Membrane Lipid Peroxidation Levels Research Articles

Penthorum chinense Pursh inhibits ferroptosis in cellular and Caenorhabditis elegans models of Alzheimer's disease

Background: Ferroptosis, a unique type of cell death triggered by iron-dependent lipid peroxidation, plays a critical role in the pathogenesis of Alzheimer's disease (AD), a debilitating condition marked by memory loss and cognitive impairment due to the accumulation of beta-amyloid (Aβ) and hyperphosphorylated Tau protein. Increasing evidence suggests that inhibitors of ferroptosis could be groundbreaking in the treatment of AD. Method: In this study, we established in vitro ferroptosis using erastin-, RSL-3-, hemin-, and iFSP1-induced PC-12 cells. Using MTT along with Hoechst/PI staining, we assessed cell viability and death. To determine various aspects of ferroptosis, we employed fluorescence probes, including DCFDA, JC-1, C11 BODIPY, Mito-Tracker, and PGSK, to measure ROS production, mitochondrial membrane potential, lipid peroxidation, mitochondrial morphology, and intracellular iron levels. Additionally, Western blotting, biolayer interferometry technology, and shRNA were utilized to investigate the underlying molecular mechanisms. Furthermore, p-CAX APP Swe/Ind- and pRK5-EGFP-Tau P301L overexpressing PC-12 cells, along with Caenorhabditis elegans (C. elegans) strains CL4176, CL2331, and BR5270, were employed to examine ferroptosis in AD models. Results: Here, we conducted a screening of our natural medicine libraries and identified the ethanol extract of Penthorum chinense Pursh (PEE), particularly its ethyl acetate fraction (PEF), displayed inhibitory effects on ferroptosis in cells. Specifically, PEF inhibited the generation of ROS, lipid peroxidation, and intracellular iron levels. Furthermore, PEF demonstrated protective effects against H2O2-induced cell death, ROS production, and mitochondrial damage. Mechanistic investigations unveiled PEF's modulation of intracellular iron accumulation, GPX4 expression and activity, and FSP1 expression. In p-CAX APP Swe/Ind and pRK5-EGFP-Tau P301L overexpressing PC-12 cells, PEF significantly reduced cell death, as well as ROS and lipid peroxidase production. Moreover, PEF ameliorated paralysis and slowing rate in Aβ and Tau transgenic C. elegans models, while inhibiting ferroptosis, as evidenced by decreased DHE intensity, lipid peroxidation levels, iron accumulation, and expression of SOD-3 and gst-4. Conclusion: Our findings highlight the suppressive effects of PEF on ferroptosis in AD cellular and C. elegans models. This study helps us better understand how ferroptosis affects AD and emphasizes the potential of PCP as a candidate for AD intervention.

Mechanism of hypoxia-induced damage to the mechanical property in human erythrocytes-band 3 phosphorylation and sulfhydryl oxidation of membrane proteins.

Introduction: The integrity of the erythrocyte membrane cytoskeletal network controls the morphology, specific surface area, material exchange, and state of erythrocytes in the blood circulation. The antioxidant properties of resveratrol have been reported, but studies on the effect of resveratrol on the hypoxia-induced mechanical properties of erythrocytes are rare. Methods: In this study, the effects of different concentrations of resveratrol on the protection of red blood cell mor-phology and changes in intracellular redox levels were examined to select an appropriate concentration for further study. The Young's modulus and surface roughness of the red blood cells and blood viscosity were measured via atomic force microsco-py and a blood rheometer, respectively. Flow cytometry, free hemoglobin levels, and membrane lipid peroxidation levels were used to characterize cell membrane damage in the presence and absence of resveratrol after hypoxia. The effects of oxida-tive stress on the erythrocyte membrane proteins band 3 and spectrin were further investigated by immunofluorescent label-ing and Western blotting. Results and discussion: Resveratrol changed the surface roughness and Young's modulus of the erythrocyte mem-brane, reduced the rate of eryptosis in erythrocytes after hypoxia, and stabilized the intracellular redox level. Further data showed that resveratrol protected the erythrocyte membrane proteins band 3 and spectrin. Moreover, resistance to band 3 pro-tein tyrosine phosphorylation and sulfhydryl oxidation can protect the stability of the erythrocyte membrane skeleton net-work, thereby protecting erythrocyte deformability under hypoxia. The results of the present study may provide new insights into the roles of resveratrol in the prevention of hypoxia and as an antioxidant.

