Search Results (481)

Postharvest lignification of juice sacs in Meizhou pomelo is a major physiological disorder that compromises fruit quality and limits sustainable industry development. Through a comprehensive three-year field study, we investigated the effects of key factors—soil organic matter, storage temperature, and tree age—on fruit lignification, and evaluated the efficacy of ten plant growth regulators (PGRs) and their combinations in mitigating granulation. Our results demonstrated that soil rich in organic matter and exchangeable calcium significantly reduced the granulation index. Constant storage at 15 °C effectively suppressed weight loss and lignification compared to fluctuating ambient temperatures. Among the tested PGRs, 28-Homobrassinolide (28-homo-BR), 28-Epihomobrassinolide (28-epi-BR), 24-Epibrassinolide (24-epi-BR), and 14-Hydroxybrassinosteroid (14-hydro-BR) exhibited the most pronounced effects in alleviating granulation. Two superior PGR combinations were subsequently identified, which functioned by synergistically downregulating the activities of key phenylpropanoid pathway enzymes—phenylalanine ammonia-lyase, 4-coumarate: CoA ligase, cinnamyl alcohol dehydrogenase, and peroxidase. This downregulation likely contributed to reduced lignin biosynthesis and accumulation. Metabolomic profiling further revealed an accumulation of phenylpropanoid precursors, including ferulic acid and p-coumaric acid, in lignified juice sacs, indicating that the overactivation of this pathway is a key metabolic feature associated with lignification. This finding provides critical evidence for the potential mechanism whereby PGRs suppress lignification, thus offering both mechanistic insights and practical strategies for controlling lignification in pomelo and other citrus fruits. Full article

In this study, the biocatalytic activity of four steroid-transforming strains isolated from the African frog Xenopus laevis and identified as Streptomyces rochei towards pregnane steroids has been investigated. All the isolated strains facilitated the reduction of the C20-carbonyl group and the structures of the metabolites were confirmed by mass spectrometric (MS) and ¹H NMR spectroscopic analyses. Hydrocortisone and progesterone were poorly transformed by the streptomycete strains, whereas cortexolone (Reichstein’s substance S) was effectively biotransformed, yielding more than 90% of 17α,20β,21α-trihydroxy-4-pregnen-3-one (20β-S). Primarily, 20α-reduction was detected when the microbial isolates were incubated with 17α-hydroxyprogesterone with the yield of 17α,20α-dihydroxy-4-pregnen-3-one (17,20α-P) reaching 70%. The biological activity of 20β-S was evaluated in Danio rerio. The results demonstrated that 20β-S modulated stress- and anxiety-related behavioral responses and activated Pgr-dependent transcriptional pathways in the brain and ovarian tissues. These observations support the potential relevance of the synthesized progestin as a functional regulator in teleost physiology. The findings enhance our understanding of the biodiversity of steroid-transforming actinomycetes inhabiting amphibians and can be successfully employed for the effective microbiological synthesis of biologically active 20-hydroxylated progestins that serve as bioregulators in teleosts. Full article

Defective graphene has emerged as a promising strategy to enhance electrochemical performance of pristine graphene (p-Gr) as anodes in lithium-ion batteries (LIBs). Herein, we perform a comprehensive first-principles study based on density functional theory (DFT) to systematically investigate the Li adsorption, charge transfer, and diffusion behaviors of p-Gr and defective graphene (d-Gr) with single vacancy (SV Gr) and double vacancy (DV5-8-5 Gr) defects, aiming to clarify the mechanism by which defects modulate Li storage performance. Structural optimization reveals that SV Gr undergoes notable out-of-plane distortion after Li adsorption, while DV5-8-5 Gr retains planar geometry but exhibits more significant C-C bond length variations compared to p-Gr. Binding energy results confirm that defects enhance Li adsorption stability, with DV5-8-5 Gr showing the strongest Li–graphene interaction, followed by SV Gr and p-Gr. Bader charge analysis and charge density difference plots further validate that defects enhance charge transfer from Li ions to graphene. Using the nudged elastic band (NEB) method, we find that defects reduce Li diffusion barriers: DV5-8-5 Gr exhibits a lower barrier than p-Gr. Our findings demonstrate that DV5-8-5 Gr exhibits the most favorable Li storage performance, providing a robust theoretical basis for designing high-performance graphene anodes for next-generation LIBs. Full article

