Transcription factor GmAlfin09 regulates endoplasmic reticulum stress in soybean via peroxidase GmPRDX6.

Soybean (Glycine max [L.] Merr.) is a valuable oil crop but is also highly susceptible to environmental stress. Thus, developing approaches to enhance soybean stress resistance is vital to soybean yield improvement. In previous studies, transcription factor Alfin has been shown to serve as an epigenetic regulator of plant growth and development. However, no studies on Alfin have yet been reported in soybean. In this study, the endoplasmic reticulum (ER) stress- and reactive oxygen species (ROS)-related GmAlfin09 was identified. Screening of genes co-expressed with GmAlfin09 unexpectedly led to the identification of soybean peroxidase 6 (GmPRDX6). Further analyses revealed that both GmAlfin09 and GmPRDX6 were responsive to ER stress, with GmPRDX6 localizing to the ER under stress. Promoter binding experiments confirmed the ability of GmAlfin09 to bind to the GmPRDX6 promoter directly. When GmAlfin09 and GmPRDX6 were overexpressed in soybean, enhanced ER stress resistance and decreased ROS levels were observed. Together, these findings suggest that GmAlfin09 promotes the upregulation of GmPRDX6, and GmPRDX6 subsequently localizes to the ER, reduces ROS levels, promotes ER homeostasis, and ensures the normal growth of soybean even under ER stress. This study highlights a vital target gene for future molecular breeding of stress-resistant soybean lines.

Self-Assembly Intermetallic PtCu3 Core with High-Index Faceted Pt Shell for High-Efficiency Oxygen Reduction.

Rational design of well-defined active sites is crucial for promoting sluggish oxygen reduction reactions. Herein, leveraging the surfactant-oriented and solvent-ligand effects, we develop a facile self-assembly strategy to construct a core-shell catalyst comprising a high-index Pt shell encapsulating a PtCu3 intermetallic core with efficient oxygen-reduction performance. Without undergoing a high-temperature route, the ordered PtCu3 is directly fabricated through the accelerated reduction of Cu2+, followed by the deposition of the remaining Pt precursor onto its surface, forming high-index steps oriented by the steric hindrance of surfactant. This approach results in a high half-wave potential of 0.911 V versus reversible hydrogen electrode, with negligible deactivation even after 15000-cycle operation. Operando spectroscopies identify that this core-shell catalyst facilitates the conversion of oxygen-involving intermediates and ensures antidissolution ability. Theoretical investigations rationalize that this improvement is attributed to reinforced electronic interactions around high-index Pt, stabilizing the binding strength of rate-determining OHads species.

Sn Bulk Phase Doping and Surface Modification on Ti4 O7 for Oxygen Reduction to Hydrogen Peroxide.

Developing stable and highly selective two-electron oxygen reduction reaction (2e- ORR) electrocatalysts for producing hydrogen peroxide (H2 O2 ) is considered a major challenge to replace the anthraquinone process and achieve a sustainable green economy. Here, we doped Sn into Ti4 O7 (D-Sn-Ti4 O7 ) by simple polymerization post-calcination method as a high-efficiency 2e- ORR electrocatalyst. In addition, we also applied plain calcination after the grinding method to load Sn on Ti4 O7 (L-Sn-Ti4 O7 ) as a comparison. However, the performance of L-Sn-Ti4 O7 is far inferior to that of the D-Sn-Ti4 O7 . D-Sn-Ti4 O7 exhibits a starting potential of 0.769 V (versus the reversible hydrogen electrode, RHE) and a high H2 O2 selectivity of 95.7 %. Excitingly, the catalyst can maintain a stable current density of 2.43 mA ⋅ cm-2 for 3600 s in our self-made H-type cell, and the cumulative H2 O2 production reaches 359.2 mg ⋅ L-1 within 50,000 s at 0.3 V. The performance of D-Sn-Ti4 O7 is better than that of the non-noble metal 2e- ORR catalysts reported so far. The doping of Sn not only improves the conductivity but also leads to the lattice distortion of Ti4 O7 , further forming more oxygen vacancies and Ti3+ , which greatly improves its 2e- ORR performance compared with the original Ti4 O7 . In contrast, since the Sn on the surface of L-Sn-Ti4 O7 displays a synergistic effect with Tin+ (3≤n≤4) of Ti4 O7 , the active center Tin+ dissociates the O=O bond, making it more inclined to 4e- ORR.

