Membrane Lipid Peroxidation Research Articles

Silicon-seed priming promotes seed germination under CA-induced autotoxicity by improving sucrose and respiratory metabolism in cucumber (Cucumis sativus L.)

Seed germination is one of the critical and sensitive stages of early plant growth, and its process is prevented by cinnamic acid (CA). Silicon (Si) plays a critical role in mitigating abiotic stresses and seed germination in plants, but little is known about its role in seed germination and physiology in CA-stressed cucumber. Here, we conducted experiments in the State Key Laboratory of Aridland Crop Science, Gansu Agricultural University from March to June 2021 to investigate the effects of Si-seed priming on growth, antioxidant capacity, sucrose mobilization and respiratory metabolism during germination under CA stress. Our results showed that seed soaking with Si (9 mmol/L) significantly reduced membrane lipid peroxidation and promoted post-germination growth of cucumber seeds under CA (2.0 mmol/L) stress. Si increased key enzyme activities in sucrose metabolism in CA-stressed seeds after germination, accelerating sucrose degradation and fructose synthesis. Si also enhanced the activities of key enzymes in the glycolytic pathway and pentose phosphate pathway in seeds, as well as in the post-germination tricarboxylic acid cycle, promoting glucose decomposition and ATP synthesis. Principal component analysis significantly separated the CK, Si, and CA + Si treatments from the CA treatment in the first principal component after 48 h of treatment. In addition, qRT-PCR analysis showed that Si induced overexpression of genes related to sucrose and respiratory metabolism in seeds treated with CA for 48 h. In conclusion, our findings provide evidence that Si priming may be an effective method to reverse CA inhibition of cucumber seeds, which effectively improve germination under CA stress by attenuating membrane lipid peroxidation and enhancing sucrose mobilization and respiratory metabolism in cucumber.

Study of the mechanism of fibroblast-like synoviocytes-derived exosomes inducing macrophages M1 polarization and CD8+T cells immune regulation ferroptosis and autophagy in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints. The pathogenesis of RA is complex, involving membrane lipid antioxidant systems, oxidative stress, and lipid peroxidation. In this study, it was found that cysteine dioxygenase 1 (CDO1) is significantly upregulated in RA fibroblast-like synoviocytes (RA-FLS) and that exosomes derived from these RA-FLS deliver CDO1 to promote M1 polarization of macrophages, thus facilitating RA progression. In the immune microenvironment, CD8+T cells play a role in immune regulation by producing cytokines such as interferon gamma (IFNγ) in various diseases. The results of this study suggested that in RA-FLS, CD8+T cells deliver IFNγ, which not only inhibits the viability of RA-FLS but also affects glutathione (GSH) through CDO1, regulating the GPX4 antioxidant signaling pathway to promote ferroptosis and autophagy in cells. It was also discovered that IFNγ enhances the expression of TRI69, ubiquitinates and degrades FSP1, thereby forming a cooperative regulation process of GPX4 and FSP1 in ferroptosis. These findings provide a new direction for the treatment of RA.

Baseline sensitivity and physiological characteristics of natural product hinokitiol against Sclerotinia sclerotiorum.

Sclerotinia sclerotiorum, a pathogenic fungus of oilseed rape, poses a severe threat to the oilseed rapeseed industry. In this study, we evaluated the potential of the natural compound hinokitiol against S. sclerotiorum by determining its biological activity and physiological characteristics. Our results showed that hinokitiol strongly inhibited the hyphae expansion of S. sclerotiorum, and its effective concentration of hyphae growing inhibition by 50% (EC50) against 103 S. sclerotiorum strains varied from 0.36 to 3.45 μg/mL, with an average of 1.23 μg/mL. Hinokitiol possessed better protective efficacy than therapeutic effects, and it exhibited no cross-resistance between carbendazim. After treatment with hinokitiol, many vesicular protrusions developed on the mycelium with rough surface and thickened cell wall. Moreover, the cell membrane permeability and glycerol content increased, while the oxalic acid declined after hinokitiol treatment. In addition, hinokitiol induced membrane lipid peroxidation and improved the production of reactive oxygen species (ROS) in S. sclerotiorum. Importantly, real-time quantitative polymerase chain reaction showed that cell wall and ROS synthesis-related genes were significantly up-regulated after hinokitiol treatment. This study revealed that hinokitiol has good biological activity against S. sclerotiorum and could be considered as an alternative bio-fungicide for the resistance management in controlling sclerotinia stem rot infected by S. sclerotiorum. These investigations provided new insights into understanding the toxic action of hinokitiol against pathogenic fungi. © 2024 Society of Chemical Industry.

