Roles of enzymatic and nonenzymatic antioxidants in plants during abiotic stress

Metabolic perturbation and oxidative damage induced by tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-ethylhexyl) phosphate (TEHP) on Escherichia coli through integrative analyses of metabolome

Organophosphate esters (OPEs) are one of the emerging environmental threats, causing the hazard to ecosystem safety and human health. Yet, the toxic effects and metabolic response mechanism after Escherichia coli (E.coli) exposed to TDCIPP and TEHP is inconclusive. Herein, the levels of SOD and CAT were elevated in a concentration-dependent manner, accompanied with the increase of MDA contents, signifying the activation of antioxidant response and occurrence of lipid peroxidation. Oxidative damage mediated by excessive accumulation of ROS decreased membrane potential and inhibited membrane protein synthesis, causing membrane protein dysfunction. Integrative analyses of GC-MS and LC-MS based metabolomics evinced that significant perturbation to the carbohydrate metabolism, nucleotide metabolism, lipids metabolism, amino acid metabolism, organic acids metabolism were induced following exposure to TDCIPP and TEHP in E.coli, resulting in metabolic reprogramming. Additionally, metabolites including PE(16:1(5Z)/15:0), PA(17:0/15:1(9Z)), PC(20:2(11Z,14Z)/12:0), LysoPC(18:3(6Z,9Z,12Z)/0:0) were significantly upregulated, manifesting that cell membrane protective molecule was afforded by these differential metabolites to improve permeability and fluidity. Overall, current findings generate new insights into the molecular toxicity mechanism by which E.coli respond to TDCIPP and TEHP stress and supply valuable information for potential ecological risks of OPEs on aquatic ecosystems.

Biochar combined with humic acid improves the soil environment and regulate microbial communities in apple replant soil

Apple replant disease (ARD) negatively affects plant growth and reduces yields in replanted orchards. In this study, biochar and humic acid were applied to apple replant soil. We aimed to investigate whether biochar and humic acid could promote plant growth and alleviate apple replant disease by reducing the growth of harmful soil microorganisms, changing soil microbial community structure, and improving the soil environment. This experiment included five treatments: apple replant soil (CK), apple replant soil with methyl bromide fumigation (FM), replant soil with biochar addition (2 %), replant soil with humic acid addition (1.5 ‰), and replant soil with biochar combined with humic acid. Seedling biomass, the activity of antioxidant enzymes in the leaves and roots, and soil environmental variables were measured. Microbial community composition and structure were analyzed using ITS gene sequencing. Biochar and humic acid significantly reduced the abundance of Fusarium and promoted the recovery of replant soil microbial communities. Biochar and humic acid also increased the soil enzymes activity (urease, invertase, neutral phosphatase, and catalase), the plant height, fresh weight, dry weight, the activity of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase), and root indexes of apple seedlings increased in replant soil. In sum, We can use biochar combined with humic acid to alleviate apple replant disease.

An Integrated Framework for Drought Stress in Plants

With global warming, drought stress is becoming increasingly severe, causing serious impacts on crop yield and quality. In order to survive under adverse conditions such as drought stress, plants have evolved a certain mechanism to cope. The tolerance to drought stress is mainly improved through the synergistic effect of regulatory pathways, such as transcription factors, phytohormone, stomatal movement, osmotic substances, sRNA, and antioxidant systems. This study summarizes the research progress on plant drought resistance, in order to provide a reference for improving plant drought resistance and cultivating drought-resistant varieties through genetic engineering technology.

Physiological and transcriptomic profiles reveal key regulatory pathways involved in cold resistance in sunflower seedlings

During sunflower growth, cold waves often occur and impede plant growth. Therefore, it is crucial to study the underlying mechanism of cold resistance in sunflowers. In this study, physiological analysis revealed that as cold stress increased, the levels of ROS, malondialdehyde, ascorbic acid, and dehydroascorbic acid and the activities of antioxidant enzymes increased. Transcriptomics further identified 10,903 DEGs between any two treatments. Clustering analysis demonstrated that the expression of MYB44a, MYB44b, MYB12, bZIP2 and bZIP4 continuously upregulated under cold stress. Cold stress can induce ROS accumulation, which interacts with hormone signals to activate cold-responsive transcription factors regulating target genes involved in antioxidant defense, secondary metabolite biosynthesis, starch and sucrose metabolism enhancement for improved cold resistance in sunflowers. Additionally, the response of sunflowers to cold stress may be independent of the CBF pathway. These findings enhance our understanding of cold stress resistance in sunflowers and provide a foundation for genetic breeding.

Sansevieria trifasciata's specific metabolite improves tolerance and efficiency for particulate matter and volatile organic compound removal

Phytoremediation has become famous for removing particulate matter (PM) and volatile organic compounds (VOCs), but the ability is affected by plant health. Lately, the priming technique was a simple approach to studying improving plant tolerance against abiotic stress by specific metabolites that accumulated, known as "memory", but the mechanism underlying this mechanism and how long this "memory" was retained in the plant was a lack of study. Sansevieria trifasciata was primed for one week for PM and VOC stress to improve plant efficiency on PM and VOC. After that, the plant was recovered for two- or five-weeks, then re-exposed to the same stress with similar PM and VOC concentrations from cigarette smoke. Primed S. trifasciata showed improved removal of PMs entirely within 2 h and VOC within 24 h. The primed plant can maintain a malondialdehyde (MDA) level and retain the "memory" for two weeks. Metabolomics analysis showed that an ornithine-related compound was accumulated as a responsive metabolite under exposure to PM and VOC stress. Exogenous ornithine can maintain plant efficiency and prevent stress by increasing proline and antioxidant enzymes. This study is the first to demonstrate plant "memory" mechanisms under PM and VOC stress.

The Physiological and Molecular Mechanisms of Exogenous Melatonin Promote the Seed Germination of Maize (Zea mays L.) under Salt Stress

Salt stress caused by high concentrations of Na+ and Cl- in soil is one of the most important abiotic stresses in agricultural production, which seriously affects grain yield. The alleviation of salt stress through the application of exogenous substances is important for grain production. Melatonin (MT, N-acetyl-5-methoxytryptamine) is an indole-like small molecule that can effectively alleviate the damage caused by adversity stress on crops. Current studies have mainly focused on the effects of MT on the physiology and biochemistry of crops at the seedling stage, with fewer studies on the gene regulatory mechanisms of crops at the germination stage. The aim of this study was to explain the mechanism of MT-induced salt tolerance at physiological, biochemical, and molecular levels and to provide a theoretical basis for the resolution of MT-mediated regulatory mechanisms of plant adaptation to salt stress. In this study, we investigated the germination, physiology, and transcript levels of maize seeds, analyzed the relevant differentially expressed genes (DEGs), and examined salt tolerance-related pathways. The results showed that MT could increase the seed germination rate by 14.28-19.04%, improve seed antioxidant enzyme activities (average increase of 11.61%), and reduce reactive oxygen species accumulation and membrane oxidative damage. In addition, MT was involved in regulating the changes of endogenous hormones during the germination of maize seeds under salt stress. Transcriptome results showed that MT affected the activity of antioxidant enzymes, response to stress, and seed germination-related genes in maize seeds under salt stress and regulated the expression of genes related to starch and sucrose metabolism and phytohormone signal transduction pathways. Taken together, the results indicate that exogenous MT can affect the expression of stress response-related genes in salt-stressed maize seeds, enhance the antioxidant capacity of the seeds, reduce the damage induced by salt stress, and thus promote the germination of maize seeds under salt stress. The results provide a theoretical basis for the MT-mediated regulatory mechanism of plant adaptation to salt stress and screen potential candidate genes for molecular breeding of salt-tolerant maize.

Neural underpinnings of fine motor skills under stress and anxiety: A review

This review offers a comprehensive examination of how stress and anxiety affect motor behavior, particularly focusing on fine motor skills and gait adaptability. We explore the role of several neurochemicals, including brain-derived neurotrophic factor (BDNF) and dopamine, in modulating neural plasticity and motor control under these affective states. The review highlights the importance of developing therapeutic strategies that enhance motor performance by leveraging the interactions between key neurochemicals. Additionally, we investigate the complex interplay between emotional-cognitive states and sensorimotor behaviors, showing how stress and anxiety disrupt neural integration, leading to impairments in skilled movements and negatively impacting quality of life. Synthesizing evidence from human and rodent studies, we provide a detailed understanding of the relationships among stress, anxiety, and motor behavior. Our findings reveal neurophysiological pathways, behavioral outcomes, and potential therapeutic targets, emphasizing the intricate connections between neurobiological mechanisms, environmental factors, and motor performance.

