Increase In Peroxidase Activity Research Articles

Biochemical and histopathological evidence for beneficial effects of Empagliflozin pretreatment on acetic acid-induced colitis in rats

BackgroundUlcerative Colitis (UC) is a disorder which oxidative stress plays a critical role in its pathogenesis. Empagliflozin (EMPA) is a sodium-glucose cotransporter-2 (SGLT2) inhibitor that has been shown to have anti-inflammatory and antioxidative effects. The aim of this study was to investigate the protective effects of EMPA on acetic acid (AA) induced colitis in rats.MethodsA total of twenty-four rats were divided into four groups (six animals in each group) as follows: (1) Control group; (2) acetic acid (AA)-induced colitis group (AA); (3) EMPA treatment group (AA + EMPA); (4) Dexamethasone (Dexa) treatment group (AA + Dexa). Animals in pre-treatment groups received EMPA (10 mg/kg, i.p.) or dexamethasone (4 mg/kg, i.p. as reference drug) for four consecutive days before induction of colitis by intra-rectal acetic acid (4% v/v) administration. Twenty-four hours after AA administration, rats were sacrificed and the colon tissues were removed for histopathological and biochemical evaluations.ResultsPretreatment with EMPA significantly decreased colon weight/length ratio (81.00 ± 5.28 mg/cm vs. 108.80 ± 5.51 mg/cm) as well as, macroscopic (2.50 ± 0.57 vs. 3.75 ± 0.25) and histological scores (3.3 ± 0.14 vs. 1.98 ± 0.14) compared to the AA-induced colitis group (p < 0.01). Pretreatment with EMPA significantly reduced malondialdehyde (MDA) (324.0 ± 15.93 vs. 476.7 ± 32.26 nmol/mg p < 0.001) and increased glutathione level (117.5 ± 4.48 vs. 94.38 ± 3.950 µmol/mg, p < 0.01) in comparison to the AA-induced colitis group. Furthermore, a significant increase in catalase (44.60 ± 4.02 vs.14.59 ± 2.03 U/mg, P < 0.01), superoxide dismutase (283.9 ± 18.11 vs. 156.4 ± 7.92 U/mg, p < 0.001), and glutathione peroxidase (10.38 ± 1.45 vs. 2.508 ± 0.37, p < 0.01) activities were observed by EMPA pretreatment when compared to the AA-induced colitis group. These results were in line with those of the reference drug.ConclusionsIt is concluded that EMPA could effectively reduce the severity of tissue injury in experimental colitis. This protective effect may be related to the antioxidative effects of EMPA drug.

Relative biochemical and physiological docking of cucumber varieties for supporting innate immunity against Podosphaera xanthii

Powdery mildew in cucumber is caused by the Podosphaera xanthii. No strategy for improving disease resistance can be successful in the absence of thorough insights into the physiological and biochemical responses of cucumber plants to powdery mildew. Therefore, a field experiment was executed to evaluate five commercial cucumber varieties (V1: Dynasty, V2: Long green, V3:Desi Kheera, V4:Thamin II, V5:Cucumber 363) for their inherent immunity to powdery mildew. Upon inoculating cucumber plants with Podosphaera xanthii, we noted differential responses among the varieties. Compared to other varieties, V1 and V2 showed higher values (P ≤ 0.05) for chlorophyll-a under control and pathogen-attacked plants respectively. The minimum value of anthocyanin content (−53.73%) was recorded in V3 as compared to other varieties post pathogen infection. All pathogen-infected cucumber varieties showed a considerable (P ≤ 0.05) loss in flavonoid content except V2. The maximum destruction for Phenolics under powdery mildew (179%) were recorded in V4, whereas V1 exhibited maximum phenolic content under control conditions. In pathogen-infected plants, the minimum AsA was recorded in V5 as compared to all other varieties. Pathogen invasion impacted significantly (P ≤ 0.05) the activity of superoxide dismutase (SOD). Besides, cucumber plants after pathogen inoculation resulted in a considerable (P ≤ 0.05) increase of peroxidase (POD) activity in V1 (5.02%), V2 (7.5%), and V3 (11%) in contrast to V4. Our results confirmed that cucumber varieties perform differently, which was brought on by distinct metabolic and physiological modifications that have an impact on growth and development. The changes in different attributes were correlated with cucumber resistance against powdery mildew. The results would help us fully harness the potential of these varieties to trigger disease management initiatives and defense responses.