Self-catalyzed nitric oxide nanocomplexes induce ferroptosis for cancer immunotherapy

Ferroptosis, triggered by membrane lipid peroxidation (LPO) and diminished antioxidants, can be induced by intracellular iron (II, Fe2+). However, the role of nitric oxide (NO) in causing Fe2+ overload for ferroptosis remains uncertain. This study reveals that NO can stimulate endogenous Fe2+ release by upregulating heme oxygenase 1 (HMOX1) expression. Here, ferritin heavy chain (FHC) siRNA and hyaluronic acid (HA)-modified Arg-stabilized zinc peroxide (AZOSH), a non-ferrous-based nanoagent, is synthesized to trigger ferroptosis by inducing intracellular Fe2+ overload. AZOSH, a self-catalyzed NO nanocomplex, effectively generates NO through a reaction of self-supplied Arginine (Arg) and hydrogen peroxide (H2O2), which promotes glutathione (GSH) consumption to downregulate glutathione peroxidase 4 (GPX4) expression and produces peroxynitrite (ONOO−) to enhance LPO. Meanwhile, NO promotes endo/lysosomal escape of siRNA by damaging membrane structures. Moreover, AZOSH significantly triggers Fe2+ overload through the synergistic effects of NO-activated HMOX1 expression and FHC siRNA-mediated ferritin sequestration. Additionally, the released Zn2+ from AZOSH induces oxidative stress by inhibiting mitochondrial function, further promoting ferroptosis. Consequently, AZOSH-mediated ferroptosis exhibits a strong cellular immunogenic response for T-cell activation and infiltration. Importantly, the integration of AZOSH with an anti-PD-1 antibody results in notable antitumor efficacy in vivo. Therefore, this study provides a novel concept of NO-induced ferroptosis, highlighting its role in enhancing PD-1-based immunotherapeutic efficacy.

Broadening horizons: the multifaceted role of ferroptosis in breast cancer

Breast cancer poses a serious threat to women’s health globally. Current radiotherapy and chemotherapy regimens can induce drug-resistance effects in cancer tissues, such as anti-apoptosis, anti-pyroptosis, and anti-necroptosis, leading to poor clinical outcomes in the treatment of breast cancer. Ferroptosis is a novel programmed cell death modality characterized by iron overload, excessive generation of reactive oxygen species, and membrane lipid peroxidation. The occurrence of ferroptosis results from the imbalance between intracellular peroxidation mechanisms (executive system) and antioxidant mechanisms (defensive system), specifically involving iron metabolism pathways, amino acid metabolism pathways, and lipid metabolism pathways. In recent years, it has been found that ferroptosis is associated with the progression of various diseases, including tumors, hypertension, diabetes, and Alzheimer’s disease. Studies have confirmed that triggering ferroptosis in breast cancer cells can significantly inhibit cancer cell proliferation and invasion, and improve cancer cell sensitivity to radiotherapy and chemotherapy, making induction of ferroptosis a potential strategy for the treatment of breast cancer. This paper reviews the development of the concept of ferroptosis, the mechanisms of ferroptosis (including signaling pathways such as GSH-GPX4, FSP1-CoQ1, DHODH-CoQ10, and GCH1-BH4) in breast cancer disease, the latest research progress, and summarizes the research on ferroptosis in breast cancer disease within the framework of metabolism, reactive oxygen biology, and iron biology. The key regulatory factors and mechanisms of ferroptosis in breast cancer disease, as well as important concepts and significant open questions in the field of ferroptosis and related natural compounds, are introduced. It is hoped that future research will make further breakthroughs in the regulatory mechanisms of ferroptosis and the use of ferroptosis in treating breast cancer cells. Meanwhile, natural compounds may also become a new direction for potential drug development targeting ferroptosis in breast cancer treatment. This provides a theoretical basis and opens up a new pathway for research and the development of drugs for the prevention and treatment of breast cancer.

Studies on the Quality and Antioxidant Status of Cryopreserved Pantja Buck Semen Supplemented with Aqueous Extract of Rosemary and Sericin in Tris Extender.