Evaluation of different bermudagrass germplasm at physiological and molecular level under shade along longitudinal and latitudinal gradients

Responses of turfgrass to shade vary in individual species, and the degree and quality of low light; therefore, the selection of low light tolerant cultivars of turfgrass is important and beneficial for turf management rather than other practices. The stolons of thirteen bermudagrass genotypes were planted with two treatments and three replications of each treatment to establish for one month in the Yangzhou University Jiangsu China greenhouse. The established plants were transferred outside of the greenhouse, and 50% shading was applied to them with a black net. After 30 days of stress treatment, the morpho-physiological and biochemical analyses were performed. The expression of genes such as HEMA, HY5, PIF4, and Cu/ZnSOD was assessed. Cynodon dactylon is a C4, and perennial that grows as lawn grass and is used as forage. Based on different indicator measurements, the most shade-tolerant germplasm was L01 and L06 along the longitudes and L09 and L10 along the latitudes. At the same time, L02 and L08 were more susceptible, respectively. However, germplasm showed greater tolerance in higher latitudes while longitudinal plants showed less stress response. The current study aimed (1) to screen out the most shade-tolerant Cynodon dactylon genotype among 13 along longitudinal and latitudinal gradients in China. (2) to examine morpho-physiological indicators of different bermudagrassgenotypes; (3) to evaluate if and how differences in various indicators of bermudagrass correlated with geographic region. This study will significantly advance the use of Cynodon germplasm in breeding, genomics, management, nomenclature, and phylogeographical study. It will decisively define whether natural selection and migration can drive evolutionary responses for populations to adapt to their new environments effectively.

Sustainable Remediation of Soil and Water Utilizing Arbuscular Mycorrhizal Fungi: A Review

Phytoremediation is recognized as an environmentally friendly technique. However, the low biomass production, high time consumption, and exposure to combined toxic stress from contaminated media weaken the potential of phytoremediation. As a class of plant-beneficial microorganisms, arbuscular mycorrhizal fungi (AMF) can promote plant nutrient uptake, improve plant habitats, and regulate abiotic stresses, and the utilization of AMF to enhance phytoremediation is considered to be an effective way to enhance the remediation efficiency. In this paper, we searched 520 papers published during the period 2000-2023 on the topic of AMF-assisted phytoremediation from the Web of Science core collection database. We analyzed the author co-authorship, country, and keyword co-occurrence clustering by VOSviewer. We summarized the advances in research and proposed prospective studies on AMF-assisted phytoremediation. The bibliometric analyses showed that heavy metal, soil, stress tolerance, and growth promotion were the research hotspots. AMF-plant symbiosis has been used in water and soil in different scenarios for the remediation of heavy metal pollution and organic pollution, among others. The potential mechanisms of pollutant removal in which AMF are directly involved through hyphal exudate binding and stabilization, accumulation in their structures, and nutrient exchange with the host plant are highlighted. In addition, the tolerance strategies of AMF through influencing the subcellular distribution of contaminants as well as chemical form shifts, activation of plant defenses, and induction of differential gene expression in plants are presented. We proposed that future research should screen anaerobic-tolerant AMF strains, examine bacterial interactions with AMF, and utilize AMF for combined pollutant removal to accelerate practical applications.

Antimalarial and antioxidant activities of novel artesunate-ellagic acid hybrid compound in vitro and in vivo

Introduction: Emergence of drug resistant strains of Plasmodium species has necessitated the search for novel antimalarials with unique mechanisms of action. Synthesis of hybrid compounds has been one approach to tackling this challenge. In this study, the synthesis of artesunate-ellagic acid hybrid compound (EA31) from ellagic acid and artesunate and its evaluation for antimalarial and antioxidant activities using in vitro and in vivo models were carried out. Method: EA31 was synthesized from artesunate and ellagic acid. The activities of the hybrid compound against Plasmodium falciparum W2 and P. berghei NK65 were evaluated, and its antioxidant activities were also determined. Results: The results revealed that EA31 was more active against P. falciparum W2 (chloroquine resistant) clone and less cytotoxic to buffalo green monkey kidney cell line compared to artesunate. EA31 was also active against Plasmodium berghei NK65 in vivo. The results revealed inhibition of β-hematin formation as one of the mechanisms of action of EA31. EA31 also exhibited antioxidant activities. Conclusion: The results revealed that EA31 may exert dual action of killing malaria parasite and mopping the reactive oxygen species that mediate the secondary complications of malaria.

Transcriptome Profiling Reveals the Response of Seed Germination of Peganum harmala to Drought Stress

Peganum harmala L. is a perennial herbaceous plant that plays critical roles in protecting the ecological environment in arid, semi-arid, and desert areas. Although the seed germination characteristics of P. harmala in response to environmental factors (i.e., drought, temperature, and salt) have been investigated, the response mechanism of seed germination to drought conditions has not yet been revealed. In this study, the changes in the physiological characteristics and transcriptional profiles in seed germination were examined under different polyethylene glycol (PEG) concentrations (0-25%). The results show that the seed germination rate was significantly inhibited with an increase in the PEG concentration. Totals of 3726 and 10,481 differentially expressed genes (DEGs) were, respectively, generated at 5% and 25% PEG vs. the control (C), with 1642 co-expressed DEGs, such as drought stress (15), stress response (175), and primary metabolism (261). The relative expression levels (RELs) of the key genes regulating seed germination in response to drought stress were in accordance with the physiological changes. These findings will pave the way to increase the seed germination rate of P. harmala in drought conditions.

Current state of knowledge of triclosan (TCS)-dependent reactive oxygen species (ROS) production

Triclosan (TCS) is widely used in a number of industrial and personal care products. This molecule can induce reactive oxygen species (ROS) production in various cell types, which results in diverse types of cell responses. Therefore, the aim of the present study was to summarize the current state of knowledge of TCS-dependent ROS production and the influence of TCS on antioxidant enzymes and pathways. To date, the TCS mechanism of action has been widely investigated in non-mammalian organisms that may be exposed to contaminated water and soil, but there are also in vivo and in vitro studies on plants, algae, mammalians, and humans. This literature review has revealed that mammalian organisms are more resistant to TCS than non-mammalian organisms and, to obtain a toxic effect, the effective TCS dose must be significantly higher. The TCS-dependent increase in the ROS level causes damage to DNA, protein, and lipids, which together with general oxidative stress leads to cell apoptosis or necrosis and, in the case of cancer cells, faster oncogenesis and even initiation of oncogenic transformation in normal human cells. The review presents the direct and indirect TCS action through different receptor pathways.

Zinc-loaded mesoporous silica nanoparticles mitigate salinity stress in wheat seedlings through silica-zinc uptake, osmotic balance, and ROS detoxification

Abiotic stresses like salinity and micronutrient deficiency majorly affect wheat productivity. Applying mesoporous silica nanoparticles (MSiNPs) as a smart micronutrient delivery system can facilitate better stress management and nutrient delivery. In this purview, we investigated the potential of MSiNPs and Zn-loaded MSiNPs (Zn-MSiNPs) on the growth and physiology of wheat seedlings exposed to salinity stress (200 mM NaCl). Initially, the FESEM, DLS, and BET analysis portrayed nanoparticles' spherical shape, nano-size, and negatively charged mesoporous surface. A sustained release of Zn+2 from Zn-MSiNPs at 30 °C, diffused light, and pH 7 was perceived with a 96.57% release after 10 days. Further, the mitigation of NaCl stress in the wheat seedlings was evaluated with two different concentrations, each of MSiNPs and Zn-MSiNPs (1 g/L and 5 g/L), respectively. A meticulous improvement in the germination and growth of wheat seedlings was observed when treated with both MSiNPs and Zn-MSiNPs. A considerable increase in chlorophyll, total protein, and sugar content was in consort with a substantial decline in MDA, electrolyte leakage, and ROS accumulation, showcasing the nanomaterials' palliating effects. Most importantly, the K+/Na+ ratio in shoots increased significantly by 3.43 and 4.37 folds after being treated with 5 g/L Zn-MSiNPs, compared to their respective control sets (0 and 200 mM NaCl). Therefore, it can be concluded that the Zn-MSiNPs can effectively restrain the effects of salinity stress on wheat seedlings.

Exploring the dynamics of ISR signaling in maize upon seed priming with plant growth promoting actinobacteria isolated from tea rhizosphere of Darjeeling

Plant growth-promoting rhizobacteria (PGPR) offer an eco-friendly alternative to agrochemicals for better plant growth and development. Here, we evaluated the plant growth promotion abilities of actinobacteria isolated from the tea (Camellia sinensis) rhizosphere of Darjeeling, India. 16 S rRNA gene ribotyping of 28 isolates demonstrated the presence of nine different culturable actinobacterial genera. Assessment of the in vitro PGP traits revealed that Micrococcus sp. AB420 exhibited the highest level of phosphate solubilization (i.e., 445 ± 2.1 µg/ml), whereas Kocuria sp. AB429 and Brachybacterium sp. AB440 showed the highest level of siderophore (25.8 ± 0.1%) and IAA production (101.4 ± 0.5 µg/ml), respectively. Biopriming of maize seeds with the individual actinobacterial isolate revealed statistically significant growth in the treated plants compared to controls. Among them, treatment with Paenarthrobacter sp. AB416 and Brachybacterium sp. AB439 exhibited the highest shoot and root length. Biopriming has also triggered significant enzymatic and non-enzymatic antioxidative defense reactions in maize seedlings both locally and systematically, providing a critical insight into their possible role in the reduction of reactive oxygen species (ROS) burden. To better understand the role of actinobacterial isolates in the modulation of plant defense, three selected actinobacterial isolates, AB426 (Brevibacterium sp.), AB427 (Streptomyces sp.), and AB440 (Brachybacterium sp.) were employed to evaluate the dynamics of induced systemic resistance (ISR) in maize. The expression profile of five key genes involved in SA and JA pathways revealed that bio-priming with actinobacteria (Brevibacterium sp. AB426 and Brachybacterium sp. AB440) preferably modulates the JA pathway rather than the SA pathway. The infection studies in bio-primed maize plants resulted in a delay in disease progression by the biotrophic pathogen Ustilago maydis in infected maize plants, suggesting the positive efficacy of bio-priming in aiding plants to cope with biotic stress. Conclusively, this study unravels the intrinsic mechanisms of PGPR-mediated ISR dynamics in bio-primed plants, offering a futuristic application of these microorganisms in the agricultural fields as an eco-friendly alternative.