Redox status of blood lymphocytes in patients with soft tissue sarcomas

Introduction. The proven significance of free radical disorders in oncopathology determines the relevance of their study in soft tissue sarcomas (STS), which are characterized by a tendency to recurrence and high mortality of patients.Aim. To study the indicators of free radical oxidation and antioxidant protection in blood lymphocytes in primary and recurrent STS, depending on the sex and age of patients.Materials and methods. In 51 patients with primary STS, T2bN0M0 (17 men and 34 women) and in 34 patients (14 men and 20 women) with relapses, the level of lipid peroxidation products – malondialdehyde and diene conjugates, activities of superoxide dismutase and glutathione peroxidase, total peroxidase activity, the level of reduced glutathione were studied by spectrophotometric methods. Patients were divided by age: ≤45 years and &gt;45 years. The comparison groups (donors) consisted of 12 men and 17 women divided into the same age subgroups.Results. In men &gt;45 years old with primary sarcomas, there was an increase in diene conjugates by 2.2 times, with relapses by 2.4 times, and in young men - only with relapses by 2.6 times. The level of malondialdehyde in men did not change with primary sarcomas, with relapses it was reduced in both age groups by 2.4–2.6 times. In women with primary STS, there was an increase in most of the studied parameters in both age groups by 1.6–1.9 times. The increase in diene conjugates level and superoxide dismutase activity was the most pronounced (&gt;3 times) in patients of the older age group. The increase in glutathione peroxidase activity in primary STS in young women was 2.3 times, and in the older age group in patients of both sexes it was 5 times. In half of the women with relapses developed no earlier than 3 years after treatment, a decrease in both lipid peroxidation products by 2.6–3.4 times was found, and in all women almost 4-fold activation of superoxide dismutase and 8-fold glutathione peroxidase with an increase in the level of reduced glutathione by 7 times took place, which was significantly higher than in men. For women of the older age group, a 3-fold increase in the ratio of superoxide dismutase/total peroxidase activity is characteristic for primary STS and almost 5-fold for recurrence.Conclusion. In primary STS, the activation of lipid peroxidation products and antioxidant enzymes in women is more pronounced than in men. Changes in most indicators are more typical for patients of older age groups, in which relapse was accompanied by a decrease in malondialdehyde in patients of both sexes and maximum activation of superoxide dismutase and glutathione peroxidase in women.

JA-mediated MYC2/LOX/AOS feedback loop regulates osmotic stress response in tea plant

Osmotic stress caused by low-temperature, drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield, particularly in tea plant. Jasmonic acid (JA) is an important phytohormone involving in plant stress. However, underlying molecular mechanisms of JA modulated osmotic stress response remains unclear. In this study, high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant. Integrated transcriptome mined a JA signaling master, MYC2 transcription factor is shown as a hub regulator that induced by mannitol, expression of which positively correlated with JA biosynthetic genes (LOX and AOS) and peroxidase genes (PER). CsMYC2 was determined as a nuclei-localized transcription activator, furthermore, Protein-DNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7, CsAOS2, CsPER1 and CsPER3 via bound with their promoters, respectively. Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant. Overexpression of CsMYC2 in Arabidopsis improved JA content, peroxidase activity and plants tolerance against mannitol stress. Together, we proposed a positive feedback loop mediated by CsMYC2, CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.

Physiological and biochemical alterations in Vigna rdiate L. triggered by sesame derived elicitors as defense mechanism against Rhizoctonia and Macrophomina infestation

