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Background: Diabetic cardiomyopathy is a serious complication of obesity with type 2 diabetes and is a major cause of mortality. Metabolic surgery, such as duodenal‐jejunal bypass (DJB), can effectively improve diabetic cardiomyopathy; however, the underlying mechanisms remain elusive. Oxidative stress is one of the pivotal mechanisms of diabetic cardiomyopathy. Our objective was to investigate the effect and potential mechanisms of DJB on oxidative stress in the heart of diabetic cardiomyopathy rats. Methods: High‐fat diet combined with intraperitoneal injection of streptozotocin was used to establish diabetic cardiomyopathy rats. DJB was performed on diabetic cardiomyopathy rats, and high glucose and palmitate were used to simulate diabetic cardiomyopathy in H9C2 cells in vitro. Sera from different groups of rats were used for experiments in vivo and in vitro. Results: DJB effectively improved oxidative stress and activated the adenosine monophosphate (AMP)‐activated protein kinase (AMPK) pathway to increase endothelial nitric oxide synthase (eNOS) phosphorylation level and the expression of antioxidative system‐related proteins and genes in the heart of diabetic cardiomyopathy rats. AMPK agonists and serum from DJB rats activated the AMPK pathway to increase eNOS phosphorylation level and the expression of antioxidative system‐related proteins and genes and decreased the content of reactive oxygen species in H9C2 cells, but this improvement was almost eliminated by the addition of AMPK inhibitors. Conclusions: DJB activates eNOS and enhances the antioxidant system by activating the AMPK pathway—and not solely by improving blood glucose—to improve oxidative stress in the heart of diabetic cardiomyopathy rats. [ABSTRACT FROM AUTHOR]

Soil salinization poses a threat to the sustainability of agricultural production and has become a global issue. Cotton is an important cash crop and plays an important role in economic development. Salt stress has been harming the yield and quality of many crops, including cotton, for many years. In recent years, soil salinization has been increasing. It is crucial to study the mechanism of cotton salt tolerance and explore diversified materials and methods to alleviate the salt stress of cotton for the development of the cotton industry. Nanoparticles (NPs) are an effective means to alleviate salt stress. In this study, zinc oxide NPs (ZnO NPs) were sprayed on cotton leaves with the aim of investigating the intrinsic mechanism of NPs to alleviate salt stress in cotton. The results show that the foliar spraying of ZnO NPs significantly alleviated the negative effects of salt stress on hydroponic cotton seedlings, including the improvement of above-ground and root dry and fresh weight, leaf area, seedling height, and stem diameter. In addition, ZnO NPs can significantly improve the salt-induced oxidative stress by reducing the levels of MDA, H2O2, and O2− and increasing the activities of major antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Furthermore, RNA-seq showed that the foliar spraying of ZnO NPs could induce the expressions of CNGC, NHX2, AHA3, HAK17, and other genes, and reduce the expression of SKOR, combined with the CBL-CIPK pathway, which alleviated the toxic effect of excessive Na+ and reduced the loss of excessive K+ so that the Na+/K+ ratio was stabilized. In summary, our results indicate that the foliar application of ZnO NPs can alleviate high salt stress in cotton by adjusting the Na+/K+ ratio and regulating antioxidative ability. This provides a new strategy for alleviating the salt stress of cotton and other crops, which is conducive to the development of agriculture. [ABSTRACT FROM AUTHOR]

Improper use of nicosulfuron (NSF) may induce harmful effects on plants during weed control. Melatonin (MT) regulates photosynthetic and physiological processes in plants. This study aimed to explore the effects of MT on alleviating NSF toxicity by measuring the growth parameters, photosynthetic capacity, and antioxidative responses in sweet corn seedlings. Compared to NSF alone, exogenous MT increased chlorophyll content, transpiration rate, net photosynthetic rate, stomatal conductance, and maximum efficiency of PSⅡ photochemistry, while reduced malondialdehyde, hydrogen peroxide, superoxide anion radical, and proline contents. Moreover, MT also increased the activity of ascorbate peroxidase and the expression levels of ZmAPX1, ZmAPX2, ZmALS1, and ZmCYP81A9. The inhibition of p-chlorophenylalanine inhibited the positive effects of MT on photosynthetic and physiological indexes. The results indicated that pretreatment with MT might effectively mitigate NSF toxicity in sweet corn seedlings.