CoFe Alloys Dispersed on Se, N Co-Doped Graphitic Carbon as Efficient Bifunctional Catalysts for Zn-Air Batteries.

The development of a stable and efficient non-noble metal catalyst with both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is paramount to achieving the widespread application of Zn-air batteries (ZABs) but remains a great challenge. Herein, a novel Co3 Fe7 alloy nanoparticle dispersed on Se, N co-doped graphitic carbon (denoted as CoFe/Se@CN) was prepared through a facile hydrothermal and pyrolysis process. The synthesized CoFe/Se@CN exhibits outstanding ORR and OER properties with an ultralow potential gap of 0.625 V, which is mainly attributed to the abundant porous structure, the rich structural defects formed by doping Se atoms, and the strong synergistic effects between the CoFe alloys and graphitic carbon nanosheet. Furthermore, the ZAB fabricated by CoFe/Se@CN shows a high peak power density of 160 mW cm-2 and a large specific capacity of 802 mA h g-1 with favorable cycling stability, outperforming that of Pt/C+RuO2 . Our study offers a plausible strategy to explore bifunctional carbon-based materials with efficient electrocatalytic properties for rechargeable ZABs.

Irinotecan plus raltitrexed as second-line treatment in locally advanced or metastatic colorectal cancer patients: a prospective open-label, single-arm, multi-center, phase II study.

BACKGROUND: Colorectal cancer is the third most common cancer and the second leading cause of cancer death. There are limited therapeutic options for the treatment of locally advanced or metastatic colorectal cancers which fail first-line chemotherapy. Phase I/II studies showed that the combined application of the raltitrexed and irinotecan has significant synergistic effect and acceptable toxicity. However, most of these previous studies have relatively small sample size. METHODS: This is a prospective open-label, single-arm, multi-center, Phase II trial. Brief inclusion criteria: patients were aged 18 to 75 years with locally advanced or metastatic colorectal cancer after failure of 5-FU and oxaliplatin therapy. Enrolled patients received raltitrexed (3 mg/m2, d1) and irinotecan (180 mg/m2, d1) each 21-day cycle until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival, and the secondary endpoints were disease control rate, objective response rate, overall survival and safety. RESULTS: A total of 108 patients were enrolled between September 2016 and May 2020. The median age was 61 years, ECOG 1 score accounts for 67.6%, the rest were ECOG 0. A total of 502 cycles were completed, with an average of 4.6 cycles and a median of 4 cycles. 108 patients were evaluated, with an objective response rate of 17.6%, and disease control rate of 76.9%. The median follow-up time was 27 months (range:3.1-61.0 m) at data cut-off on March 2023. Median progression-free survival was 4.9 months (95% CI 4.1-5.7) and median overall survival was 13.1 months (95% CI 12.2-15.5). The most common adverse events that were elevated are alanine aminotransferase increased, aspartate aminotransferase increased, fatigue, diarrhoea, neutrocytopenia, thrombocytopenia, hypohemoglobin, and leukocytopenia. Most of the adverse events were Grade I/II, which were relieved after symptomatic treatment, and there were no treatment-related cardiotoxicities and deaths. CONCLUSIONS: The combination of raltitrexed and irinotecan as second-line treatment for mCRC could be a reliable option after failure of standard 5-Fu-first-line chemotherapy in locally advanced or metastatic colorectal cancers, especially for patients with 5-FU intolerance (cardiac events or DPD deficiency patients). TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03053167, registration date was 14/2/2017.

Fetal overgrowth and weight trajectories during infancy and adiposity in early childhood.