Improving agricultural products by the stimulation of plant growth and defense mechanisms by priming with plant extracts is needed to attain sustainability in agriculture. This study focused to consider the possible improvement in Vigna radiata L. seed germination rate, plant growth, and protection against the natural stress by increasing the defense mechanisms through the incorporation of Sesamum indicum phytochemical compounds with pre-sowing seed treatment technologies. The gas chromatography coupled with mass spectroscopy (GC–MS) analysis revealed that the methanol extract of S. indicum leaf extract contained eight major bioactive compounds, namely, 2-ethylacridine (8.24%), tert-butyl (5-isopropyl-2-methylphenoxy) dimethylsilane (13.25%), tris(tert-butyldimethylsilyloxy) arsane (10.66%), 1,1,1,3,5,5,5-heptamethyltrisiloxane (18.50%), acetamide, N-[4-(trimethylsilyl) phenyl (19.97%), 3,3-diisopropoxy-1,1,1,5,5,5-hexamethyltrisiloxane (6.78%), silicic acid, diethyl bis(trimethylsilyl) ester (17.71%) and cylotrisiloxane, hexamethyl-(4.89%). The V. radiata seeds were treated with sesame leaf extract seeds at concentrations 0, 10, 25, 50, and 100 mg/L. Sesame leaf extract at 50 and 100 mg/L concentrations was effective in increasing the germination percentage and the fresh and dry weights of roots and shoots. The increased peroxidase activity was noticed after treatment with S. indicum extract. In addition, disease percentage (< 60%) of both fungal pathogens (Rhizoctonia and Macrophomina) was significantly reduced in V. radiata plants treated with 100 mg/L of sesame leaf extract. These results revealed that physiochemical components present in S. indicum mature leaf extract significantly enhanced growth and defense mechanism in green gram plants.

The Effect of Benzo(1,2,3)-thiadiazole-7-carbothioic Acid S-Methyl Ester (BTH) and Its Cholinium Ionic Liquid Derivative on the Resistance Induction and Antioxidant Properties of Tomato (Solanum lycopersicum L.).

Tomatoes are one of the most important vegetables thanks to their taste attributes and nutritional value. Their cultivation is threatened by various pathogens including viruses. The application of resistance inducers (RI), such as benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) may be used to enhance plant performance against viruses. Here we aimed to compare the impact of BTH and its choline derivative (Chol-BTH) on resistance induction and antioxidant properties of healthy plants and tomato mosaic virus (ToMV)-infected ones. The response of tomato plants to treatment with BTH or Chol-BTH was manifested by increased expression of not only pathogenesis-related (PR) genes but also WRKY and Jasmonate Zim-domain protein (JAZ) genes and increased jasmonic acid (JA) levels. The effect of BTH as a resistance inducer was observed early after application, while with Chol-BTH the plant defense system reacted more strongly after 8 days. The antioxidant properties of RI-treated tomatoes are related to both glutathione content and peroxidase activity. In the case of BTH, an increase in these activities occurred early after application, while in the case of Chol-BTH, the glutathione level was particularly high in the plant early after treatment, and high peroxidase activity was observed 8 days post-treatment. Overall, the collected results indicate that Chol-BTH, due to its physicochemical parameters (e.g., good solubility) and biological activity (increased expression of lignification-related genes, supported by increases in peroxidase activity and total phenolic compounds levels), can also be a very useful agent inducing tomato resistance against viral pathogens.

Effects of Hydroxyethyl Cellulose and Sulfated Rice Bran Polysaccharide Coating on Quality Maintenance of Cherry Tomatoes during Cold Storage.

Cherry tomatoes are easily damaged due to their high moisture content. A composite coating was developed to delay deterioration and prolong storage by mixing antibacterial sulfated rice bran polysaccharides (SRBP) and edible hydroxyethyl cellulose (HEC) with film-forming properties. The effects of HEC, HEC-5% SRBP, and HEC-20% SRBP preservative coatings on the maintenance of the quality of cherry tomatoes (LycopersivonesculentumMill., Xiaohuang F2) during cold storage were investigated. The HEC-20% SRBP coating significantly reduced tomato deterioration and weight loss, delayed firmness loss, decreased polyphenol oxidase activity, and increased peroxidase activity. Furthermore, cherry tomatoes treated with HEC-20% SRBP maintained high levels of titratable acid, ascorbic acid, total phenols, and carotenoids. Cherry tomatoes coated with HEC-SRBP also had higher levels of volatile substances and a greater variety of these substances compared to uncoated tomatoes. In conclusion, the HEC-20% SRBP coating effectively delayed deterioration and preserved cherry tomatoes' nutrient and flavor qualities during postharvest cold storage, suggesting it could be a novel food preservation method.