Abstract Background Diabetic cardiomyopathy is a serious complication of obesity with type 2 diabetes and is a major cause of mortality. Metabolic surgery, such as duodenal‐jejunal bypass (DJB), can effectively improve diabetic cardiomyopathy; however, the underlying mechanisms remain elusive. Oxidative stress is one of the pivotal mechanisms of diabetic cardiomyopathy. Our objective was to investigate the effect and potential mechanisms of DJB on oxidative stress in the heart of diabetic cardiomyopathy rats. Methods High‐fat diet combined with intraperitoneal injection of streptozotocin was used to establish diabetic cardiomyopathy rats. DJB was performed on diabetic cardiomyopathy rats, and high glucose and palmitate were used to simulate diabetic cardiomyopathy in H9C2 cells in vitro. Sera from different groups of rats were used for experiments in vivo and in vitro. Results DJB effectively improved oxidative stress and activated the adenosine monophosphate (AMP)‐activated protein kinase (AMPK) pathway to increase endothelial nitric oxide synthase (eNOS) phosphorylation level and the expression of antioxidative system‐related proteins and genes in the heart of diabetic cardiomyopathy rats. AMPK agonists and serum from DJB rats activated the AMPK pathway to increase eNOS phosphorylation level and the expression of antioxidative system‐related proteins and genes and decreased the content of reactive oxygen species in H9C2 cells, but this improvement was almost eliminated by the addition of AMPK inhibitors. Conclusions DJB activates eNOS and enhances the antioxidant system by activating the AMPK pathway—and not solely by improving blood glucose—to improve oxidative stress in the heart of diabetic cardiomyopathy rats.

Maximizing amendment potential is an emphasis in the HM-contaminated field of phytoremediation by hyperaccumulators due to the low bioavailability of HMs in soils and small biomass yields of plants. This study investigated the influence of different types and concentrations of plant growth regulators on Cd phytoremediation by Solanum nigrum in contaminated soil. Our conclusions showed that the shoot Cd extractions (μg plant−1) and the root and shoot biomasses at all the treatments remarkedly increased compared with that of the CK (p < 0.05), while the Cd concentrations at root and aboveground parts by S. nigrum, the extractable Cd concentrations, and pH value of soils did not change significantly compared with the CK (p < 0.05). Furthermore, correlation analysis showed that the shoot Cd phytoaccumulation and the root and aboveground biomasses of S. nigrum were particularly dependent upon the application of CTK and GA3 concentration gradient (p < 0.05). Moreover, some related physicochemical indexes were determined for supervising the growth conditions of plants, and these results pointed out that after exogenous PGRs treatments, the chlorophyll content and antioxidative enzymes POD and SOD activities in vivo of plants clearly advanced, while the H2O2 and MDA contents and CAT apparently declined. These consequence demonstrated that the exogenous PGR addition prominently reinforced the Cd phytoextraction capacity of S. nigrum in contaminated soil by stimulating plant growth and increasing shoot yields. [ABSTRACT FROM AUTHOR]

Improper use of nicosulfuron (NSF) may induce harmful effects on plants during weed control. Melatonin (MT) regulates photosynthetic and physiological processes in plants. This study aimed to explore the effects of MT on alleviating NSF toxicity by measuring the growth parameters, photosynthetic capacity, and antioxidative responses in sweet corn seedlings. Compared to NSF alone, exogenous MT increased chlorophyll content, transpiration rate, net photosynthetic rate, stomatal conductance, and maximum efficiency of PSII photochemistry, while reduced malondialdehyde, hydrogen peroxide, superoxide anion radical, and proline contents. Moreover, MT also increased the activity of ascorbate peroxidase and the expression levels of ZmAPX1, ZmAPX2, ZmALS1, and ZmCYP81A9. The inhibition of p-chlorophenylalanine inhibited the positive effects of MT on photosynthetic and physiological indexes. The results indicated that pretreatment with MT might effectively mitigate NSF toxicity in sweet corn seedlings. [ABSTRACT FROM AUTHOR]

