Enhanced Antioxidant Enzyme Research Articles

Response of tomatoes to inactivated endophyte LSE01 under combined stress of high-temperature and drought

Endophytes can assist crops in adapting to high temperatures and drought conditions, thereby reducing agricultural losses. However, the mechanism through which endophytes regulate crop resistance to high temperatures and drought stress remains unclear, and concerns regarding safety and stability exist with active endophytes. Thus, heat-treated endophytic bacteria LSE01 (HTB) were employed as a novel microbial fertilizer to investigate their effects on plant adaptation to high temperatures and drought conditions. The results indicated that the diameter and weight of tomatoes treated with HTB under stress conditions increased by 23.04% and 71.15%, respectively, compared to the control. Tomato yield did not significantly decrease compared to non-stress conditions. Additionally, the contents of vitamin C, soluble sugars, and proteins treated with HTB increased by 18.81%, 11.54%, and 99.75%, respectively. Mechanistic research revealed that HTB treatment enhances tomato's stress resistance by elevating photosynthetic pigment and proline contents, enhancing antioxidant enzyme activities, and reducing the accumulation of MDA. Molecular biology research demonstrates that HTB treatment upregulates the expression of drought-resistant genes (GA2ox7, USP1, SlNAC3, SlNAC4), leading to modifications in stomatal conductance, plant morphology, photosynthetic intensity, and antioxidant enzyme synthesis to facilitate adaptation to dry conditions. Furthermore, the upregulation of the heat-resistant gene (SlCathB2-2) can increases the thickness of tomato cell walls, rendering them less vulnerable to heat stress. In summary, HTB endows tomatoes with the ability to adapt to high temperatures and drought conditions, providing new opportunities for sustainable agriculture.

Cardioprotective effects of Ganoderma atrum polysaccharide in a type 2 diabetes mellitus involvement with gut-derived metabolites and NLRP3 inflammasome

The study aimed to explore the effects of Ganoderma atrum polysaccharide (PSG) on diabetic cardiomyopathy in type 2 diabetic rats. Results suggested that PSG significantly attenuated diabetic cardiomyopathy, as evidenced by alleviating heart histopathological changes and LDH release, mitigating weight loss, and improving fasting blood glucose and serum insulin levels. PSG could also reduce ROS generation and malondialdehyde contents, while significantly enhancing antioxidant enzyme activities and Nrf2 expression. Furthermore, PSG reduced inflammation by suppressing NLRP3 inflammasome, caspase-1, TLR4, NF-κB p65 expression, IL-1β and IL-6 secretion. Moreover, PSG treatment significantly manipulated intestinal microbiota metabolites, including short-chain fatty acids, plasma lipopolysaccharide, and trimethylamine N-oxide. These metabolites might mediate gut-heart communication through interaction with NLRP3 inflammasome. Collectively, PSG attenuated diabetic cardiomyopathy by activating the Nrf2 antioxidant pathway, controlling inflammation via NLRP3/Caspase-1/IL-1β signaling, and using gut microbial metabolites as alternative biomarkers for predicting the mechanisms of diabetic cardiomyopathy and assessing PSG interventions.

Antioxidant Defense System and Physiological Insights to Drought Stress in Urtica dioica L.

Urtica dioicais an endemic perennial plant of rocky habitat of Western Black Sea region of Turkey. To understand drought responses and tolerance mechanism of Seseli resinosum Freyn & Sint., relative water content (RWC), chlorophyll fluorescence, proline accumulation, lipid peroxidation (TBARS), hydrogen peroxide (H2O2) content and changes in antioxidant enzymes were assayed in polyethylene glycol (PEG) 6000 (5, 10 and 15%) induced drought stress in the present study. Leaf RWC maintained unchanged, while chlorophyll fluorescence reduced with high level of PEG (15%). Additionally, H2O2 and proline accumulation were determined with the increase of PEG application, but no increase in the amount of TBARS was determined. Moreover, the increment in H2O2 content under drought was accompanied by increased in glutathione reductase, catalase and superoxide dismutase activities. On the other hand, PEG-induced drought stress caused a reduction in peroxidase and ascorbate peroxidase activities. These results suggest that endemic Urtica dioica plant have an efficient drought tolerance, as displayed by enhanced antioxidant enzyme activities with maintaining water status under drought conditions. In this study, important information about physiological and antioxidative responses of endemic Urtica dioica was revealed for the first time.