Introduction: Rosemary shrub/plant and Sericin have been documented to show antioxdative properties, however their role in improving post thaw semen quality has not been well established. Objectives: The present study was conducted to investigate the effect of Rosemary leaves extract and Sericin protein on post-thaw quality of Pantja buck semen. Methods: In the first experiment, 32 ejaculates were collected from 4 sexually mature Pantja bucks and pooled to form 8 pooled samples. The pooled samples were evaluated for seminal attributes (sperm motility, viability, morphology, plasma membrane integrity, and acrosomal integrity), status of antioxidative enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and lipid-peroxidation (malondialdehyde) of sperm plasma membrane before dilution. In the second experiment, pooled samples were divided into three equal aliquots as group-C (Control), group-R (Rosemary), and group-S (Sericin). Aliquots of group-C were diluted in glycerolated Egg Yolk Tris (EYT) extender, whereas aliquots of group-R and group-S were additionally supplemented with 4.0% v/v Rosemary leaves extract and 0.25% w/v Sericin, respectively, and again examined for the above parameters at the post-dilution, post-equilibration, and post-thawing stages of semen freezing. Results: Significant differences (p < 0.05) were observed in the values of seminal attributes, level of enzymatic antioxidants, and lipid per-oxidation between group C and R and between group C and S at the post-thaw stage of semen freezing. However Sericin was nonsignificantly better than Rosemary in improving post-thaw semen quality. Conclusion: The results of the present study on limited semen samples in Pantja buck demonstrated that compared to the control group, both Rosemary aqueous extract (4%) and Sericin protein (0.25%) as an additive in TRIS extender, showed better cryoprotective effects resulting in improved post-thaw seminal characteristics.

Exogenous Calcium Enhances Castor Tolerance to Saline–Alkaline Stress by Regulating Antioxidant Enzyme Activity and Activating Ca2+ and ROS Signaling Crosstalk

Saline–alkaline stress is a major factor limiting agricultural development, with calcium (Ca2+) playing a role in regulating plant tolerance through multiple signaling pathways. However, the specific mechanisms by which Ca2+ mediates saline–alkaline stress tolerance at the molecular level remain incompletely understood. This study investigates the effects of exogenous Ca2+ application on enhancing plant tolerance to saline–alkaline stress, focusing on its impact on the antioxidant system and Ca2+ and reactive oxygen species (ROS) signaling pathways. Through physiological assays and transcriptomic analyses, we evaluated oxidative damage markers, antioxidant enzyme activities, and the expression of key Ca2+ and ROS signaling genes. The results showed that saline–alkaline stress significantly elevated ROS levels, which led to increased membrane lipid peroxidation and induced upregulation of antioxidant response elements in castor roots. Exogenous calcium treatment reduced ROS accumulation by increasing superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and decreasing malondialdehyde (MDA) levels, demonstrating a marked improvement in the antioxidant system. Transcriptomic analysis identified CAT2 (LOC107261240) as the primary target gene associated with increased CAT activity in response to exogenous calcium. Additionally, the upregulation of specific Ca2+ channels, Ca2+ sensors, ROS receptors, and antioxidant-related genes with calcium treatment highlights the critical role of Ca2+–ROS signaling crosstalk in enhancing stress tolerance. Protein–protein interaction analysis identified APX3 and other hub genes involved in Ca2+–ROS signaling transduction and the regulation of antioxidant activity. These findings enhance our understanding of calcium’s complex regulatory roles in plant abiotic stress responses, offering new theoretical insights for improving crop resilience in agriculture.

ERD14 regulation by the HY5- or HY5-MED2 module mediates the cold signal transduction of asparagus bean.

Cold stress affects the growth, development, and yield of asparagus bean (Vigna unguiculata subsp. sesquipedalis). Mediator (MED) complex subunits regulate the cold tolerance of asparagus bean, but the underlying regulatory mechanisms remain unclear. Here, VunMED2 positively responds to cold stress of asparagus beans. Under cold acclimation and freezing treatment, the survival rate, ROS scavenging activity, and expression levels of VunMED2 were increased in VunMED2 transgenic plants. Natural variation in the promoter of VunMED2 in two different cold-tolerant asparagus beans was observed. Under cold stress, the expression of the GUS reporter gene was higher in cold-tolerant plants than in cold-sensitive plants, and the expression of the GUS reporter gene was tissue-specific. VunHY5 positively influenced the expression of VunMED2 by binding to the E-box motif, and the transcriptional activation of the promoter was stronger in the cold-tolerant variety than in cold-sensitive plants. VunHY5 overexpression improved plant freezing resistance by increasing the antioxidant capacity and expression of dehydrin genes. VunHY5 and VunMED2 play a synergistic role in binding to the G-box/ABRE motif and transcriptionally activating the expression of VunERD14. VunERD14 complemented the med2 mutant, which could positively respond to plant freezing resistance by reducing membrane lipid peroxidation and improving the antioxidant capacity. Therefore, the VunHY5-VunERD14 module and the VunHY5-VunMED2-VunERD14 positive cascade effect are involved in the cold signal transduction in asparagus bean. Our findings have implications for the breeding of asparagus bean varieties with improved cold tolerance.