In the current study, we successfully synthesized the zinc oxide nanoparticles (ZnO-NPs) via an efficient, facile, and cost-effective method of the modified hydrothermal synthesis approach, and examined their effectiveness in alleviating arsenic (As) stress in Brassica juncea. The synthesized ZnO-NPs were analyzed using a variety of experimental techniques viz. XRDs, SEM micrographs, EDAX/Mapping pattern, Raman Spectroscopy Pattern, and X-ray photoemission spectroscopy analysis. All of these analyses revealed that ZnO-NPs were highly pure with no internal defects and could potentially be used in plant applications. Hence, we further determined the effect of these nanoparticles in modulation of As tolerance in B. juncea plants by examining the various growth attributes, photosynthesis parameters, antioxidant activities, and enzyme activities. Our results demonstrated that As-stress inhibited growth, photosynthesis-related parameters, reduced protein content, as well as carbonic anhydrase, nitrate reductase, and RuBisCO; however, these attributes were substantially up-regulated by the supply of ZnO-NPs to the leaves. Furthermore, As stress-induced increases in malondialdehyde and H 2 O 2 levels are partially reversed by ZnO-NP in the As-stressed plants. Overall, supplementation positively regulated As tolerance in B. juncea by altering the key enzymes involved in ROS detoxification, which in turn prevented As-induced oxidative damage to the plant tissues. Hence, our study clarified the potential involvement of the newly synthesized ZnO-NPs in alleviating As stress in plants. Furthermore, this is the first report to elucidate the effect of the ZnO-NPs synthesized by the hydrothermal reaction route on As-stress modulation in B. juncea. [Display omitted] • Arsenic (As) stress affects growth and biomass yield in mustard plants. • As toxicity decreased pigment system and alters biochemical attributes and antioxidants. • Supplementation of zinc oxide nanoparticles (ZnO-NPs) enhanced growth and protects pigments. • ZnO-NPs regulates antioxidant system and As uptake in mustard. [ABSTRACT FROM AUTHOR]

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. Reactive oxygen species metabolism is detailed under normal versus stressed conditions, elaborating on the modes and process of uptake and translocation of nanoparticles. The two-fold regulatory roles of nanoparticles are discussed. A molecular dissection of the role of nanoparticles is presented, in controlling transcriptomic expression and modulating molecular crosstalk with other growth regulators, ions, reactive nitrogen species and other signalling molecules. Potential roles and regulation of nanoparticles and their utility for green synthesis within a sustainable agricultural industry are explored. [ABSTRACT FROM AUTHOR]

Soil salinization poses a threat to the sustainability of agricultural production and has become a global issue. Cotton is an important cash crop and plays an important role in economic development. Salt stress has been harming the yield and quality of many crops, including cotton, for many years. In recent years, soil salinization has been increasing. It is crucial to study the mechanism of cotton salt tolerance and explore diversified materials and methods to alleviate the salt stress of cotton for the development of the cotton industry. Nanoparticles (NPs) are an effective means to alleviate salt stress. In this study, zinc oxide NPs (ZnO NPs) were sprayed on cotton leaves with the aim of investigating the intrinsic mechanism of NPs to alleviate salt stress in cotton. The results show that the foliar spraying of ZnO NPs significantly alleviated the negative effects of salt stress on hydroponic cotton seedlings, including the improvement of above-ground and root dry and fresh weight, leaf area, seedling height, and stem diameter. In addition, ZnO NPs can significantly improve the salt-induced oxidative stress by reducing the levels of MDA, H2O2, and O2− and increasing the activities of major antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Furthermore, RNA-seq showed that the foliar spraying of ZnO NPs could induce the expressions of CNGC, NHX2, AHA3, HAK17, and other genes, and reduce the expression of SKOR, combined with the CBL-CIPK pathway, which alleviated the toxic effect of excessive Na+ and reduced the loss of excessive K+ so that the Na+/K+ ratio was stabilized. In summary, our results indicate that the foliar application of ZnO NPs can alleviate high salt stress in cotton by adjusting the Na+/K+ ratio and regulating antioxidative ability. This provides a new strategy for alleviating the salt stress of cotton and other crops, which is conducive to the development of agriculture.

Aluminum (Al) is one of the most abundant element in the world. But aluminum exposure and accumulation causes serious diseases, related with free radicals. Reduced glutathione (GSH) is a tripeptide with intracellular antioxidant effects. This study aimed to investigate the role of GSH on adenosine deaminase (ADA), antioxidant system, and aluminum and zinc (Zn) levels in acute aluminum toxicity. In this study, Sprague–Dawley rats (n = 32) were used. The rats were divided into four equal groups (n = 8). Group I received 0.5 mL intraperitoneal injection of 0.9% saline solution (NaCI), Group II received single-dose AlCI3, Group III was given GSH for seven days, and Group IV was given AlCI3 single dose, and at the same time, 100 mg/kg GSH was given for seven days. At the end of the trial, blood samples were collected by cardiac puncture. Serum total antioxidant status (TAS) and Zn levels were lower in the aluminum-administered group than the control group. In contrast, plasma total oxidant status (TOS) and aluminum concentrations and ADA activity were found higher in the aluminum-administered group than in the control group. Unlike the other groups, group GSH administrated with aluminum was similar to the control group. As a result, GSH administration has a regulatory effect on ADA activity, antioxidant system, and Zn levels in experimental aluminum toxicity. In addition, GSH may reduce the oxidant capacity increased by Al administration and may have a tolerant role on the accumulated serum Al levels. But long-term experimental Al toxicity studies are needed to reach a firm conclusion. [ABSTRACT FROM AUTHOR]