Response of photosynthetic characteristics and antioxidant system in the leaves of safflower to NaCl and NaHCO3

KEY MESSAGE

Compared with NaCl, NaHCO3 caused more serious oxidative damage and photosynthesis inhibition in safflower by down-regulating the expression of related genes. Salt-alkali stress is one of the important factors that limit plant growth. NaCl and sodium bicarbonate (NaHCO3) are neutral and alkaline salts, respectively. This study investigated the physiological characteristics and molecular responses of safflower (Carthamus tinctorius L.) leaves treated with 200 mmol L-1 of NaCl or NaHCO3. The plants treated with NaCl treatment were less effective at inhibiting the growth of safflower, but increased the content of malondialdehyde (MDA) in leaves. Meanwhile, safflower alleviated stress damage by increasing proline (Pro), soluble protein (SP), and soluble sugar (SS). Both fresh weight and dry weight of safflower was severely decreased when it was subjected to NaHCO3 stress, and there was a significant increase in the permeability of cell membranes and the contents of osmotic regulatory substances. An enrichment analysis of the differentially expressed genes (DEGs) using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes identified significant enrichment of photosynthesis and pathways related to oxidative stress. Furthermore, a weighted gene co-expression network analysis (WGCNA) showed that the darkgreen module had the highest correlation with photosynthesis and oxidative stress traits. Large numbers of transcription factors, primarily from the MYB, GRAS, WRKY, and C2H2 families, were predicted from the genes within the darkgreen module. An analysis of physiological indicators and DEGs, it was found that under saline-alkali stress, genes related to chlorophyll synthesis enzymes were downregulated, while those related to degradation were upregulated, resulting in inhibited chlorophyll biosynthesis and decreased chlorophyll content. Additionally, NaCl and NaHCO3 stress downregulated the expression of genes related to the Calvin cycle, photosynthetic antenna proteins, and the activity of photosynthetic reaction centers to varying degrees, hindering the photosynthetic electron transfer process, suppressing photosynthesis, with NaHCO3 stress causing more pronounced adverse effects. In terms of oxidative stress, the level of reactive oxygen species (ROS) did not change significantly under the NaCl treatment, but the contents of hydrogen peroxide and the rate of production of superoxide anions increased significantly under NaHCO3 stress. In addition, treatment with NaCl upregulated the levels of expression of the key genes for superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), the ascorbate-glutathione cycle, and the thioredoxin-peroxiredoxin pathway, and increased the activity of these enzymes, thus, reducing oxidative damage. Similarly, NaHCO3 stress increased the activities of SOD, CAT, and POD and the content of ascorbic acid and initiated the glutathione-S-transferase pathway to remove excess ROS but suppressed the regeneration of glutathione and the activity of peroxiredoxin. Overall, both neutral and alkaline salts inhibited the photosynthetic process of safflower, although alkaline salt caused a higher level of stress than neutral salt. Safflower alleviated the oxidative damage induced by stress by regulating its antioxidant system.

Exogenous of different elicitors: proline and ornithine on Sansevieria trifasciata under particulate matter (PM) and volatile organic compounds (VOC)

Phytoremediation has become famous for removing particulate matter (PM) and volatile organic compounds (VOC) in situ. Plants for removing PM and VOC were associated with botanical biofilters to attract pollution to the plant. On the other hand, persistent pollution exposure can lower plant health and phytoremediation effectiveness; therefore, improving plant tolerance against stress is necessary. Various elicitors can enhance plant tolerance to certain stressors. This study aims to investigate different elicitors to maintain plant health and improve the use of plants in phytoremediation for PM and VOC pollution. This experiment used Sansevieria trifasciata hort. ex Prain under PM and VOC stress. Exogenous elicitors, such as proline, ornithine, and a commercial product, were applied to the leaf parts before exposure to PM and VOC stress. The initial concentrations of PM1, PM2.5, and PM10 were 300-350, 350-450, and 400-500 µg m-3, respectively, while the VOC concentration was 2.5-3.0 mg m-3. The plant was stressed for 7 days. The result indicated that ornithine 10 mM is vital in improving plant tolerance and inducing antioxidant enzymes against PM and VOC, while proline 50 mM and a commercial product could not reduce plant stress. This study suggests that ornithine might be an important metabolite to improve plant tolerance to PM and VOC.

5-Aminolevulinic acid treatment mitigates pesticide stress in bean seedlings by regulating stress-related gene expression and retrotransposon movements

Overdoses of pesticides lead to a decrease in the yield and quality of plants, such as beans. The unconscious use of deltamethrin, one of the synthetic insecticides, increases the amount of reactive oxygen species (ROS) by causing oxidative stress in plants. In this case, plants tolerate stress by activating the antioxidant defense mechanism and many genes. 5-Aminolevulinic acid (ALA) improves tolerance to stress by acting exogenously in low doses. There are many gene families that are effective in the regulation of this mechanism. In addition, one of the response mechanisms at the molecular level against environmental stressors in plants is retrotransposon movement. In this study, the expression levels of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), and stress-associated protein (SAP) genes were determined by Q-PCR in deltamethrin (0.5 ppm) and various doses (20, 40, and 80 mg/l) of ALA-treated bean seedlings. In addition, one of the response mechanisms at the molecular level against environmental stressors in plants is retrotransposon movement. It was determined that deltamethrin increased the expression of SOD (1.8-fold), GPX (1.4-fold), CAT (2.7-fold), and SAP (2.5-fold) genes, while 20 and 40 mg/l ALA gradually increased the expression of these genes at levels close to control, but 80 mg/l ALA increased the expression of these genes almost to the same level as deltamethrin (2.1-fold, 1.4-fold, 2.6-fold, and 2.6-fold in SOD, GPX, CAT, and SAP genes, respectively). In addition, retrotransposon-microsatellite amplified polymorphism (REMAP) was performed to determine the polymorphism caused by retrotransposon movements. While deltamethrin treatment has caused a decrease in genomic template stability (GTS) (27%), ALA treatments have prevented this decline. At doses of 20, 40, and 80 mg/L of ALA treatments, the GTS ratios were determined to be 96.8%, 74.6%, and 58.7%, respectively. Collectively, these findings demonstrated that ALA has the utility of alleviating pesticide stress effects on beans.

Sirt5-mediated lysine desuccinylation regulates oxidative stress adaptation in Magnaporthe oryzae during host intracellular infection

Plant pathogenic fungi elaborate numerous detoxification strategies to suppress host reactive oxygen species (ROS), but their coordination is not well-understood. Here, we show that Sirt5-mediated protein desuccinylation in Magnaporthe oryzae is central to host ROS detoxification. SIRT5 encodes a desuccinylase important for virulence via adaptation to host oxidative stress. Quantitative proteomics analysis identified a large number of succinylated proteins targeted by Sirt5, most of which were mitochondrial proteins involved in oxidative phosphorylation, TCA cycle, and fatty acid oxidation. Deletion of SIRT5 resulted in hypersuccinylation of detoxification-related enzymes, and significant reduction in NADPH : NADP+ and GSH : GSSG ratios, disrupting redox balance and impeding invasive growth. Sirt5 desuccinylated thioredoxin Trx2 and glutathione peroxidase Hyr1 to activate their enzyme activity, likely by affecting proper folding. Altogether, this work demonstrates the importance of Sirt5-mediated desuccinylation in controlling fungal process required for detoxifying host ROS during M. oryzae infection.

Non-proteinogenic amino acids mitigate oxidative stress and enhance the resistance of common bean plants against Sclerotinia sclerotiorum

White mold, caused by the necrotrophic fungus Sclerotinia sclerotiorum, is a challenging disease to common bean cultivation worldwide. In the current study, two non-proteinogenic amino acids (NPAAs), γ-aminobutyric acid (GABA) and ß-alanine, were suggested as innovative environmentally acceptable alternatives for more sustainable management of white mold disease. In vitro, GABA and ß-alanine individually demonstrated potent dose-dependent fungistatic activity and effectively impeded the radial growth and development of S. sclerotiorum mycelium. Moreover, the application of GABA or ß-alanine as a seed treatment followed by three root drench applications efficiently decreased the disease severity, stimulated plant growth, and boosted the content of photosynthetic pigments of treated S. sclerotiorum-infected plants. Furthermore, although higher levels of hydrogen peroxide (H2O2), superoxide anion (O2 •-), and malondialdehyde (MDA) indicated that S. sclerotiorum infection had markedly triggered oxidative stress in infected bean plants, the exogenous application of both NPAAs significantly reduced the levels of the three studied oxidative stress indicators. Additionally, the application of GABA and ß-alanine increased the levels of both non-enzymatic (total soluble phenolics and flavonoids), as well as enzymatic (catalase [CAT], peroxidases [POX], and polyphenol oxidase [PPO]) antioxidants in the leaves of S. sclerotiorum-infected plants and improved their scavenging activity and antioxidant efficiency. Applications of GABA and ß-alanine also raised the proline and total amino acid content of infected bean plants. Lastly, the application of both NPAAs upregulated the three antioxidant-related genes PvCAT1, PvCuZnSOD1, and PvGR. Collectively, the fungistatic activity of NPAAs, coupled with their ability to alleviate oxidative stress, enhance antioxidant defenses, and stimulate plant growth, establishes them as promising eco-friendly alternatives for white mold disease management for sustainable bean production.