Brassinolide alleviated drought stress faced by bulbil formation of Pinellia ternata by reducing ROS metabolism and enhancing AsA-GSH cycle

Drought occurs frequently because of global climate change. The involvement of brassinolide (BR) in regulating plant tolerance to stress is one of its research hotspots. Bulbil formation and development of Pinellia ternata is the key to its yield formation. However, drought in spring and waterlogging in summer often occur in the bulbil development process, which seriously affects the yield and quality of P. ternata. The study investigated the effects of BR and BR biosynthesis inhibitors (propiconazole, PCZ) on formation and growth of P. ternata bulbil under spring drought and rehydration condition. The results showed that BR treatment improved the biomass of P. ternata by increasing the bulbils formation, tillers numbers, and fresh weight of bulbils, tuber, steam and leaf when compared with control or PCZ groups both in drought and rehydration condition. Compared with the control or PCZ groups, BR application significantly elevated the photosynthetic pigment contents, PSⅡ photoprotective capacity, osmosis-regulating substance levels, and active ingredients contents in P. ternata both in drought and rehydration conditions, which promoted the growth of P. ternata. In addition, BR application enhanced antioxidant contents (AsA, GSH, AsA/DHA ratio, GSH/GSSG ratio) and enzymes activities (SOD, APX, DHAR, MDHAR), but reduced the levels of membrane lipid peroxidation and reactive oxygen in P. ternata both in drought and rehydration conditions. This study revealed that BR application could help P. ternata to cope with the drought stress during bulbil formation periods by improving AsA-GSH cycle and diminishing ROS damage.

Effects of gibberellic acid, kinetin and indole butyric acid mixture on sorghum salinity tolerance and grain yield in saline-alkali coastal zone.

The development and utilization of coastal saline-alkali lands hold significant importance in mitigating the shortage of cultivated land resources in China, enhancing the agro-ecological environment in coastal saline and alkaline areas, and ensuring national food security. We set up both pot and field trials (randomized block design) at Xinxiang experimental station of Institute of Crop Science, Chinese Academy of Agricultural Sciences (ICS-CAAS) and Dongying Yellow River Delta Modern Agricultural Research Base in Shandong Province in 2021 and 2022, respectively. The experimental materials, Jiliang 1 and Jiliang 2, underwent seed dressing with GKI composites at concentrations of 2.5 and 5 mL·kg-1. These composites, which contained the main components of gibberellin, kinetin, and indole butyric acid, were denoted as GKI2.5 and GKI5.0, respectively. The control plots (CK) received water seed dressing. The aim was to assess the regulatory effects of GKI on salt tolerance and grain sorghum yield. Compared to CK, the GKI2.5 and GKI5.0 seed dressing treatments significantly enhanced the growth and development of the two grain sorghum varieties, increased antioxidant enzyme activity and soluble protein content of sorghum leaves, while reducing leaf malondialdehyde content. Moreover, the GKI treatments increased leaf net photosynthetic rate. Under field conditions, yields of Jiliang 1 and Jiliang 2 were enhanced by an average of 17.1% and 19.1%, respectively. In conclusion, GKI seed dressing treatment effectively promoted the growth and development of sorghum under salt stress. It enhanced the antioxidant and osmoregulatory capacities of leaves, reduced the level of membrane lipid peroxidation, and improved net photosynthetic rate of leaves, which together improved the salt tolerance and sorghum yield.

Post-Harvest Application of Nanoparticles of Titanium Dioxide (NPs-TiO2) and Ethylene to Improve the Coloration of Detached Apple Fruit.

In this study, we analyzed the effects of treatments with titanium dioxide nanoparticles (NPs-TiO2) and ethylene on anthocyanin biosynthesis and reactive oxygen species (ROS) metabolism during light exposure in ripe 'red delicious' apples. Both treatments led to improved anthocyanins biosynthesis in detached mature apples, while the NPs-TiO2 had less impact on the fruit firmness, TSS, TA, and TSS/TA ratio. Furthermore, the effects of both treatments on the expression of anthocyanin-related enzymes and transcription factors in the apple peel were evaluated at the gene level. The differentially expressed genes induced by the two treatments were highly enriched in the photosynthesis and flavonoid biosynthesis pathways. The expression of structural genes involved in anthocyanin biosynthesis and ethylene biosynthesis was more significantly upregulated in the ethylene treatment group than in the NPs-TiO2 treatment group, and the opposite pattern was observed for the expression of genes encoding transcription factors involved in plant photomorphogenesis pathways. In addition, the ROS levels and antioxidant capacity were higher and the membrane lipid peroxidation level was lower in fruit in the NPs-TiO2 treatment group than in the ethylene treatment group. The results of this study reveal differences in the coloration mechanisms induced by NPs-TiO2 and ethylene in apples, providing new insights into improving the color and quality of fruits.

