Search Results (177)

Atmospheric nitrogen deposition is increasing worldwide, with profound implications for plant nitrogen acquisition and ecosystem nutrient cycling, particularly in nitrogen-limited systems. In this study, we investigated how inorganic nitrogen form regulates nitrogen uptake in H. altissima through pot experiments by applying ammonium nitrogen, nitrate nitrogen, mixed nitrogen, and a nitrogen-free control in Songnen grassland ecosystems at the eastern end of Eurasia. Soil abiotic properties, root morphological traits, and nitrogen uptake dynamics were jointly quantified using integrative modeling in combination with ¹⁵N stable isotope tracing. Relative to the no-nitrogen control, both ammonium and nitrate nitrogen significantly altered soil physicochemical conditions and stimulated root development, with ammonium consistently exhibiting stronger effects. Ammonium and nitrate applications reduced soil pH by 4.83% and 6.25%, increased electrical conductivity by 2.01% and 1.17%, and enhanced inorganic nitrogen pools by 115.84% and 45.69%, respectively. Root morphological traits were significantly enhanced under ammonium, nitrate, and mixed nitrogen treatments. ¹⁵N tracing further demonstrated that ammonium nitrogen significantly increased root ¹⁵N uptake compared with the no-nitrogen control (p < 0.05) and promoted a 20.10% greater allocation of absorbed nitrogen to aboveground biomass than nitrate nitrogen. Collectively, these findings highlight nitrogen form as a key regulator of soil–plant nitrogen coupling, with ammonium nitrogen more effectively enhancing nitrogen acquisition and internal translocation than nitrate. Full article

The olive tree hosts diverse endophytic fungi that may contribute to plant protection and growth. In this study, a preliminary screening of olive-associated fungal endophytes was conducted. A total of 67 fungal endophytes were isolated from the leaves and roots of the Greek cultivars Amfissa and Kalamon and identified using morphological and molecular approaches; 28 representative strains were selected for functional evaluation. Dual culture assays revealed substantial antagonistic activity against major phytopathogens, with growth inhibition ranging from 19.05% to 100%. Notably, strains F.KALl.8 and F.AMFr.15 showed the strongest suppression across pathogens. Interaction phenotyping revealed all major interaction types (A, B, C) and subtype C1/C2, with several strains producing pigmentation zone lines or hyphal ridges at contact sites. The assessment of plant growth-related effects using Arabidopsis thaliana as a model system showed that three strains (F.AMFr.15, F.KALr.4, F.KALr.38A) significantly increased seedling biomass (up to ~16% above the control), whereas nine strains caused severe growth reduction and disease symptoms. Beneficial strains also altered root architecture, inhibiting primary root elongation while inducing extensive lateral root formation. Collectively, these findings highlight the functional diversity of olive-associated fungal endophytes and identify promising candidate strains, particularly F.AMFr.15 (identified as Clonostachys sp.), for further host-specific validation as potential biological control and plant growth-promoting agents. Full article

Waterlogging is a major abiotic stress that restricts plant growth, productivity, and survival by disrupting root aeration and altering hormonal homeostasis. To elucidate the physiological and molecular responses associated with flooding tolerance in Liriodendron hybrids (Liriodendron chinense × Liriodendron tulipifera), this study investigated its morphological, physiological, and transcriptomic changes under 0, 1, 3, and 6 days of waterlogging. Roots exhibited rapid decay, while leaves showed delayed chlorosis and reduced chlorophyll content. Changes in antioxidant enzyme activities reflected enhanced antioxidant capacity, with superoxide dismutase (SOD) activity decreasing and peroxidase (POD) and catalase (CAT) activities increasing. Hormone measurements indicated organ-specific patterns, including abscisic acid (ABA) accumulation in leaves and decreased indole-3-acetic acid (IAA) and gibberellin (GA) levels in both roots and leaves. Transcriptome profiling revealed extensive transcriptional adjustments in hormone biosynthesis, signaling, and stress-responsive pathways, including divergent regulation of ABA-associated genes in leaves and roots and broad downregulation of auxin- and gibberellin-related genes. Key ABA biosynthetic genes (NCED1, ABA2) and signaling components (PYL4, PP2C, ABF) were upregulated in leaves but downregulated in roots, whereas auxin (YUC6) and gibberellin (GA20ox) genes were generally suppressed. These coordinated physiological and molecular responses suggest organ-differentiated adaptation to waterlogging in Liriodendron hybrids, highlighting candidate pathways and genes for further investigation and providing insights for improving flooding tolerance in woody species. Full article

