Non-enzymatic Defense Systems Research Articles

Yield and quality of saffron (Crocus sativus L.) in response to priming treatments and water deficit

Despite being the most expensive spice, saffron is generally exposed to drought stress during its life cycle. The application of some effective compounds in the plants, can make it strong against environmental stresses such as water deficit. Therefore, the effect of saffron corm priming on the quantitative, qualitative, and physiological responses of this crop under drought stress was investigated in a split-plot experiment as a randomized complete block design with three replicates in two experimental years, 2022 and 2023. The treatments of the on-field experiment included 50 % Field capacity (FC) (equal to 2500 m3ha−1) and 70 % FC (equal to 3800 m3 ha−1) as the main plot and pretreatments (Corm priming) at six levels of KNO3 (3:1000), Indole-3-acetic acid (1 mg l−1), Gibberellin (300 ppm), Silicon dioxide nanoparticles (100 ppm), Hydro-priming (distilled water) and non-priming (control) as sub-plots. The results revealed the increase of petal and stigma dry weights with the application of IAA priming agents under 70 % FC irrigation as compared to 50 % FC. Based on the findings, the petal dry weights decreased, under 50 % FC in the growing season (2022 and 2023), as compared to 70 % FC conditions. Water use efficiency increased significantly with the use of IAA compared to other treatments in the second year. Water deficit led to an increase in leaf proline content and total soluble sugar. The amounts of picrocrocin improved by 5.6 % with decreasing irrigation water from 70 % to 50 % FC in both experimental years. Moreover, the highest amounts of safranal were gained when corms were exposed to IAA. Priming with IAA increased the dry weight of daughter corms compared to other priming treatments. The N and P absorbed by saffron corm decreased to 29.2 % and 28.6 % at 70 % and 50 % FC, respectively. The highest K+ uptake was recorded with the application of IAA under 70 % FC. Overall, this work indicated that an increase in saffron yield and the quality of flowers is associated with an increase in dry weight of daughter corms, ion absorption in corms and the activity of non-enzymatic defense system caused by the application of IAA under different soil moisture.

Structural characterization and antioxidant activity mechanism of the ferulic acid-rich subfraction from sugar beet pectin

The feruloylated sugar chain in sugar beet pectin (SBP) is a natural polyphenol-polysaccharide complex. Its low abundance often leads to be neglected, thereby hindering its bioactivity and mechnism research. In this study, SBP-3 A, a novel feruloylated polysaccharide fragment, was isolated from sugar beet pectin utilizing enzymatic digestion. The presence of ferulic acid on SBP-3 A was confirmed through high-performance liquid chromatography (HPLC), with a mass fraction of 22.5 μg/mg. The average molecular weight was determined to be 33.31 kDa. Methylation analysis, and nuclear magnetic resonance (NMR) spectra revealed that SBP-3 A is a heteroglycan with the main chain structure of →2)-α-Rhap-(1 → 4)-α-GalpA-(1 → 2)-α-Rhap-(1→, and the branched chain structure of ferulic acid (FA) → 3,4)-β-Galp-(1 → 2,4)-α-Rhap-(1→. Subsequently, the antioxidant activity of SBP-3 A was evaluated using the Caenorhabditis elegans (C. elegans). SBP-3 A improved antioxidant enzymes and non-enzymatic defense system, decreased reactive oxygen species levels, and up-regulated the mRNA expression of sod-3, skn-1, and daf-16, while down-regulated the expression of age-1 in C. elegans. Moreover, SBP-3 A modulated the gut flora by favorably affecting the abundances of Lactobacillus, Ligilactobacillus, and Akkermansia, thereby enhancing antioxidant capacity in C. elegans. Consequently, the aforementioned findings support the potential application of SBP-3 A as a functional food for treating oxidative stress-related illnesses.

Arbuscular mycorrhizal fungi enhanced resistance to low-temperature weak-light stress in snapdragon (Antirrhinum majus L.) through physiological and transcriptomic responses.

Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive role in regulating growth and enhancing abiotic stress tolerance in plants. Nevertheless, the molecular mechanisms by AMF improve the LT combined with WL (LTWL) tolerance in snapdragon remain mostly unknown. We compared the differences in root configuration, osmoregulatory substances, enzymatic and non-enzymatic antioxidant enzyme defense systems and transcriptome between AMF-inoculated and control groups under LT, WL, low light, and LTWL conditions. Our analysis showed that inoculation with AMF effectively alleviated the inhibition caused by LTWL stress on snapdragon root development, and significantly enhanced the contents of soluble sugars, soluble proteins, proline, thereby maintaining the osmotic adjustment of snapdragon. In addition, AMF alleviated reactive oxygen species damage by elevating the contents of AsA, and GSH, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR). RNA-seq analysis revealed that AMF regulated the expression of genes related to photosynthesis (photosystem I related proteins, photosystem II related proteins, chlorophyll a/b binding protein), active oxygen metabolism (POD, Fe-SOD, and iron/ascorbate family oxidoreductase), plant hormone synthesis (ARF5 and ARF16) and stress-related transcription factors gene (bHLH112, WRKY72, MYB86, WRKY53, WRKY6, and WRKY26) under LTWL stress. We concluded that mycorrhizal snapdragon promotes root development and LTWL tolerance by accumulation of osmoregulatory substances, activation of enzymatic and non-enzymatic antioxidant defense systems, and induction expression of transcription factor genes and auxin synthesis related genes. This study provides a theoretical basis for AMF in promoting the production of greenhouse plants in winter.

Antioxidative and Anti-photooxidative Potential of Interruptins from the Edible Fern Cyclosorus terminans in Human Skin Cells.

<p>Background: Human skin is exposed daily to oxidative stress factors such as UV light, chemical pollutants, and invading organisms. Reactive oxygen species (ROS) are intermediate molecules that cause cellular oxidative stress. In order to survive in an oxygen-rich environment, all aerobic organisms, including mammals, have evolved enzymatic and non-enzymatic defence systems. The interruptins from an edible fern Cyclosorus terminans possess antioxidative properties and can scavenge intracellular ROS in adipose-derived stem cells. <p> Objectives: This study aimed to evaluate the antioxidative efficacy of interruptins A, B, and C in cultured human dermal fibroblasts (HDFs) and epidermal keratinocytes (HEKs). Moreover, the anti-photooxidative activity of interruptins in ultraviolet (UV)-exposed skin cells was investigated. <p> Methods: The intracellular ROS scavenging capacity of interruptins in skin cells was measured by flow cytometry. Their induction effects on gene expression of the endogenous antioxidant enzymes was monitored using real-time polymerase chain reaction. <p> Results: Interruptins A and B, but not interruptin C, were highly effective in ROS scavenging, particularly in HDFs. Interruptins A and B upregulated gene expression of superoxide dismutase (SOD)1, SOD2, catalase (CAT), and glutathione peroxidase (GPx) in HEKs, but they only induced SOD1, SOD2, and GPx gene expression in HDFs. Additionally, interruptins A and B efficiently suppressed UVA- and UVB-induced ROS generation in both HEKs and HDFs. <p> Conclusion: The results suggest that these naturally occurring interruptins A and B are potent natural antioxidants and therefore may have the potential in the future of inclusion in antiaging cosmeceutical products.</p>.

Microbial biostimulant counteracts negative effects of herbicides on oilseed rape growth

Use of herbicides in agriculture aids enormously the weed control. However, these products may also negatively affect both ecosystem and human health. As such the aim of this study was to analyze the effects of a herbicide containing the active substances clopyralid and picloram on the growth of oilseed rape cv. ‘Visby’ and to investigate the possibilities of using biologically active, environmentally friendly microbial biostimulants to accelerate plant growth and eliminate the adverse effects of herbicides. Biometrical parameters (aboveground plant height, dry plant weight) as well as biochemical markers (hydrogen peroxide production, total polyphenols concentration, antioxidant activity, lipid peroxidation level, photosynthetic pigments chlorophyll a, chlorophyll b and their ratio, carotenoids) were measured. The study showed that the herbicide containing clopyralid + picloram at doses recommended by the manufacturer showed a negative effect on oilseed rape growth. Microbial biostimulant “NaturGel” used prior to herbicide alleviated the damage of herbicide, moreover increased growth and development processes of tested plants, through serving as an activator of the non-enzymatic defence system. Thus, microbial biostimulant “NaturGel” is used to solve the problems of reducing herbicide use and increasing oilseed rape yields. Partially replacing herbicides with the microbial biostimulant “NaturGel”, strengthens crop vitality, increases competitiveness with weeds, improves yield quality, and the sustainability of agricultural land use. This knowledge can be used to provide practical guidance for farmers to reduce the use of herbicides in agro-ecosystems and make a step-by-step transition towards organic farming, while it may also serve as information on side-effects of commonly used herbicides at recommended doses.

