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Biochar application to soil has proven to be an excellent approach for decreasing the concentration of auto-toxic compounds and promoting plant growth in continuous-cropping fields. However, the mechanisms underlying the action pathway among biochars, auto-toxic compounds and tobacco remain unknown. In this study, we conducted an experiment tracking the incidence rate of black rot and auto-toxic compounds for a 3-year continuous-cropping tobacco pot trial in response to biochar treatment intensity compared with that of non-biochar treatment. Biochar inhibited the incidence of black rot. Using ultra-high-performance liquid chromatography-mass spectrometry (UPLC‒MS/MS), we revealed that biochar can effectively decrease the concentration of p-hydroxybenzoic acid (PHA), which is associated with the incidence rate of black rot (R2 = 0.890, p < 0.05). The sorption kinetics and isotherm of PHA sorption on biochar indicate that the coexistence of heterogeneous and monolayer sorption plays an important role in the adsorption process. Using Molecular dynamics (MD), Density functional theory (DFT) and Independent gradient model (IGM) analyses, we provide evidence that van der Waals force (vdW), π-π bonds and H-bonds between biochar and PHAs are the dominant factors that affect adsorption capacity. Moreover, the molecular adsorption rate (Nbiochar: NPHAs = 1:4) was theoretically calculated. In contrast, biochar dramatically increased nutrient retention capacity and improved soil properties, further enhancing tobacco quality, including its agronomic and physiological traits. Therefore, we considered that biochar not only relieved continuous cropping but also improved soil properties suitable for tobacco growth. Together, we demonstrate that the action of biochar in continuously cropped soil improves soil traits and alleviates auto-toxic compound toxicity. These data contribute to the direction of modified biochar application to improve continuous-cropping soil.

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The catalytic wet air oxidation (CWAO) of p-hydroxybenzoic acid (p-HBA) was conducted in a batch reactor at 140 °C, and at a total air pressure of 50 bar over Ru-based catalysts. Four materials were selected as supports - TiO2, CeO2-TiO2, ZrO2-TiO2, and La2O3-TiO2 - all of which had mesopores in their texture and pollutant adsorption capacities. The supports were prepared by the sol-gel method, and then impregnated with 3 wt% of Ru precursor. Such characterization techniques as N2-sorption, XRD, XPS, H2-TPR, NH3-TPD, TEM, and HAADF-STEM were used to analyze the different solids. The correlation between catalytic activities and physicochemical properties was discussed. A significant specific surface area (SBET), a large amount of surface-active oxygen, and Lewis acidity sites were observed on cerium-containing catalysts (Ru/CeTi). Fresh Ru catalysts containing cerium showed higher activity than Ru/TiO2, Ru/ZrTi, and Ru/LaTi catalysts. It is assumed that the acidic sites and surface oxygen trap the p-HBA molecule, thus increasing the catalytic properties of the Ru particles which interact with the surface oxygen through the cerium redox process (Ce3+/Ce4+). As the presence of cerium increases surface-active oxygen, it inhibits the deposition of carbon on the surface of the Ru catalyst. The pseudo-second order (PSO) model adequately described the kinetic data of the p-HBA oxidation reaction using Ru catalysts.

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Hemicellulose extracted from ecalyptus APMP pulping waste liquor and undergoes etherification modification to produce carboxymethyl hemicellulose (CMHC). Subsequently, CMHC undergoes esterification reaction with p-hydroxybenzoic acid to synthesize a novel polysaccharide-based preservative known as carboxymethyl hemicellulose p-hydroxybenzoate (P-CMHC). The synthesis conditions of P-CMHC were optimized using the response surface methodology, resulting in an optimal esterification condition that achieved a degree of substitution of 0.232. P-CMHC exhibits excellent antioxidant activity, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activities. Additionally, it demonstrates favorable hygroscopic and moisturizing properties. Thiazole blue (MTT) experiments evaluating cell proliferation rate indicate that P-CMHC possesses negligible cytotoxicity, making it a promising, safe, and healthy preservative. Consequently, it can be considered as a new material for applications in the fields of biomedicine, food, and cosmetics.