Secondary somatic embryogenesis (SSE) represents a powerful tool for clonal propagation, efficient genetic modification, and plant conservation, enabling the continuous production of secondary somatic embryos (SSEs) from previously formed embryogenic tissues. The efficiency of SSE is determined both by external factors such as exogenous hormonal and environmental conditions and internal cues such as explant type and genotype. Auxins, particularly synthetic 2,4-dichlorophenoxyacetic acid (2,4-D), represent key factors in inducing and maintaining embryogenic competence, while cytokinins often modulate the differentiation and proliferation of SSEs. The interplay of plant growth regulators (PGRs) not only affects the frequency of SSE induction, but also the morphology and proper development of the resulting embryos. Here, we provide a comprehensive review on hormonal treatments, especially the role of auxins and cytokinins and environmental factors such as temperature, light, and culture medium composition, that shape the embryogenic potential in SSE, with species-specific responses frequently being observed. The importance of primary explant selection, as well as the liquid phase and potential scale-up with bioreactors, are also discussed. Other challenges related to genotype recalcitrance, limited efficiency, maturation and conversion rates, and the lack of an advanced molecular approach are further addressed, providing a framework for improved regeneration and reliability across diverse species. Full article

Plant growth regulators (PGRs) significantly contribute to enhancing crop quality and yield. There is an urgent market demand for innovative natural PGRs. Marine natural products have the potential to serve as valuable sources of PGRs. To discover natural siderophore-type PGRs from marine natural products, according to a systematic pipeline for efficient lead-structure discovery from microbial natural products (SPLSD), a unique desferrioxamine-like siderophore biosynthetic gene cluster was discovered and activated by genome mining and culture regulation from a novel species, Streptomonospora nanhaiensis 12A09^T. Some potentially new desferrioxamine derivatives were further discovered by the LC-MS/MS molecular network. Three new desferrioxamine derivatives, desferrioxamines C1, C2, and G3 (1–3) and three known ones, terragine E (4) and desferrioxamines E and D2 (5–6), were selectively isolated and identified using chromatography and spectroscopy techniques from S. nanhaiensis 12A09^T. In the ferric iron-chelating assay, 4 and 5 showed moderate Fe (III)-complexing capability, compared with desferrioxamine mesylate. In the plant growth-regulatory assay, 1, 5, and 6 potently boosted the root length of Oryza sativa and Brassica campestris seedlings, equivalent to gibberellin. This study reports the first discovery of desferrioxamine derivatives exhibiting plant growth-promoting activity. These findings offer valuable lead compounds for PGRs. Full article

Photosystem I (PSI) photoinhibition (PI(I)) is gaining traction as a potentially more significant threat to plant performance than photoinhibition of photosystem II (PSII). The increased focus is facilitated by the implementation of specific protocols that induce PI(I), such as artificial fluctuating light (FL) and repetitive short saturating pulses (rSPs). rSPs were long considered a specific sub-case of FL. However, recent evidence suggests that PI(I) proceeds via at least two distinct, treatment-dependent mechanisms, leading to damage at the donor or acceptor side of PSI. This discovery suggests that rSPs and FL represent distinct photoinhibitory stresses and that different mechanisms protect PSI against FL and rSPs. This study comparatively analyzed the effects of FL and rSPs on PSI activity in Arabidopsis thaliana wild-type plants and a selection of mutants (pgr5, pgrl1, stn7, tap38/pph1, and pgr1), previously noted or hypothesized to have altered PI(I) sensitivity relative to the wild type. The results of this work, particularly the contrasting sensitivity of tap38/pph1 compared to the wild type under FL and rSP conditions, strongly suggest that pulsed illumination and fluctuating light are distinct photoinhibitory treatments, and different mechanisms protect PSI against them. Full article