Biocontrol of chocolate spot disease of broad bean (Vicia faba L.) caused by Botrytis fabae using biosynthesized reduced graphene oxide/silver nanocomposite

This study was demonstrated to investigate the effects of reduced graphene oxide/silver nanocomposite (rGO/AgNC) on controlling the chocolate spot disease of broad bean (Vicia faba L.) caused by Botrytis fabae. rGO/AgNC was green synthesized using the cell-free supernatant of Escherichia coli D8 in the presence of sunlight and room temperature. rGO/AgNC revealed a broad UV–vis absorption peak at 433 nm. Transmission electron microscopy (TEM) images of rGO/AgNC confirmed the presence of spherical-shaped silver nanoparticles (AgNPs) with an average size of 7–26 nm. Zeta analysis of rGO/AgNC displayed their positive charge (+18.9 mV) and the good dispersion of AgNPs on the surface of rGO. rGO/AgNC had good antifungal activity against B. fabae in a dose-dependent pattern. In vivo, rGO/AgNC-treatment study on faba bean plants showed the biocidal action of rGO/AgNC (150 μg/ml) against B. fabae and completely prevented the pathogen infection. In addition, there was an increase in total phenolic content, peroxidase, and polyphenol oxidase activity, and protein content of rGO/AgNC-treated plants. Plants treated with rGO/AgNC displayed a typical cell morphology in their ultrastructure, including cell membranes and chloroplasts with ellipsoidal shapes and large starch grains. These are all encouraging findings for the use of the biosynthesized rGO/AgNC as a safe and efficient antifungal agent against B. fabae.

Physiological and Molecular Analysis Revealed the Role of Silicon in Modulating Salinity Stress in Mung Bean

Salinity stress acts as a significant deterrent in the course of optimal plant growth and productivity, and mung bean, being a relay crop in the cereal cropping system, is severely affected by salinity. Silicon (Si), on the other hand, has exhibited promising outcomes with regards to alleviating salinity stress. In order to understand the critical mechanisms underlying mung bean (Vigna radiata L.) tolerance towards salt stress, this study examined the effects of different salinity concentrations on antioxidant capacity, proteome level alterations, and influence on Si-transporter and salt-responsive genes. Salinity stress was seen to effect the gaseous exchange machinery, decrease the soluble protein and phenolic content and NR activity, and increase the accumulation of reactive oxygen species. An efficient regulation of stomatal opening upon Si application hints towards proficient stomatal conductance and CO2 fixation, resulting in efficient photosynthesis leading to proficient plant growth. The soluble protein and phenolic content showed improved levels upon Si supplementation, which indicates an optimal solute transport system from source to sink. The content of superoxide radicals showed a surge under salinity stress treatment, but efficient scavenging of superoxide radicles was noted under Si supplementation. Salinity stress exhibited more damaging effects on root NR activity, which was notably enhanced upon Si supplementation. Moreover, the beneficial role of Si was further substantiated as there was notable Si accumulation in the leaves and roots of salinity-stressed mung bean plants. Furthermore, Si stimulated competent ROS scavenging by reinforcing the antioxidant enzyme activity, as well coordinating with their isozyme activity, as expressed by the varying band intensities. Similarly, the Si-mediated increase in peroxidase activity may reveal changes in the mechanical characteristics of the cell wall, which are in turn associated with salinity stress adaptation. Proteomic investigations revealed the upregulation or downregulation of several proteins, which were thereafter identified by LC−MS/MS. About 45 proteins were identified and were functionally classified into photosynthesis (24%), metabolic process (19%), redox homeostasis (12%), transmembrane transport (10%), stress response (7%), and transcription regulation (4%). The gene expression analysis of the silicon transporter genes (Lsi1, Lsi2, and Lsi3) and SOS pathway genes (SOS1, SOS2, and SOS3) indicated the role of silicon in mitigating salinity stress. Hence, the findings of this study can facilitate a profound understanding of the potential mechanisms adopted by mung bean due to exogenous Si application during salinity stress.