The present study investigated the effects of copper oxide nanoparticles (CuO NPs) at concentrations of 0, 5, 10, 20, and 40 mg/L on micropropagation and the accumulation of lipophilic metabolites in Ajuga multiflora, a medicinally valuable ornamental species. The highest number of adventitious shoots (29.4 shoots per explant) was obtained on the shoot induction medium with 5 mg/L CuO NPs. Shoot production gradually decreased at higher CuO NPs concentrations, falling to just 1.1 shoots per explant at 40 mg/L CuO NPs. A similar pattern was seen in axillary shoot multiplication (22.4 shoots per explant at 5 mg/L CuO NPs). However, the maximum shoot fresh weight (0.269 g) was reached on the shoot multiplication medium containing 10 mg/L CuO NPs. Root induction was most effective at 5–10 mg/L CuO NPs, while higher concentrations (20 or 40 mg/L CuO NPs) suppressed or inhibited root formation and altered plantlet morphology. Notably, this study is among the first to assess CuO NPs’ effects across multiple regeneration stages rather than focusing on just one morphogenic event. This emphasizes the importance of optimizing the dose not only for initial shoot induction but also for later multiplication and rooting, ensuring effective micropropagation. Metabolite analysis showed that both the type of organ (microshoots vs. leaves) and CuO NPs concentration significantly affected the levels of α-tocopherol, carotenoids, sterols, and fatty acids. Leaves had higher amounts of α-tocopherol and total carotenoids compared to microshoots. The phytosterol levels also varied, with leaves containing more 22-dehydroclerosterol and total phytosterols, while microshoots had more clerosterol. Treatment with 5 mg/L CuO NPs increased phytosterol accumulation in both organs. CuO NPs significantly influenced the fatty acid profiles. In microshoots, total polyunsaturated fatty acids (PUFAs) increased and total saturated fatty acids (SFAs) decreased with higher CuO NPs levels. Conversely, in leaves, higher CuO NPs concentrations led to increased SFAs and decreased PUFAs, along with a significant rise in the omega-6 (n-6)/n-3 PUFAs ratio. These findings suggest that controlled application of CuO NPs can serve as an elicitor to boost phytochemical production during micropropagation. Full article

The expansion ratio of bamboo forests has significantly influenced soil nutrient cycling in broad-leaved forests through alterations in vegetation composition. However, the extent to which varying expansion ratios of bamboo within broad-leaved forest areas (MRB) affect soil enzyme activities and stoichiometric ratio in karst regions with yellow limestone soil remains poorly understood. Therefore, we examined five MRB levels (<20%, 20–40%, 40–60%, 60–80%, and >80%) and three soil depths (0–20 cm, 20–40 cm, and 40–60 cm) to analyze variations in soil microbial resource limitation within a field experiment conducted in a karst region. The results revealed showed that root morphology was significantly less developed at both low (<20%) and high (≥80%) expansion ratios than at moderate expansion ratios (40–60%) and exhibited a decreasing trend with increasing soil depth. The soil TC (46.43 g·kg⁻¹), SOC (80.05 g·kg⁻¹) and N:P (0.96) reached their highest values in the 40–60% MRB, whereas the pH (4.61), BD (0.42 g·cm⁻³), AN (20.28 g·kg⁻¹) and C:N (45.51) were lowest at 0–20 cm. Moreover, the CBH and the E_C:N ratio at 40–60 cm depth in the 0–20% MRB were significantly 2.64 and 1.31 times greater than those at 0–20 cm depth in the 40–60% MRB. Mantel and structural equation modeling (SEM) analyses revealed that soil enzyme activity and stoichiometric ratios are indirectly influenced by soil bulk density (β = −0.156) and root characteristics (β = −0.630). Overall, both C and P limitations are present at the lowest MRB (<20%), whereas other MRB ranges exhibit only P limitation without C limitation. Our results highlight that soil nutrient availability in karst regions of Southwest China is influenced by vegetation structure. These findings provide a scientific foundation for achieving the green and sustainable management of bamboo forests within broad-leaved forest ecosystems. Full article