Arbuscular mycorrhizal symbiosis and melatonin synergistically suppress heat-induced leaf senescence involves in abscisic acid, gibberellin, and cytokinin-mediated pathways in perennial ryegrass

Leaf senescence is a prominent symptom of heat injury observed in cool-season plants. The application of melatonin (MT) and inoculation with mycorrhizal fungi can mitigate heat-induced leaf senescence. The current research aims to examine the individual and combined effects of arbuscular mycorrhizal (AM) inoculation and MT application on heat-related leaf senescence in perennial ryegrass (Lolium perenne L.). In addition, whether the effects of these treatments were in any way associated with abscisic acid (ABA), gibberellin (GA), and cytokinin (CTK) for exerting the bioactivity. According to the results, the suppression of heat-mediated leaf senescence using MT treatment and AM inoculation manifested as increased photosynthesis, turf quality (TQ), and plant growth, and reduced membrane lipid peroxidation levels as well as the chlorophyll catabolic genes (CCGs) and senescence-associated genes (LpSAG12.1 and Lph36) transcript levels in the heat-stressed plants. MT application and AM inoculation elevated the internal MT, GA, and CTK levels, while reducing the ABA levels in the heat-stressed plants. In addition, the MT biosynthesis genes (LpTDC1, LpTDC2, LpCOMT1, LpASMT1, and LpASMT3), the ABA catabolic gene, the GA biosynthesis genes, CTK biosynthesis genes, along with the associated signal transduction response transcription factors (TFs) (type-B ARRs) exhibited increased levels, whereas the expressions of the GA and CTK catabolic genes and the biosynthesis and signal transduction genes related to ABA exhibited decreased levels after MT application and AM inoculation in the heat-stressed plants. Furthermore, the application of exogenous MT notably elevated the AM colonization rate at high temperature (HT) condition. After 28 days of heat stress, compared to the treatment with neither AMF nor MT application, AM combined with MT achieved a synergistic effect, resulting in a 25.32%, 87.21%, 58.69%, 57.17%, and 28.46% increase in TQ, leaf chlorophyll content, net photosynthesis (Pn), leaf photochemical efficiency (Fv/Fm), and relative water content (RWC), respectively, in perennial ryegrass. Additionally, this treatment significantly reduced the electrolyte leakage (EL), hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels by 30.76%, 38.19%, and 31.95%, respectively, and also significantly reduced the transcription levels of CCGs and senescence-associated genes. Consequently, it was inferred that a combination of AM and MT treatments promotes plant growth and development and suppresses heat-induced leaf senescence in plants.

Effects of cellulose nanofibrils treatment on antioxidant properties and aroma of fresh-cut apples.

Horticultural products tend to deteriorate during postharvest storage and processing. In this study, cellulose nanofibers (CNFs) were prepared from wood to investigate the effects of CNF treatment on the storage quality, aroma composition, and antioxidant system of fresh-cut apple (Malus domestica) wedges. Compared with control treatment, CNF coating treatment significantly improved the appearance of apple wedges; reduced the decay rate of apple wedges; and delayed the decline in weight loss, firmness, and titratable acid during storage. Gas chromatography-mass spectrometry showed that CNF treatment could maintain the aroma components of apple wedges (stored for 4days). Further investigations showed that CNF treatment increased the antioxidant system level and decreased reactive oxygen species content and membrane lipid peroxidation level of apple wedges. Overall, this study showed that CNF coating could effectively maintain the quality of fresh-cut apples during cold storage.