Exogenous Application of Methyl Jasmonate Promotes Yield and Grain Quality of Rice under Terminal Drought Stress

Exogenous application of methyl jasmonate (MeJA) improves rice drought tolerance, but its effects on rice yield and quality under drought stress during the reproductive phase remain unclear. A pot experiment was conducted to measure rice yield, grain quality, and starch physicochemical properties under three treatments: continuous flooding irrigation throughout the whole growth season (CF), ten days of −40 kPa drought stress at the heading stage (DS), and foliar spraying 100 μmol L−1 MeJA on the first three days of the ten-day −40 kPa heading stage drought stress (DM). An inbred japonica rice variety, Huaidao 5, was the experimental material, and each treatment had 11 replicates for sampling. The results indicated that DS significantly reduced rice yield and quality compared to CF. With increases in superoxide dismutase (+22.2%), peroxidase activities (+10.5%), catalase (+5.0%), and proline content (+5.7%), DM significantly increased 1000-grain weight (+8.6%), filled grain percentage (+3.6%), and yield (+11.1%) compared with DS. Regarding grain quality, DM significantly decreased the chalkiness degree (−12.3%) and protein content (−3.9%) but increased the amylose content (+17.2%) and taste value (+7.3%) relative to DS. In addition, DM improved breakdown viscosity (+17.8%), gelatinization enthalpy (+17.2%), retrogradation enthalpy (+28.0%), 1045/1022 cm−1 ratio (+3.0%), and starch granule morphology compared to DS. In conclusion, exogenous application of 100 μmol L−1 MeJA enhanced the antioxidant capacity of rice leaves, and thus improved starch physicochemical properties to increase grain yield and quality under terminal drought stress.

Polyphosphate fertilizer impacts the enzymatic and non-enzymatic antioxidant capacity of wheat plants grown under salinity

By 2050, the predicted global population is set to reach 9.6 billion highlighting the urgent need to increase crop productivity to meet the growing demand for food. This is becoming increasingly challenging when soils are saline and/or deficient in phosphorus (P). The synergic effect of P deficiency and salinity causes a series of secondary stresses including oxidative stress. Reactive Oxygen Species (ROS) production and oxidative damage in plants caused either by P limitation or by salt stress may restrict the overall plant performances leading to a decline in crop yield. However, the P application in adequate forms and doses could positively impact the growth of plants and enhances their tolerance to salinity. In our investigation, we evaluated the effect of different P fertilizers forms (Ortho-A, Ortho-B and Poly-B) and increasing P rates (0, 30 and 45 ppm) on the plant's antioxidant system and P uptake of durum wheat (Karim cultivar) grown under salinity (EC = 3.003 dS/m). Our results demonstrated that salinity caused a series of variations in the antioxidant capacity of wheat plants, at both, enzymatic and non-enzymatic levels. Remarkably, a strong correlation was observed between P uptake, biomass, various antioxidant system parameters and P rates and sources. Soluble P fertilizers considerably enhanced the total plant performances under salt stress compared with control plants grown under salinity and P deficiency (C+). Indeed, salt-stressed and fertilized plants exhibited a robust antioxidant system revealed by the increase in enzymatic activities of Catalase (CAT) and Ascorbate peroxidase (APX) and a significant accumulation of Proline, total polyphenols content (TPC) and soluble sugars (SS) as well as increased biomass, Chlorophyll content (CCI), leaf protein content and P uptake compared to unfertilized plants. Compared to OrthoP fertilizers at 45 ppm P, Poly-B fertilizer showed significant positive responses at 30 ppm P where the increase reached + 18.2% in protein content, + 156.8% in shoot biomass, + 93% in CCI, + 84% in shoot P content, + 51% in CAT activity, + 79% in APX activity, + 93% in TPC and + 40% in SS compared to C+. This implies that PolyP fertilizers might be an alternative for the suitable management of phosphorus fertilization under salinity.

Effect of sodium alginate–gelatin–polyvinyl pyrrolidone microspheres on cucumber plants, soil, and microbial communities under lead stress