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The leaves of the olive tree (Olea europaea L.) are one of the major solid wastes from the olive industry. Globally, the European Union is the largest producer of olive by-products, with Spain, Italy, Greece, and Portugal accounting for almost the entire production. Many questions remain to be solved concerning olive leaves (OL), including those related to possible differences in composition and/or biological activities depending on their geographical origin. In the present work, OL from Spain, Italy, Greece, and Portugal have been characterized according to their phytochemical profile, antioxidant capacity, neuroprotective activity, and anti-inflammatory effects. The Spanish and Italian OL samples presented the highest antioxidant and neuroprotective activities, while the Greek OL showed the lowest. These results were strongly associated with the content of oleoside methyl ester and p-hydroxybenzoic acid for the Spanish and Italian samples, respectively, whereas the content of decarboxymethyl elenolic acid dialdehyde form (hydrated) was negatively associated with the mentioned biological activities of the Greek samples. No country-related effect was observed in the anti-inflammatory activity of OL. Comprehensively, this work could provide a useful tool for manufacturers and R&D departments in making environmentally friendly decisions on how OL can be used to generate nutraceutical products based on the composition and origin of this by-product.

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The wide distribution of p-hydroxybenzoic acid (PHBA) in the environments has attracted great concerns due to its potential risks to organisms. Bioremediation is considered a green way to remove PHBA from environment. Here, a new PHBA-degrading bacterium Herbaspirillum aquaticum KLS-1was isolated and its PHBA degradation mechanisms were fully evaluated. Results showed that strain KLS-1 could utilize PHBA as the sole carbon source and completely degrade 500 mg/L PHBA within 18 h. The optimal conditions for bacterial growth and PHBA degradation were pH values of 6.0-8.0, temperatures of 30 °C-35 °C, shaking speed of 180 rpm, Mg2+ concentration of 2.0 mM and Fe2+ concentration of 1.0 mM. Draft genome sequencing and functional gene annotations identified three operons (i.e., pobRA, pcaRHGBD and pcaRIJ) and several free genes possibly participating in PHBA degradation. The key genes pobA, ubiA, fadA, ligK and ubiG involved in the regulation of protocatechuate and ubiquinone (UQ) metabolisms were successfully amplified in strain KLS-1 at mRNA level. Our data suggested that PHBA could be degraded by strain KLS-1 via the protocatechuate ortho-/meta-cleavage pathway and UQ biosynthesis pathway. This study has provided a new PHBA-degrading bacterium for potential bioremediation of PHBA pollution.

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Coenzyme Q (CoQ) is an essential component of the electron transport system in aerobic organisms. CoQ10 has ten isoprene units in its quinone structure and is especially valuable as a food supplement. However, the CoQ biosynthetic pathway has not been fully elucidated, including synthesis of the p-hydroxybenzoic acid (PHB) precursor to form a quinone backbone. To identify the novel components of CoQ10 synthesis, we investigated CoQ10 production in 400 Schizosaccharomyces pombe gene-deleted strains in which individual mitochondrial proteins were lost. We found that deletion of coq11 (an S. cerevisiae COQ11 homolog) and a novel gene designated coq12 lowered CoQ levels to ∼4% of that of the WT strain. Addition of PHB or p-hydroxybenzaldehyde restored the CoQ content and growth and lowered hydrogen sulfide production of the Δcoq12 strain, but these compounds did not affect the Δcoq11 strain. The primary structure of Coq12 has a flavin reductase motif coupled with an NAD+ reductase domain. We determined that purified Coq12 protein from S. pombe displayed NAD+ reductase activity when incubated with ethanol-extracted substrate of S. pombe. Because purified Coq12 from Escherichia coli did not exhibit reductase activity under the same conditions, an extra protein is thought to be necessary for its activity. Analysis of Coq12-interacting proteins by LC-MS/MS revealed interactions with other Coq proteins, suggesting formation of a complex. Thus, our analysis indicates that Coq12 is required for PHB synthesis, and it has diverged among species.