Water stress and increased ploidy level enhance antioxidant enzymes, phytohormones, phytochemicals and polyphenol accumulation of tetraploid induced wallflower

Wallflower (Erysimum cheiri (L.) Crantz) is a profitable plant in the food, cosmetic, and pharmaceutical industries, as it produces valuable phenolic compounds. It is also an important flower in the floriculture industry cultivated mainly in the gardens and pots. Nonetheless, water scarcity as a worldwide phenomenon has deteriorated its growth and productivity. A main mechanism for drought tolerance is genome duplication and increased ploidy level, where more metabolites are produced. In this regard, diploid and tetraploid-induced plants of E. cheiri were subjected to well-watered (100% field capacity) and water deficit (50% field capacity) conditions for 30 days. Under water deficit conditions, the tetraploid wallflowers conserved their relative water content (RWC) at 85%, while the RWC of diploid plants was reduced to 68%. The chromosome-doubled plants showed advantages under water stress due to their higher osmotic adjustment by increased total soluble sugar and proline content, stronger antioxidant enzymes’ activity of SOD, CAT, APX, and POD, and enhanced non-enzymatic defense systems (i.e., total phenolic and flavonoid contents), compared with their control diploids. Also, stress hormones such as abscisic acid, salicylic acid, jasmonic acid, and auxins were increased in tetraploid plants under low water conditions, though cytokinin and gibberellin phytohormones were decreased as an adaptive strategy in the stress condition. Furthermore, chlorogenic acid and gallic acid were identified as the main phenolic compounds in 4x Erysimum leaves. The superiority of tetraploids over the diploid plants under water stress might be attributed to the extensive reprogramming of genes involved in hormonal signaling, reactive oxygen species detoxification, osmotic adjustment, and enhanced antioxidant defense system. The polyploidization technique combined with water scarcity, have proved fruitful for the production of excess secondary metabolites for various industrial uses.

Inhibitory Effect of Quercetin on Oxidative Endogen Enzymes: A Focus on Putative Binding Modes.

Oxidative stress is defined as an imbalance between the production of free radicals and reactive oxygen species (ROS) and the ability of the body to neutralize them by anti-oxidant defense systems. Cells can produce ROS during physiological processes, but excessive ROS can lead to non-specific and irreversible damage to biological molecules, such as DNA, lipids, and proteins. Mitochondria mainly produce endogenous ROS during both physiological and pathological conditions. Enzymes like nicotinamide adenine dinucleotide phosphate oxidase (NOX), xanthine oxidase (XO), lipoxygenase (LOX), myeloperoxidase (MPO), and monoamine oxidase (MAO) contribute to this process. The body has enzymatic and non-enzymatic defense systems to neutralize ROS. The intake of bioactive phenols, like quercetin (Que), can protect against pro-oxidative damage by quenching ROS through a non-enzymatic system. In this study, we evaluate the ability of Que to target endogenous oxidant enzymes involved in ROS production and explore the mechanisms of action underlying its anti-oxidant properties. Que can act as a free radical scavenger by donating electrons through the negative charges in its phenolic and ketone groups. Additionally, it can effectively inhibit the activity of several endogenous oxidative enzymes by binding them with high affinity and specificity. Que had the best molecular docking results with XO, followed by MAO-A, 5-LOX, NOX, and MPO. Que's binding to these enzymes was confirmed by subsequent molecular dynamics, revealing different stability phases depending on the enzyme bound. The 500 ns simulation showed a net evolution of binding for NOX and MPO. These findings suggest that Que has potential as a natural therapy for diseases related to oxidative stress.

Study on the antioxidant activity of peptides from soybean meal by fermentation based on the chemical method and AAPH-induced oxidative stress.