Lead is highly persistent and toxic in soil, hindering plant growth. Microspheres are a novel, functional, and slow-release preparation commonly used for controlled release of agricultural chemicals. However, their application in the remediation of Pb-contaminated soil has not been studied; furthermore, the remediation mechanism involved has not been systematically assessed. Herein, we evaluated the Pb stress mitigation ability of sodium alginate–gelatin–polyvinyl pyrrolidone composite microspheres. Microspheres effectively attenuated the Pb toxic effect on cucumber seedlings. Furthermore, they boosted cucumber growth, increased peroxidase activity, and chlorophyll content, while reducing malondialdehyde content in leaves. Microspheres promoted Pb enrichment in cucumber, especially in roots (about 4.5 times). They also improved soil physicochemical properties, promoted enzyme activity, and increased soil available Pb concentration in the short term. In addition, microspheres selectively enriched functional (heavy metal-tolerating and plant growth promoting) bacteria to adapt to and resist Pb stress by improving soil properties and nutrients. These results indicated that even a small amount (0.025–0.3 %) of microspheres can significantly reduce the adverse effects of Pb on plants, soil, and bacterial communities. Composite microspheres have shown great value in Pb remediation, and their application potential in phytoremediation is also worth evaluating to expand the application.

Assessment of Oxidative Stress Parameters for some of Baghdad City Fuel Stations Workers

Because of inhalation of the volatile substances and unintended ingestion, the risk of health problems for fuelling employees exposed to gasoline vapours in gas stations is increased. Therefore, the goal of the study was to compare the oxidative stress state of healthy volunteers, who served as the control group, to Iraqi male fuelling staff, who served as the exposed groups. The levels of total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI), malondialdehyde (MDA), Uric acid (UA), and total peroxidase activity were measured. A total of 102 subjects divided into three groups according to the duration of fuel vapours exposure: 25 exposed for 1-10 years (G1), 50 exposed for 11-19 years (G2) and 27 exposed for ≥ 20 years (G3), as well as 50 healthy people as a control group (C). The results exhibited that the levels of TOS, OSI, MDA, and total peroxidase activity were highly significant increased in all exposed groups (G1, G2 &amp; G3) as compared to the C. A highly significant decrease was observed in TAS levels in all exposed groups in comparison with the C, while there was no significant difference in UA levels in all studied groups. The exposure to petrol associated with significant increase of TOS, OSI, MDA and total peroxidase activity with a significant decrease of TAS among workers in fuel stations and they increased oxidative stress, which likely resulted in negative impacts on human health later on as a result of prolonged labour at gas stations.

Extraction Potential of Lolium perenne L. (Perennial Rye Grass) for Metals in Landfill Soil: Its Tolerance and Defense Strategies

Landfill sites open and close frequently throughout the world, taking over a significant amount of land and leaving it contaminated and unavailable to the surrounding population for use. Different forms of remediation methods have been employed to rehabilitate contaminated land to a state that poses less of a threat to the environment. Phytoremediation is one of the remediation techniques that has proven to be effective, economical and easier to implement compared to other methods. The main aim of this study was to explore the potential use of Lolium perenne L. to remediate and restore metal-contaminated landfill soil and determine its stress tolerance mechanism(s). The metal uptake, determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectroscopy (ICP-MS), revealed that Lolium perenne accumulate a higher amount of metals in the roots than in leaves, which was further confirmed by the translocation factor (TF) values of all of the metals that were below 1, ranging between 0.2 and 0.8, while Cu, Cr and Pb had a bioaccumulation factor (BCF) &gt; 1. This confirms that L. perenne is capable of absorbing metals into the root matrix but might restrict further movement into other parts of the plant as a defense mechanism against metal toxicity. In response to metal-induced stress, L. perenne displayed an increase in enzyme activity of superoxide dismutase, glutathione S-transferase, peroxidase and amylases in plants grown in landfill soil. Peroxidases displayed the highest level of enzyme activity, while total amylolytic activity had the most significant increase in activity over time. Although not a hyperaccumulator, L. perenne is a potential candidate for the phytoremediation of landfill soil and the phytostabilization of Cu, Cr and Pb.

Peroxidase activity as a biochemical marker of insecticide use in vegetables

The insecticides use is important for crop improvement and protection, but in excessive amounts, they would induce a dysfunction of metabolic enzymatic systems in plant tissues, leading to undesirable qualitative changes. In this context, we are interested in peroxidase (POD), an important enzyme in plant physiology but whose activity seems to be conditioned by the presence of insecticides in the soil. This work aims to study the impact of locally used insecticides (chlorpyrifos and dimethoate) on the activity of POD in parsley, onion, celery and garlic grown in soils treated or not. POD extraction was performed using Tris-HCl buffer (pH 7.3); its activity was measured using the substrate o-dianisidine in the presence of H2O2. Our result showed that POD activity for insecticide treated parsley, celery and onions increased by 30 % 127 % and 341 % respectively, however did not change significantly for garlic. Thus, the action of these chemicals is not trivial because they may alter non-target pathways, especially when doses are not adjusted accordingly. We found that insecticide stress would increase POD activity in all vegetables except garlic, which showed tolerance to insecticides. Our findings suggest that organic farming conditions could minimize peroxidase activity in parsley, celery and onion. We add that overproduction of POD negatively affects the quality and reduces the shelf life of vegetables, thus would be a very interesting biomarker of insecticide stress.