Endophytic fungi are able to induce tolerance to salt stress in date palm seedlings (Phoenix dactylifera L.).

Date palm, typically considered a salinity-resistant plant, grows in arid and semi-arid regions worldwide, and experiences decreased growth and yields under salt stress. This study investigates the efficacy of endophytic fungi (EF) in enhancing the salinity tolerance of date palm seedlings. In this experiment, EF were isolated from date tree roots and identified morphologically. Following molecular identification, superior strains were selected to inoculate date palm seedlings (Phoenix dactylifera L., cv. Mazafati). The seedlings were subjected to varying levels of salinity stress for 4months, utilizing a completely randomized factorial design with two factors: fungal strain type (six levels) and salinity stress (0, 100, 200, and 300mM sodium chloride). The diversity analysis of endophytic fungi in date palm trees revealed that the majority of isolates belonged to the Ascomycota family, with Fusarium and Alternaria being the most frequently isolated genera. In this research, the application of fungal endophytes resulted in increased dry weight of roots, shoots, root length, plant height, and leaf number. Additionally, EF symbiosis with date palm seedling roots led to a reduction in sodium concentration and an increase in potassium and phosphorus concentrations in aerial parts under salt-stress conditions. While salinity elevated lipid peroxidation, consequently increasing malondialdehyde (MDA) levels, EF mitigated damage from reactive oxygen species (ROS) by enhancing antioxidant enzyme activity, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), while promoting proline and total soluble sugar (TSS) accumulation. The colonization percentage generally increased with salinity stress intensity in most strains. According to the results, the application of EF can alleviate the adverse effects of salinity stress and enhance the growth of date palm seedlings under saline conditions.

Selenomethionine alleviates decabromodiphenyl ether-induced oxidative stress and ferroptosis via the NRF2/GPX4 pathway in the chicken brain

Decabromodiphenyl ether (BDE209) is a toxic environmental pollutant that can cause neurotoxicity, behavioral abnormalities, and cognitive impairment in animals. However, the specific mechanisms of BDE209-induced neurological injury and effective preventative and therapeutic interventions are lacking. Even though selenomethionine (Se-Met) has a significant detoxification effect and protects the nervous system, it remains unclear whether Se-Met can counteract the toxic effects of BDE209. For the in vivo test, we randomly divided 60 1-week-old hy-line white variety chicks into the Con, BDE209, Se-Met, and BDE209 +Se-Met groups. In vitro experiments were performed, exposing chick embryo brain neurons to BDE209, Se-Met, N-Acetylcysteine (NAC, a ROS inhibitor), and RSL3 (a GPX4 inhibitor). We demonstrated that BDE209 induced oxidative stress and ferroptosis in the chicken brain, which mainly manifested as mitochondrial atrophy, cristae breakage, increased Fe2+ and MDA content, decreased antioxidant enzyme activity, and the inhibition of the NRF2/GPX4 signaling pathway in the brain neurons. However, Se-Met supplementation reversed these changes by activating the NRF2/GPX4 pathway, reducing mitochondrial damage, enhancing antioxidant enzyme activity, and alleviating ferroptosis. This study provides insight into the mechanism of BDE209-related neurotoxicity and suggests Se-Met as an effective preventative and control measure against BDE209 poisoning.

Effects of Plant Regulators on the Seed Germination and Antioxidant Enzyme Activity of Cotton under Compound Salt Stress.