Novel flavonoid derivatives containing 1,2,4-triazole Schiff bases as potential antifungal agents: design, synthesis, and biological evaluation

A series of flavonol derivatives containing 1,2,4-triazole Schiff base was designed, synthesized and tested for their biological activities. The results of the biological activity test showed that compounds exhibited the obvious antifungal activities against Sclerotinia sclerotiorum (S.s), Rhizoctonia solani (R.s), Botrytis cinerea (B.c) and Phomopsis sp (P.s). Among them, K14 showed excellent antimicrobial activity against B.c with the half maximal effective concentration (EC50) of 7.6 µg/mL as compared to azoxystrobin (18.0 µg/mL). Additionally, the in vivo protective and therapeutic activities of K14 on blueberry leaves were 94.1 and 88.7 % respectively, surpassing than that of the control drug azoxystrobin (91.6 and 74.4 %) at 200 µg/mL. The results of SEM showed that the mycelium appeared wrinkled, folded and changed in morphology after being treated with K14. In addition, fluorescence microscopy (FM) and cytoplasmic leakage assays showed that the cell membrane of B.c was disrupted. Further study of malondialdehyde (MDA) and relative conductivity measurements indicated that the normal function of cells is affected by K14 by increasing cell membrane permeability and promoting membrane lipid peroxidation. These results indicate that flavonol derivatives containing 1,2,4-triazole Schiff bases are expected to provide a new prospect for the development of novel fungicides.

AmiRNA Technology Enhances Tomato Disease Resistance by Suppressing Plant-Pathogen Interaction Pathways through Inhibiting TYLCV Replication.

Tomato yellow leaf curl virus disease has seriously threatened the quality and yield of tomatoes. In this study, we investigated the role of amiRNA technology in disease resistance in tomatoes (cherry tomato and large-fruited tomato) and analyzed the physiological and molecular mechanisms of disease resistance in transgenic plants. TYLCV contains six functional genes, of which the C1, C2, and V1 genes have more phosphorylation sites and glycosylation sites, and the protein structure is more complex. The virus replication was inhibited, the peroxidation of membrane lipids was reduced, and disease resistance was enhanced in all transgenic cherry tomato (J6) plants in which the C1, C2, and V1 genes were silenced, respectively. Similarly, silencing of the C1 gene enhanced disease resistance in large-fruited tomatoes. In conclusion, amiRNA technology hinders viral replication, leading to reduced activity of the tomato plant-pathogen interaction pathway and weakening tomato-virus interactions, thereby improving disease resistance.

Mechanisms of ROS-induced mitochondria-dependent apoptosis in Phaeodactylum tricornutum under AgNPs exposure

IntroductionNanomaterials such as silver nanoparticles (AgNPs) have gained widespread application across various fields. However, the large-scale production and application of AgNPs have raised concerns about their distribution in the environment and potential pollution issues.MethodsThis study investigates the toxic effects of AgNPs on the diatom Phaeodactylum tricornutum by employing electron microscopy for cellular observation, quantifying apoptotic cell numbers, and measuring antioxidant indicators. The research examines how varying concentrations of AgNPs induce stress in P. tricornutum and the specific mechanisms of the toxic effect.ResultsThe findings reveal that AgNPs induce apoptosis in P. tricornutum cells by triggering a mitochondria-mediated pathway, marked by a decrease in mitochondrial membrane potential and the activation of caspase enzymes. Additionally, AgNP exposure results in an overproduction of reactive oxygen species (ROS) within the algal cells, leading to lipid peroxidation of the cell membrane and a consequent increase in malondialdehyde (MDA) levels. This oxidative stress response induces the upregulation of antioxidant enzyme activities in an attempt to mitigate the excessive ROS.DiscussionROS is identified as the primary factor responsible for inducing mitochondria-mediated apoptosis. The research results will provide a theoretical basis for understanding the toxic effects and mechanisms of AgNPs on marine microalgae.