The potential of SiK® fertilization in the resilience of chestnut plants to drought - a biochemical study.

Silicon is an essential mineral nutrient, that plays a crucial role in the metabolic, biochemical, and functional mechanisms of many crops under environmental stress. In the current study, we evaluated the effect of SiK® fertilization on the biochemical defense response in plants exposed to water stress. Castanea sativa plants were fertilized with different concentrations of potassium silicate (0, 5, 7.5, and 10 mM of SiK®) and exposed to a non-irrigation phase and an irrigation phase. The results indicate that silicon promoted the synthesis of soluble proteins and decreased the proline content and the oxidative stress (reduced electrolyte leakage, lipid peroxidation, and hydrogen peroxide accumulation) in tissues, due to an increase in ascorbate peroxidase, catalase, and peroxidase activity, which was accompanied by the rise in total phenol compounds and the number of thiols under drought conditions. This study suggests that exogenous Si applications have a protective role in chestnut plants under water deficit by increasing their resilience to this abiotic stress.

Insight into the plant-associated bacterial interactions: Role for plant arsenic extraction and carbon fixation

This study investigated the interactions between rhizosphere and endosphere bacteria during phytoextraction and how the interactions affect arsenic (As) extraction and carbon (C) fixation of plants. Pot experiments, high-throughput sequencing, metabonomics, and network analysis were integrated. Results showed that positive correlations dominated the interconnections within modules (>95 %), among modules (100 %), and among keystone taxa (>72 %) in the bacterial networks of plant rhizosphere, root endosphere, and shoot endosphere. This confirmed that cooperative interactions occurred between bacteria in the rhizosphere and endosphere during phytoextraction. Modules and keystone taxa positively correlating with plant As extraction and C fixation were identified, indicating that modules and keystone taxa promoted plant As extraction and C fixation simultaneously. This is mainly because modules and keystone taxa in plant rhizosphere, root endosphere, and shoot endosphere carried arsenate reduction and C fixation genes. Meanwhile, they up-regulated the significant metabolites related to plant As tolerance. Additionally, shoot C fixation increased peroxidase activity and biomass thereby facilitating plant As extraction was confirmed. This study revealed the mechanisms of plant-associated bacterial interactions contributing to plant As extraction and C fixation. More importantly, this study provided a new angle of view that phytoextraction can be applied to achieve multiple environmental goals, such as simultaneous soil remediation and C neutrality.

Combination of 3’,4’,5,7-tetrahydroxy isoflavone and active modified atmosphere packaging inhibits yellowing, maintains quality, and prolongs shelf life of fresh peeled water chestnuts (Eleocharis dulcis)

Yellowing and quality loss shorten the shelf life of fresh peeled water chestnuts (FPWCs). The purpose of this study was to elucidate the mechanism by which the combination of 3’,4’,5,7-tetrahydroxy isoflavone (3’,4’,5,7-THIF) and active modified atmosphere packaging (AMAP) prolonged the shelf life of FPWCs. FPWCs were treated with 1.0% 3’,4’,5,7-THIF, AMAP (18.3% O2, 81.7% N2), and a combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2). The yellowing extent, mass loss rate, enzymatic activities, yellowing substance concentrations, quality, and microorganisms of FPWCs were analyzed. The results showed that the three treatments all inhibited the increase in the mass loss rate and activity of peroxidase and lowered the eriodictyol concentration. AMAP (18.3% O2, 81.7% N2) and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) inhibited the respiration of FPWCs and increased the total soluble solids, titratable acidity, and ascorbic acid concentrations. The three treatments had no significant effects on the activities of polyphenol oxidase and phenylalanine lyase and naringenin concentration. 3’,4’,5,7-THIF (1.0%), AMAP (18.3% O2, 81.7% N2), and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) prolonged the shelf life of FPWCs by 6, 6, and 12 d, respectively. The combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) was optimal among the three treatment methods. These results suggested that the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) might be used to extend the shelf life of FPWCs in practice.