Salinity stress significantly hampers cotton seed germination and seedling growth. Employing plant growth regulators stands out as an effective strategy to mitigate salt stress. In this study, we assessed the impact of varying concentrations of natural composite salt conditions (0%, 0.6%, and 1.2%) on cotton seed germination, seedling growth, and physiology. Additionally, we explored the effects of compound sodium nitrophenolate (CSN: 2 mg·L-1 and 10 mg·L-1), 24-epibrassinolide (EBR: 0.02 mg·L-1 and 0.1 mg·L-1), and gibberellic acid (GA: 60 mg·L-1 and 300 mg·L-1), against a control (CK: distilled water) group. The results indicate that with an increase in the composite salt concentration, the germination potential (GP) and germination rate (GR) of cotton seeds gradually decrease. Simultaneously, the fresh weight and root vitality of seedlings also correspondingly decrease, while the degree of membrane lipid peroxidation increases. Under high-salt (1.2%) conditions, soaking treatments with CSN and EBR significantly enhance both GP (45-59% and 55-64%) and GR (30-33% and 39-36%) compared to the CK. However, the GA treatment does not increase the GP and GR of cotton. Moreover, under high-salt (1.2%) conditions, CSN and EBR treatments result in the increased activities of superoxide dismutase (56-66% and 71-80%), peroxidase (20-24% and 37-51%), and catalase (26-32% and 35-46%). Consequently, cotton exhibits a relatively good tolerance to natural composite salts. Soaking treatments with CSN and EBR effectively improve cotton germination by enhancing antioxidant enzyme activities, thereby strengthening cotton's tolerance to salt stress. These findings offer new insights for enhancing the salt tolerance of cotton.

Sodium nitroprusside (SNP) treatment increases the postharvest resistance of apple fruit to Alternaria alternata by enhancing antioxidant enzyme activity

Black spot disease, caused by the fungal pathogen Alternaria alternata, commonly infects apple (Malus domestica) during postharvest storage and transportation, diminishing fruit quality, contaminating the fruit with toxins, and causing significant economic losses. Here, we investigated the effect of 0.1 mmol L−1 sodium nitroprusside (SNP), a nitric oxide donor, on lesion diameter, fruit quality, and reactive oxygen species (ROS) metabolism in A. alternata-inoculated apples. SNP not only effectively decreased lesion diameter but also maintained fruit quality and cell membrane integrity. Additionally, SNP enhanced antioxidant enzyme activity and genes encoding of peroxidase (POD), glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), and decreased hydrogen peroxide (H2O2) and superoxide anion (O2•−) production, malondialdehyde (MDA) concentration, and membrane permeability. Collectively, these results demonstrate that SNP inhibits ROS accumulation and increases antioxidant enzyme activity, and that the mechanism of SNP-induced resistance is related to the regulation of ROS metabolism.

Coronatine-Induced Maize Defense against Gibberella Stalk Rot by Activating Antioxidants and Phytohormone Signaling.

One of the most destructive diseases, Gibberella stalk rot (GSR), caused by Fusarium graminearum, reduces maize yields significantly. An induced resistance response is a potent and cost-effective plant defense against pathogen attack. The functional counterpart of JAs, coronatine (COR), has attracted a lot of interest recently due to its ability to control plant growth and stimulate secondary metabolism. Although several studies have focused on COR as a plant immune elicitor to improve plant resistance to pathogens, the effectiveness and underlying mechanisms of the suppressive ability against COR to F. graminearum in maize have been limited. We investigated the potential physiological and molecular mechanisms of COR in modulating maize resistance to F. graminearum. COR treatment strongly enhanced disease resistance and promoted stomatal closure with H2O2 accumulation, and 10 μg/mL was confirmed as the best concentration. COR treatment increased defense-related enzyme activity and decreased the malondialdehyde content with enhanced antioxidant enzyme activity. To identify candidate resistance genes and gain insight into the molecular mechanism of GSR resistance associated with COR, we integrated transcriptomic and metabolomic data to systemically explore the defense mechanisms of COR, and multiple hub genes were pinpointed using weighted gene correlation network analysis (WGCNA). We discovered 6 significant modules containing 10 candidate genes: WRKY transcription factor (LOC100279570), calcium-binding protein (LOC100382070), NBR1-like protein (LOC100275089), amino acid permease (LOC100382244), glutathione S-transferase (LOC541830), HXXXD-type acyl-transferase (LOC100191608), prolin-rich extensin-like receptor protein kinase (LOC100501564), AP2-like ethylene-responsive transcription factor (LOC100384380), basic leucine zipper (LOC100275351), and glycosyltransferase (LOC606486), which are highly correlated with the jasmonic acid-ethylene signaling pathway and antioxidants. In addition, a core set of metabolites, including alpha-linolenic acid metabolism and flavonoids biosynthesis linked to the hub genes, were identified. Taken together, our research revealed differentially expressed key genes and metabolites, as well as co-expression networks, associated with COR treatment of maize stems after F. graminearum infection. In addition, COR-treated maize had higher JA (JA-Ile and Me-JA) levels. We postulated that COR plays a positive role in maize resistance to F. graminearum by regulating antioxidant levels and the JA signaling pathway, and the flavonoid biosynthesis pathway is also involved in the resistance response against GSR.