BACKGROUND: Large-for-gestational age (LGA), a marker of fetal overgrowth, has been linked to obesity in adulthood. Little is known about how infancy growth trajectories affect adiposity in early childhood in LGA. METHODS: In the Shanghai Birth Cohort, we followed up 259 LGA (birth weight >90th percentile) and 1673 appropriate-for-gestational age (AGA, 10th-90th percentiles) children on body composition (by InBody 770) at age 4 years. Adiposity outcomes include body fat mass (BFM), percent body fat (PBF), body mass index (BMI), overweight/obesity, and high adiposity (PBF >85th percentile). RESULTS: Three weight growth trajectories (low, mid, and high) during infancy (0-2 years) were identified in AGA and LGA subjects separately. BFM, PBF and BMI were progressively higher from low- to mid-to high-growth trajectories in both AGA and LGA children. Compared to the mid-growth trajectory, the high-growth trajectory was associated with greater increases in BFM and the odds of overweight/obesity or high adiposity in LGA than in AGA children (tests for interactions, all P < 0.05). CONCLUSIONS: Weight trajectories during infancy affect adiposity in early childhood regardless of LGA or not. The study is the first to demonstrate that high-growth weight trajectory during infancy has a greater impact on adiposity in early childhood in LGA than in AGA subjects. IMPACT: Large-for-gestational age (LGA), a marker of fetal overgrowth, has been linked to obesity in adulthood, but little is known about how weight trajectories during infancy affect adiposity during early childhood in LGA subjects. The study is the first to demonstrate a greater impact of high-growth weight trajectory during infancy (0-2 years) on adiposity in early childhood (at age 4 years) in subjects with fetal overgrowth (LGA) than in those with normal birth size (appropriate-for-gestational age). Weight trajectory monitoring may be a valuable tool in identifying high-risk LGA children for close follow-ups and interventions to decrease the risk of obesity.

Enzyme-Triggered Polyelectrolyte Complex for Responsive Delivery of α-Helical Polypeptides to Optimize Antibacterial Therapy.

Responsive nanomaterials hold significant promise in the treatment of bacterial infections by recognizing internal or external stimuli to achieve stimuli-responsive behavior. In this study, we present an enzyme-responsive polyelectrolyte complex micelles (PTPMN) with α-helical cationic polypeptide as a coacervate-core for the treatment of Escherichia coli (E. coli) infection. The complex was constructed through electrostatic interaction between cationic poly(glutamic acid) derivatives and phosphorylation-modified poly(ethylene glycol)-b-poly(tyrosine) (PEG-b-PPTyr) by directly dissolving them in aqueous solution. The cationic polypeptide adopted α-helical structure and demonstrated excellent broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria, with a minimum inhibitory concentration (MIC) as low as 12.5 µg mL-1 against E. coli. By complexing with anionic PEG-b-PPTyr, the obtained complex formed ß-sheet structures and exhibited good biocompatibility and low hemolysis. When incubated in a bacterial environment, the complex cleaved its phosphate groups triggered by phosphatases secreted by bacteria, exposing the highly α-helical conformation and restoring its effective bactericidal ability. In vivo experiments confirmed accelerated healing in E. coli-infected wounds.

Mitofilin in cardiovascular diseases: Insights into the pathogenesis and potential pharmacological interventions.

The impact of mitochondrial dysfunction on the pathogenesis of cardiovascular disease is increasing. However, the precise underlying mechanism remains unclear. Mitochondria produce cellular energy through oxidative phosphorylation while regulating calcium homeostasis, cellular respiration, and the production of biosynthetic chemicals. Nevertheless, problems related to cardiac energy metabolism, defective mitochondrial proteins, mitophagy, and structural changes in mitochondrial membranes can cause cardiovascular diseases via mitochondrial dysfunction. Mitofilin is a critical inner mitochondrial membrane protein that maintains cristae structure and facilitates protein transport while linking the inner mitochondrial membrane, outer mitochondrial membrane, and mitochondrial DNA transcription. Researchers believe that mitofilin may be a therapeutic target for treating cardiovascular diseases, particularly cardiac mitochondrial dysfunctions. In this review, we highlight current findings regarding the role of mitofilin in the pathogenesis of cardiovascular diseases and potential therapeutic compounds targeting mitofilin.

Strategic exploration of whole grain cereals in modulating the glycaemic response.