Dissolved Organic Matter from Earthworm Casts Restrained the Phytotoxicity of Soil Glyphosate to Citrus (Poncirus trifoliata (L.) Raf.) Plants

A large amount of glyphosate enters the soil at a high frequency, forming “pseudo-persistent” pollutants that, in turn, threaten soil ecological function and crop growth. Earthworm casts (EWCs) are a sound organic alternative to chemical fertilizers to promote crop growth. Dissolved organic matter from EWCs (EWC-DOM) is supposed to be a more mobile and bioavailable fraction. However, the effect of EWC-DOM on the phytotoxicity of glyphosate remains largely unknown. This study examines glyphosate-induced oxidative stress and its impact on antioxidant and detoxification enzymes in citrus plants grown in soils with and/or without EWC-DOM. The results suggest that EWC-DOM could reduce the membrane lipid peroxidation level, thus slowing down the aging of plants in order to maintain stronger resilience, with more active antioxidant enzymes (including SOD, POD, and CAT) and detoxification enzymes (including GST, laccase, CPR, and UGTs) that could effectively remove reactive oxygen species (ROS) caused by glyphosate stress, thereby alleviating the damage of ROS accumulation on plant tissues. Our data indicate that incorporating EWC-DOM should be a sound way to protect citrus plants from the phytotoxicity caused by using glyphosate for orchard weeding. This has major implications for the sustainable and healthy development of citrus production.

Effect of thallus melanisation on the sensitivity of lichens to heat stress

Extreme climatic phenomena such as heat waves, heavy rainfall and prolonged droughts are one of the main problems associated with ongoing climate change. The global increase in extreme rainfalls associated with summer heatwaves are projected to increase in amplitude and frequency in the near future. However, the consequences of such extreme events on lichens are largely unknown. The aim was to determine the effect of heat stress on the physiology of lichen Cetraria aculeata in a metabolically active state and to verify whether strongly melanised thalli are more resistant than poorly melanised thalli. In the present study, melanin was extracted from C. aculeata for the first time. Our study showed that the critical temperature for metabolism is around 35 °C. Both symbiotic partners responded to heat stress, manifested by the decreased maximum quantum yield of PSII photochemistry, high level of cell membrane damage, increased membrane lipid peroxidation and decreased dehydrogenase activity. Highly melanised thalli were more sensitive to heat stress, which excludes the role of melanins as compounds protecting against heat stress. Therefore, mycobiont melanisation imposes a trade-off between protection against UV and avoidance of damage caused by high temperature. It can be concluded that heavy rainfall during high temperatures may significantly deteriorate the physiological condition of melanised thalli. However, the level of membrane lipid peroxidation in melanised thalli decreased over time after exposure, suggesting greater efficiency of antioxidant defence mechanisms. Given the ongoing climate changes, many lichen species may require a great deal of plasticity to maintain their physiological state at a level that ensures their survival.

Membrane lipid peroxidation in lichens determined by the TBARS assay as a suitable biomarker for the prediction of elevated level of potentially toxic trace elements in soil

The use of biomarkers defined as measurable biological parameters at the sub-organism level in which structural or functional changes indicate the presence of pollutants is a promising approach to identify affected sites. The aim of the study was to test the suitability of the level of membrane lipid peroxidation in the widespread epigeic lichen Cladonia rei for the assessment of soil pollution and to develop an effective method to recognise elevated concentrations of potentially toxic trace elements in soil. We collected lichen and soil substrate samples from variously polluted sites and determined the level of membrane lipid peroxidation in the thalli using the thiobarbituric acid-reactive substances (TBARS) assay. Based on the concentrations of Zn, Pb, Cd and As in the soil samples, we calculated the Pollution Load Index (PLI) for particular sampling sites to consider the combined effect of several toxic elements. The model of relationships between TBARS concentrations and PLI revealed that membrane lipid peroxidation does not increase linearly with PLI value, which suggests that above a certain threshold, oxidative stress induced activation of defence aimed at counteracting deleterious effects. We observed that if PLI exceeded the value of 100, the concentrations of TBARS were markedly increased and did not drop below 30 nmol g−1 DW. On the other hand, in lichen samples collected at sites with PLI < 10, TBARS concentrations were lower and as a rule did not exceed 25 nmol g−1 DW. Therefore, we concluded that the effect of soil pollution on membrane lipid peroxidation in the thalli of C. rei can be used in passive soil quality biomonitoring, according to the principle that an increased level of membrane lipid peroxidation is predictive for increased concentrations of elements in the host substrate. Given that this species has not been analysed in detail for the use of biomarkers, this study establishes a baseline and supports practicable use of TBARS concentrations in lichens as biomarkers.

Transcriptomics and physiological analyses reveal that sulfur alleviates mercury toxicity in rice (Oryza sativa L.)