Enhancing cold and drought tolerance in cotton: a protective role of SikCOR413PM1

The present study explored the potential role of cold-regulated plasma membrane protein COR413PM1 isolated from Saussurea involucrata (Matsum. & Koidz)(SikCOR413PM1), in enhancing cotton (Gossypium hirsutum) tolerance to cold and drought stresses through transgenic methods. Under cold and drought stresses, the survival rate and the fresh and dry weights of the SikCOR413PM1-overexpressing lines were higher than those of the wild-type plants, and the degree of leaf withering was much lower. Besides, overexpressing SikCOR413PM1 overexpression increased the relative water content, reduced malondialdehyde content and relative conductivity, and elevated proline and soluble sugar levels in cotton seedlings. These findings suggest that SikCOR413PM1 minimizes cell membrane damage and boosts plant stability under challenging conditions. Additionally, overexpression of this gene upregulated antioxidant enzyme-related genes in cotton seedlings, resulting in enhanced antioxidant enzyme activity, lowered peroxide content, and reduced oxidative stress. SikCOR413PM1 overexpression also modulated the expression of stress-related genes (GhDREB1A, GhDREB1B, GhDREB1C, GhERF2, GhNAC3, and GhRD22). In field trials, the transgenic cotton plants overexpressing SikCOR413PM1 displayed high yields and increased environmental tolerance. Our study thus demonstrates the role of SikCOR413PM1 in regulating stress-related genes, osmotic adjustment factors, and peroxide content while preserving cell membrane stability and improving cold and drought tolerance in cotton.

Pre-storage calcium chloride and aloe vera gel coatings mitigate internal browning and senescence scald in ‘Conference’ pears

Physiological disorders pose significant challenges to the quality and shelf life of ‘conference’ pears. This study investigates the efficacy of calcium chloride (CaCl2) and aloe vera (AV) gel treatments in reducing internal browning and senescence scald in ‘Conference’ pears. Four groups were evaluated: a control, individual 2 % CaCl2, 15 % AV gel treatments, and a combined CaCl2 and AV gel treatment. Pears having following maturity indices (TSS 12 %, ho 90, and Firmness 67 N) were then stored at 2 ± 1 °C, 85±5 % RH for 180 d The fruits were removed from cold storage to room temperature and kept at 20±3 °C and 65±5 % RH followed by physicochemical and sensory analyses. The combined treatment proved most effective in preserving quality and reducing internal browning and senescence scald. Treated pears displayed reduced respiration rates, ethylene production, internal browning, senescence scald, and weight loss. Moreover, the combined treatment resulted in higher TA and lower TSS compared to the control after 180 d of storage. The reduction in internal browning and senescence scald can be attributed to enzyme activity modulation. The combined treatment increased catalase (CAT) and superoxide dismutase (SOD) activity, reducing oxidative stress. This, in turn, minimized oxidative reactions leading to internal browning. Furthermore, the treatment inhibited polyphenol oxidase (PPO) and peroxidase (POD) activity, enzymes responsible for browning reactions. Lower PPO and POD activity contributed to reduced internal browning and senescence scald. The combined actions of enhanced antioxidant enzymes and decreased browning-related enzymes synergistically reduced internal browning. In conclusion, the combined CaCl2 and AV gel treatment effectively mitigated internal browning and senescence scald in pears and also received the highest score in sensory analysis. Enhanced antioxidant enzyme activity (CAT and SOD) and reduced PPO and POD activity collectively contributed to this reduction. This eco-friendly approach presents a sustainable strategy for extending shelf life and enhancing pear quality, providing an alternative to traditional chemical interventions for managing physiological disorders.