Floral induction in late-maturing litchi is vulnerable to warm, humid winters with insufficient chilling. The late cultivar ‘Ziniangxi’ was evaluated during January–February 2024 in an experimental orchard in Hainan, China, when chilling accumulation was very low, with only seven days having a mean air temperature ≤ 15 °C. Under this marginal-chill context, the effects of plant growth regulator (PGR) applications on bud fate were assessed using six single-agent and thirteen composite PGR–nutrient treatments plus a water control, applied as four foliar sprays during floral induction. In the untreated control, the final flowering proportion of tagged shoots was 0.33 in the single-agent trial and 0.05 in the composite trial. In contrast, ABA (3.33 mg L⁻¹) increased flowering to 0.53, and ethephon- or brassinolide-based applications to 0.40–0.47. The most effective composite formulations raised flowering further to 0.50–0.63. These composite applications also increased leaf starch from about 4 mg g⁻¹ FW in the control to approximately 8–9 mg g⁻¹ FW ($p<0.05$), whereas sucrose concentrations showed only small differences among treatments. Across trials, shoots that became floral consistently exhibited higher leaf starch than vegetative shoots. Gene-expression analyses indicated that floral buds had higher transcript abundance of LcFUL and lower transcript levels of LcFLC and other floral repressors than vegetative buds, consistent with their assignment to floral versus vegetative categories. Overall, the results suggest that appropriately timed ethephon–ABA-based PGR programs, supplemented with BR or 6-BA and nutrients, can partially improve floral induction in ‘Ziniangxi’ under warm, low-chill winters and provide a basis for designing PGR strategies for late litchi cultivars facing insufficient winter chilling. Full article

Soybean (Glycine max) is a globally important crop, but its productivity is often limited by suboptimal nodulation and nitrogen fixation, particularly under stress conditions. Bradyrhizobium diazoefficiens strain USDA110 is widely applied to enhance nodulation, yet its efficiency can be further improved by phytohormone modulation. This study examined the effects of seed coatings containing plant growth regulators (PGRs)—acetylsalicylic acid (ASA), aminoethoxyvinylglycine (AVG), Indole-3-butyric acid (IBA), and 6-benzylaminopurine (BAP)—at varying concentrations (5, 50, and 500 nM), in combination with USDA110, on nodulation, nitrogenase activity, ethylene emission, physiological traits, and yield of soybean cultivar CM60. Laboratory assays identified 50 nM AVG, 5 nM IBA, and 5 nM ASA as optimal treatments, significantly enhancing nodule number and nitrogenase activity more than 32% and 28%, as, respectively, compared to untreated seeds. Greenhouse trials in pots, both under well-watered and water stress conditions, showed that USDA110 + AVG/IBA significantly improved photosynthetic rate (+21 and +18% compared to USDA110 alone) and increased plant height. Notably, USDA110 + AVG/IBA treatments sustained higher seed weight under drought, increasing it by over 25%, indicating strong synergistic effects in mitigating stress impacts. These findings highlighted that integrating USDA110 with specific PGRs represented a promising strategy to optimize nitrogen fixation and enhanced soybean productivity under both favorable and challenging conditions. Full article

Bamboo seeds (often called bamboo rice) are nutritionally rich, offering protein, fiber, and essential minerals like potassium and manganese. Chimonobambusa utilis seeds, especially, represent an underexplored nutritional resource with exceptional edible and agricultural potential. Here, we report that Ch. utilis seeds contain remarkably high levels of unsaturated fatty acids (67.39% of total lipids), with linoleic and linolenic acids comprising 36.5% and 26.7%, respectively, exceeding major vegetable oils by 1.5 to 3.3-fold. Comprehensive plant growth regulator (PGR) screening revealed distinct regulatory patterns: gibberellic acid (GA₃, 8.66 µM) exhibits biphasic dose–response kinetics, cytokinins (6-BA, 222.0 µM) show nonlinear responses transitioning from low-concentration inhibition to high-concentration promotion with preferential lateral root induction, while auxins (NAA, 134.2 µM) demonstrate unimodal responses with concentration-dependent efficacy, achieving the strongest root-promoting effect (27% increase, p < 0.05). Mechanistically, optimal phytohormone treatments sustained elevated soluble sugar levels and differentially modulated key enzymes. Notably, 6-BA potently suppressed sucrose synthase activity while NAA maximally stimulated starch biosynthetic enzyme activities (AGPase and GBSS), identifying sucrose metabolism as a pivotal regulatory node. Comparative evaluation of germination capacity and seedling vigor revealed that individual treatments with 8.66 µM GA₃, 222.0 µM 6-BA, or 134.2 µM NAA achieved the best performance among tested concentrations, reducing germination time by 5 days and increasing germination percentage by 4.2 to 6.3% relative to control. These findings establish Ch. utilis as a premium oil crop candidate and provide mechanistic insights into phytohormone-mediated germination control with broad implications for bamboo seed biology and propagation optimization. Full article