Mercury (Hg) is one of the most dangerous contaminants and has sparked global concern since it poses a health risk to humans when consumed through rice. Sulfur (S) is a crucial component for plant growth, and S may reduce Hg accumulation in rice grains. However, the detailed effects of S and the mechanisms underlying S-mediated responses in Hg-stressed rice plants remain unclear. Currently, to investigate the effects of S addition on rice growth, Hg accumulation, physiological indexes, and gene expression profiles, rice seedlings were hydroponically treated with Hg (20 µmol/L HgCl2) and Hg plus elemental sulfur (100 mg/L). S application significantly reduced Hg accumulation in Hg-stressed rice roots and alleviated the inhibitory effects of Hg on rice growth. S addition significantly reduced Hg-induced reactive oxygen species generation, membrane lipid peroxidation levels, and activities of antioxidant enzymes while increasing glutathione content in leaves. Transcriptomic analysis of roots identified 3,411, 2,730, and 581 differentially expressed genes in the control (CK) vs. Hg, CK vs. Hg + S, and Hg vs. Hg + S datasets, respectively. The pathway of S-mediated biological metabolism fell into six groups: biosynthesis and metabolism, expression regulation, transport, stimulus response, oxidation reduction, and cell wall biogenesis. The majority of biological process-related genes were upregulated under Hg stress compared with CK treatment, but downregulated in the Hg + S treatment. The results provide transcriptomic and physiological evidence that S may be critical for plant Hg stress resistance and will help to develop strategies for reduction or phytoremediation of Hg contamination.

Interaction effect of fungicide and chitosan on non-target lichenized fungi

Excessive use of plant growth stimulants and pesticides is currently a considerable problem, especially in agriculture, horticulture, and arboriculture. Understanding the impacts of these compounds and their combinations on non-target organisms is crucial to minimize unintended consequences, while maintaining their use in plant protection. The aim of this study was to test how long-term spraying with different solutions of natural biostimulator chitosan, synthetic fungicide Switch 62.5 WG, and their combinations affects the physiology of epiphytic lichen Xanthoria parietina naturally occurring in fruit orchards and farmlands. We showed that fungicides composed of fludioxionil and cypronidil, as well as the combined use of such fungicides together with chitosan, can cause the considerable impairment of lichen physiology, and these disturbances relate to both algal and fungal partners of the symbiotic association. This negative effect was especially visible in the loss of cell membrane integrity, the high level of membrane lipid peroxidation, and changes in chlorophyll fluorescence parameters on the last day of the experiment. The combined use of these agents also leads to clear disturbances in the functioning of the mitochondrial respiratory chain, which was manifested by increased NADH dehydrogenase activity, while the use of these compounds separately led to a decrease in the activity of this enzyme. We concluded that the regular use of these agents in fruit tree cultivation may cause serious ecological consequences for epiphytic lichen communities as a result of the death of lichen thalli. This study suggests that the impact of some plant protection agents, both individually and in combinations, merits further attention in terms of their impact on non-target fungi.

Widely targeted metabolomics analysis reveals the mechanism of quality improvement of flue-cured tobacco.

Flue-curing of top leaves with stems is a widely applied curing technology. Owing to the presence of stems, the quality of flue-cured leaves was significantly improved. However, the contribution of stems to flue-cured leaves is still unknown. In this study, the differences in physicochemical properties and metabolomics data between separated leaves (stem(-)) and leaves with stems (stem(+)) were investigated. The metabolic profiling of stem(+) was significantly different from that of stem(-), with phytohormone indole-3-acetic acid (IAA) being one of the most differential metabolites. The presence of stems reduced the rate of water loss in leaves, which led to less ROS accumulation, higher antioxidant enzyme activities and a lower level of membrane lipid peroxidation in stem(+) than in stem(-). The presence of stems also helped maintain the cellular membrane integrity of leaf cells by preventing the accumulation of IAA in leaf cells. Better cellular membrane integrity during flue-curing means a lower risk of leaf browning. In addition, stem(+) had a lower starch content than stem(-) because of a higher level of amylase activity. In summary, these results indicated that the presence of stems caused metabolism changes in leaves, prevented flue-cured leaves from browning and enhanced starch degradation in leaves during flue-curing.