Changes in Growth and Heavy Metal and Phenolic Compound Accumulation in Buddleja cordata Cell Suspension Culture under Cu, Fe, Mn, and Zn Enrichment

Buddleja cordata cell suspension cultures could be used as a tool for investigating the capabilities of this species to tolerate heavy metals (HMs) and for assessing the effects of HMs on the accumulation of phenolic compounds in this species. It grows in a wide range of habitats in Mexico, including ultramafic soils, and mobilizes some HMs in the soil. The mobilization of these HMs has been associated with phenolic substances. In addition, this species is used in Mexican traditional medicine. In the present study, a B. cordata cell suspension culture was grown for 18 days in a culture medium enriched with Cu (0.03-0.25 mM), Fe (0.25-1.5 mM), Mn (0.5-3.0 mM), or Zn (0.5-2.0 mM) to determine the effects of these HMs on growth and HM accumulation. We also assessed the effects of the HMs on phenolic compound accumulation after 1 and 18 days of HM exposure. Cells were able to grow at almost all tested HM concentrations and accumulated significant amounts of each HM. The highest accumulation levels were as follows: 1160 mg Cu kg-1, 6845 mg Fe kg-1, 3770 mg Mn kg-1, and 6581 mg Zn kg-1. Phenolic compound accumulation was affected by the HM exposure time and corresponded to each HM and its concentration. Future research should analyze whole plants to determine the capabilities of Buddleja cordata to accumulate abnormally high amounts of HM and to evaluate the physiological impact of changes in the accumulation of phenolic compounds.

QTLs and Genes for Salt Stress Tolerance: A Journey from Seed to Seed Continued

Rice (Oryza sativa L.) is a crucial crop contributing to global food security; however, its production is susceptible to salinity, a significant abiotic stressor that negatively impacts plant germination, vigour, and yield, degrading crop production. Due to the presence of exchangeable sodium ions (Na+), the affected plants sustain two-way damage resulting in initial osmotic stress and subsequent ion toxicity in the plants, which alters the cell's ionic homeostasis and physiological status. To adapt to salt stress, plants sense and transfer osmotic and ionic signals into their respective cells, which results in alterations of their cellular properties. No specific Na+ sensor or receptor has been identified in plants for salt stress other than the SOS pathway. Increasing productivity under salt-affected soils necessitates conventional breeding supplemented with biotechnological interventions. However, knowledge of the genetic basis of salinity stress tolerance in the breeding pool is somewhat limited because of the complicated architecture of salinity stress tolerance, which needs to be expanded to create salt-tolerant variants with better adaptability. A comprehensive study that emphasizes the QTLs, genes and governing mechanisms for salt stress tolerance is discussed in the present study for future research in crop improvement.

Allelic variation of PmCBF03 contributes to the altitude and temperature adaptability in Japanese apricot (Prunus mume Sieb. et Zucc.)

Japanese apricot is an important subtropical deciduous fruit tree in China, widely distributed in different altitude areas. How does it adapt to the different temperature environments in these areas? In this study, we identified a low-temperature transcription factor PmCBF03 on chromosome 7 through adaptive analysis of populations at different altitudes, which has an early termination single nucleotide polymorphism mutation. There were two different types of variation, PmCBF03A type in high-altitude areas and PmCBF03T type in low-altitude areas. PmCBF03A gene increased the survival rate, Fv/Fm values, antioxidant enzyme activity, and expression levels of antioxidant enzyme genes, and reducing electrolyte leakage and accumulation of reactive oxygen species in transgenic Arabidopsis under low temperature and freezing stress. Simultaneously, PmCBF03A gene promoted the dormancy of transgenic Arabidopsis seeds than wild-type. Biochemical analysis demonstrated that PmCBF03A directly bound to the DRE/CRT element in the promoters of the PmCOR413, PmDAM6 and PmABI5 genes, promoting their transcription and enhanced the cold resistance and dormancy of the overexpressing PmCBF03A lines. While PmCBF03T gene is unable to bind to the promoters of PmDAM6 and PmABI5 genes, leading to early release of dormancy to adapt to the problem of insufficient chilling requirement in low-altitude areas.

Integrated Ca, Mg, Cu, and Zn supply upregulates leaf anatomy and metabolic adjustments in Eucalyptus seedlings

Adaptive responses to abiotic stresses such as soil acidity in Eucalyptus-the most widely planted broad-leaf forest genus globally-are poorly understood. This is particularly evident in physiological and anatomical disorders that inhibit plant development and wood quality. We aimed to explore how the supply of Ca and Mg through liming (lime), combined with Cu and Zn fertilization (CZF), influences physiological and anatomical responses during Eucalyptus grandis seedlings growth in tropical acid soil. Therefore, related parameters of leaf area and leaf anatomy, stomatal size, leaf gas exchange, antioxidant system, nutrient partitioning, and biomass allocation responses were monitored. Liming alone in Eucalyptus increased specific leaf area, stomatal density on the abaxial leaf surface, and Ca and Mg content. Also, Eucalyptus exposed only to CZF increased Cu and Zn content. Lime and CZF increased leaf blade and adaxial epidermal thickness, and improved the structural organization of the spongy mesophyll, promoting increased net CO2 assimilation, and stomatal conductance. Fertilization with Ca, Mg, Cu, and Zn positively affects plant nutrition, light utilization, photosynthetic rate, and antioxidant performance, improving growth. Our results indicate that lime and CZF induce adaptive responses in the physiological and anatomical adjustments of Eucalyptus plantation, thereby promoting biomass accumulation.

Drought-Adapted Mediterranean Diet Plants: A Source of Bioactive Molecules Able to Give Nutrigenomic Effects per sè or to Obtain Functional Foods

The Mediterranean diet features plant-based foods renowned for their health benefits derived from bioactive compounds. This review aims to provide an overview of the bioactive molecules present in some representative Mediterranean diet plants, examining their human nutrigenomic effects and health benefits as well as the environmental advantages and sustainability derived from their cultivation. Additionally, it explores the facilitation of producing fortified foods aided by soil and plant microbiota properties. Well-studied examples, such as extra virgin olive oil and citrus fruits, have demonstrated significant health advantages, including anti-cancer, anti-inflammatory, and neuroprotective effects. Other less renowned plants are presented in the scientific literature with their beneficial traits on human health highlighted. Prickly pear's indicaxanthin exhibits antioxidant properties and potential anticancer traits, while capers kaempferol and quercetin support cardiovascular health and prevent cancer. Oregano and thyme, containing terpenoids like carvacrol and γ-terpinene, exhibit antimicrobial effects. Besides their nutrigenomic effects, these plants thrive in arid environments, offering benefits associated with their cultivation. Their microbiota, particularly Plant Growth Promoting (PGP) microorganisms, enhance plant growth and stress tolerance, offering biotechnological opportunities for sustainable agriculture. In conclusion, leveraging plant microbiota could revolutionize agricultural practices and increase sustainability as climate change threatens biodiversity. These edible plant species may have crucial importance, not only as healthy products but also for increasing the sustainability of agricultural systems.

Types of Membrane Transporters and the Mechanisms of Interaction between Them and Reactive Oxygen Species in Plants

Membrane transporters are proteins that mediate the entry and exit of substances through the plasma membrane and organellar membranes and are capable of recognizing and binding to specific substances, thereby facilitating substance transport. Membrane transporters are divided into different types, e.g., ion transporters, sugar transporters, amino acid transporters, and aquaporins, based on the substances they transport. These membrane transporters inhibit reactive oxygen species (ROS) generation through ion regulation, sugar and amino acid transport, hormone induction, and other mechanisms. They can also promote enzymatic and nonenzymatic reactions in plants, activate antioxidant enzyme activity, and promote ROS scavenging. Moreover, membrane transporters can transport plant growth regulators, solute proteins, redox potential regulators, and other substances involved in ROS metabolism through corresponding metabolic pathways, ultimately achieving ROS homeostasis in plants. In turn, ROS, as signaling molecules, can affect the activity of membrane transporters under abiotic stress through collaboration with ions and involvement in hormone metabolic pathways. The research described in this review provides a theoretical basis for improving plant stress resistance, promoting plant growth and development, and breeding high-quality plant varieties.

Cytokinin deficiency confers enhanced tolerance to mild, but decreased tolerance to severe salinity stress in in vitro grown potato

Cytokinin (CK) is a plant hormone that plays crucial roles in regulating plant growth and development. CK-deficient plants are widely used as model systems for investigating the numerous physiological roles of CK. Since it was previously shown that transgenic or mutant CK-deficient Arabidopsis and Centaurium plants show superior tolerance to salinity, we examined the tolerance of three CK-deficient potato lines overexpressing the Arabidopsis thaliana CYTOKININ OXIDASE/DEHYDROGENASE2 (AtCKX2) gene to 50 mM, 100 mM, 150 mM, and 200 mM NaCl applied in vitro. Quantification of visible salinity injury, rooting and acclimatization efficiency, shoot growth, water saturation deficit, and chlorophyll content confirmed that the CK-deficient potato plants were more tolerant to low (50 mM) and moderate (100 mM) NaCl concentrations, but exhibited increased sensitivity to severe salinity stress (150 and 200 mM NaCl) compared to non-transformed control plants. These findings were corroborated by the data distribution patterns according to principal component analysis. Quantification of the activity of superoxide dismutases, peroxidases, and catalases revealed an impaired ability of AtCKX2-transgenic lines to upregulate the activity of antioxidant enzymes in response to salinity, which might contribute to the enhanced sensitivity of these potato lines to severe salt stress. Our results add complexity to the existing knowledge on the regulation of salinity tolerance by CK, as we show for the first time that CK-deficient plants can exhibit reduced rather than increased tolerance to severe salt stress.