In the current context, diabetes presents itself as a widespread and complex global health issue. This study explores the significant influence of food microstructure and food matrix components interaction (protein, lipid, polyphenols, etc.) on the starch digestibility and the glycaemic response of post-prandial glycemia, focusing on the potential effectiveness of incorporating bioactive components from whole grain cereals into dietary strategies for the management and potential prevention of diabetes. This study aims to integrate the regulation of postprandial glycaemic homeostasis, including the complexities of starch digestion, the significant potential of bioactive whole grain components and the impact of food processing, to develop a comprehensive framework that combines these elements into a strategic approach to diabetes nutrition. The convergence of these nutritional strategies is analyzed in the context of various prevalent dietary patterns, with the objective of creating an accessible approach to mitigate and prevent diabetes. The objective remains to coalesce these nutritional paradigms into a coherent strategy that not only addresses the current public health crisis but also threads a preventative approach to mitigate future prevalence and impact.

Tanshinone IIA alleviates bleomycin-induced pulmonary fibrosis by inhibiting Zbtb16.

Pulmonary fibrosis is a complex disease that can occur in a variety of clinical settings. The Zinc Finger and BTB Domain Containing 16 (Zbtb16) is a transcription factor and has not been studied in pulmonary fibrosis. Lung tissues from rats which were treated with bleomycin and Tanshinone IIA (Tan IIA) were collected for mRNA sequencing. Zbtb16, a differentially expressed gene, was screened. Using adeno-associated virus to knock down Zbtb16 in rats, it was found that the lung index and the content of hydroxyproline in lung tissue were decreased. HE and Masson staining revealed that pathological symptoms of lung histopathology were relieved after Zbtb16 knockdown. Protein expressions of α-SMA, Collagen I and Fibronectin were significantly decreased after Zbtb16 knockdown in vivo and in vitro. Meanwhile, the protein content of TGF-ß1 and the phosphorylation of Smad2/3 were inhibited by Zbtb16 knockdown. Conversely, under the treatment of Tan IIA and TGF-ß1, overexpression of Zbtb16 improved cell viability, increased the expression of fibrosis-related proteins, and promoted the phosphorylation of Smad 2/3. All above demonstrates that Zbtb16 inhibition ameliorates pulmonary fibrosis and suppresses the TGF-ß/Smad pathway. Furthermore, Zbtb16 mediates the inhibitory process of Tan IIA on pulmonary fibrosis. This study provides a novel candidate therapeutic target for pulmonary fibrosis.

Construction of Fe/Co-N4 Single-Atom Sites for the Oxygen Reduction Reaction in Zinc-Air Batteries.

Insight into the modulation effect of oxygen reduction reaction (ORR) active centers is of profound significance but remains a great challenge. Here, we designed Co, Fe dual-metal single-atom sites (CoFe-DSAs/NC) uniformly anchored on nitrogen-doped multiwalled carbon nanotubes for boosting ORR performance through regulating the 4d electronic orbitals of the Co-N4 active site. Mechanism studies revealed that for the first time the neighboring Fe-N4 atomic sites were able to regulate the d-band center of Co-N4 single-atom active centers while maintaining the balance of adsorption-desorption affinity for O2 and oxygen-containing species on Co-N4, thereby resulting in a superior ORR performance with a positive half-wave potential (0.90 V vs RHE). The assembled zinc-air battery based on CoFe-DSAs/NC exhibited an increased open-circuit voltage (1.48 V) and an elevated specific capacity (782.33 mAh·g-1). The work provides a new clue for reasonably designing high-performance ORR catalysts through adjusting the d-band center of active sites.

In-Sb Covalent Bonds over Sb2Se3/In2Se3 Heterojunction for Enhanced Photoelectrochemical Water Splitting.

Antimony selenide is a promising P-type photocatalyst, but it has a large number of deep energy level defects, leading to severe carrier recombination. The construction of a heterojunction is a common way to resolve this problem. However, the conventional heterojunction system inevitably introduces interface defects. Herein, we employ in situ synthesis to epitaxially grow In2Se3 nanosheets on Sb2Se3 nanorods and form In-Sb covalent interfacial bonds. This petal-shaped heterostructure reduced interface defects and enhanced the efficiency of carrier separation and transport. In this work, the photocurrent density in the proposed Sb2Se3/In2Se3 photocathode is 0.485 mA cm-2 at 0 VRHE, which is 30 times higher than that of pristine Sb2Se3 and it has prominent long-term stability for 24 h without obvious decay. The results reveal that the synergy of the bidirectional built-in electric field constructed between In2Se3 and Sb2Se3 and the solid In-Sb interfacial bonds together build a high-efficiency transport channel for the photogenerated carriers that display enhanced photoelectrochemical (PEC) water-splitting performance. This work provides efficient guidance for reducing interface defects via the in situ synthesis and construction of interfacial bonds.