Sex-specific physiological and biochemical responses of Litsea cubeba under waterlogging stress

The sex of dimorphic plants is affected by stress tolerance. Litsea cubeba is a diecious species of ecological importance in southern China, and waterlogging is one of the most common abiotic stressors that this species suffers. However, differences between male and female L. cubeba under waterlogging stress have not been well studied. In this study, we examined the sex-specific physiological, metabolic, and biochemical responses of L. cubeba to waterlogging. The results showed that female and male L. cubeba plants exhibited sex-related differences in response to waterlogging stress. Males under waterlogging conditions experienced more serious oxidative damage than females, whereas females of L. cubeba under waterlogging conditions possessed superior antioxidant defense systems, including better enzymatic and nonenzymatic antioxidants, higher total chlorophyll and carotenoid contents, higher fermentative enzyme activities and root activity, and higher soluble sugar and proline contents. In addition, females exhibited higher malondialdehyde, ascorbic acid, and glutathione contents in the Yifeng (YF) and Huangshan (HS) varieties, whereas males had higher malondialdehyde, ascorbic acid, and glutathione contents in the Baise (BS) and Jiangle (JL) varieties. These results indicate that although the level of membrane lipid peroxidation and degree of damage to the membrane structure were higher and more serious in females under waterlogged stress, females possessed better cellular defense mechanisms against damage and could maintain a better cellular balance between defense and damage. Comprehensive indicators showed that female plants of L. cubeba are more tolerant to waterlogging than males, which would contribute to developing a sustainable population and maintaining a stable yield. Overall, our research provides insights into the adaptation mechanisms of L. cubeba trees subjected to waterlogging stress and provides a better understanding of sexually dimorphic responses to waterlogging stress. • Litsea cubeba exhibited sex-specific responses under waterlogging stress. • Higher oxidation resistance due to a better antioxidant defense system in female. • Females could change to anaerobic respiration faster to adapt to waterlogging stress. • Better tolerance to waterlogging in female is benefit to sustainable population and stable yield.

Paclobutrazol Ameliorates Low-Light-Induced Damage by Improving Photosynthesis, Antioxidant Defense System, and Regulating Hormone Levels in Tall Fescue.

Paclobutrazol (PBZ) is a plant-growth regulator (PGR) in the triazole family that enhances plant tolerance to environmental stresses. Low-light (LL) intensity is a critical factor adversely affecting the growth of tall fescue (Festuca arundinacea Schreb.). Therefore, in this study, tall fescue seedlings were treated with PBZ under control and LL conditions to investigate the effects of PBZ on enhancing LL stress resistance by regulating the growth, photosynthesis, oxidative defense, and hormone levels. Our results reveal that LL stress reduced the total biomass, chlorophyll (Chl) content, photosynthetic capacity, and photochemical efficiency of photosystem II (PSII) but increased the membrane lipid peroxidation level and reactive oxygen species (ROS) generation. However, the application of PBZ increased the photosynthetic pigment contents, net photosynthetic rate (Pn), maximum quantum yield of PSII photochemistry (Fv/Fm), ribulose-1,5-bisphosphate carboxylase (RuBisCO) activity, and starch content. In addition, PBZ treatment activated the antioxidant enzyme activities, antioxidants contents, ascorbate acid-glutathione (AsA-GSH) cycle, and related gene expression, lessening the ROS burst (H2O2 and O2∙−). However, the gibberellic acid (GA) anabolism was remarkably decreased by PBZ treatment under LL stress, downregulating the transcript levels of kaurene oxidase (KO), kaurenoic acid oxidase (KAO), and GA 20-oxidases (GA20ox). At the same time, PBZ treatment up-regulated 9-cis-epoxycarotenoid dioxygenase (NCED) gene expression, significantly increasing the endogenous abscisic acid (ABA) concentration under LL stress. Thus, our study revealed that PBZ improves the antioxidation and photosynthetic capacity, meanwhile increasing the ABA concentration and decreasing GA concentration, which ultimately enhances the LL stress tolerance in tall fescue.