Methyl jasmonate reduces cadmium toxicity by enhancing phenol and flavonoid metabolism and activating the antioxidant defense system in pigeon pea (Cajanus cajan)

Cadmium (Cd) is absorbed by plant roots from soil along with essential nutrients and affects plant growth and productivity. Methyl jasmonate (Me-JA) play important roles to mitigate Cd toxicity in plants. We have investigated the role of Me-JA to ameliorate Cd toxicity in Pigeon pea (Cajanus cajan). Plant root growth, biomass, cellular antioxidant defense system and expression of key regulatory genes in molecular and signaling process have been analyzed. Two Cajanus cajan varieties AL-882 and PAU-881 were grown at 25 °C, 16/8h light/dark conditions in three biological replicates at 5 mM Cd concentration, three concentration of Me-JA (0, 10 nM, 100 nM) and two concentrations in combination of Me-JA + Cd (10 nM Me-JA +5 mM Cd, 100 nM Me-JA +5 mM Cd). The seedlings were exposed to Cd stress consequently plants showed decrease in primary root growth (60.71%, in AL-882 and 8.33%, in PAU-881), shoot and root biomass and antioxidant enzymes activities. Me-JA treatment resulted in increased primary root growth (63.64%, in AL-882) and overall plant biomass. Oxidative stress generated due to Cd stress was counter balanced by Me-JA treatment. Me-JA reduced H2O2 free radicals formation and enhanced antioxidant enzyme activities and phenolic content in stressed seedlings. Me-JA treatment increased expression of CALM, IP3, CDPK2, MPKs (involved in calcium and kinase signaling pathways) and reduced expression of metal transporters (IRT1 and HMA3) genes. This reduction in metal transporters gene expression is a probable reason for low toxicity effect of Cd in root after Me-JA treatment which has potential implications in reducing the risk of Cd in the food chain.

Storage Stability Assessment of Indigenous Guava Fruits (Psidium guajava L.) cv. “Gola” in Response to γ-Irradiation

Postharvest losses in fruits and vegetables pose a key challenge to the global horticulture industry. Improved storage stability of horticultural commodities through irradiation is a technological intervention which has greater compliance over more than 60 foods and food products. The present study was intended to explore the effect of γ-irradiation doses on the postharvest quality of fresh guava fruits stored under ambient (temperature 20 ± 2 °C, RH 85%) conditions. Various storage specific quality attributes including physiological weight loss, respiration rate (CO2), ethylene estimation, ripening index, fruit firmness, ascorbic acid, nutraceutical potential, and enzyme kinetics were evaluated during postharvest storage at four days of interval. The results indicated that the fruits irradiated at doses (0.8 kGy and 1.0 kGy) exhibited significant reduction in physiological parameters in contrast with untreated fruit samples. Firmness, total phenolic compounds, flavonoids, and radical scavenging activity were successfully retained in irradiated fruit samples up to twenty days of storage. The respiration and ethylene production rates were suppressed in irradiated guava fruits compared to control. Moreover, it has also been discovered that the fruits exposed to 1.0 kGy had considerably decreased the polyphenol oxidase (PPO) activity compared to nonirradiated fruits, thus resulting in lowering the enzymatic browning. Aside from that, irradiation guava fruits had considerably enhanced antioxidant enzyme activity ( P ≤ 0.05 ) in terms of catalase, peroxidase, and superoxide dismutase. In conclusion, the study revealed that γ -rays irradiation doses up to 1.0 kGy might be considered effective to improve the postharvest storage of native guava fruits variety with intact nutritional attributes.