In-vivo and in-silico studies to identify toxicity mechanisms of permethrin with the toxicity-reducing role of ginger

In this study, the toxic effects of permethrin on Allium cepa L. and the protective role of Zingiber officinale rhizome extract (Zoex) were investigated. In this context, 6 different groups were formed. While the control group was treated with tap water, the groups II and III were treated with 10 µg/mL and 20 µg/mL Zoex, respectively, and the group IV was treated with 100 µg/L permethrin. The protective effect of Zoex against permethrin toxicity was studied as a function of dose, and groups V and VI formed for this purpose were treated with 10 µg/mL Zoex + 100 µg/L permethrin and 20 µg/mL Zoex + 100 µg/L permethrin, respectively. After 72 h of germination, cytogenetic, biochemical, physiological, and anatomical changes in meristematic cells of A. cepa were studied. As a result, permethrin application decreased the mitotic index (MI) and increased the frequency of micronuclei (MN), and chromosomal abnormalities. The increase in malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) and the decrease in glutathione (GSH) indicate that permethrin causes oxidative damage. Compared to the control group, a 68.5% decrease in root elongation (p < 0.05) and an 81.8% decrease (p < 0.05) in weight gain were observed in the permethrin-treated group. It was found that the application of Zoex together with permethrin resulted in regression of all detected abnormalities, reduction in the incidence of anatomical damage, MN and chromosomal aberrations, and improvement in MI rates. The most significant improvement was observed in group VI treated with 20 µg/mL Zoex, and Zoex was also found to provide dose-dependent protection. The toxicity mechanism of permethrin was also elucidated by molecular docking and spectral studies. From the data obtained during the study, it was found that permethrin has toxic effects on A. cepa, a non-target organism, while Zoex plays a protective role by reducing these effects.

Selenium nanoparticles improved biochemical and physiological properties and antioxidant systems of savoury under drought stress

To investigate the effectiveness of selenium (Se) and Se nanoparticles (Se-NPs) in improving biochemical and physiological characteristics of savoury in drought stress conditions, a factorial experiment based on the completely randomised design with three replications was used. Results demonstrate that Se-NPs considerably enhanced several biochemical parameters, such as relative water content (RWC), antioxidant enzymes activity, and total soluble protein in drought and normal conditions. At the stress level from 100 to 40% of field capacity, a gradual decrease in chlorophyll and CARs contents was observed and under stress and normal conditions, the application of Se-NPs (10 mg L-1) led to an increase in the content of pigments. Total soluble protein, total phenolic and flavonoid contents showed significant increases in plants treated with Se-NPs under drought stress. Generally, the use of Se-NPs in drought stress conditions can be effective in improving the growth, biochemical, and physiological characteristics of savoury.

Leptolyngbya sp. XZMQ and Bacillus XZM co-inoculation reduced sunflower arsenic toxicity by regulating rhizosphere microbial structure and enzyme activity

Microorganisms are of great significance for arsenic (As) toxicity amelioration in plants as soil fertility is directly affected by microbes. In this study, we innovatively explored the effects of indigenous cyanobacteria (Leptolyngbya sp. XZMQ) and plant growth-promoting bacteria (PGPB) (Bacillus XZM) on the growth and As absorption of sunflower plants from As-contaminated soil. Results showed that single inoculation and co-inoculation stimulated the growth of sunflower plants (Helianthus annuus L.), enhanced enzyme activities, and reduced As contents. In comparison to the control group, single innoculation of microalgae and bacteria in the rhizosphere increased extracellular polymeric substances (EPS) by 21.99% and 14.36%, respectively, whereas co-inoculation increased them by 35%. Compared with the non-inoculated group, As concentration in the roots, stems and leaves of sunflower plants decreased by 38%, 70% and 41%, respectively, under co-inoculation conditions. Inoculation of Leptolyngbya sp. XZMQ significantly increased the abundance of nifH in soil, while co-inoculation of cyanobacteria and Bacillus XZM significantly increased the abundance of cbbL, indicating that the coupling of Leptolyngbya sp. XZMQ and Bacillus XZM could stimulate the activity of nitrogen-fixing and carbon-fixing microorganisms and increased soil fertility. Moreover, this co-inoculation increased the enzyme activities (catalase, sucrase, urease) in the rhizosphere soil of sunflower and reduced the toxic effect of As on plant. Among these, the activities of catalase, peroxidase, and superoxide dismutase decreased. Meanwhile, co-inoculation enables cyanobacteria and bacteria to attach and entangle in the root area of the plant and develop as symbiotic association, which reduced As toxicity. Co-inoculation increased the abundance of aioA, arrA, arsC, and arsM genes in soil, especially the abundance of microorganisms with aioA and arsM, which reduced the mobility and bioavailability of As in soil, hence, reduced the absorption of As by plants. This study provides a theoretical basis for soil microbial remediation in mining areas.

Toxicity of ZnFe-SO4 layered double hydroxide in Tetradesmus obliquus and evaluation of some physiological responses of the microalgae for stress management

Layered double hydroxides (LDHs), regarding their physical and structural properties, have different and wide applications industry and their increasing use may raise ecological and human health concerns. However, the potential toxicity mechanisms of LDHs in different organisms are still unclear. In the present work, after synthesizing of ZnFe-SO4 LDH and studying of its characterization by XRD, FT-IR, SEM, EDX-mapping, TEM and Raman, its toxicity in Tetradesmus obliquus was evaluated. According to experimental results, the growth of the algae and content of photosynthetic pigments were significantly decreased after treatment with 100 mg/L of ZnFe-SO4 LDH. The high dose exposure to the LDH also inhibited the activity of SOD and POD enzymes, possibly due to the LDH- catalyzed reactive oxygen species production. In addition, lipid peroxidation and the content of phenolic compounds, as no-enzymatic antioxidants were increased by enhancement of the LDH concentration. The rise of phenol, flavonoids and MDA contents could be regarded as some manifestations and responses to the toxic effects of the contaminant in the algae cells. The results provided a better understanding of the undesirable effects and toxicity of LDHs in aquatic organisms.

Silicon and arbuscular mycorrhizal fungi alleviate chromium toxicity in Brassica rapa by regulating Cr uptake, antioxidant defense expression, the glyoxalase system, and secondary metabolites

The potential contribution of silicon (Si) (300 mg kg-1 potash silica) or arbuscular mycorrhizal fungi (AMF) (Rhizophagus irregularis) to reduce chromium toxicity (Cr; 0 and 300 mg kg-1) in Brassica rapa was examined in this work. Under Cr stress, Si and AMF were used separately and in combination (no Si, or AMF, Si, AMF, and Si + AMF). Brassica rapa growth, colonization, photosynthesis, and physio-biochemical characteristics decreased under Cr stress. Oxidative stress was a side effect of Cr stress and was associated with high levels of methylglyoxal (MG), hydrogen peroxide (H2O2), lipid peroxidation (MDA), and maximum lipoxygenase activity (LOX). On the other hand, quantitative real-time PCR analyses of gene expression showed that under Cr stress, the expression of genes for secondary metabolites and antioxidant enzymes was higher than that under the control. The co-application of Si and AMF activated the plant defense system by improving the antioxidative enzymes activities, the potassium citrate and glutathione pool, the glyoxalase system, metabolites, and genes encoding these enzymes under Cr stress. Under the influence of Cr stress, oxidative stress was reduced by the coordinated control of the antioxidant and glyoxalase systems. However, the restricted Cr uptake and root and shoot accumulation of Si and AMF co-applied to only Cr-stressed plants was more significant. In summary, Si and AMF applied together successfully counteract the deleterious effects of Cr stress and restore growth and physio-biochemical characteristics. As a result, the beneficial effects of the combined Si and AMF application may be attributed to mycorrhizae-mediated enhanced Si absorption and metal resistance.

Unraveling lipid peroxidation-mediated regulation of redox homeostasis for sustaining plant health

Lipid peroxidation (LPO) is a complex process that, depending on the context, can either result in oxidative injury or promote redox homeostasis. LPO is a series of reactions in which polyunsaturated fatty acids are attacked by free radicals that result in the synthesis of lipid peroxides. LPO can alter membrane fluidity and operation and produce secondary products that amplify oxidative stress. LPO can activate cellular signaling pathways that promote antioxidant defense mechanisms that provide oxidative stress protection by elevating antioxidant enzyme action potentials. Enzymatic and nonenzymatic mechanisms tightly regulate LPO to prevent excessive LPO and its adverse consequences. This article emphasizes the dual nature of LPO as a mechanism that can both damage cells and regulate redox homeostasis. In addition, it also highlights the major enzymatic and nonenzymatic mechanisms that tightly regulate LPO to prevent excessive oxidative damage. More importantly, it emphasizes the importance of understanding the cellular and biochemical complexity of LPO for developing strategies targeting this process for efficient management of plant stress.