Identification and characterization of two Bacillus anthracis bacteriophages.

Anthrax is an acute infectious zoonotic disease caused by Bacillus anthracis, a bacterium that is considered a potential biological warfare agent. Bacillus bacteriophages shape the composition and evolution of bacterial communities in nature and therefore have important roles in the ecosystem community. B. anthracis phages are not only used in etiological diagnostics but also have promising prospects in clinical therapeutics or for disinfection in anthrax outbreaks. In this study, two temperate B. anthracis phages, vB_BanS_A16R1 (A16R1) and vB_BanS_A16R4 (A16R4), were isolated and showed siphovirus-like morphological characteristics. Genome sequencing showed that the genomes of phages A16R1 and A16R4 are 36,569 bp and 40,059 bp in length, respectively. A16R1 belongs to the genus Wbetavirus, while A16R4 belongs to the genus Hubeivirus and is the first phage of that genus found to lyse B. anthracis. Because these two phages can comparatively specifically lyse B. anthracis, they could be used as alternative diagnostic tools for identification of B. anthracis infections.

Structure-Based Discovery of the SARS-CoV-2 Main Protease Noncovalent Inhibitors from Traditional Chinese Medicine.

Traditional Chinese medicine (TCM) has been extensively employed for the treatment of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is demand for discovering more SARS-CoV-2 Mpro inhibitors with diverse scaffolds to optimize anti-SARS-CoV-2 lead compounds. In this study, comprehensive in silico and in vitro assays were utilized to determine the potential inhibitors from TCM compounds against SARS-CoV-2 Mpro, which is an important therapeutic target for SARS-CoV-2. The ensemble docking analysis of 18263 TCM compounds against 15 SARS-CoV-2 Mpro conformations identified 19 TCM compounds as promising candidates. Further in vitro testing validated three compounds as inhibitors of SARS-CoV-2 Mpro and showed IC50 values of 4.64 ± 0.11, 7.56 ± 0.78, and 11.16 ± 0.26 µM, with EC50 values of 12.25 ± 1.68, 15.58 ± 0.77, and 29.32 ± 1.25 µM, respectively. Molecular dynamics (MD) simulations indicated that the three complexes remained stable over the last 100 ns of production run. An analysis of the binding mode revealed that the active compounds occupy different subsites (S1, S2, S3, and S4) of the active site of SARS-CoV-2 Mpro via specific poses through noncovalent interactions with key amino acids (e.g., HIS 41, ASN 142, GLY 143, MET 165, GLU 166, or GLN 189). Overall, this study provides evidence indicating that the three natural products obtained from TCM could be further used for anti-COVID-19 research, justifying the investigation of Chinese herbal medicinal ingredients as bioactive constituents for therapeutic targets.

Multiple infections secondary to immunosuppression after Chlamydia psittaci infection: a case report.

This study presents the clinical profile of a 74-year-old male patient admitted to the hospital due to a 20-day history of coughing, chest tightness, and dyspnea. Upon admission, the patient presented with fever, tachycardia, and tachypnea. Clinical examination revealed evidence of lung infection, sepsis, and multi-organ dysfunction, alongside abnormal blood gas analysis and elevated C-reactive protein (CRP) levels. Pathogen testing confirmed Chlamydia psittaci (C. psittaci), infection. Throughout the treatment course, the patient developed concurrent fungal and viral infections, necessitating a comprehensive approach involving combined antibiotic and antifungal therapy. Despite encountering treatment-related complications, the patient demonstrated clinical improvement with aggressive management. This case underscores the importance of recognizing immune suppression subsequent to Chlamydia infection, emphasizing the critical role of early diagnosis, intervention, and standardized treatment protocols in enhancing patient prognosis.