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Sensitive skin is a well- known skin condition showing sensory irritation to daily used products such as cosmetics or pharmaceuticals, possibly containing sensory irritants. Methylparaben (MP), widely used as a preservative, is a representative sensory irritant and hydrolyzed in the skin. We aimed to clarify the relationship between MP sensory irritation and MP hydrolysis. First, we investigated the percutaneous penetration and hydrolysis of MP by using an ex vivo pig skin system and confirmed that topically applied MP was immediately hydrolyzed to p-hydroxybenzoic acid (PHBA). We next evaluated whether MP or PHBA causes sensory irritation using a well-used stinging test in human skin and found that MP, but not PHBA, induced irritation. Additionally, MP, but not PHBA, increased intracellular calcium in cultured TRPA1-expressed HEK293 cells, supporting the stimulatory activity of MP. Five and 10 individuals with sensitive and non-sensitive skin, respectively, were selected by a questionnaire and stinging test. In their biopsied skin samples, MP hydrolytic activity was significantly lower in sensitive than non-sensitive skin. Finally, we examined the activity of carboxylesterase (CES), which promptly hydrolyzes MP to PHBA. By using specific inhibitors of CES and CES2, we found that CES1 was responsible for MP metabolism. Our study suggests that low skin metabolism of topical agents is one of the causes of skin sensory irritation and resultant sensitive skin.

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An environmentally friendly physical processing method, hydrothermal treatment (HT), was used to increase the content of specific compounds and antioxidant activities of seed-used pumpkin byproducts. The influence of hydrothermal temperature (80 °C-160 °C) and time (30-150 min) on changes in polyphenols and antioxidation was evaluated. The results revealed that the maximum free polyphenol content (140 °C for 120 min) was 3.96-fold higher than the untreated samples. Elevated temperature and long duration changed phenolic acid contents. For example, p-coumaric acid, rutin and chlorogenic acid exhibited a decreasing trend, and p-hydroxybenzoic acid, quercetin and cinnamic acid showed an increasing trend. Compared to controls, HT was significantly associated with increased antioxidant activities. To comprehensively reveal the influence of hydrothermal temperature and time on changes in polyphenolic content, back propagation artificial neural network (BP-ANN) models with accurate prediction ability were developed, and the results exhibited well-fitted and strong approximation ability (R2 > 0.95 and RMSE < 2 %) and stability.

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A promising drying technology, namely combined freeze-drying and far-infrared drying (FD-FIRD) was employed to dehydrate seed-used pumpkin (SUP) and its effects on physical characteristics (color, microstructure, texture, shrinkage), bioactive components (phenolics and carotenoids) of SUP were evaluated. The low-field nuclear magnetic resonance (LF-NMR) was used to analyze moisture state and distribution during FD process, which is beneficial for choosing appropriate moisture transfer point. Results showed that most free water (87.29 %) was removed when drying time reached 25 h, thus retaining original tissue structure of sample with almost no deformation during later FIRD process. Therefore, FD for 25 h followed by FIRD for 2 h (FD25-FIRD2) sample exhibited similar appearance with FD sample. The free phenolics content of FD-FIRD samples was 14.97 %-26.60 % higher than that of FD depending on FIRD duration. Especially, p-coumaric acid content of FD25-FIRD2 sample increased of 32.23 %. Besides, FD-FIRD performed higher retention for carotenoids showing 3.00-3.39 folds than FIRD.

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Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disease characterized by intestinal inflammatory cell infiltration and intestinal mucosal damage. The mechanism by which diet contributes to the pathogenesis of IBD remains largely unknown. In this study, we explored the therapeutic effect of p-hydroxybenzoic acid (HA), a phenolic acid mainly derived from dietary polyphenols in the gut, on DSS-induced colitis. HA intervention effectively relieved the dextran sulfate sodium salt (DSS)-induced colitis, reduced inflammation, and enhanced mucosal barrier function, as evidenced by an increment of goblet cell numbers and MUC2. These effects were largely dependent on the gut microbiota (GM), as antibiotics treatment substantially attenuated the improvement of colitis by HA. On the other hand, transplantation of GM from colitis mice treated with HA significantly reduced the colitis induced by DSS. Our study demonstrates that HA ameliorates DSS-induced colitis by improving the mucosal barrier in a GM-dependent manner. This study provides new dietary choices for the prevention and treatment of IBD.