Background/Objectives: Diode lasers are used as adjuncts for endodontic disinfection, but their depth-resolved effects on root dentin are insufficiently described. This ex vivo study used optical coherence tomography (OCT) to qualitatively document laser-related morphological signatures on canal walls. Methods: Palatal roots from extracted maxillary first molars were standardized and hemisectioned to create specimens allocated to a conventional diode-laser protocol, a higher-power protocol, or control. A 940-nm diode laser with endodontic tips was applied per group. Swept-source OCT acquired serial B-scans along the root length. Two endodontists reviewed images for thermally induced morphological alterations (TIMAs). Reporting is descriptive. Results: OCT revealed laser-related hyper-reflective linear/radial signatures extending from the canal lumen toward the external root surface in laser-treated specimens. Qualitatively, signatures appeared more conspicuous and extended deeper with the higher-power protocol than with the conventional protocol. Findings were most evident in the coronal/middle thirds. Control specimens served to contextualize background appearances from preparation and sectioning. Representative B-scans illustrate typical patterns. The novelty of the present study results from the identification of areas of morphological alteration through the OCT examination of the walls of the root canals. Conclusions: Depth-resolved OCT can visualize dentinal alterations associated with diode-laser irradiation in an ex vivo model. These observations support careful parameter selection and motivate in situ studies with concurrent temperature monitoring and histologic correlation. Full article

This study aimed to evaluate the impact of UVC (Ultraviolet C Radiation), detergent foam, and alcohol (70%) sterilization methods on the surface morphology of acrylonitrile–butadiene–styrene (ABS) specimens using a novel SEM (Scanning Electron Microscope) image processing approach. Twelve 3D-printed specimens were prepared, and five concentric circular regions of interest (ROIs) per specimen were analyzed. Three quantitative descriptors—defect area fraction, anisotropy ratio, and RMS (Root Mean Square) roughness—were extracted to assess surface alterations. To validate the image-based findings, EDX (Energy-Dispersive X-ray Spectroscopy) elemental analysis for carbon (C), nitrogen (N), and oxygen (O) was employed as a complementary and traditional benchmark technique. Statistical comparisons and p-value heat maps revealed strong convergence between SEM and EDX results. UVC sterilization consistently preserved surface morphology and elemental stability, showing the lowest defect fraction (p = 0.2684), balanced anisotropy (p = 0.02481), and minimal oxygen incorporation (O = 7.6). Foam sterilization produced intermediate effects, with significant anisotropy changes (p = 0.007456) and reduced nitrogen (19.6). Alcohol sterilization induced the most severe damage, characterized by high defect density, increased roughness, and elemental imbalance (N = 17.3, O = 13.9), confirming oxidative degradation. The convergence of SEM and EDX outcomes demonstrates that SEM image processing is a reliable novel method validated by traditional elemental analysis. Together, these approaches provide a robust framework for ranking sterilization efficacy, with UVC identified as the most favorable method, detergent foam as an acceptable alternative, and alcohol as the least effective due to its destabilizing effects. Full article