Environment Endurable, Self-Healing, Super-Adhesive, and Mechanically Strong Ionogels for Reliable Sensing.

Ionogels possess high conductivity, stretchability, and adhesion, making them promising as flexible sensors. However, it remains challenging to fabricate an ionogel which integrates excellent environment endurance, superior mechanical strength, high self-healing efficiency, and super adhesion. Herein, a supramolecular ionic liquid is synthesized using calcium chloride and 1-butyl-3-methylimidazolium chloride. An advanced ionogel based on this supramolecular ionic liquid is conveniently constructed by a one-pot method with acrylamide and acrylic acid as monomers. The supramolecular cross-linking network, formed by affluent coordination interactions, hydrogen bonds, and electrostatic interactions, provides the ionogel with ideal mechanical strength (tensile strength up to 1.7 MPa), high self-healing efficiency (up to 149%), super adhesion (up to 358 kPa on aluminum), excellent solvent tolerance (less than 10% weight increase, high mechanical and sensing performance retention after being soaked in organic solvents), and low-temperature endurance (breaking elongation can reach 87% at -30 °C). The supramolecular ionogels can function as multi-mode sensors, capable of monitoring strain and different amplitudes of human movements in real-time. Moreover, the sensing performance of ionogels remains unaffected even after being self-healed or exposure to organic solvents. It is expected that this study could offer valuable design ideas to construct advanced gel materials applicable in complicated environment.

Sex difference in trait empathy is encoded in the human anterior insula.

Females are considered the more empathic sex. This conventional view, however, has been challenged in the past few decades with mixed findings. These heterogeneous findings could be caused by the fact that empathy is a complex and multifaceted construct. To clarify whether sex differences exist in certain dimensions of empathy and whether they are associated with specific neural bases, this study measured trait empathy using the interpersonal reactivity index (IRI) and collected brain structural and functional magnetic resonance imaging data in a large sample of healthy participants (206 males vs. 302 females). We found that females scored higher in the personal distress (PD) subscale than males, but they were comparable to males in other IRI subscales. Sex difference in PD was encoded by brain structural (e.g. gray matter volume in left anterior insula [AI]) and functional (e.g. resting-state functional connectivity between left AI and temporoparietal junction/inferior frontal gyrus) characteristics. Notably, the relationship between sex and PD was indirect-only and serially mediated by AI-associated structural and functional characteristics. Altogether, our results suggested that sex difference existed in self-oriented affective empathy (i.e. PD) and highlighted the importance of the AI, both structurally and functionally, in mediating the sex difference in trait empathy.

Analysis of the current status and associated risk factors of cognitive function in Tibetan hypertensive patients at various altitudes.

OBJECTIVE: This study aims to explore the current cognitive status and identify risk factors associated with cognitive function in Tibetan hypertensive patients living at various altitudes. METHODS: The Simple Mental Status Scale (MMSE) was used to evaluate the cognitive function of 611 Tibetan hypertensive patients at various altitudes in Gannan Tibetan Autonomous Prefecture. Afterward, we conducted an analysis to identify the factors influencing their cognitive function. RESULTS: The study found that the prevalence of cognitive dysfunction was 22.3%, with a higher incidence at high altitude (group D 29.0%) compared to low altitude (group A 16.0%). The study conducted a binary logistic regression analysis to identify the risk factors for cognitive dysfunction. The analysis revealed that altitude, age, body mass index, marital status, education, income level, and blood pressure control level were all significant risk factors. After controlling for age, body mass index, marital status, educational level, income level, and blood pressure control level, the risk of developing cognitive dysfunction was 2.773 times higher (p < .05) for individuals in group C at high altitude and 2.381 times higher (p < .05) for individuals in group D at high altitude compared to those in group A at low altitude. CONCLUSIONS: Altitude plays a role in the development of cognitive dysfunction in hypertensive patients. Tibetan hypertensive patients living at high altitudes may be at a higher risk of cognitive dysfunction compared to those living at lower altitudes. Therefore, interventions should be targeted to prevent or mitigate potential cognitive impairment.

Arabidopsis thaliana YUC1 reduced fluoranthene accumulation by modulating IAA content and antioxidant enzyme activities.