Seed treatment with ascorbic acid and proline improved salt tolerance in tomato (Solanum lycopersicum L. cv. Roma) by enhancing antioxidant enzyme activity

Seed treatment with ascorbic acid and proline improved salt tolerance in tomato (Solanum lycopersicum L. cv. Roma) by enhancing antioxidant enzyme activity

Browning inhibition in fresh-cut Chinese water chestnut under high pressure CO2 treatment: Regulation of reactive oxygen species and membrane lipid metabolism.

Fresh-cut Chinese water chestnut (CWC) was treated with high pressure CO2 (HPCD) to inhibit the browning reactions, and the underlying mechanism was investigated in this study. Results showed that HPCD at 2MPa pressure significantly inhibited lipoxygenase activity and enhanced superoxide dismutase activity, leading to decreased malondialdehyde and H2O2 contents in surface tissue. Moreover, HPCD could reduce total phenols/flavonoids content of surface tissue. Compare with control, homoeriodictyol, hesperetin, and isorhamnetin contents of 2MPa HPCD-treated samples on day 10 were reduced by 95.72%, 94.31%, and 94.02%, respectively. Furthermore, HPCD treatment enhanced antioxidant enzyme activities, and improved the O2- scavenging ability and reducing power of inner tissue. In conclusion, by regulating ROS and membrane lipid metabolism, HPCD treatment with appropriate pressure could retard the biosynthesis of flavonoids and enzymatic oxidation of phenolic compounds in surface tissue, and enhance antioxidant activity of inner tissue, thereby, delaying the quality deterioration of fresh-cut CWC.

Combination of curcumin and catalase protects against chondrocyte injury and knee osteoarthritis progression by suppressing oxidative stress

Knee Osteoarthritis (KOA) is an age-related progressive degenerative joint disease, which is featured with pain, joint deformity, and disability. Accumulating evidence indicated oxidative stress plays a crucial role in the occurrence and development of KOA. Curcumin is a polyphenolic compound with significant antioxidant activity among various diseases while catalase (CAT) is an enzyme degrading hydrogen peroxide in treating oxidative diseases. We previously showed that the expression of CAT was low in cartilage. However, the combination of curcumin and CAT in KOA is still elusive. In this study, we demonstrated that the combination of curcumin and CAT has the potential to inhibit the IL1β-induced chondrocyte apoptosis without cytotoxicity in vitro. Mechanistically, we found that the synergistic application curcumin and CAT not only promotes curcumin's regulation of the NRF2/HO-1 signaling pathway to enhance antioxidant enzyme expression to remove superoxide radicals, but also CAT can further remove downstream hydrogen peroxide which enhances the ability to scavenge reactive oxygen species (ROS). In vivo, studies revealed that combination of curcumin and catalase could better inhibit oxidative stress-induced chondrocyte injury by promoting the expression of ROS scavenging enzymes. In sum, the combination of curcumin and catalase can be used to treat KOA. Thus, combination of curcumin and catalase may act as a novel therapeutic agent to manage KOA and our research gives a rationale for their combined use in the therapeutic of KOA.

Curcumin Protects Pheochromocytoma Cells Against Hydrogen Peroxide-Induced Oxidative Stress