Potential application of melatonin in reducing boron toxicity in rice seedlings through improved growth, cell wall composition, proline, and defense mechanisms

Melatonin (MT) has been demonstrated to provide defense against both biotic and abiotic stressors. Boron toxicity (BT) can significantly limit the growth and production of plants. However, few studies have been conducted on whether MT is effective in attenuating B toxicity in different plants. In order to evaluate the efficacy of exogenous MT treatment in reducing the negative impact of BT on rice seedlings, this study examined the influence of MT on growth, antioxidant capacity, cell wall composition, and proline metabolism in rice seedlings under hydroponics. Four treatments were established: MT (50 μM), MT + BT (50 μM MT + 800 μM B), BT (800 μM), and CK (control) in a completely randomized design. The results indicate that BT had a significant detrimental effect on the shoot length, root length, and root and shoot fresh weights of rice seedlings by 11.96%, 27.77%, 25.69%, and 18.67%, respectively as compared to the control treatment. However, exogenous MT application increased these parameters and reduced B accumulation in aboveground parts (14.05%) of the plant. Exogenous MT also increased the endogenous melatonin content and antioxidant enzyme activities (64.45%, 71.61%, 237.64%, and 55.42% increase in superoxide dismutase, ascorbate peroxidase, and peroxidase activities, respectively), while decreasing reactive oxygen species levels and oxidized forms of glutathione and ascorbic acid. Additionally, MT enhanced the biosynthesis of proline by decreasing proline dehydrogenase (ProDH) and increasing the GSH (glutathione) and ASA (ascorbic acid) contents. Exogenous MT also increased cell wall components that can increase B adsorption to the cell wall. Overall, these findings suggest that MT application can be a potential solution for strengthening the stress tolerance of rice seedlings, particularly under conditions of B toxicity. In regions where soil contains high levels of boron, the use of MT could enhance rice crop yields and quality.

Differential Expression of Antioxidant Enzymes in Chlorine-Resistant Acinetobacter and Serratia spp. Isolated from Water Distribution Sites in Mumbai: A Study on Mechanisms of Chlorine Resistance for Sustainable Water Treatment Strategies

Chlorination is a widely used process for disinfecting drinking water, but the emergence of chlorine-resistant bacteria has become a significant concern. While previous research has focused on identifying chlorine-resistant organisms, there has been limited investigation into the mechanisms behind chlorine resistance. Some bacterial isolates that display resistance to chlorine treatment may protect themselves using various mechanisms, including biofilm production, antibiotic resistance, horizontal transfer of antibiotic resistance genes, or producing antioxidant enzymes. Given that chlorination employs hypochlorous acid (HOCl), which is an extremely potent oxidizing agent, the most critical mechanism to investigate is antioxidant enzymes. This study investigated the antioxidant profile of eight chlorine-resistant isolates (three of the Serratia sp. and five of the Acinetobacter) after chlorine exposure. The profiles, both between and within species, were noticeably different. Among the isolates, Acinetobacter junii NA 3-2 showed a significant increase in the specific activity of superoxide dismutase, catalase, and ascorbate peroxidase after exposure to 20 ppm chlorine. In the guaiacol peroxidase (GPX) assay, only isolates belonging to Serratia marcescens showed GPX activity, and Serratia marcescens 3929-1 showed significant increase after exposure to 20 ppm of chlorine. None of the isolates belonging to Acinetobacter spp. showed GPX activity. Additionally, almost all control samples exhibited some enzyme activity, which may explain their survival against chlorine treatment in reservoirs. Principal component analysis revealed no strain-dependent similarities, while the balance of scavenging enzymes changed, as demonstrated in the heat map. Thus, this study suggests that antioxidant enzymes may be one mechanism of protection for some bacterial species against oxidative stress from chlorination, resulting in chlorine resistance. Understanding the mechanism of chlorine resistance is critical to identifying potential solutions. This study highlights the need to consider more modern approaches to disinfecting drinking water.