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Pogostemon cablin (patchouli) cultivation is challenged by serious soil sickness, of which autotoxins accumulation is a major cause. p-hydroxybenzoic acid (p-HBA) is one of the main autotoxins of patchouli. However, the molecular mechanism underlying the response of patchouli to p-HBA remains unclear. In this study, RNA-sequencing combined with physiological analysis was used to monitor the dynamic transcriptomic and physiological changes in patchouli seedlings 0, 6, 12, 24, 48, and 96 h after p-HBA treatment. p-HBA stress inhibited root biomass accumulation, induced excessive hydrogen peroxide accumulation and lipid peroxidation, and activated most antioxidant enzymes. Compared with that of the control, the osmotic adjustment substance content was elevated with treatment. Subsequently, 15,532, 8,217, 8,946, 2,489, and 5,843 differentially expressed genes (DEGs) at 6, 12, 24, 48, and 96 h after p-HBA treatment, respectively, were identified in patchouli roots. GO functional enrichment analysis showed that the DEGs were enriched mainly in plasma membrane, defense response, response to chitin, DNA-binding transcription factor activity and abscisic acid-activated signaling pathway. The upregulated genes were involved in glycolysis/gluconeogenesis, cysteine and methionine metabolism, starch and sucrose metabolism, biosynthesis of unsaturated fatty acids, and linoleic acid metabolism. Genes associated with MAPK signaling pathway-plant, plant-pathogen interaction, plant hormone signal transduction were downregulated with p-HBA treatment. These pathways are related to root browning and rotting, leading to plant death.

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In blood coagulation, circulating platelets and coagulation factors are crucial for the primary process because thrombi are generated by fibrin clotting with fibrinogen, thrombin, FXIIIa, and platelet activation. Therefore, strategies to reduce the activity of key coagulation factors, or interfere with their functions and delay the activation of platelets can be used as important tools to suppress excessive blood clot formation and platelet hyperactivation. This study examined the antithrombotic activity and hematological toxicity of PA, IVA, and 4-HA isolated from M. tricuspidata (Carr.) Bur in several in vitro experiments and inhibitor assays. We found that PA, IVA, and 4-HA attenuated the formation of fibrin polymers/clots and degraded the blood clots. These compounds inhibited the activities of procoagulant proteases and fibrinoligase, and prolonged the coagulation time. There was a significant reduction in platelet function and ATP or serotonin levels in thrombin-activated platelets. An inhibitor study showed that PA exhibited a mixed inhibition type for thrombin, an uncompetitive inhibition type for FXa, and a non-competitive inhibition type for FXIIIa and IVA, while 4-HA exhibited an uncompetitive inhibition type for thrombin and non-competitive inhibition type for FXa and FXIIIa. These three compounds (up to 50 µg/mL) were not toxic to blood cells.

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Coupling the cultivation of microalgae with wastewater treatment is a promising technology to recover bioresources from wastewater. However, toxic pollutants in wastewater seriously inhibit the growth of microalgae and the removal of pollutants. Phenolic acids are similar to phytohormones, could potentially relieve the toxicity to microalgae and simultaneously promote pollutant degradation and lipid accumulation. Chlorella and 4-chlorophenol (4-CP) were utilized to simulate the toxic wastewater treatment, and the roles of two typical phenolic acids, such as p-hydroxybenzoic acid (p-HBA) and caffeic acid (CA), were explored. The 0.2 µM concentration of p-HBA or CA improved the specific growth rate by 7.6% by enhancing photosynthesis and DNA replication. The oxidative damage caused by 4-CP was reduced by 30.3-49.7% via the synthesis of more antioxidant enzymes and the direct scavenging of free radicals by phenolic acids. Furthermore, the 4-CP removal rate increased by 27.0%, and toxic 4-CP was degraded into non-toxic compounds. The phenolic acids did not change the 4-CP degradation pathway but accelerated its removal and detoxification by enhancing the expression of 4-CP degradation enzymes. Simultaneously, lipid production increased by 20.5-23.1% due to the upregulation of enzymes related to fatty acid and triacylglycerol synthesis. Trace phenolic acids stimulated the mitogen-activated protein kinase signaling cascade and the calcium signaling pathway to regulate the physiology of the microalgae and protect cells from toxic stress. This study provides a promising new strategy for toxic wastewater treatment and bioresource recovery.

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p-Hydroxybenzoic acid (p-HBA), which exists extensively in plants, is well known for its anti-inflammatory effects, but various adverse side effects have also been reported. Previous research has found that acid translated to its sodium salt improves the safety profile of compounds. Therefore, we hypothesized that p-HBA translated to sodium p-hydroxybenzoate would improve its safety profile. In the present study, we evaluated the toxicity of sodium p-hydroxybenzoate after 90 days of repeated oral toxicity experiments according to OECD guidelines in male and female Sprague-Dawley rats. Sodium p-hydroxybenzoate was administered orally to SD rats at doses of 0, 125, 250, and 500 mg/kg body weight (BW)/day for 90 days. All animals survived to the end of the study, and no sodium p-hydroxybenzoate treatment-associated mortality or clinical changes were observed during the study period. Sodium p-hydroxybenzoate did not promote any clinical signs of toxicologically relevant effects, including changes in body weight, food intake and urinalysis parameters, in male or female SD rats. Dose-related alterations in hematological parameters, organ weights and histopathological findings in hepatic tissue were examined in animals of both sexes in the 500 mg/kg BW/day group. Based on the study, the no-observed-adverse-effect level (NOAEL) for sodium p-hydroxybenzoate was determined to be 250 mg/kg BW/day in both male and female rats.

