau coal mining area. Soil samples from four depths (0–100 cm) were analyzed using high-throughput sequencing for nutrient content; carbon components, soil organic carbon (SOC), particulate organic carbon (POC), mineral-associated organic carbon (MAOC), dissolved organic carbon (DOC), microbial biomass organic carbon (MBC), and readily oxidizable organic carbon (ROC); microbial diversity. Shrubland soils exhibited significantly higher total nitrogen (TN), total phosphorus (TP), and organic carbon components (SOC, MAOC, and POC) than other vegetation types (p < 0.05), with the greatest carbon accumulation noted in the surface layer depths (0–20 cm). Microbial communities displayed vegetation-specific patterns: abundant taxa (e.g., Actinobacteria, Proteobacteria) dominated nutrient cycling and exhibited resilience to environmental gradients, while rare taxa (e.g., Methylomirabilota, Olpidiomycota) correlated strongly with labile carbon fractions (DOC and POC) and demonstrated metabolic flexibility. Mantel tests identified soil pH, TN, and organic carbon components as key drivers of microbial community divergence (p < 0.01). Shrubland vegetation enhanced soil nutrient retention and carbon stabilization, whereas the mixed grass–shrub systems promoted niche partitioning among rare taxa. These findings highlight the roles of vegetation-mediated carbon inputs and environmental filtering in shaping microbial assembly, providing a scientific framework for optimizing restoration strategies in mining ecosystems. Full article

This study systematically investigates the mechanistic effects of multifactor interactions (including soil properties, climatic conditions, and cultivation practices) on the productivity parameters (grain yield, stover yield, dry biomass, harvest index) of maize cultivars of different maturity groups in the arid region of Xinjiang, China. Twelve representative maize-growing counties were selected as study sites, where we collected maize samples to measure HI, grain yield, stover yield, and soil physicochemical properties (e.g., organic matter content, total nitrogen, and available phosphorus). Additionally, climate data (effective accumulated temperature) and agronomic parameters (planting density) were integrated to comprehensively analyze the interactive effects of multiple environmental factors on HI using structural equation modeling (SEM). The results demonstrated significant varietal differences in HI across maturity periods. Specifically, early-maturing cultivars showed the highest average HI (0.58), significantly exceeding those of medium-maturing (0.55) and late-maturing varieties (0.54). Environmental analysis further revealed that soil phosphorus content (both available and total phosphorus), elevation, and organic matter content significantly positively affected HI, whereas soil bulk density and electrical conductivity exhibited negative impacts. Notably, HI exhibited a strong negative correlation with stover yield (R² = 0.49), but remained relatively stable across different dry matter (DM) and grain yield levels. Despite the strong positive correlation between DM and grain yield (R² = 0.81), the relative stability of HI suggests that yield improvement requires balanced optimization of both DM and partitioning efficiency. This study provides crucial theoretical foundations for optimizing high-yield maize cultivation systems, regulating fertilizer application rates and their ratios, and improving the configuration of planting density in arid regions. These findings offer practical guidance for sustainable agricultural development in similar environments. Full article

Historical landrace collections, such as the Watkins Wheat Collection, harbor immense genetic diversity that holds the potential to transform our understanding of crop resilience and adaptation. This study employs a novel integrative phenotyping approach to dissect regional adaptation and nitrogen stress resilience in Watkins wheat landraces under contrasting nitrogen regimes. By leveraging a multidimensional framework, including stress indices, geographic analyses, and multivariate clustering, this work identifies 48 landraces with contrasting responses to nitrogen limitation. High-performing genotypes, such as WATDE0013 and WATDE0020, exhibited superior biomass partitioning under stress, reflecting historical adaptation to low-input agroecosystems spanning Europe, Asia, and North Africa. These findings emphasize the value of phenotypic plasticity in nitrogen use efficiency (NUE) improvement. In contrast, low-performing accessions, such as WATDE1055, highlighted vulnerabilities to nitrogen limitation, illustrating the importance of comprehensive phenotypic screening for gene-bank prioritization. Regional adaptation patterns, elucidated through geographic analyses, uncovered stress-resilient genotypes clustered in historically marginal agricultural regions, revealing adaptive traits shaped by environmental selection pressures. Principal component analysis (PCA) and hierarchical clustering delineated five distinct phenotypic groups, enhancing our understanding of evolutionary trajectories within this collection. This integrative approach transcends traditional phenotyping methods by linking phenotype, genotype, and geographic context to uncover nuanced adaptive traits. By bridging gene bank conservation with a systems-level understanding of crop evolution, this study provides actionable insights and a robust framework for breeding climate-resilient wheat varieties. These findings underscore the critical role of preserving genetic diversity in landraces to address global challenges in nitrogen stress and climate resilience. Full article