Machine Learning Insights into Ascorbic Acid-Enhanced Germination of Black Cumin (Nigella sativa L.) under Cadmium Stress

AbstractThe objective of the present work is to study the impact of seed priming with varying concentrations of ascorbic acid (vitamin C) on the germination process of black cumin (Nigella sativa) under cadmium (Cd) stress. As expected, Cd had a great effect on germination rates and seedling growth. However, the application of ascorbic acid during seed priming effectively alleviated Cd stress and significantly increased seed vigor. Primed seeds exhibited markedly elevated final germination percentage, germination index, mean germination time, seedling length, seedling vigor index, and reduced abnormal seedling percentage. Additionally, vitamin priming reduced membrane lipid peroxidation, in treated seeds. Moreover, seed priming elicited a considerable increase in peroxidase and catalase activity, thus mitigating stress effects and augmenting seed vitality. Our experimental data allowed us to establish 100–150 mg/L as the optimal concentration range for ascorbic acid in seed priming of black cumin. These insights were further corroborated through modeling techniques based on supervised machine learning. Notably, XGBoost emerged as a proficient tool for predicting final germination percentage, mean germination time, seedling vigor index, abnormal seedling percentage, and peroxidase activity, while SVR demonstrated aptitude in forecasting catalase activity and germination index. The Gaussian method exhibited superior performance in predicting malondialdehyde content. These comprehensive findings substantiate the premise that vitamin priming with ascorbic acid serves as a promising strategy to ameliorate germination outcomes under Cd-induced stress conditions.

SNP alleviates ferric and salt stress in Phaseolus vulgaris seeds

Seed germination and early development are delicate events often influenced by various environmental factors. Among these factors, the accumulation of salts and heavy metals in the soil is noteworthy. This study aimed to observe the effect of priming with solutions of sodium nitroprusside, polyethylene glycol 6000, and potassium nitrate on the germination of Phaseolus vulgaris seeds exposed to toxic conditions of iron and sodium chloride. Seeds were germinated on plates placed in a growth chamber at a constant temperature of 25°C and a 12-hour photoperiod. The percentage of germination, germination speed, root and shoot lengths, catalase, peroxidase activities, and malondialdehyde content were evaluated. Exposure to high concentrations of sodium chloride and iron reduced germination percentage, germination speed, root and shoot lengths of treated plants. Only sodium nitroprusside treatment mitigated the effects of stressors. No increase in malondialdehyde content was observed in any treatment, suggesting no lipid peroxidation of membranes. However, all treatments showed increased catalase activity, possibly indicating oxidative stress and metabolic damage. Sodium nitroprusside stands out as a stress alleviator for sodium chloride and iron accumulation during the germination phase.

Iron-Induced Lipid Oxidation Alters Membrane Mechanics Favoring Permeabilization.

Ferroptosis is a form of regulated necrosis characterized by the iron-dependent accumulation of lipid peroxides in cell membranes. However, how lipid oxidation via iron-mediated Fenton reactions affects the biophysical properties of cellular membranes and how these changes contribute to the opening of plasma membrane pores are major questions in the field. Here, we characterized the dynamics of membrane alterations during lipid oxidation induced onsite by Fenton reactions in chemically defined in vitro model membrane systems. We find that lipid vesicle permeabilization kinetically correlates with the appearance of malondialdehyde (MDA), a product of lipid oxidation. Iron-induced lipid oxidation also alters the lateral organization of supported lipid bilayers (SLBs) with lipid phase coexistence in a time-dependent manner, reducing the lipid phase mismatch and the circularity of liquid ordered domains, which indicates a decrease in line tension at the phase boundaries. Further analysis of oxidized SLBs by force spectroscopy reveals a significant decrease in the average membrane breakthrough force upon oxidation, resulting from changes in lipid bilayer organization that make it more susceptible to permeabilization. Our findings suggest that lipid oxidation via iron-mediated Fenton-like reactions induces strong changes in membrane lipid interactions and mechanical properties leading to reduced line tension in the permeabilized state of the bilayer, which promotes membrane pore formation.

Chorein deficiency promotes ferroptosis.