Preparation and antioxidant activities of soybean peptides using solid fermentation to decrease the content of trypsin inhibitor (TI) and antigen protein were investigated in this study. The results showed the optimal fermentation conditions were as follows: fermentation time 48 h, the ratio of material to solvent 1:2, inoculum size 12%, and the ratio of Lactic acid bacteria and Aspergillus oryzae 2:1. The hydrolysate was were divided into four components of <1, 1-3, 3-5, and >5 kDa by ultrafiltration based on molecular weight, and the <1 kDa peptides expressed the highest antioxidant activities. Meanwhile, the cell antioxidant activity of the <1 kDa soybean peptides was investigated using AAPH-induced erythrocyte hemolysis, which effectively inhibited erythrocyte hemolysis with the inhibit rate of 85.8% through inhibition of the ROS intracellular generation. In addition, soybean peptides could significantly restore the intracellular antioxidant enzymes (SOD, GSH-Px, and CAT) activities, as well as inhibited intracellular MDA generation and depletion of GSH. The intracellular antioxidant detoxifying mechanism of soybean peptides was associated with both non-enzymatic and enzymatic defense systems. According to this study, fermentation could effectively improve the antioxidant activities of soybean peptides.

Physiological Aspects of Interaction of Nanoparticles with Plant and Microorganism Cells

Nanoparticles (NPs) are materials with unique physical and chemical properties that are less than 100 nm in size. They are widely used in various fields of industry, medicine and agriculture. In agribusiness nanomaterials are used as nanofertilisers and nanopesticides. This fact requires a detailed study of the physiological, biochemical and molecular genetic responses of cells of living organisms – plants, fungi and animals – to interaction with nanomaterials. This review article provides information on the mechanisms of nanoparticle absorption, movement and molecular interaction in plant organisms, as well as mechanisms of their antibacterial and fungicidal activity. Available scientific resources devoted to the physiological features of nanoparticle absorption by plants indicate two possible ways of their penetration into the plant organism – apoplastic and symplastic. In plant cells, nanoparticles act as reactive oxygen species (ROS), causing oxidative stress and triggering enzymatic and non-enzymatic defence systems that result in both inhibition of physiological processes and stimulation of plant growth and development and, consequently, increased yield. The effect on the plant organism is species-specific and depends on the type of nanomaterial and its concentration. Detailed laboratory and field studies are required to determine the specific effect of nanomaterials on a particular plant species, while complying with all toxicological safety standards to avoid environmental contamination with nanomaterials. Nanoparticles act on microorganism cells as physical and chemical disruptors – they change the permeability of cell walls and organelle membranes, protein configuration, damage DNA, leading to physical destruction of cells. Such properties of nanoparticles define antimicrobial and fungicidal activities of nanoparticles. However, nanoparticles should be used cautiously in crop production, as both plant life and productivity depend largely on microbial symbionts, and their effect on microbial cells is not species-specific.

Nickel chloride generates cytotoxic ROS that cause oxidative damage in human erythrocytes

BackgroundNickel is a heavy metal that is regarded as a possible hazard to living organisms due to its toxicity and carcinogenicity. Nickel chloride (NiCl2), an inorganic divalent Ni compound, has been shown to cause oxidative stress in cells by altering the redox equilibrium. We have investigated the effect of NiCl2 on isolated human erythrocytes under in vitro condition. MethodsIsolated erythrocytes were treated with different concentrations of NiCl2 (25–500 µM) for 24 h at 37 ºC. Hemolysates were prepared and several biochemical parameters were analyzed in them. ResultsTreatment of erythrocytes with NiCl2 enhanced the intracellular generation of reactive oxygen species (ROS). A significant increase in hydrogen peroxide levels and oxidation of proteins and lipids was also seen. This was accompanied by a reduction in levels of nitric oxide, glutathione, free amino groups and total sulfhydryl groups. NiCl2 treatment impaired both enzymatic and non-enzymatic defense systems, resulting in lowered antioxidant capacity and diminished ability of cells to quench free radicals and reduce metal ions. NiCl2 exposure also had an inhibitory effect on the activity of enzymes involved in pathways of glucose metabolism (glycolytic and pentose phosphate shunt pathways). Increased level of methemoglobin, which is inactive in oxygen transport, was also seen. The rate of heme breakdown increased resulting in the release of free iron. Exposure to NiCl2 led to considerable cell lysis, indicating damage to the erythrocyte membrane. This was supported by the inhibition of membrane bound enzymes and increase in the osmotic fragility of NiCl2 treated cells. NiCl2 treatment caused severe morphological alterations with the conversion of normal discocytes to echinocytes. All changes were seen in a NiCl2 concentration-dependent manner. ConclusionNiCl2 generates cytotoxic ROS in human erythrocytes which cause oxidative damage that can decrease the oxygen carrying capacity of blood and also lead to anemia.