Plant growth regulators (PGRs) are natural or synthetic substances that control and manipulate plant physiological processes, controlling branching and vegetative growth. Maintaining roadside vegetation through frequent mowing is costly, dangerous, and unsustainable. This narrative literature review proposes a revolution in this management by conducting a systematic literature review on the strategic application of PGRs on roadsides. Practices such as the application of plant growth regulators, the use of native cover crops, and bioengineering techniques with stabilizing species were analyzed. Previous studies have shown that the use of regulators such as mepiquat chloride and paclobutrazol reduces plant height and aboveground biomass, favoring growth control and compacting the plant architecture. The environmental and operational impacts related to vegetation control on roadside strips were also considered. Integrated with LiDAR technology for precise monitoring, this model establishes a new paradigm: smart, safe, and sustainable. Therefore, it is hoped that this compendium will fill a gap in national guidelines by offering an evidence-based protocol guideline for the use of PGR as an alternative to traditional management methods, thus reducing the number of mowing and weeding operations in highway right-of-way areas. Full article

Pinus koraiensis, as a keystone tree species, possesses immense economic and ecological value. However, the present cultivation of high-quality seedlings in Pinus koraiensis plantations remains hindered by prohibitively high costs and inadequate technological advancements. Additionally, the species’ prolonged growth cycle and low yield, when compounded by issues such as excessive harvesting, may result in supply constraints. Plant growth regulators (PGRs), a class of naturally occurring or synthetically derived chemical compounds, are capable of modulating plant development and physiology. These regulators exert notable effects by enhancing root proliferation, facilitating lignification, influencing plant architecture, and augmenting yield. Owing to their operational simplicity and relatively low cost, PGR applications hold substantial promise for cultivating Pinus koraiensis seedlings with superior traits. In this study, four-year-old Pinus koraiensis seedlings were employed to evaluate the impacts of three PGRs (paclobutrazol, chlormequat chloride, and diethyl aminoethyl hexanoate), alongside varied application methods (dosage and frequency), on the growth, physiological, and photosynthetic parameters of the seedlings. The findings revealed that treatment with 1.5 g/L paclobutrazol produced the most pronounced effects across a range of indicators. Specifically, this treatment markedly enhanced growth traits (e.g., branch diameter, new shoot length, lateral branch length, aboveground fresh and dry weights, root fresh and dry weights, lateral root dry weight, and number of second-order roots), physiological attributes (e.g., increased superoxide dismutase and peroxidase activities, elevated lignin content, and reduced relative conductivity and malondialdehyde levels), and photosynthetic metrics (e.g., elevated net photosynthetic rate, stomatal conductance, transpiration rate, and maximum net photosynthetic rate), thereby constituting the optimal treatment combination. Full article

The spice Ferula assa-foetida L., also known as asafoetida, is widely recognized for its medicinal and culinary applications. The non-native status of the plant and the prolonged dormancy of its seeds pose significant challenges for large-scale cultivation in India. In vitro organogenesis offers an effective solution to these obstacles. Establishing reliable in vitro regeneration protocols requires standardized statistical methods to evaluate univariate and multivariate data for optimizing specific traits. However, these methods have limitations when handling complex, nonlinear inputs, often producing large prediction errors that reduce the reliability of trait optimization. This study developed an in vitro regeneration system for F. assa-foetida L. and identified optimal PGRs for somatic embryogenesis and shoot organogenesis through image-based morphological analysis. Predictive models were created using DL and ML algorithms. Calli induced from leaf explants was cultured on the Murashige and Skoog medium supplemented with various combinations and concentrations of thidiazuron (TDZ), 6-benzylaminopurine (BAP), and α-naphthaleneacetic acid (NAA), as experimental variables. Seven ML approaches, namely random forest (RF), support vector machine (SVM), k-nearest neighbours (kNN), decision tree (DT), extreme gradient boosting (XG Boost), naïve bayes, and logistic regression, alongside five DL models—convolutional neural network (CNN), MobileNet, region-based convolutional neural network (RCNN), residual neural network (ResNet), and visual geometry group (VGG19)—were employed to predict the best PGRs for somatic embryogenesis and shoot organogenesis. Among them, the convolutional neural network (CNN) achieved the highest accuracy (87%), outperforming baseline ML models such as logistic regression and decision tree (82%). This pioneering study in F. assa-foetida L. presents an AI-driven, image-based framework for predicting optimal PGRs, offering a scalable approach to enhance micropropagation in endangered medicinal plants. Full article