Ferroptosis is a type of programmed cell death owed to an intracellular accumulation of iron resulting in the generation reactive oxygen species, which in turn can cause peroxidation of plasma membrane lipids and ultimately result in cell death. We investigated the potential involvement of VPS13A deficiency in ferroptosis. The VPS13A gene encodes for chorein, and its deficiency is a molecular cause of chorea-acanthocytosis (ChAc), a Huntington-like disease with neurodegeneration in the striatum. In our previous study, we found male infertility characterized by increased malondialdehyde staining of the spermatozoa in the testes of the ChAc model mice. Thus, in this study we performed metabolome analysis of sperm extracted from the epididymis of the ChAc model mice, which revealed decreased cystine levels, suggesting an association between chorein deficiency and ferroptosis. We then investigated the role of chorein in ferroptosis using VPS13A knockdown (VPS13A-KD) HEK293 cells. We found that VPS13A-KD cells displayed a significantly diminished resistance to tert-Butyl hydroperoxide (tBHP)-induced lipid peroxidation and cell death compared to control cells, which could be rescued by treatment with ferrostatin-1. Moreover, VPS13A-KD cells showed Fe(II) accumulation, suggesting an impaired capacity for divalent iron removal. In the cytosolic fraction of VPS13A-KD cells, the protein level of glutathione peroxidase 4 (GPX4) was significantly reduced, suggesting that dysfunction of chorein impairs GPX4 transport, thereby facilitating ferroptosis. These results suggest that ferroptosis may contribute to neurodegeneration in ChAc caused by loss of chorein function.

An Innovative Approach: Alleviating Cadmium Toxicity in Grapevine Seedlings Using Smoke Solution Derived from the Burning of Vineyard Pruning Waste.

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl2 to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m-2.sn-1), and total phenolic content (1.89 mg.g-1), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g-1). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg-1), catalase (CAT) (1.55 U.mg-1), and ascorbate peroxidase (APX) (3.03 U.mg-1). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms.

Functions of exogenous strigolactone application and strigolactone biosynthesis genes GhMAX3/GhMAX4b in response to drought tolerance in cotton (Gossypium hirsutum L.)

BackgroundDrought stress markedly constrains plant growth and diminishes crop productivity. Strigolactones (SLs) exert a beneficial influence on plant resilience to drought conditions. Nevertheless, the specific function of SLs in modulating cotton’s response to drought stress remains to be elucidated.ResultsIn this study, we assess the impact of exogenous SL (rac-GR24) administration at various concentrations (0, 1, 5, 10, 20 µM) on cotton growth during drought stress. The findings reveal that cotton seedlings treated with 5 µM exogenous SL exhibit optimal mitigation of growth suppression induced by drought stress. Treatment with 5 µM exogenous SL under drought stress conditions enhances drought tolerance in cotton seedlings by augmenting photosynthetic efficiency, facilitating stomatal closure, diminishing reactive oxygen species (ROS) generation, alleviating membrane lipid peroxidation, enhancing the activity of antioxidant enzymes, elevating the levels of osmoregulatory compounds, and upregulating the expression of drought-responsive genes. The suppression of cotton SL biosynthesis genes, MORE AXILLARY GROWTH 3 (GhMAX3) and GhMAX4b, impairs the drought tolerance of cotton. Conversely, overexpression of GhMAX3 and GhMAX4b in respective Arabidopsis mutants ameliorates the drought-sensitive phenotype in these mutants.ConclusionThese observations underscore that SLs significantly bolster cotton’s resistance to drought stress.

Effects of nickel, lead, and copper stress on the growth and biochemical responses of Aegilops tauschii seedlings

Heavy metal pollution causes severe abiotic stress in cereal crops around the world. This study investigated the effects of different concentrations (0, 100, 200, and 300 mg·kg–1) of nickel, lead, and copper stress on the growth and biochemical responses of Aegilops tauschii seedlings, to provide a reference for research on the mechanism of invasion and screening potential sources of wheat tolerance genes. The results showed that nickel, lead, and copper stress caused a significant decrease in the contents of chlorophyll a, chlorophyll b, and chlorophyll (a + b) in A. tauschii, thereby inhibiting photosynthesis to different degrees and hindering seedling growth, which was reflected in significant reductions in plant height and root length, with the most notable effect observed under stress by 300 mg·kg–1 lead. As the concentration of heavy metals increased, the activities of antioxidant enzymes (SOD, POD, and APX), non-enzymatic antioxidants (GSH and AsA), and the contents of osmotic regulatory substances (proline and soluble proteins) in A. tauschii significantly increased. Additionally, heavy metal stress increased H2O2 and TBARS levels. However, when the nickel, lead, and copper concentrations reached 300 mg·kg–1, no significant differences were found in H2O2 or TBARS levels compared to those in the CK group. To summarize, A. tauschii can mitigate the accumulation of ROS and membrane lipid peroxidation caused by heavy metal stress through self-regulation, thus exhibiting a certain degree of tolerance to stress caused by different concentrations of nickel, lead, and copper. Finally, the evaluation using the membership function method revealed that among the three heavy metals, A. tauschii exhibited the strongest adaptation to Cu, followed by Ni and Pb.