Primary plant nutrients modulate the reactive oxygen species metabolism and mitigate the impact of cold stress in overseeded perennial ryegrass.

Overseeded perennial ryegrass (Lolium perenne L.) turf on dormant bermudagrass (Cynodon dactylon Pers. L) in transitional climatic zones (TCZ) experience a severe reduction in its growth due to cold stress. Primary plant nutrients play an important role in the cold stress tolerance of plants. To better understand the cold stress tolerance of overseeded perennial ryegrass under TCZ, a three-factor and five-level central composite rotatable design (CCRD) with a regression model was used to study the interactive effects of nitrogen (N), phosphorus (P), and potassium (K) fertilization on lipid peroxidation, electrolyte leakage, reactive oxygen species (ROS) production, and their detoxification by the photosynthetic pigments, enzymatic and non-enzymatic antioxidants. The study demonstrated substantial effects of N, P, and K fertilization on ROS production and their detoxification through enzymatic and non-enzymatic pathways in overseeded perennial ryegrass under cold stress. Our results demonstrated that the cold stress significantly enhanced malondialdehyde, electrolyte leakage, and hydrogen peroxide contents, while simultaneously decreasing ROS-scavenging enzymes, antioxidants, and photosynthetic pigments in overseeded perennial ryegrass. However, N, P, and K application mitigated cold stress-provoked adversities by enhancing soluble protein, superoxide dismutase, peroxide dismutase, catalase, and proline contents as compared to the control conditions. Moreover, N, P, and, K application enhanced chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in overseeded perennial ryegrass under cold stress as compared to the control treatments. Collectively, this 2-years study indicated that N, P, and K fertilization mitigated cold stress by activating enzymatic and non-enzymatic antioxidants defense systems, thereby concluding that efficient nutrient management is the key to enhanced cold stress tolerance of overseeded perennial ryegrass in a transitional climate. These findings revealed that turfgrass management will not only rely on breeding new varieties but also on the development of nutrient management strategies for coping cold stress.

Does phenotyping of Hypericum secondary metabolism reveal a tolerance to biotic/abiotic stressors?

In this review we summarize the current knowledge about the changes in Hypericum secondary metabolism induced by biotic/abiotic stressors. It is known that the extreme environmental conditions activate signaling pathways leading to triggering of enzymatic and non-enzymatic defense systems, which stimulate production of secondary metabolites with antioxidant and protective effects. Due to several groups of bioactive compounds including naphthodianthrones, acylphloroglucinols, flavonoids, and phenylpropanes, the world-wide Hypericum perforatum represents a high-value medicinal crop of Hypericum genus, which belongs to the most diverse genera within flowering plants. The summary of the up-to-date knowledge reveals a relationship between the level of defense-related phenolic compounds and interspecific differences in the stress tolerance. The chlorogenic acid, and flavonoids, namely the amentoflavone, quercetin or kaempferol glycosides have been reported as the most defense-related metabolites associated with plant tolerance against stressful environment including temperature, light, and drought, in association with the biotic stimuli resulting from plant-microbe interactions. As an example, the species-specific cold-induced phenolics profiles of 10 Hypericum representatives of different provenances cultured in vitro are illustrated in the case-study. Principal component analysis revealed a relationship between the level of defense-related phenolic compounds and interspecific differences in the stress tolerance indicating a link between the provenance of Hypericum species and inherent mechanisms of cold tolerance. The underlying metabolome alterations along with the changes in the activities of ROS-scavenging enzymes, and non-enzymatic physiological markers are discussed. Given these data it can be anticipated that some Hypericum species native to divergent habitats, with interesting high-value secondary metabolite composition and predicted high tolerance to biotic/abiotic stresses would attract the attention as valuable sources of bioactive compounds for many medicinal purposes.