Introduction: The aim of this study was to evaluate the effect of corticotomy incision depth on tooth movement and stress distribution in the periodontal ligament (PDL) during orthodontic expansion using finite element analysis (FEA). The demand for accelerated and biologically safe orthodontic techniques has highlighted the importance of understanding biomechanical responses to surgical adjuncts like corticotomy. Objective: The aim of this study is to assess the effect of corticotomy depth on tooth movement and periodontal ligament stress distribution during orthodontic treatment using finite element analysis. Materials and methods: A 3D FEM model was developed based on CBCT and intraoral scans to replicate anatomical structures and simulate clinical orthodontic scenarios. Four conditions were analyzed: no corticotomy and corticotomy incisions of 1 mm, 2 mm, and 3 mm depths, applied between roots and above the apex region. Different cortical bone densities were tested using Young’s modulus values (12,500 MPa–27,500 MPa). Stress and displacement values were measured in both the crown and root regions. Results: The 3 mm corticotomy, penetrating through the cortical plate into the cancellous bone, significantly increased crown displacement (up to 26% in low-density bone) and altered root tipping patterns, reducing root movement relative to the crown. Shallower incisions (1–2 mm) had minimal effects. Despite increased movement, stress concentration in the cervical PDL region remained high across all scenarios, particularly in the premolar area, exceeding the 4.7 kPa threshold associated with tissue ischemia. Conclusions: Corticotomy depth is a critical factor for optimizing orthodontic tooth movement. Penetration into cancellous bone (3 mm) appears necessary to induce both: not only the Regional Acceleratory Phenomenon (RAP) but also to enhance displacement. However, this approach does not significantly reduce cervical PDL stress and offers limited periodontal protection. Individual planning based on bone density, morphology, and anatomical limitations is essential for balancing treatment efficiency and periodontal safety. Full article

Thigmomorphogenesis denotes a suite of anatomical, physiological, biochemical, biophysical, and molecular responses of plants to mechanical stimulation. This phenomenon is evolutionarily conserved among diverse plant lineages; however, the magnitude and character of the response are strongly determined by both the frequency and intensity of the applied stimulus. In angiosperms, thigmomorphogenetic reactions typically occur gradually, reflecting a complex interplay of morphological alterations, biochemical adjustments, and genetic reprogramming. In dicotyledonous plants, thigmomorphogenesis is commonly expressed as a reduction in leaf blade surface area, shortening of petioles, decreased plant height, radial thickening of stems, and modifications in root system architecture. In monocotyledons, in turn, mechanical stress frequently results in stem rupture below the inflorescence, with concomitant shortening and increased flexibility of younger internodes. These specific traits can be explained by structural features of monocot secondary walls as well as by the absence of vascular cambium and lateral meristems. Mechanical stimulation has been shown to initiate a cascade of responses across multiple levels of plant organization. The earliest events involve activation of mechanoresponsive genes (e.g., TCH family), followed by enzymatic activation, biochemical shifts, and downstream physiological and molecular adjustments. Importantly, recent findings indicate that prolonged mechanical stress may significantly suppress auxin biosynthesis, while leaving auxin transport processes unaffected. Moreover, strong interdependencies have been identified between thigmostimulation, gibberellin biosynthesis, and flowering intensity, as well as between mechanical stress and signaling pathways of other phytohormones, including abscisic acid, jasmonic acid, and ethylene. At the molecular scale, studies have demonstrated a robust correlation between the expression of specific calmodulin isoforms and the GH3.1 gene, suggesting a mechanistic link between mechanosensing, hormone homeostasis, and regulatory feedback loops. The present study consolidates current knowledge and integrates novel findings, emphasizing both morphological and cellular dimensions of thigmomorphogenesis. In particular, it provides evidence that mechanical stress constitutes a critical modulator of hormonal balance, thereby shaping plant growth, development, and adaptive potential. Full article

Native plant species show significant promise for the remediation and rehabilitation of mine tailings contaminated with heavy metals (HM). Nonetheless, the harmful impact of HM can decrease plant survival, growth and reproduction, thereby diminishing the effectiveness of phytoremediation. Consequently, incorporating organic amendments into mine tailings, like biochar, can promote plant growth, decreasing the bioavailability of HM and their eventual potential to alter the food chain. This study aims to evaluate the capability of coconut fiber biochar in combination with Sanvitalia procumbens to phytostabilize HM in mine tailings by analyzing the effect of coconut fiber biochar on HM bioaccumulation levels (roots and leaves), as well as on morphological, physiological, and genotoxic parameters of S. procumbens grown in mine tailing substrate and mine tailing/biochar. Also, a physicochemical analysis of coconut fiber biochar was conducted. This research was conducted over 100 days on plants grown in greenhouse settings using two different substrates (mine tailing and agrolite [75/25 v/v] and mine tailing and coconut fiber biochar [75/25 v/v]). Every 25 days, 12 plants were selected per treatment for analysis. The bioaccumulation pattern exhibited by S. procumbens was Zn > Pb > Cu > Cd, in root and leaf tissues for both treatments. S. procumbes grown in mine tailing/biochar substrate showed the lowest HM bioaccumulation levels in both tissues in comparison to mine tailing substrate: Zn from 2.95 to 2.50 times lower; Pb 3.04 to 2.82; Cu 3.10 to 2.12; and Zn 2.12 to 3.00 in roots and leaves, respectively. The coconut fiber biochar was rich in functional groups, such as carboxyl and hydroxyl groups, which could favor HM adsorption. Immobilization percentage of HM by coconut fiber biochar showed the following pattern: Pb (66.33%) > Zn (64.50%) > Cu (62.82%) > Cd (55.39%). Incorporating coconut fiber biochar as an amendment improves HM phytostabilization efficiency by reducing their bioaccumulation, increasing biomass production and chlorophyll concentration, and reducing genetic damage levels. This strategy represents a sustainable approach towards reducing the ecological risk of HM biomagnification, alleviating the adverse effects of HM exposure on ecosystem health. Full article