In this study, an efficient and eco-friendly method was developed for continuous liquid–liquid extraction of lutein from microalgae Chlorella vulgaris. By employing a limonene-based biphasic liquid system, high-purity lutein was successfully obtained from the crude extract in a single run via centrifugal partition chromatography (CPC). Evaluation and optimization results demonstrated that limonene could effectively serve as a replacement for n-hexane as the solvent system for lutein extraction, exhibiting natural renewability and minimal environmental impact. Furthermore, the elution–extrusion operation mode was employed to fully exploit the liquid nature of the stationary phase in the extraction process, allowing for continuous sampling and separation without interruption. This proposed protocol offers a sustainable and environmentally friendly alternative for extracting valuable ingredients from microalgae biomass, demonstrating its potential as a scalable solution for producing lutein-enriched ingredients applicable to functional foods and nutraceuticals. Full article

In perennial trees, wood development is a carbon-demanding process, pivotal for secondary cell wall (SCW) formation and xylem development. Sugars, functioning both as carbon substrates and signaling molecules, orchestrate cambial proliferation and xylem differentiation. However, few molecular candidates involved in the sugar-mediated regulation of wood development have been characterized. Cell wall invertases (CWINs), a subclass of the invertase enzyme family localized in the apoplastic space, catalyze the irreversible hydrolysis of sucrose into glucose and fructose, thereby governing carbon allocation in sink tissues. Here, PtoCWIN4 shows preferential expression in the stem of Populus tomentosa and has a high efficiency in sucrose cleavage activity. We demonstrated that the knockout of PtoCWIN4 results in stunted growth, aberrant branching patterns, and compromised secondary xylem formation. In contrast, mutant lines displayed enhanced SCW thickness accompanied by elevated cellulose and hemicellulose accumulation. Following this, the knockout of PtoCWIN4 led to impaired carbon partitioning from sucrose to hexose metabolites during wood development, corroborating the enzyme’s role in sustaining sucrose hydrolysis. Collectively, these findings establish PtoCWIN4 as a master regulator of sucrose-to-hexose conversion, a metabolic gateway critical for balancing structural biomass production and developmental growth during wood formation. Full article

Developing high phosphorus (P) efficient rice varieties is essential for sustainable phosphate resource conservation. This study evaluated 16 rice cultivars from four breeding eras: ancient (<1940), early conventional (1940–2000), modern conventional (2000–2020), and hybrid rice (2000–2020). Using pot experiments in low-P soil, we examined two P treatments: P0 (no P application, simulating low-P stress) and P50 (50 kg hm⁻¹ P application, normal P input). We systematically compared agronomic traits, P distribution patterns, and P uptake efficiency across breeding generations. The result showed that modern breeding significantly increased root biomass, shoot biomass, and grain yield while reducing plant height. Low-P stress (P0) had minimal impact on growth traits but negatively affected P uptake, particularly plant P content and accumulation patterns. Under P0 treatment, modern conventional varieties maintained a higher stem P concentration (0.47–0.65 g·kg⁻¹ vs. 0.27–0.49 g·kg⁻¹ in hybrid varieties; 0.47–0.65 g·kg⁻¹ vs. 0.18–0.28 g·kg⁻¹ in ancient varieties, p < 0.05). P allocation strategies varied significantly across breeding eras. Root P accumulation ratios decreased from ancient to modern varieties, while modern conventional rice had the highest stem P storage (24.1–30.5%), and hybrid rice allocated the largest partition of 76.4–78.1% P to grains. Additionally, P uptake efficiency and P fertilizer productivity increased by 131.09% and 91.21% (p < 0.01) from ancient to modern conventional rice, with hybrids exhibiting the highest values for both parameters. Principal component analysis (PCA) revealed distinct trait clusters separating ancient, conventional, and hybrid rice based on the agronomic traits, P uptake, and rhizosphere soil parameters. Random forest analysis identified that, under low-P conditions, root P content was the strongest predictor of grain yield, whereas under normal P conditions, rhizosphere pH had the highest relationship to grain yield. These findings demonstrate that modern breeding has enhanced P adaptation through optimized root architecture and organ-specific P allocation strategies, which providing valuable insights for developing future P-efficient rice varieties. Full article