Plant hormones and neurotransmitter interactions mediate antioxidant defenses under induced oxidative stress in plants.

Due to global climate change, abiotic stresses are affecting plant growth, productivity, and the quality of cultivated crops. Stressful conditions disrupt physiological activities and suppress defensive mechanisms, resulting in stress-sensitive plants. Consequently, plants implement various endogenous strategies, including plant hormone biosynthesis (e.g., abscisic acid, jasmonic acid, salicylic acid, brassinosteroids, indole-3-acetic acid, cytokinins, ethylene, gibberellic acid, and strigolactones) to withstand stress conditions. Combined or single abiotic stress disrupts the normal transportation of solutes, causes electron leakage, and triggers reactive oxygen species (ROS) production, creating oxidative stress in plants. Several enzymatic and non-enzymatic defense systems marshal a plant’s antioxidant defenses. While stress responses and the protective role of the antioxidant defense system have been well-documented in recent investigations, the interrelationships among plant hormones, plant neurotransmitters (NTs, such as serotonin, melatonin, dopamine, acetylcholine, and γ-aminobutyric acid), and antioxidant defenses are not well explained. Thus, this review discusses recent advances in plant hormones, transgenic and metabolic developments, and the potential interaction of plant hormones with NTs in plant stress response and tolerance mechanisms. Furthermore, we discuss current challenges and future directions (transgenic breeding and genome editing) for metabolic improvement in plants using modern molecular tools. The interaction of plant hormones and NTs involved in regulating antioxidant defense systems, molecular hormone networks, and abiotic-induced oxidative stress tolerance in plants are also discussed.

Investigation of biochemical changes in the leaves of Curcuma caesia Roxb. under sucrose-induced osmotic stress environment

Curcuma caesia Roxb., also known as black turmeric, is a rare rhizomatous herb in the Zingiberaceae family. In the present study, we used the two different sucrose concentrations (3% and 9% sucrose) in Murashige and Skoog medium supplemented with 8 mg/l benzyladenine, 8 mg/l kinetin, 100 mg/l citric acid, 200 mg/l adenine sulfate and 2 mg/l indole-3-acetic acid to investigate the biochemical differences in the leaves of C. caesia. Biochemical parameters such as total sugar, proline, protein, chlorophyll, and hydrogen peroxide (H2O2) content, as well as superoxide dismutase (SOD) and catalase (CAT) activity, were analyzed to study the differences. All the parameters were performed on the 0th and 30th day after inoculation (DAI). It has been found that as sucrose concentration raised from 3% to 9% sucrose, the SOD activity, as well as the total sugar, proline, protein, chlorophyll, and H2O2 content increases significantly at 30th DAI. These increased enzymatic and non-enzymatic defense systems, thus helping the plant to maintain its growth under a stressed environment.

Exogenous brassinolide improves the antioxidant capacity of Pinellia ternata by enhancing the enzymatic and nonenzymatic defense systems under non-stress conditions.

Brassinolide (BR) improves the antioxidant capacity of plants under various abiotic stresses. However, it is not clear about the effect of BR on the antioxidant capacity in plants under non-stress conditions. In the present study, the antioxidant defense response of Pinellia ternata was to be assessed by applying BR and propiconazole (Pcz) under non-stress conditions. BR treatment enhanced the flavonoid content, peroxidase, and ascorbate peroxidase (APX) activity by 12.31, 30.62, and 25.08% and led to an increase in 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity by 4.31% and a decrease in malondialdehyde content by 1.04%. Exogenous application of BR improved the expression levels of PAL, CHS, CHI, and DFR genes by 3. 18-, 3. 39-, 2. 21-, and 0.87-fold in flavonoid biosynthesis, PGI, PMI, and GME genes by 6. 60-, 1437. 79-, and 3.11-fold in ascorbic acid (ASA), biosynthesis, and γECs and GSHS genes by 6.08- and 2.61-fold in glutathione (GSH) biosynthesis pathway, and the expression of these genes were inhibited by Pcz treatment. In addition, BR treatment promoted the ASA–GSH cycle by enhancing the expression of APX, DHAR, and MDHAR genes, which were enhanced by 3. 33-, 157. 85-, and 154.91-fold, respectively. These results provided novel insights into the effect of BR on the antioxidant capacity in bulbil of P. ternata under non-stress conditions and useful knowledge of applying BR to enhance the antioxidant capacity of plants.