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A type of pH-sensitive multi-targeted brain tumor site-specific liposomes (Lip-CTPP) co-modified with p-hydroxybenzoic acid (p-HA) and triphenylphosphonium (TPP) were designed and prepared to co-load doxorubicin (DOX) and lonidamine (LND). Lip-CTPP are promising potential carriers to exert the anti-glioma effect of DOX and LND collaboratively given the following features: 1) Lip-CTPP have a good pharmacokinetic behavior; 2) Lip-CTPP can cross the blood-brain barrier (BBB) and recognize tumor cells through the affinity of p-HA and dopamine/sigma receptors; 3) Lip-CTPP are highly positive charged once the acid-sensitive amide bonds are cleaved in endo/lysosomes to expose TPP and protonate amine groups; 4) the positive charged Lip-CTPP escape from endo/lysosomes and accumulate in mitochondria through electrostatic adsorption; 5) DOX and LND are released and synergistically increase anti-tumor efficacy. Our in vitro and in vivo results confirmed that Lip-CTPP could greatly elevate the inhibition rate of tumor cell proliferation, migration and invasion, promote apoptosis and necrosis, and interfere with mitochondrial function. In addition, Lip-CTPP could significantly prolong the survival time of glioma bearing mice, narrow the tumor region and inhibit the infiltration and metastasis capability of glioma cells. Collectively, Lip-CTPP are promising nano formulations to enhance the synergistic effect of DOX and LND in glioma treatment.

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Cosmetics, cosmeceuticals, and variable healthcare products used parabens, among other excipients, for their preservative and antimicrobial activities. Paraben derivatives exhibit distinguished physiochemical properties that enable them to be compatible with the formulation of cosmetic agents in different dosage forms. In addition to their potency and efficacy, parabens are economically efficient as they have low-manufacturing costs. Despite the desirable characteristics, the safety of parabens use is controversial after detecting these chemicals in various biological tissues after repetitive and long-term use of formulations containing them. The use of parabens drew public health attention after scientific reports linked skin exposure to parabens with health issues, in particular, breast cancer. In response, worldwide authorities set regulations for the allowance concentrations of paraben to be used in variable cosmetic products.

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Quinoa is rich in phenolics which are benefit for human health for their outstanding antioxidant capacity, anti-inflammatory property and special biological functions. However, most of phenolics existed as bound form that with low bioavailability in quinoa. In this study, extrusion technique was applied for the release of bound phenolics in red quinoa (RQ), and effects of extruded temperature (120 °C, 140 °C, 160 °C and 180 °C) on the release of characteristic phenolics of RQ was investigated as well. Phenolics both presented as free and bound forms were identified in RQ and extruded quinoa samples, and result showed rutin, ferulic acid and vanillic acid were most common. The content of bound phenolics in RQ was 155.52 mg/kg, however, in extruded red quinoa (ERQ) was 77.25 mg/kg (ERQ-140 °C)-84.08 mg/kg (ERQ-120 °C). In corresponding, free phenolics in RQ was 22.15 mg/kg, while in ERQ was 41.04 mg/kg (ERQ-140 °C)-47.25 mg/kg (ERQ-160 °C). In conclusion, extrusion was excellent for the release of bound phenolics in quinoas and the best extruded temperature was 160 °C. Extrusion technique was potential in the processing of quinoa.