VvATG6 contributes to copper stress tolerance by enhancing the antioxidant ability in transgenic grape calli

Autophagy, a conserved degradation and reuse process, plays a crucial role in plant cellular homeostasis during abiotic stress. Although numerous autophagy-related genes (ATGs) that regulate abiotic stress have been identified, few functional studies have shown how they confer tolerance to copper (Cu) stress. Here, we cloned a novel Vitis vinifera ATG6 gene (VvATG6) which was induced by 0.5 and 10 mM Cu stress based on transcriptomic data, and transgenic Arabidopsis thaliana, tobacco (Nicotiana tabacum), and grape calli were successfully obtained through Agrobacterium-mediated genetic transformation. The overexpression of VvATG6 enhanced the tolerance of transgenic lines to Cu. After Cu treatment, the lines that overexpressed VvATG6 grew better and increased their production of biomass compared with the wild-type. These changes were accompanied by higher activities of antioxidant enzymes and a lower accumulation of deleterious malondialdehyde and hydrogen peroxide in the transgenic plants. The activities of superoxide dismutase, peroxidase, and catalase were enhanced owing to the elevation of corresponding antioxidant gene expression in the VvATG6 overexpression plants under Cu stress, thereby promoting the clearance of reactive oxygen species (ROS). Simultaneously, there was a decrease in the levels of expression of RbohB and RbohC that are involved in ROS synthesis in transgenic plants under Cu stress. Thus, the accelerated removal of ROS and the inhibition of its synthesis led to a balanced ROS homeostasis environment, which alleviated the damage from Cu. This could benefit from the upregulation of other ATGs that are necessary for the production of autophagosomes under Cu stress. To our knowledge, this study is the first to demonstrate the protective role of VvATG6 in the Cu tolerance of plants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-024-01415-y.

Consequences of excess urea application on photosynthetic characteristics and nitrogen metabolism of Robinia pseudoacacia seedlings

Urea is the most frequently used nitrogen (N) fertilizer worldwide. However, the mechanisms in plants to cope with excess urea are largely unknown, especially for woody legumes that can meet their N demand by their own N2-fixation capacity. Here, we studied the immediate consequences of different amounts of urea application and exposure duration on photosynthesis, N metabolism, and the activity of antioxidative enzymes of Robinia pseudoacacia seedlings. For this purpose, seedlings were grown for 3 months under normal N availability with rhizobia inoculation and, subsequently, 50 mg N kg-1 was applied to the soil twice with urea as additional N source. Our results show that excess urea application significantly promoted photosynthesis, which increased by 80.3% and 84.7% compared with CK after the 1st and 2nd urea applications, respectively. The increase in photosynthesis translated into an increase in root and nodule biomass of 88.7% and 82.0%, respectively, while leaf biomass decreased by 4.8% after the first application of urea. The N content in leaves was 92.6% higher than in roots, but excess urea application increased the N content of protein and free amino acids in roots by 25.0%, and 43.3%, respectively. Apparently, enhanced root growth and N storage in the roots constitute mechanisms to prevent the negative consequences of excess N in the shoot upon urea application. Nitrate reductase (NR) activity of leaves and roots increased by 74.4% and 26.3%, respectively. Glutathione reductase (GR) activity in leaves and roots was enhanced by 337% and 34.0%, respectively, but then decreased rapidly to the initial level before fertilization. This result shows that not only N metabolism, but also antioxidative capacity was transiently promoted by excess urea application. Apparently, excess urea application initially poses oxidative stress to the plants that is immediately counteracted by enhanced scavenging of reactive oxygen species via enhanced GR activity.

Extracellular Self- and Non-Self DNA Involved in Damage Recognition in the Mistletoe Parasitism of Mesquite Trees

Psittacanthus calyculatus parasitizes mesquite trees through a specialized structure called a haustorium, which, in the intrusive process, can cause cellular damage in the host tree and release DAMPs, such as ATP, sugars, RNA, and DNA. These are highly conserved molecules that primarily function as signals that trigger and activate the defense responses. In the present study, we generate extracellular DNA (exDNA) from mesquite (P. laevigata) tree leaves (self-exDNA) and P. calyculatus (non-self exDNA) mistletoe as DAMP sources to examine mesquite trees' capacity to identify specific self or non-self exDNA. We determined that mesquite trees perceive self- and non-self exDNA with the synthesis of O2•-, H2O2, flavonoids, ROS-enzymes system, MAPKs activation, spatial concentrations of JA, SA, ABA, and CKs, and auxins. Our data indicate that self and non-self exDNA application differs in oxidative burst, JA signaling, MAPK gene expression, and scavenger systems. This is the first study to examine the molecular biochemistry effects in a host tree using exDNA sources derived from a mistletoe.

Long term effects of ionising radiation in the Chernobyl Exclusion zone on DNA integrity and chemical defence systems of Scots pine (Pinus sylvestris)

The Chernobyl Nuclear Power Plant (ChNPP) accident in 1986 resulted in extremely high levels of acute ionising radiation, that killed or damaged Scots pine (Pinus sylvestris) trees in the surrounding areas. Dead trees were cleared and buried, and new plantations established a few years later. Today, more than three decades later, gamma and beta-radiation near the ChNPP is still elevated compared with ambient levels but have decreased by a factor of 300 and 100, respectively. In the present work, Scots pine-trees growing at High (220 μGy h-1), Medium (11 μGy h-1), and Low (0.2 μGy h-1) total (internal + external) dose rates of chronically elevated ionising radiation in the Chernobyl Exclusion zone were investigated with respect to possible damage to DNA, cells and organelles, as well as potentially increased levels of phenolic and terpenoid antioxidants. Scots pine from the High and Medium radiation sites had elevated levels of DNA damage in shoot tips and needles as shown by the COMET assay, as well as increased numbers of resin ducts and subcellular abnormalities in needles. Needles from the High radiation site showed elevated levels of monoterpenes and condensed tannins compared with those from the other sites. In conclusion, more than three decades after the ChNPP accident substantial DNA damage and (sub)cellular effects, but also mobilisation of stress-protective substances possessing antioxidant activity were observed in Scots pine trees growing at elevated levels of ionising radiation. This demonstrates that the radiation levels in the Red Forest still significantly impact the plant community.

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.

Caffeine Produced in Rice Plants Provides Tolerance to Water-Deficit Stress

Exogenous or endogenous caffeine application confers resistance to diverse biotic stresses in plants. In this study, we demonstrate that endogenous caffeine in caffeine-producing rice (CPR) increases tolerance even to abiotic stresses such as water deficit. Caffeine produced by CPR plants influences the cytosolic Ca2+ ion concentration gradient. We focused on examining the expression of Ca2+-dependent protein kinase genes, a subset of the numerous proteins engaged in abiotic stress signaling. Under normal conditions, CPR plants exhibited increased expressions of seven OsCPKs (OsCPK10, OsCPK12, OsCPK21, OsCPK25, OsCPK26, OsCPK30, and OsCPK31) and biochemical modifications, including antioxidant enzyme (superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase) activity and non-enzymatic antioxidant (ascorbic acid) content. CPR plants exhibited more pronounced gene expression changes and biochemical alterations in response to water-deficit stress. CPR plants revealed increased expressions of 16 OsCPKs (OsCPK1, OsCPK2, OsCPK3, OsCPK4, OsCPK5, OsCPK6, OsCPK9, OsCPK10, OsCPK11, OsCPK12, OsCPK14, OsCPK16, OsCPK18, OsCPK22, OsCPK24, and OsCPK25) and 8 genes (OsbZIP72, OsLEA25, OsNHX1, OsRab16d, OsDREB2B, OsNAC45, OsP5CS, and OsRSUS1) encoding factors related to abiotic stress tolerance. The activity of antioxidant enzymes increased, and non-enzymatic antioxidants accumulated. In addition, a decrease in reactive oxygen species, an accumulation of malondialdehyde, and physiological alterations such as the inhibition of chlorophyll degradation and the protection of photosynthetic machinery were observed. Our results suggest that caffeine is a natural chemical that increases the potential ability of rice to cope with water-deficit stress and provides robust resistance by activating a rapid and comprehensive resistance mechanism in the case of water-deficit stress. The discovery, furthermore, presents a new approach for enhancing crop tolerance to abiotic stress, including water deficit, via the utilization of a specific natural agent.