Skin aging, including photoaging, is primarily triggered by chronic exposure to solar radiation, which induces free radical formation, cellular deoxyribonucleic acid (DNA) damage, and structural skin alterations. Achillea millefolium L. (Asteraceae) is rich in phenolic compounds and alkamides, substances known for their antioxidant activity. This study aimed to develop and characterize a photoprotective phytocosmetic nanoemulsion containing crude root extract of A. millefolium. The extract exhibited a total phenolic content of 3.067 ± 1.911 µg GAE/mL, potent antioxidant activity (EC₅₀ = 69.11 ± 8.899 µg/mL), moderate tyrosinase inhibition (19 ± 1.8%), and no cytotoxicity in keratinocytes. The extract was incorporated into nanoemulsions at concentrations of 0.1%, 0.5%, and 1%. The resulting droplets showed mean diameters of 217 to 230 nm, with a significant increase in the polydispersity index (PDI) after extract addition (p < 0.05). Transmission electron microscopy (TEM) confirmed the spherical morphology of the droplets. The in vitro sun protection factor (SPF) was 14 ± 0.9 in the control formulation and increased to 15 ± 2.0 (0.1%), 22 ± 5.2 (0.5%), and 17 ± 1.0 (1%), suggesting a synergistic effect between the extract and chemical filters. All formulations demonstrated UVA/UVB ratio > 0.6, a pH near to 5, occlusive properties, and good spreadability. The results indicate that A. millefolium extract holds potential for safe photoprotective formulations, offering a valuable antioxidant and depigmenting activity in addition to enhancing the SPF. This position is an innovative alternative to phytocosmetic development. Full article

Phages play a role in shaping ecosystems by controlling host abundance via cell lysis, driving host evolution via horizontal gene transfer, and promoting nutrient cycling. The genus Bradyrhizobium includes bacteria able to symbiotically nodulate the roots of soybean (Glycine max), providing the plant with a direct source of biologically fixed nitrogen. Optimizing this symbiosis can minimize the use of nitrogen fertilizers and make soybean production more sustainable. Phages targeting Bradyrhizobium may modify their hosts’ genotype, alter phenotypic traits such as symbiotic effectiveness, and mediate competition among strains for nodulation sites. Sixteen phages were isolated against B. diazoefficiens strain USDA110 and B. elkanii strains USDA94 and USDA31. Comparative analyses revealed host species-dependent diversity in morphology, host range, and genome composition, leading to the identification of three previously undescribed phage species. Remarkably, all B. elkanii phages shared a siphophage morphology and formed a single species with >97% nucleotide identity, even when isolated from farms separated by up to ~70 km, suggesting genomic stability across geographic scales. In contrast, phages isolated against B. diazoefficiens had a podophage-like morphology, exhibited greater genetic diversity, and divided into two distinct species. Although no phages were recovered against the B. japonicum strains or native Delaware Bradyrhizobium isolates tested, some Delaware Bradyrhizobium isolates showed susceptibility in a host range assay. The phage genomes demonstrated features predicting phenotypes. The phage terminase genes predicted headful packaging which promotes generalized transduction. The B. elkanii phages all carried tmRNA genes capable of rescuing stalled ribosomes, and all but one of the phages isolated against the two host species carried DNA polymerase A indicating greater phage control of genome replication. State-of-the-art structural annotation of a hypothetical gene shared by the B. diazoefficiens phages, having a mean amino acid identity of ~25% and similarity of ~35%, predicted a putative tail fiber function. Together this work expands the limited knowledge available on soybean Bradyrhizobium phage ecology and genomics. Full article