Objective: Oxidative stress represents a characteristic of neurodegenerative diseases, which may be alleviated by the functional food component—curcumin. However, the underlying mechanism remains unclear. The current study aimed to address how curcumin protects variant differentiated pheochromocytoma (PC12) cells against hydrogen peroxide (H2O2)-induced cell stress, using low- and high-differentiated PC12 cells, and validated in old-aged mice. Methods: The MTT assay was first carried out to test the cell viability upon H2O2 and/or curcumin treatment and cellular lipid peroxidation was assessed as cellular damages by quantifying the amount of cellular malondialdehyde. Cellular oxidative stress was determined by measuring the cellular and mitochondrial ROS levels, and total cellular antioxidant capacities were determined as the ABTS free radical scavenging ability (ABTS) and Fe3+ reduction ability of cells. The activities and expression of major antioxidant enzymes, including glutathione peroxidase (GPx), superoxidase dismutase (SOD) and catalase (CAT), were also tested. Furthermore, oxidative phosphorylation of mitochondria was assessed by measuring the ATP level and the ADP/ATP ratio. Finally, the antioxidant activity of curcumin was determined in 6-month-old mice by measuring cellular antioxidant capacity and antioxidant enzyme activities. Results: H2O2 caused oxidative damage and decreased cell viability, which was reversed by curcumin with different dosed effects in variant differentiated PC12 cells. Moreover, curcumin's protective effect was attributed to an enhanced antioxidant enzyme system. In consistent, curcumin recovered H2O2-deteriorated oxidative phosphorylation. Further studies verified that curcumin significantly improved the antioxidant capacity of old-aged mice, which may have elevated oxidative stress. Conclusion: Taken together, curcumin improved the antioxidant capacity of variant differentiated PC12 cells and old-aged mice, which was closely associated with the modulation of mitochondrial function and antioxidant enzyme system. This study may shed light on the molecular mechanism underlying the alleviation of neurodegenerative diseases by natural polyphenols.

Sinomenine Ameliorates IL-1β-Induced Intervertebral Disc Degeneration in Rats Through Suppressing Inflammation and Oxidative Stress via Keap1/Nrf2/NF-κB Signaling Pathways.

To investigate the molecular mechanism underlying the inhibitory effect of sinomenine (SN) on interleukin-1β (IL-1β)-induced apoptosis in nucleus pulposus cells (NPCs), and to evaluate the potential role of SN in preventing intervertebral disk degeneration (IDD). The Rat NPCs were cultured in vitro and identified using Hematoxylin-Eosin (HE) staining, toluidine blue staining, and immunofluorescence analysis. NPCs were pretreated with or without SN, then induced with IL-1β to assess cell viability, ROS levels, apoptotic rates, and wound healing ability. Relevant protein expression was detected using Elisa, qPCR and Western Blot techniques. NPCs were pretreated with SN, either alone or in combination with Nrf2-IN-1 or SC, before being induced to undergo apoptosis by IL-1β. Apoptosis was detected using Hoechst staining, while qPCR and Western Blot techniques assessed protein expression. Rat caudal intervertebral discs were induced with IDD, with or without SN injection, and then co-injected with IL-1β. The levels of IDD were evaluated using HE staining and modified saffron-O-fix green cartilage staining. Relevant protein expression was detected using Elisa, qPCR, and Western Blot techniques. IL-1β significantly reduced NPC activity, induced ROS accumulation and apoptosis, decreased cell healing rate, promoted the expression and secretion of inflammatory factors, and inhibited extracellular matrix synthesis. However, pretreatment with SN effectively reversed these effects. Inhibition of the Keap1/Nrf2 signaling pathway or activation of the NF-κB signaling pathway significantly attenuated the cytoprotective effects of SN and increased apoptosis. Acupuncture combined with IL-1β injection markedly induced intervertebral disc degeneration in rat caudal spine, upregulated inflammatory factors expression and secretion, and downregulated extracellular matrix synthesis. SN intervention notably enhanced antioxidant enzyme expression and reversed these outcomes. SN can prevent IL-1β-induced apoptosis of NPCs and ameliorate IDD by activating the Keap1/Nrf2 pathway and inhibiting the NF-κB signaling pathway.

Physiological factors contribute to increased competitiveness of grass relative to sedge, forb and legume species under different N application levels