Mushroom production and economic value on a global scale are significantly increasing. On the other hand, food safety has raised concerns; however, limited research exists on the presence of plant growth regulator (PGR) residues in edible mushrooms. Herein, this study appears to be the first to comprehensively investigate PGR residual characteristics and assess their associated dietary exposure risks to consumers. A total of 105 edible mushroom samples of seven different varieties were analyzed, and the overall detection rate was 81%. The residual level of PGRs ranged from below the limit of detection to 6.308 mg/kg. Among varieties, 100% of A. aegerita, T. fuciformis Berk, and H. erinaceus samples contained at least one PGR residue. Dietary exposure risks were assessed using both deterministic and probabilistic approaches. Calculated values of both %ADI (acceptable daily intake) and %ARfD (acute reference dose)were below 100 and do not indicate a potential health concern with respect to edible mushroom consumption. However, several PGRs had a relatively high %ADI or %ARfD value, suggesting that the Maximum Residual Limits (MRLs) and associated regulatory norms should be immediately established. This work not only provides valuable information for edible mushroom consumers but also an important reference for the risk management decision. Full article

The genus Corydalis, belonging to the Papaveraceae family, is widely distributed across the Northern Hemisphere, primarily in Asia. This study aimed to investigate the effect of plant growth regulators (PGRs) on callus induction, and of light quality and intensity on indirect shoot organogenesis, dl-Tetrahydropalmatine (dl-THP) accumulation, and activities of antioxidant enzymes in Corydalis turtschaninovii Besser. Calli were successfully induced from the leaf, tuber, and petiole explants with different PGR combinations. The best callus induction from leaf, tuber, and petiole explants were obtained in the medium supplemented with 3 mg·L⁻¹ kinetin (Kn) combined with 0.8 mg·L⁻¹ naphthalene acetic acid (NAA), 3 mg·L⁻¹ benzyl adenine (BA) combined with 0.8 mg·L⁻¹ NAA, and 2 mg·L⁻¹ BA combined with 0.5 mg·L⁻¹ NAA, respectively. For indirect shoot organogenesis, calli were cultured on the Murashige and Skoog (MS) medium under dark (D), white (W), red (R), blue (B), or 1:1 mixture of red and blue (RB) light-emitting diodes (LEDs) at an intensity of 25 or 50 µmol·m⁻²·s⁻¹ photosynthetic photon flux density (PPFD) for six weeks. The RB treatment increased biomass accumulation of the callus, and promoted the induction of the shoot from the callus, whereas the R treatment promoted the dl-THP accumulation, especially with the higher light intensity. Light quality and intensity significantly influenced the activities of antioxidant enzymes and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity in calli, with the most pronounced effects observed under B or RB light treatments. Taken together, the application of monochromatic LED or combinations of red and blue LEDs could be used for the callus culture for different purposes in vitro. Full article

Background and Clinical Significance: Collagenous colitis is an uncommon form of microscopic colitis characterized by chronic watery diarrhea and thickening of the subepithelial collagen layer. While various medications have been implicated in its pathogenesis, paclitaxel-associated collagenous colitis remains exceptionally rare in the literature. Recognition of this adverse event is crucial for appropriate management, particularly in patients receiving dose-modified chemotherapy regimens. This case highlights the importance of considering drug-induced collagenous colitis in cancer patients presenting with severe diarrhea during chemotherapy. Case Presentation: We report a 71-year-old Japanese male with metastatic breast cancer who developed acute-onset collagenous colitis during paclitaxel treatment. His primary tumor was invasive ductal carcinoma with hormone receptor-positive, HER2-negative disease (ER+, PgR+, HER2-, Ki-67 46%) and progressive metastatic disease. Given pre-existing renal dysfunction, paclitaxel was initiated at 60% dose reduction. Sixteen days after treatment initiation, the patient experienced abrupt onset of profuse watery diarrhea with approximately 10 bowel movements daily, necessitating hospital admission. Colonoscopic evaluation demonstrated increased vascular permeability and superficial mucosal erosions. Histopathological analysis revealed diagnostic features of collagenous colitis with a markedly thickened subepithelial collagen band measuring 23 μm. Following immediate cessation of paclitaxel, the patient experienced complete resolution of diarrheal symptoms without subsequent relapse. Conclusions: This case represents a rare manifestation of paclitaxel-induced collagenous colitis. Clinicians should maintain heightened awareness of this potential complication in patients receiving taxane-based chemotherapy who develop significant diarrhea. Prompt recognition and immediate drug discontinuation are essential for favorable outcomes and symptom resolution. Full article