Low-molecular-weight organic acid-mediated tolerance and Pb accumulation in centipedegrass under Pb stress

Lead (Pb) is one of the most harmful, toxic pollutants to the ecological environment and humans. Centipedegrass, a fast-growing warm-season turfgrass, is excellent for Pb pollution remediation. Exogenous low-molecular-weight organic acid (LMWOA) treatment is a promising approach for assisted phytoremediation. However, the effects of this treatment on the tolerance and Pb accumulation of centipedegrass are unclear. This study investigated these effects on the physiological growth response and Pb accumulation distribution characteristics of centipedegrass. Applications of 400 μM citric acid (CA), malic acid (MA) and tartaric acid (TA) significantly reduced membrane lipid peroxidation levels of leaves and improved biomass production of Pb-stressed plants. These treatments mainly increased peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities and enhanced free protein (Pro), ascorbic acid (AsA) and phytochelatins (PCs) contents, ultimately improving the Pb tolerance of centipedegrass. Their promoting effects decreased as follows: TA>CA>MA. All the treatments decreased root Pb concentrations and increased stem and leaf Pb concentrations, thus increasing total Pb accumulation and TF values. MA had the best and worst effects on Pb accumulation and Pb transportation, respectively. CA had the best and worst effects on Pb transportation and Pb accumulation, respectively. TA exhibited strong effects on both Pb accumulation and transport. Furthermore, all treatments changed the subcellular Pb distribution patterns and distribution models of the chemical forms of Pb in each tissue. The root Pb concentration was more highly correlated with the Pb subcellular fraction distribution pattern, while the stem and leaf Pb concentrations were more highly correlated with the distribution models of the chemical forms of Pb. Overall, TA improved plant Pb tolerance best and promoted both Pb absorption and transportation well and is considered the best candidate for Pb-contaminated soil remediation with centipedegrass. This study provides a new idea for Pb-contaminated soil remediation with centipedegrass combined with LMWOAs.

Arbuscular Mycorrhizal Fungi and Endophytic Fungi Activate Leaf Antioxidant Defense System of Lane Late Navel Orange.

Arbuscular mycorrhizal (AM) fungi and endophytic fungi collectively symbiose well with plants and, thus, stimulate plant growth; however, it is not clear whether field inoculation of the fungi enhances the resistance potential of plants, particularly in citrus. In the present study, we inoculated AM fungi (Acaulospora scrobiculata, Diversispora spurca, and D. versiformis) and endophytic fungi (Piriformospora indica) on an eight-year-old lane late navel orange (Citrus sinensis (L.) Osb) trees grafted on Poncirus trifoliata in a field, and we analyzed the response of the leaf antioxidant defense system. Approximately 2 years after inoculation, the root fungal colonization rate and soil hyphal length significantly increased. Fungal inoculation significantly increased the activity of leaf antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, and the content of non-enzymatic antioxidants, such as reduced ascorbic acid and reduced glutathione. As a result, fungi-inoculated plants maintained lower concentrations of hydrogen peroxide and superoxide anion radicals and lower levels of membrane lipid peroxidation (according to malondialdehyde level) in leaves than uninoculated plants. Among them, inoculation of D. spurca and A. scrobiculata showed relatively higher effects in enhancing the antioxidant defense system than the other fungi. Furthermore, inoculation of D. spurca induced expressions of CsFe-SOD, CsMn-SOD, CsPOD, CsCAT1, and CsPRR7; inoculation of A. scrobiculata and D. versiformis induced expressions of CsCAT1; CsCAT1 and CsPOD were also induced by inoculation of P. indica. All four inoculations almost upregulated expressions of CsFAD6. AM fungi had superior effects than endophytic fungi (e.g., P. indica). According to our findings, inoculation with beneficial fungi, specifically mycorrhizal fungus D. spurca, activated the antioxidant defense system of field citrus trees, thus, having potentially superior resistance in inoculated plants.

Anti-inflammatory role demonstrated both in vitro and in vivo models using nonsteroidal tetranortriterpenoid, Nimbin (N1) and its analogs (N2 and N3) that alleviate the domestication of alternative medicine.