Polydatin Prevents Electron Transport Chain Dysfunction and ROS Overproduction Paralleled by an Improvement in Lipid Peroxidation and Cardiolipin Levels in Iron-Overloaded Rat Liver Mitochondria.

Increased intramitochondrial free iron is a key feature of various liver diseases, leading to oxidative stress, mitochondrial dysfunction, and liver damage. Polydatin is a polyphenol with a hepatoprotective effect, which has been attributed to its ability to enhance mitochondrial oxidative metabolism and antioxidant defenses, thereby inhibiting reactive oxygen species (ROS) dependent cellular damage processes and liver diseases. However, it has not been explored whether polydatin is able to exert its effects by protecting the phospholipid cardiolipin against damage from excess iron. Cardiolipin maintains the integrity and function of electron transport chain (ETC) complexes and keeps cytochrome c bound to mitochondria, avoiding uncontrolled apoptosis. Therefore, the effect of polydatin on oxidative lipid damage, ETC activity, cytochrome levels, and ROS production was explored in iron-exposed rat liver mitochondria. Fe2+ increased lipid peroxidation, decreased cardiolipin and cytochromes c + c1 and aa3 levels, inhibited ETC complex activities, and dramatically increased ROS production. Preincubation with polydatin prevented all these effects to a variable degree. These results suggest that the hepatoprotective mechanism of polydatin involves the attenuation of free radical production by iron, which enhances cardiolipin levels by counteracting membrane lipid peroxidation. This prevents the loss of cytochromes, improves ETC function, and decreases mitochondrial ROS production.

Physiological and Transcriptomic Analyses Reveal the Role of the Antioxidant System and Jasmonic Acid (JA) Signal Transduction in Mulberry (Morus alba L.) Response to Flooding Stress

In recent decades, the frequency of flooding has increased as a result of global climate change. Flooding has become one of the major abiotic stresses that seriously affect the growth and development of plants. Mulberry (Morus alba L.) is an important economic tree in China. Flooding stress is among the most severe abiotic stresses that affect the production of mulberry. However, the physiological and molecular biological mechanisms of mulberry responses to flooding stress are still unclear. In the present study, reactive oxygen species (ROS) metabolism, antioxidant mechanism, and plant hormones in mulberry associated with the response to flooding stress were investigated using physiological and transcriptomic analysis methods. The results showed significant increases in the production rate of superoxide anion (O2•−) and the content of hydrogen peroxide (H2O2) in leaves on the 5th day of flooding stress. This led to membrane lipid peroxidation and elevated malondialdehyde (MDA) levels. Antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) exhibited enhanced activities initially, followed by fluctuations. The ascorbic acid–glutathione (AsA-GSH) cycle played a crucial role in scavenging ROS, promoting the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). Transcriptomic analysis revealed the up-regulation of the gene-encoding antioxidant enzymes (APX, MDHAR, GPX, GR, GST) involved in ROS scavenging and stress tolerance mechanisms. Jasmonic acid (JA) levels and the expression of JA synthesis-related genes increased significantly in mulberry leaves under flooding stress. This activation of the JA signaling pathway contributed to the plant’s adaptability to flooding conditions. Proline (Pro) and soluble sugar (SS) contents increased notably in response to flooding stress. Proline helped maintain cell turgor and protected enzymes and membranes from damage, while soluble sugars supported anaerobic respiration and energy supply. However, soluble protein (SP) content decreased, suggesting inhibition of protein synthesis. The study provides insights into mulberry’s flooding tolerance mechanisms, guiding future molecular breeding efforts. This summary captures the key findings and implications of the study on mulberry’s response to flooding stress, focusing on physiological and molecular mechanisms identified in the research.