In alpine grasslands, increased N deposition is increasing the dominance of grasses relative to other functional types according to our previous study Shen et al. (2022). However, the mechanisms that drive this compositional change are not fully understood. We measured the effects of 4–6 years' N addition to simulate N deposition at rates of 0 (CK), 8 (N1), 24 (N2), 40 (N3), 56 (N4), and 72 (N5) kg N ha−1 year−1 on dominant representatives of four functional types, Leymus secalinus (grass), Carex capillifolia (sedge), Potentilla multifidi (non-leguminous forb), and Medicago ruthenica (legume), in the alpine grassland on the Qinghai-Tibetan Plateau (QTP). In-situ experiment showed that N addition increased aboveground biomass in L. secalinus but had negative or neutral effects on aboveground biomass in the other species. Consistent with this finding, N addition increased net photosynthesis, chlorophyll content, and rubisco activity in L. secalinus with less positive effects on the other species. Nitrogen addition increased leaf N content in L. secalinus and C. capillifolia and reduced leaf non-structural carbohydrate content in all four species. In L. secalinus, the highest N addition rate (N5) reduced MDA content, a marker of oxidative stress, by enhancing antioxidant enzyme activity. Overall, our findings suggested that physiological factors can contribute to increased competitiveness of grass relative to sedge, forb and legume species under high N application levels. The rapid growth of this grass species reduces resource availability to non-grass species, increasing its dominance in the alpine meadow.

Assessment of application of ZnO nanoparticles on physiological profile, root architecture and antioxidant potential of Solanum lycopersicum

Plant growth can be impacted by ZnO nanoparticles (ZnO-NPs), in addition to their effects on photosynthesis and seed germination. The degree to which nanoparticles (NPs) enhance or inhibit shoot and root growth can vary depending on the specific type of NPs and their concentrations. This research aimed to explore the effects of ZnO-NPs on tomato plants (Solanum lycopersicum L.). The study measured the growth of the plants, their photosynthetic abilities, chlorophyll, physiology responses, antioxidant activities in 24-day-old plants. The results indicated that ZnO-NPs applications improved germination percentage (30.7%), shoot length (47.6%) and root length (33.1%) of the tomato plants, particularly at 75 μg/mL, and enhanced chlorophyll content in a manner proportional to the concentration. Moreover, in current research, it has been found that ZnO-NPs applications improved antioxidant response, and production of antioxidant enzymes. ZnO-NPs also had a beneficial impact on various root parameters including number of root tips (29.6%), number of branching points (16.6%), average diameter (46.2%), branching frequency (26.6%), total root length (33.1%), network area (26.3%), surface area (24.0%), perimeter (22.0%) and root volume (25.2%). Above 75 μg/mL, a reduction in all of them have been noticed, which indicates that concentrations of ZNPs above 75 μg/mL are harmful to tomato plants. Moreover, ZNPs appear to stimulate the transcription of various genes which have antioxidant activities, implying that they may bolster the plant's defense mechanism by enhancing antioxidant enzyme activity. According to our best knowledge, this is a novel aspect to study of impact of ZnO-NPs on root architecture of Solanum lycopersicum L.

Melatonin interaction with abscisic acid in the regulation of abiotic stress in Solanaceae family plants.

Solanaceous vegetable crops are cultivated and consumed worldwide. However, they often confront diverse abiotic stresses that significantly impair their growth, yield, and overall quality. This review delves into melatonin and abscisic acid (ABA) biosynthesis and their roles in abiotic stress responses. It closely examines the intricate interplay between melatonin and ABA in managing stress within plants, revealing both collaborative and antagonistic effects and elucidating the underlying molecular mechanisms. Melatonin and ABA mutually influence each other's synthesis, metabolism and that of other plant hormones, a key focus of this study. The study highlights melatonin's role in aiding stress management through ABA-dependent pathways and key genes in the melatonin-ABA interaction. Specifically, melatonin downregulates ABA synthesis genes and upregulates catabolism genes, leading to reduced ABA levels. It also directly scavenges H2O2, enhancing antioxidant enzyme activities, thereby underscoring their collaborative role in mediating stress responses. Moreover, the interplay between melatonin and ABA plays an essential role in multiple physiological processes of plants, including stomatal behaviors, wax accumulation, delay leaf senescence, seed germination, and seedlings growth, among others. Recognizing these relationships in Solanaceae vegetable crops holds great importance for improving agricultural practices and crop quality. In summary, this review offers a comprehensive overview of recent studies on the melatoninand ABA interplay, serving as a valuable resource for researchers and breeders dedicated to fortifying crop resilience and productivity within challenging environments.