Human health may benefit from the study of natural compounds and phytoconstituents that can protect from inflammation. We investigated Nimbin (N1), a member of the ring C Seco-tetranortriterpenoids family, and its semi-natural analog deacetyl Nimbin namely N2 and N3 for their anti-inflammatory properties. As key findings, N1, N2, and N3 were able to improve wound healing by cell proliferation in a period of 24 h and were able to reduce the reactive oxygen species (ROS) production in Madin-Darby Canine Kidney cells which were screened using dichloro-dihydro fluorescein diacetate (DCF-DA) staining. When the zebrafish larvae were subjected to DCF-DA assay N1, N2, and N3 were able to substantially reduce the ROS levels in a dose-dependent manner. In zebrafish larvae, the cell death indicates the fluorescent intensity due to acridine orange staining that was found to be dramatically decreasing upon the treatment of N1, N2, and N3. The cell membrane lipid peroxidation levels were also reduced in a dose-dependent manner upon the treatment of Nimbin and its analogs indicating lesser blue fluorescent levels. Among the Nimbin and its analogs, N2 was subjected to have better activity. To confirm the activity of N1, N2, and N3, in silico characterization was performed using Density functional theory and molecular docking. As a result, N2 exhibited the lowest electronegative value and highest binding energy when docked with anti-inflammatory and antioxidant proteins CAT, COX, GP, IL-1, and MPO. Furthermore, the therapeutic potential of N2 must be explored at the molecular level as well as in clinical studies for the treatment of inflammation-associated diseases.

Multiple metals and agricultural use affects oxidative stress biomarkers in freshwater Aegla crabs

Metals and agrochemicals are among the main aquatic contaminants, being able to trigger oxidative stress in exposed organisms. The objective of this work was to evaluate the correlation between the level of oxidative stress biomarkers in Aegla crabs (Crustacea, Anomura) with (i) the set of metals present in the streams sediment and (ii) with land uses of three hydrographic basins. The study was carried out in streams (≤ 2nd order) of hydrographic basins in southern Brazil (Basins of Rio Suzana, Rio Ligeirinho-Leãozinho and Rio Dourado). In these streams were quantified the land uses and Cu, Cr, Cd, Fe, Mn and Zn concentrations in the sediment. The enzymes Catalase (CAT) and Glutathione Reductase (GR), as well as the level of membrane lipid peroxidation (TBARS), were analyzed in adult females. The PCA analysis showed that the distribution of metals was different between the basins. Cd, Cr and Fe were correlated positively with CAT and negatively with TBARS and GR. The Dourado basin had the lowest concentrations of these three metals and the highest levels of TBARS. However, in Dourado basin there is predominance of agriculture land use, and TBARS was positively correlated with agricultural land use. Besides in Dourado basin, GR activity was higher than in the others basins, indicating a compensatory response in relation to CAT inhibition. The basins of Suzana and Ligeirinho-Leãozinho rivers had lower TBARS values, which may be due to the induction of CAT in response to metals accumulated in sediment. In summary, this work indicates that in the basins with a higher concentration of toxic metals there is an adaptive response of CAT induction, which reduces TBARS in Aegla. On the other hand, in the basin with lower metallic contamination, TBARS occurrence was primarily influenced by agricultural land use.

Synergistically enhanced Salmonella Typhimurium reduction by sequential treatment of organic acids and atmospheric cold plasma and the mechanism study

Salmonella, a foodborne pathogen, has been frequently associated with recalls of fresh food products, including poultry meat products. Atmospheric cold plasma (ACP) is a novel non-thermal technology, which has potential to reduce pathogens in food products. This study demonstrates the synergistic interactions of food grade organic acids (i.e., lactic acid (LA) or gallic acid (GA)) and ACP to inactivate Salmonella enterica Typhimurium ATCC 13311 inoculated on polycarbonate membrane filter paper and poultry meat surface. Organic acids were used in the form of a spray to enhance dispersion on samples surface. The sequential treatment of organic acid followed by ACP synergistically reduced S. Typhimurium on poultry meat surface. Irrespective of the type of organic acid, an average reduction of more than 3.5 log CFU/cm2 in S. Typhimurium on filter paper was obtained, when a combination of 10 mM LA or GA with an ACP exposure of 30 s was tested. However, the individual treatments of LA, GA, and ACP resulted in only 0.4, 0.3, 1.2 log CFU/cm2 reduction in S. Typhimurium, respectively. On poultry meat surface, a higher level of organic acid concentration (i.e., 50 mM) in combination with 30 s ACP was required to achieve more than 2.5 log CFU/cm2 reduction in S. Typhimurium. Our investigation on inactivation mechanisms revealed that the sequential treatment of LA or GA with ACP resulted in a significantly higher level of membrane permeability and membrane lipid peroxidation in S. Typhimurium cells. Additionally, the combined treatment significantly reduced the cell metabolic activity and affected the intracellular reactive oxygen species level of S. Typhimurium. In summary, this study demonstrated the potential synergistic benefits of combining organic acids and ACP to achieve a higher level of bacterial inactivation.