Biochemical markers of environmental stress tolerance in finger millet [Eleusine coracana (L.) Gaertn.] germplasm of Central Himalayan Region

Availability of the germplasm of suitable crops for cultivation in environmental stress prone and resource poor terrains is crucial for food security in these regions. Rich diversity of millets, which are highly tolerant to extreme weather conditions, is obtainable in the Central Himalayan Region (CHR). However, biochemical evaluation of available germplasm for food security is a major apprehension yet to be addressed properly. In this backdrop expeditions were conducted to tap and evaluate the germplasm variability of finger millet [Eleusine coracana (L.) Gaertn.]. Germplasm accessions (314) having traits of agronomic importance were collected and evaluated for three consecutive years. In addition to set of biochemical traits, yield was recorded to find out suitable germplasm for large scale cultivation/breeding programme. At flowering stage variability in antioxidants level of leaves such as glutathione and ascorbate ranged from 105.27 to 423.63 mmol g−1 FW and 4.89–10.21 mmol g−1 FW respectively. Extensive variableness in the activity of enzymes which are important for multiple abiotic stress tolerance viz., catalase (115–855 mmol H2O2 decomposed min−1 mg−1 protein), peroxidase (1.24–6.35 mmol substrate min−1 mg−1 protein), superoxide dismutase (1236–2963 enzyme U mg−1 protein), glutathione reductase (0.53–2.14 mmol substrate min−1 mg−1 protein), ascorbate peroxidase (1.86–7.04 mmol substrate min−1 mg−1 protein), monodehydroascorbate reducatase (1.11–4.41 mmol substrate min−1 mg−1 protein), dehydroascorbate reducatase (0.34–1.36 mmol substrate min−1 mg−1 protein) was also recorded. Worldwide Abiotic/environmental stresses hamper agricultural production. Enzymatic and non-enzymatic defence system precisely controls this situation. Hence, biochemical evaluation might be an appropriate strategy for identification of suitable germplam to combat the problem of food security in such areas.

Biliary cirrhosis-induced cardiac abnormality in rats: Interaction between Farnesoid-X-activated receptors and the cardiac uncoupling proteins 2 and 3.

This study aimed to evaluate the relationship between Farnesoid-X-activated receptors (FXR) as nuclear regulators of the antioxidant defense system as well as cardiac mitochondrial carrier proteins of UCP2 and UCP3 in cardiac damage induced by cirrhosis. Twenty-two male Wistar rats (200-250 g) were randomly divided into 3 experimental groups, including a control group (n=6), a sham-operated group (n=8), and a bile duct ligated (BDL) group (n=8). Four weeks after surgical intervention, biochemical assessment (AST, ALT, GGT, LDH, and ALP), histological observation, and molecular evaluation (FXR, UCP2, UCP3, BNP, Caspase3, and GAPDH) using real-time RT-PCR were performed. Compared with the sham-operation group, the BDL group showed a significant rise in liver enzymes of AST, ALT, GGT, LDH, and ALP. Defined fibrotic and necrotic bundles and thick reticulin fibers were also found in BDL liver tissue. Besides liver morphological alterations, left ventricles of BDL ones were also associated with defined cardiomyocyte hypertrophy, myofiber vacuolization, and clear pigmentation. Findings showed a significant up-regulation of cardiac Brain Natriuretic Peptide (BNP) along with marked down-regulation in hepatic FXR, cardiac FXR, and cardiac UCP2 and UCP3. However, the expression of caspase 3 in the cardiac tissue was not affected by BDL operation during 4 weeks. Expression of FXR as an upstream regulator of cellular redox status, besides the non-enzymatic ROS buffering defense system of cardiac UCPs, has a pivotal role in the pathogenesis of cirrhotic-induced cardiac abnormality in rats.