Indole-3-acetic acid (IAA) can regulate plant growth and thus modulate the accumulation of polycyclic aromatic hydrocarbons (PAHs). However, the effect of endogenous IAA on PAHs accumulation and its influencing factors remains unclear. To unravel this, two different IAA expression genotypes of Arabidopsis thaliana, i.e., IAA-underproducing yucca1D [YUC1] mutant and wild type [WT]) were selected and treated with different fluoranthene (Flu) concentrations (0 mg/L [CK], 5 mg/L [Flu5], and 20 mg/L [Flu20]) to reveal the impact mechanism of endogenous IAA on Flu uptake by plants. The results indicated that under Flu5 treatment, the bioconcentration factors (BCF) and translocation factors (TF) of Flu in WT were 41.4 % and 14.3 % higher than those in YUC1. Similarly, under Flu20 treatment, the BCF and TF of Flu in WT were also 42.2 % and 8.2 % higher than those in YUC1. In addition, the BCF and TF were 72.5 % and 35.8 % higher under Flu5 treatment compared to Flu20 treatment for WT, and 73.4 % and 28.6 % higher respectively for YUC1. Moreover, WT exhibited higher plant growth (biomass, root morphology indicators [root length, root area and number of tips]) and IAA content compared to YUC1 under identical Flu treatments. Plant growth and IAA content declined with the increase of Flu concentration in both YUC1 and WT leaves compared with CK treatment. Conversely, in WT roots, root biomass and morphology indicators promoted followed by a decrease as the concentration of Flu increased. Additionally, the antioxidant enzyme activities (SOD, POD, and CAT) of WT were 11.1 %, 16.7 %, and 28.9 % higher than those of YUC1 under Flu5 treatment, and 13.6 %, 12.9 %, and 26.5 % higher under Flu20 treatment. Compared with CK treatment, SOD and POD activities promoted with increasing Flu concentration, whereas CAT activities decreased. Variability separation analysis revealed that level of IAA primarily influenced Flu accumulation in WT or under Flu5 treatments, whereas antioxidant enzyme activity primarily affected Flu accumulation in YUC1 or under Flu20 treatments. Exploring the relationship between the IAA synthesis gene YUCCA and IAA levels, alongside Flu accumulation, could yield novel insights into the regulation of PAH accumulation in plants.

Endogenous IAA affected fluoranthene accumulation by regulating H+-ATPase and SOD activity in ryegrass.

This study explores the role of endogenous indole-3-acetic acid (IAA) in modulating plant responses to pollution stress and its effect on pollutant accumulation, with a focus on fluoranthene (Flu) in ryegrass. To elucidate the mechanism, we employed an IAA promoter (α-aminobutyric acid [α-AB]) and an IAA inhibitor (naphthylphthalamic acid [NPA]) to regulate IAA levels and analyze Flu uptake characteristics. The experimental setup included a Flu treatment group (ryegrass with Flu addition) and a control group (ryegrass without Flu). Our findings demonstrate that Flu treatment enhanced IAA content and plant growth in ryegrass compared to the control. The Flu+AB treatment further enhanced these effects, while the Flu+NPA treatment exhibited a contrasting trend. Moreover, Flu+AB treatment led to increased Flu accumulation, in contrast to the inhibitory effect observed with Flu+NPA treatment. Flu treatment also enhanced the activities of key antioxidant enzymes (SOD, POD, CAT) and increased soluble sugar and protein levels, indicative of enzymatic and nonenzymatic defense responses, respectively. The Flu+AB treatment amplified these responses, whereas the Flu+NPA treatment attenuated them. Significantly, Flu treatment raised H+-ATPase activity compared to the control, an effect further elevated by Flu+AB treatment and diminished by Flu+NPA treatment. A random forest analysis suggested that Flu accumulation dependency varied under different treatments: it relied more on H+-ATPase activity under Flu+AB treatment and more on SOD activity under Flu+NPA treatment. Additionally, Flu+AB treatment boosted the transpiration rate in ryegrass, thereby increasing the Flu translocation factor, a trend reversed by Flu+NPA treatment. This research highlights crucial factors influencing Flu accumulation in ryegrass, offering potential new avenues for controlling the gathering of contaminants within plant systems.