The pesticide thiamethoxam induced toxicity in Brassica juncea and its detoxification by Pseudomonas putida through biochemical and molecular modifications

Insecticides are extensively exploited by humans to destroy the pests one such compound thiamethoxam is widely used over crops to offer control over wide-array of sucking insect pests. The present study unravels the detoxification potential of Pseudomonas putida in thiamethoxam exposed B. juncea seedlings. The thiamethoxam application curtailed the fresh weight, dry weight and seedling length by 106.22%, 80.29% and 116.78% while P. putida revived these growth parameters in thiamethoxam exposed B. juncea seedlings by 59.65%, 72.99% and 164.56% respectively. The exogenous supplementation of P. putida resuscitated the photosynthetic efficiency of B. juncea seedlings exposed to thiamethoxam as total chlorophyll, chlorophyll a, chlorophyll b, carotenoid, flavonoid and anthocyanin contents were enhanced by 169.42%, 62.90%, 72.89%, 78.53%, 47.36% and 515.15% respectively in contrast to TMX exposed seedlings. Further, P. putida pre-treatment reinvigorated the osmoprotectant content in B. juncea seedlings grown in thiamethoxam as trehalose, glycine betaine and proline contents were thrusted by 21.20%, 58.98% and 34.26% respectively. The thiamethoxam exposure exorbitated the superoxide anion, hydrogen peroxide and MDA levels by 223.03%, 130.18% and 74.63% while P. putida supplementation slackened these oxidative burst levels by 41.75%, 3.79% and 29.09% respectively in thiamethoxam treated seedlings. Notably, P. putida inoculation in thiamethoxam exposed seedlings upregulated the enzymatic antioxidant and non-enzymatic antioxidant activities as SOD, CAT and glutathione were enhanced by 163.76%, 99.29% and 114.91% respectively in contrast to thiamethoxam treated seedlings. The gene expression analysis exhibited the negative impact of thiamethoxam on B. juncea seedlings as conferred by upregulation of chlorophyllase by 443.86 folds whereas P. putida application in thiamethoxam exposed seedlings downregulated the chlorophyllase expression by 248.73 folds and upregulated CXE, GST, NADH and POD genes by 0.44, 4.07, 1.43 and 0.98 folds respectively suggesting the molecular-level thiamethoxam detoxification efficiency of P. putida.

Synergistic action of Pseudomonas fluorescens with melatonin attenuates salt toxicity in mustard by regulating antioxidant system and flavonoid profile

Salt stress is an alarming abiotic stress that reduces mustard growth and yield. To attenuate salt toxicity effects, plant growth-promoting rhizobacteria (PGPR) offers a sustainable approach. Among the various PGPR, Pseudomonas fluorescens (P. fluorescens NAIMCC-B-00340) was chosen for its salt tolerance (at 100 mM NaCl) and for exhibiting various growth-promoting activities. Notably, P. fluorescens can produce auxin, which plays a role in melatonin (MT) synthesis. Melatonin is a pleiotropic molecule that acts as an antioxidant to scavenge reactive oxygen species (ROS), resulting in stress reduction. Owing to the individual role of PGPR and MT in salt tolerance, and their casual nexus, their domino effect was investigated in Indian mustard under salt stress. The synergistic action of P. fluorescens and MT under salt stress conditions was found to enhance the activity of antioxidative enzymes and proline content as well as  promote the production of secondary metabolites. This led to reduced oxidative stress following effective ROS scavenging, maintained photosynthesis, and improved growth. In mustard plants treated with MT and P. fluorescens under salt stress, eight flavonoids showed significant increase. Kaempferol and cyanidin showed the highest concentrations and are reported to act as antioxidants with protective functions under stress. Thus, we can anticipate that strategies involved in their enhancement could provide a better adaptive solution to salt toxicity in mustard plants. In conclusion, the combination of P. fluorescens and MT affected antioxidant metabolism and flavonoid profile that could be used to mitigate salt-induced stress and bolster plant resilience.

Salinity alleviates arsenic stress-induced oxidative damage via antioxidative defense and metabolic adjustment in the root of the halophyte Salvadora persica

MAIN CONCLUSION

Arsenic tolerance in the halophyte Salvadora persica is achieved by enhancing antioxidative defense and modulations of various groups of metabolites like amino acids, organic acids, sugars, sugar alcohols, and phytohormones. Salvadora persica is a facultative halophyte that thrives under high saline and arid regions of the world. In present study, we examine root metabolic responses of S. persica exposed to individual effects of high salinity (750 mM NaCl), arsenic (600 µM As), and combined treatment of salinity and arsenic (250 mM NaCl + 600 µM As) to decipher its As and salinity resistance mechanism. Our results demonstrated that NaCl supplementation reduced the levels of reactive oxygen species (ROS) under As stress. The increased activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR) maintained appropriate levels of ROS [superoxide (O2•-) and hydrogen peroxide (H2O2)] under salinity and/or As stress. The metabolites like sugars, amino acids, polyphenols, and organic acids exhibited higher accumulations when salt was supplied with As. Furthermore, comparatively higher accumulations of glycine, glutamate, and cystine under combined stress of salt and As may indicate its role in glutathione and phytochelatins (PCs) synthesis in root. The levels of phytohormones such as salicylate, jasmonate, abscisic acid, and auxins were significantly increased under high As with and without salinity stress. The amino acid metabolism, glutathione metabolism, carbohydrate metabolism, tricarboxylic acid cycle (TCA cycle), phenylpropanoid biosynthesis, and phenylalanine metabolism are the most significantly altered metabolic pathways in response to NaCl and/or As stress. Our study decoded the important metabolites and metabolic pathways involved in As and/or salinity tolerance in root of the halophyte S. persica providing clues for development of salinity and As resistance crops.

Nanoparticles regulate redox metabolism in plants during abiotic stress within hormetic boundaries

Abiotic stress management remains under scrutiny because of the unpredictable nature of climate, which undergoes abrupt alterations. Population pressure, loss of cultivable lands, environmental pollution and other anthropogenic disturbances add to the problem and grossly hinder ongoing management strategies. This has driven increasing effort to find better performing, eco-friendly and reliable alternatives that can contribute to sustainable agricultural practices to manage abiotic stress. Nanotechnology and its implementation in agriculture have emerged as a promising option to cater to the problem of abiotic stress. Induction of reactive oxygen species (ROS) is an inevitable phenomenon linked to stress. Nanoparticles (NPs) perform dual actions in regulating ROS biology. The bidirectional roles of NPs in modulating ROS generation and/or ROS detoxification is tightly coupled within the hormetic boundaries. Nonetheless, how these NPs control the ROS metabolism within hormetic limits demands extensive investigation. This review focuses on the details of ROS metabolism under normal versus stressed conditions. It shall elaborate on the types, modes and process of uptake and translocation of NPs. The molecular dissection of the role of NPs in controlling transcriptomic expressions and modulating molecular crosstalks with other growth regulators, ions, reactive nitrogen species and other signalling molecules shall also be detailed. Throughout, this review aims to summarise the potential roles and regulation of NPs and consider how they can be used for green synthesis within a sustainable agricultural industry.

Investigating the response mechanisms of bread wheat mutants to salt stress

Mutation breeding is among the most critical approaches to promoting genetic diversity when genetic diversity is narrowed for a long time using traditional breeding methods. In the current study, 15 wheat mutants created by gamma radiation and three salt-tolerant wheat cultivars were studied under no salinity stress (Karaj) and salinity stress (Yazd) during three consecutive growing seasons from 2017 to 2020 (M05 to M07 generations mutants). Results showed that salinity induced lipid peroxidation and enhanced ion leakage in all genotypes however, M6 and M15 showed the least ion leakage increment. It was also observed that the activity of antioxidant enzymes including SOD, CAT, POX, APX and GR increased with salinity; the maximum increase in antioxidant activity was belonged to M15, M09, M06 and M05. All genotypes had higher protein content in salinity stress conditions; M07 and M12 showed the lowest (1.8%) and the highest (17.3%) protein increase, respectively. Zeleny sedimentation volume increased under salinity stress conditions in all genotypes except M06, C2, C3, and M07. The result indicated that salinity stress increased wet gluten in all genotypes. M10 and M08 showed the highest (47.8%) and the lowest (4%) wet gluten increment, respectively. M06 and M11 mutants showed the lowest (6.1%) and the highest (60.7%) decrement of grain yield due to salinity stress, respectively. Finally, M04, M05, M07, M13, and M14 were known as genotypes with high grain yield in both no salinity and salinity stress conditions. In other word, these genotypes have higher yield stability. The results of the current study revealed that gamma irradiation could effectively be used to induce salinity tolerance in wheat.

Multi-level biological effects of diverse alkyl chains phthalate esters on cotton seedlings (Gossypium hirsutum L.): Insights into individual, physiological-biochemical and molecular perspectives

Phthalate esters (PAEs) are organic contaminants that pose environmental threat and safety risks to soil health and crop production. However, the ecological toxicity of different PAEs to cotton and the underlying mechanisms are not clear. This study investigated the ecotoxic effects and potential mechanisms of different alkyl-chain PAEs, including dioctyl phthalate (DOP), dibutyl phthalate (DBP), and diethyl phthalate (DEP) on cotton seedlings at multiple levels. The results showed that PAEs significantly hindered the growth and development of cotton. The chlorophyll content decreased by 1.87-31.66 %, accompanied by non-stomatal photosynthetic inhibition. The antioxidant system was activated by the three PAEs in cotton seedlings, while the osmotic potential was boosted intracellularly. Additionally, PAEs significantly interfered with functional gene expression and exhibited genotoxicity. Risk assessment results indicated that the ecotoxicity was DOP >DBP >DEP, with a "dose-response" relationship. The affinity between the three PAEs and catalase increased as the alkyl chain length increased, further supporting the toxicity sequence. Surprisingly, the bioconcentration factors of short-chain DEP were 8.07 ± 5.89 times and 1837.49 ± 826.83 times higher than those of long-chain DBP and DOP, respectively. These results support the ecological risk assessment of PAEs in cotton and provide new insights into determining the toxicity levels of different PAEs.