Effect of silicon on the young maize plants exposed to nickel stress

Nickel (Ni) is involved in several physiological processes in plants but its excess in environment has many phytotoxic effects. Silicon (Si), an element required for optimal plant performance, has been shown to have beneficial effects for plants coping with various types of stresses. Here we studied the alleviative potential of Si (2.5 mM) added to hydroponically grown maize (Zea mays L.) plants under Ni (100 μM) stress. Ni decreased most of the growth parameters, total chlorophyll (Chl) and leaf relative water content (RWC), and catalase (CAT; EC 1.11.1.6) activity, while leaf water loss (LWL), contents of proline (Pro), hydrogen peroxide (H2O2) and ascorbate (AsA), membrane lipid peroxidation and activities of peroxidase (POX; EC 1.11.1.7) and superoxide dismutase (SOD; EC 1.15.1.1) were increased. Supplementation of Si to Ni-treated plants enhanced the leaf area, Chl content, RWC, CAT and POX (only in younger leaf) activities and decreased LWL, the contents of Pro (in younger leaf), H2O2 (roots) and AsA, lipid peroxidation and POX and SOD activities. We may conclude that Si mitigated the Ni-induced stress in maize by amelioration of the leaf water deficient status (Pro, RWC, LWL), enhancing membrane stability (MDA) and influencing enzymatic (SOD, POX, CAT) and non-enzymatic (Pro, AsA) defence systems. The increased Chl content and leaf area improve overall plant performance.

Mechanical Wounding Induces Catalase Gene (VsCat) in Leaves of Common Vetch

Background: In plants, wounding can result from mechanical injuries or from biotic factors induced by herbivores infestation and pathogen infection. Wounding enhances the production of reactive oxygen species (ROS). Enzymatic and nonenzymatic defense systems have been reported in plants to immediately combat increased levels of ROS. Plant catalases are encoded by a multigene family and are the major scavenging enzymes catalyzing the dismutation of toxic hydrogen peroxide to water and dioxygen. Methods: In the preasent work, a quantitative real-time PCR was used to quantify the expression level of a catalase gene from common vetch (Vicia sativa; VsCat) in response to mechanical wounding. Result: The results of the time course study showed that the transcript levels of VsCat were significantly increased in wounded leaves at all-time points examined with a peak expression of 7.6 folds at 2 h post wounding. The increased expression of VsCat might represent a direct defense against elevated H2O2 generated during wounding.

Sequential Antioxidants Foliar Application Can Alleviate Negative Consequences of Salinity Stress in Vicia faba L.

Salinity is one of the most limiting abiotic stresses in agricultural productivity. Exogenously applied antioxidants successfully enabled salt-stressed plants to cope with stress. Two-season field experiments were conducted consecutively in 2016/17 and 2017/18 to study the effects of foliar applications of singular (ascorbate, AsA; proline, Pro; and glutathione, GSH) or sequential (AsA-Pro-GSH and GSH-Pro-AsA) antioxidants on growth, yield, physio-biochemical attributes, and enzymatic and non-enzymatic antioxidative defense system of Vicia faba L. (CV. Sakha-1) plants grown under saline soil conditions (EC = 4.53 dS m−1). Under soil salinity conditions, AsA, Pro, or GSH-Pro-ASA improved growth and productivity, photosynthesis efficiency, stomatal conductance (gs), plant water status, as well as enzymatic and non-enzymatic antioxidants. However, sequential AsA-Pro-GSH foliar application followed by singular GSH significantly exceeded all other treatments (i.e., AsA, Pro, and GSH-Pro-AsA), improving growth characteristics (shoot length, shoot fresh and dry weights, and leaves area), photosynthesis efficiency, stomatal conductance, plant water status, and yield and its components (green pods weight/plant−1, green pods yield/hectare−1, and seed yield/hectare−1), as well as enzymatic (ascorbate peroxidase, catalase, superoxide dismutase, and glutathione reductase) and non-enzymatic (AsA, GSH, Pro, phenolic aglycone, phenolic glycosides) antioxidants compared to control. Overall, our results clearly demonstrate that sequential AsA-Pro-GSH foliar application has a positive effect on salt-stressed Vicia faba plants.