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Environmental remediation has become more effective when using nanotechnologies. In this study, iron oxide (α-Fe2O3) nanospheres with different cobalt doping levels (xCo-Fe2O3) were synthesised and applied in the heterogeneous activation of peroxymonosulfate (PMS) for the degradation of p-hydroxybenzoic acid (p-HBA). The catalyst (3Co-Fe2O3) with 3% Co doping exhibits the best performance for PMS activation, possibly because of the larger specific surface area and the tailored catalyst surface as confirmed by X-ray photoelectron spectroscopy (XPS). Reaction parameters were investigated to optimise the degradation efficiency. The metal ions leaching tests confirmed the higher stability of the catalyst, thanks to the leaching suppression by the doping of Co2+. The main contribution of free radicals (SO4•- and •OH) was confirmed by electron paramagnetic resonance (EPR) spectra, whereas partial contribution of oxygen anions and singlet oxygen (O2•-, 1O2) was observed during the quenching tests. Finally, a radical based degradation mechanism was proposed for the removal of p-HBA. It is expected to open up a novel perspective for the application of iron oxide as a potential catalyst for the removal of emerging contaminants.

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ETHNOPHARMACOLOGICAL RELEVANCE: Valeriana fauriei root (VF) is a crude drug registered in the Japanese Pharmacopeia 17th Edition and a known substitute for V. officinalis (VO). Although VO has been pharmacologically evaluated for its sedative effects and mechanism of action, data regarding VF remain scarce. AIM OF THE STUDY: We compared the binding affinity of VF and VO extracts, as well as examined the active ingredients in the VF extract, on flunitrazepam sites of γ-aminobutyric acid receptor type A (GABAA receptor). Furthermore, we confirmed whether these active ingredients were distributed in the brain of mice orally administered the VF extract. MATERIALS AND METHODS: We prepared the assay system to evaluate the binding activity of flunitrazepam sites of GABAA receptor using a 96-well plate and assessed the activities of VF and VO extracts. We then analyzed their constituents using HPLC with principal component analysis (PCA) and evaluated active ingredients correlated with their activities. The distribution of active ingredients in the plasma and brain of mice orally administered the VF extract prepared with different emulsifiers were analyzed by LC-MS/MS. RESULTS: The ethanol extract of VF exhibited significantly higher activity on flunitrazepam sites of GABAA receptor than VO. For the VF extract, kessyl glycol diacetate (KGD) was markedly associated with the binding activities; however, active ingredients included KGD, kessyl glycol 8-acetate (KG8), α-kessyl acetate (α-KA), and coniferyl isovalerate (CI). For VO, valerenic acid and five other compounds were associated with the binding affinity on flunitrazepam sites of GABAA receptor. On emulsifying the VF extract with a fat-soluble glycerin fatty acid ester, the plasma and brain distributions of KGD tended to be higher, those of KG8 were significantly more than 10-times higher, and those of α-KA was lower than those of the VF extract emulsified with water-soluble gum arabic, after oral administration in mice. CONCLUSIONS: Based on the binding activity on flunitrazepam sites of GABAA receptor and brain distribution, KGD, KG8, and α-KA can be considered active ingredients of VF. The addition of a fat-soluble emulsifier promoted the absorption of KGD, the main active ingredient, and KGD was metabolized to KG8 in the body. The present results suggest a possible mechanism underlying the sedative effect for VF, and these three compounds can be used as marker compounds to evaluate the quality of VF products.

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Accumulation of p-hydroxybenzoic acid (PHBA) in soil causes autotoxicity stress in cucumber. When the stress is mitigated by PHBA-degrading bacteria, plant metabolites have not been detected. To explore mechanisms underlining the mitigation, plant metabolites have not been combined with rhizospheric microbes, antioxidant and soil enzymes. In this study, a strain P620 of Klebsiella decomposed PHBA to acetyl CoA. Cucumber was sown into soil supplemented with P620 and/or PHBA. After addition with P620, P620 colonization and the enriched bacterial genera were observed in rhizosphere. Compared to PHBA stress alone, the combination of P620 application and PHBA stress improved plant growth, decreased PHBA concentration in soil, and increased the activities of five soil enzymes and eight antioxidant enzymes in leaves. Metabolomic and transcriptomic analysis highlighted that P620 application decreased the intensities of MAG(18:3) isomer 4, MAG(18:3) isomer 2, lysoPC 18:3 (2n isomer), 2'-deoxyadenosine-5'-monophosphate, pyridoxine, and glucarate O-phosphoric acid in PHBA-stressed leaves and down-regulated the expression of genes related to these metabolites. We propose a mechanism that P620 application alters microbial communities in PHBA-contaminated soil. Thus, the application reduces PHBA concentration in soil, activates antioxidant and soil enzymes, and also influences metabolites in leaves by affecting plant transcriptome, mitigating PHBA stress in cucumber.

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