ROS interplay between plant growth and stress biology: Challenges and future perspectives

In plants, reactive oxygen species (ROS) have emerged as a multifunctional signaling molecules that modulate diverse stress and growth responses. Earlier studies on ROS in plants primarily focused on its toxicity and ROS-scavenging processes, but recent findings are offering new insights on its role in signal perception and transduction. Further, the interaction of cell wall receptors, calcium channels, HATPase, protein kinases, and hormones with NADPH oxidases (respiratory burst oxidase homologues (RBOHs), provides concrete evidence that ROS regulates major signaling cascades in different cellular compartments related to stress and growth responses. However, at the molecular level there are many knowledge gaps regarding how these players influence ROS signaling and how ROS regulate them during growth and stress events. Furthermore, little is known about how plant sensors or receptors detect ROS under various environmental stresses and induce subsequent signaling cascades. In light of this, we provided an update on the role of ROS signaling in plant growth and stress biology. First, we focused on ROS signaling, its production and regulation by cell wall receptor like kinases. Next, we discussed the interplay between ROS, calcium and hormones, which forms a major signaling trio regulatory network of signal perception and transduction. We also provided an overview on ROS and nitric oxide (NO) crosstalk. Furthermore, we emphasized the function of ROS signaling in biotic, abiotic and mechanical stresses, as well as in plant growth and development. Finally, we conclude by highlighting challenges and future perspectives of ROS signaling in plants that warrants future investigation.

Transcriptomic and genetic approaches reveal that low-light-induced disease susceptibility is related to cellular oxidative stress in tomato

The impact of low light intensities on plant disease outbreaks represents a major challenge for global crop security, as it frequently results in significant yield losses. However, the underlying mechanisms of the effect of low light on plant defense are still poorly understood. Here, using an RNA-seq approach, we found that the susceptibility of tomato to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) under low light was associated with the oxidation-reduction process. Low light conditions exacerbated Pst DC3000-induced reactive oxygen species (ROS) accumulation and protein oxidation. Analysis of gene expression and enzyme activity of ascorbate peroxidase 2 (APX2) and other antioxidant enzymes revealed that these defense responses were significantly induced by Pst DC3000 inoculation under normal light, whereas these genes and their associated enzyme activities were not responsive to pathogen inoculation under low light. Additionally, the reduced ascorbate to dehydroascorbate (AsA/DHA) ratio was lower under low light compared with normal light conditions upon Pst DC3000 inoculation. Furthermore, the apx2 mutants generated by a CRISPR-Cas9 gene-editing approach were more susceptible to Pst DC3000 under low light conditions. Notably, this increased susceptibility could be significantly reduced by exogenous AsA treatment. Collectively, our findings suggest that low-light-induced disease susceptibility is associated with increased cellular oxidative stress in tomato plants. This study sheds light on the intricate relationship between light conditions, oxidative stress, and plant defense responses, and may pave the way for improved crop protection strategies in low light environments.

Physiological and Cellular Ultrastructural Responses of Sesuvium portulacastrum under Cd Stress Grown Hydroponically

This study aimed to investigate the physiological and cellular mechanisms of Sesuvium portulacastrum under heavy metal stress to evaluate possible tolerance and adaptation mechanisms in a metal-polluted environment. The physiological and cellular ultrastructural responses of S. portulacastrum were studied hydroponically under exposure to a range of cadmium (Cd) concentrations (50 µM to 600 µM) for 28 days. The activity of antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), changes in chlorophyll, and cellular ultrastructural content were examined. There was no significant difference in chlorophyll content in the leaf under the stress of 300 μM, but 400 μM and 600 μM Cd stress showed significantly decreased chlorophyll content. The SOD activity indicates an increase under the Cd stress of 100 μM for leaves, 300 μM for stems, and 50 μM for roots; after that, the SOD activity gradually decreased with increasing Cd concentrations. But POD activity was considerably increased with increasing Cd stress. CAT activity showed a gradual increase in concentrations until 300 μM of Cd stress and then decreased sharply in roots, stems, and leaf tissues. Cd stress had a considerable impact on the structure of the roots, stems, and leaves cells, such as distorted and thinner cell walls and the deformation of chloroplasts, mitochondria, and other organelles. Therefore, the increased number of nucleolus in the cell nucleus suggests that cells may be able to maintain their protein synthesis in a stressful environment. This study concludes that SOD is the dominant antioxidant enzyme activity during low Cd toxicity (<100 μM), while POD is the dominant enzyme activity during higher Cd toxicity (>100 μM).

Effects of hydrogen sulfide on the growth and physiological characteristics of Miscanthus sacchariflorus seedlings under cadmium stress

As a gas signal molecule, hydrogen sulfide (H2S) can participate in many physiological and biochemical processes such as seed germination and photosynthesis regulation. In order to explore the regulatory effect of H2S on the growth of Miscanthus sacchariflorus under Cd stress and to provide sufficient theoretical basis for the complex action of H2S and energy plants to remediate soil pollution. In this experiment, the effects of different concentrations of H2S (10, 25, 50, 100, 300, 400, 500 μmol·L-1 (μM)) pretreatment on the growth index, lipid peroxidation degree, chlorophyll (Chl) content, osmoregulation substance content, antioxidant enzyme activity and non-enzymatic antioxidant content of M. sacchariflorus under Cd stress (50 μM) were studied. The results showed that under Cd stress, the reactive oxygen species (ROS) content in the body of M. sacchariflorus was unbalanced, and the growth were severely inhibited, the activities of antioxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD) significantly decreased, and the content of osmoregulation substance, ascorbic acid (AsA) and glutathione (GSH) significantly increased. With the increase of H2S concentration, its effect on resisting Cd stress can be shown as "low concentration promotes, high concentration inhibits". When the concentration of H2S ≤ 300 μM, although there was no significant difference in Cd content compared with Cd treatment alone, it can regulate the activities of peroxidase (POD), SOD, glutathione reductase (GR) and monodehydroascorbate reductase (MDHAR), increase the content of osmoregulation substances, oxidized glutathione (GSSG), and the transformation rate of AsA and dehydroascorbic acid (DHA) to reduce the oxidative damage and improve the growth and photosynthetic indicators of plants; when the concentration of H2S ≥ 400 μM, Cd content in the ground and root decreased significantly, but the transport factor increased significantly, the growth status of M. sacchariflorus were more severely inhibited by the combined stress of H2S and Cd. In this experiment, it was found that the concentration of H2S pretreatment ≤ 300 μM could regulate the growth of M. sacchariflorus under Cd stress to normal level, and when the treatment concentration was 50 μM, the effect was the best. It will provide a new idea for the treatment of contaminated soil by energy plants.

Impacts of salinity stress on crop plants: improving salt tolerance through genetic and molecular dissection

Improper use of water resources in irrigation that contain a significant amount of salts, faulty agronomic practices such as improper fertilization, climate change etc. are gradually increasing soil salinity of arable lands across the globe. It is one of the major abiotic factors that inhibits overall plant growth through ionic imbalance, osmotic stress, oxidative stress, and reduced nutrient uptake. Plants have evolved with several adaptation strategies at morphological and molecular levels to withstand salinity stress. Among various approaches, harnessing the crop genetic variability across different genepools and developing salinity tolerant crop plants offer the most sustainable way of salt stress mitigation. Some important major genetic determinants controlling salinity tolerance have been uncovered using classical genetic approaches. However, its complex inheritance pattern makes breeding for salinity tolerance challenging. Subsequently, advances in sequence based breeding approaches and functional genomics have greatly assisted in underpinning novel genetic variants controlling salinity tolerance in plants at the whole genome level. This current review aims to shed light on physiological, biochemical, and molecular responses under salt stress, defense mechanisms of plants, underlying genetics of salt tolerance through bi-parental QTL mapping and Genome Wide Association Studies, and implication of Genomic Selection to breed salt tolerant lines.

Global transcriptome profiling reveals root- and leaf-specific responses of barley (Hordeum vulgare L.) to H2O2

In cereal crops, such as barley (Hordeum vulgare L.), the ability to appropriately respond to environmental cues is an important factor for yield stability and thus for agricultural production. Reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), are key components of signal transduction cascades involved in plant adaptation to changing environmental conditions. H2O2-mediated stress responses include the modulation of expression of stress-responsive genes required to cope with different abiotic and biotic stresses. Despite its importance, knowledge of the effects of H2O2 on the barley transcriptome is still scarce. In this study, we identified global transcriptomic changes induced after application of 10 mM H2O2 to five-day-old barley plants. In total, 1883 and 1001 differentially expressed genes (DEGs) were identified in roots and leaves, respectively. Most of these DEGs were organ-specific, with only 209 DEGs commonly regulated and 37 counter-regulated between both plant parts. A GO term analysis further confirmed that different processes were affected in roots and leaves. It revealed that DEGs in leaves mostly comprised genes associated with hormone signaling, response to H2O2 and abiotic stresses. This includes many transcriptions factors and small heat shock proteins. DEGs in roots mostly comprised genes linked to crucial aspects of H2O2 catabolism and oxidant detoxification, glutathione metabolism, as well as cell wall modulation. These categories include many peroxidases and glutathione transferases. As with leaves, the H2O2 response category in roots contains small heat shock proteins, however, mostly different members of this family were affected and they were all regulated in the opposite direction in the two plant parts. Validation of the expression of the selected commonly regulated DEGs by qRT-PCR was consistent with the RNA-seq data. The data obtained in this study provide an insight into the molecular mechanisms of oxidative stress responses in barley, which might also play a role upon other stresses that induce oxidative bursts.