The early stages of plant–microbe interaction are critical for establishing beneficial symbioses. We investigated how the endophytic fungus Fusarium solani strain FsK modulates tomato (Solanum lycopersicum) development and hormone pathways during in vitro co-cultivation. Seedlings were sampled at three early interaction stages (pre-contact, T1; initial contact, T2, 3 days post-contact, T3). Root traits and root and leaf transcripts for abscisic acid (ABA) and ethylene (ET) pathways were quantified, alongside fungal ET-biosynthesis genes. FsK altered root system architecture, increasing root area, lateral root number, root-hair length, and fresh biomass. These morphological changes coincided with tissue- and time-specific shifts. In leaves, FsK broadly affected ABA biosynthetic and homeostasis genes (ZEP1, NCED1, ABA2, AAO1, ABA-GT, BG1), indicating reduced de novo synthesis with enhanced deconjugation of stored ABA. ET biosynthesis was curtailed in leaves via down-regulation of ACC oxidase (ACO1–3), with isoform-specific changes in ACC synthase (ACS). The ET receptor ETR1 was transiently expressed early (T1–T2). FsK itself showed staged activation of fungal ET-biosynthesis genes. These results reveal coordinated fungal–plant hormone control at the transcriptional level that promotes root development during early interaction and support FsK’s potential as a biostimulant. Full article

The lotus (Nelumbo nucifera Gaertn.) is an ornamental aquatic plant, highly valued in Asian cultures for its religious symbolism, culinary uses, and medicinal properties. However, the lotus exhibits low genetic diversity in nature, which limits the genetic resources available for breeding programs. Gamma irradiation is an effective method for inducing genetic variation in lotus breeding. The present study examines the gamma sensitivity of lotus seedlings, along with the morphological and anatomical changes induced by various gamma dosages. The results showed that high-dose gamma irradiation (≥100 Gy) significantly inhibited seedling growth and altered most anatomical parameters, each exhibiting distinct dose–response patterns except for midrib diameter. The 100 Gy treatment resulted in the maximum stem diameter, while root diameter peaked at 500 Gy, and the highest dose (600 Gy) produced the largest petioles. Gamma irradiation also triggered tannin accumulation and reduced aerenchyma formation in the leaves. The obtained results demonstrate organ-specific responses to gamma irradiation in the lotus, with leaves being the most sensitive, while petioles, stems, and roots exhibited more variable dose-dependent effects. Full article

Background/Objectives: Gingival recession poses significant challenges in periodontal therapy, particularly in procedures aimed at achieving predictable root coverage and long-term stability of grafts. Conditioning of the root surface plays a crucial role in improving biomaterial adhesion and facilitating periodontal regeneration. This in vitro study aimed to evaluate the morphological and microroughness alterations of root cementum following different mechanical and chemical conditioning protocols commonly used in mucogingival surgery. Methods: Forty extracted human single-rooted teeth were randomly allocated into eight groups: untreated control, mechanical scaling alone, and scaling combined with ethylenediaminetetraacetic acid (EDTA), citric acid, phosphoric acid, tetracycline, doxycycline, or saline. Surface roughness was measured using contact profilometry, while structural modifications were analyzed via scanning electron microscopy. Results: Statistically significant intergroup differences (p < 0.05) were observed. Baneocin treatment produced the most conservative changes, with limited surface roughness and minimal structural alteration, whereas phosphoric acid, tetracycline, and EDTA caused pronounced demineralization and surface porosity. Citric acid and doxycycline induced moderate alterations, with partial preservation of cementum integrity. The null hypothesis assuming no surface or morphological changes was rejected. Conclusions: These findings indicate that low-aggressiveness agents may achieve an optimal balance between surface decontamination and cementum preservation, which is critical for enhancing graft integration and improving clinical outcomes in root coverage surgery. Full article