Naringenin and apigenin are common flavonoids derived from edible plants with the potential to alleviate inflammation and improve skin antioxidation. This study aimed to evaluate the effects of naringenin and apigenin on oleic acid-induced skin damage in mice and compare their underlying mechanisms of action. Triglycerides and non-esterified fatty acids were significantly decreased by naringenin and apigenin, while apigenin intervention resulted in a better recovery of skin lesions. Naringenin and apigenin improved the antioxidative abilities of the skin by increasing catalase and total antioxidant capacity levels and decreasing malondialdehyde and lipid peroxide levels. The release of skin proinflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor α, was inhibited after naringenin and apigenin pretreatments, but naringenin only promoted the excretion of IL-10. Additionally, naringenin and apigenin regulated antioxidant defense and inflammatory response by activating nuclear factor erythroid-2 related factor 2-dependent mechanisms and suppressing the expression of nuclear factor-kappa B. In summary, naringenin and apigenin are prospective ingredients that contribute to the amelioration of skin damage by activating anti-inflammatory and antioxidative responses. [ABSTRACT FROM AUTHOR]

Facing climate change, the development of innovative agricultural technologies securing food production becomes increasingly important. Plasma-treated water (PTW) might be a promising tool to enhance drought stress tolerance in plants. Knowledge about the efects of PTW on the physiology of plants, especially on their antioxidative system on a long-term scale, is still scarce. In this work, PTW was applied to barley leaves (Hordeum vulgare cv. Kosmos) and various constituents of the plants’ antioxidative system were analyzed 30 days after treatment. An additional drought stress was performed after foliar PTW application followed by a recovery period to elucidate whether PTW treatment improved stress tolerance. Upon PTW treatment, the Total Antioxidant Capacity (TAC) in leaves and roots was lower in comparison to deionized water treated plants. In contrast, PTW treatment caused a higher content of chlorophyll, quantum yield and total ascorbate content in leaves compared to deionized water treated plants. After additional drought application and subsequent recovery period, an enhancement of values for TAC, contents of malondialdehyde, glutathione as well as activity of ascorbate peroxidase indicated a possible upregulation of antioxidative properties in roots. Hydrogen peroxide and nitric oxide might mediate abiotic stress tolerance and are considered as key components of PTW. [ABSTRACT FROM AUTHOR]

The article presents the results of studies of acute intoxication in Danio Rerio fish by chlorpyrifos at concentrations 0.5 mg/L; 0.75 mg/L and 1 mg/L of aquarium water for 24 h and its influence on the content of TBK-active products, catalase activity (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPO), glutathione reductase (GR) in their tissues. After 24 h in the fish staying in water with chloropyrifos added in concentrations 0.75 mg/L and 1 mg/L we have revealed an increase of the content of TBK-active products in the studied tissues compared to the control values. The linear nature of the growth of the CAT enzymatic activity in the tissues of head and torso due to the effects of chloropyrifos in doses of 0.5 mg/L; 0.75 mg/L and 1 mg/L. was shown. On the background of the catalase activity growth in Danio rerio, in 24 h after the action of the toxicant, there was an inversely proportional dependence between the dose of chlorpyrifos and the activity of GPOs in both investigated parts of the fish body. In the tissues of the head and torso, inhibition of SOD activity for the action of chlorpyrifos has been established. The activity of this enzyme was the lowest at the chlorpyrifos concentration 0.75 mg/L. The obtained results complement the data on the toxic effect of chlorpyrifos on ichthyofauna and on the course of chlorpyrifos-induced oxidative stress in Danio rerio fish. The obtained data can be used in the development of additional biochemical markers of chlorpyrifos and other phosphor organic compounds intoxication and in toxicological and environmental experiments, taking into account the growing intensity of the use of insecticidal preparations in agricultural production and everyday life.

Agricultural production is continuously constrained by number of biotic and abiotic stresses. Among all, water deficit is one of the major abiotic stresses, which adversely affects crop growth and productivity. Drought impairs normal growth, reduces leaf expansion, stem extension and root proliferation, disrupts water relation and water use efficiency. It interferes with the synthesis of photosynthetic pigments, resulting in the decline of light harvesting, generation of reducing power, and reduction of gas exchange and carbon fixation, which in turn, leads to the decline in plant growth and productivity water relations and reduces water-use efficiency in plants and it finally leads to biomass and final yield reduction of crop plants. However, plants develop some mechanisms of drought tolerance, avoidance or escape. This review presents some aspects of changes in plant at morphological, physiological and biochemical levels induced by drought. [ABSTRACT FROM AUTHOR]

Naringenin and apigenin are common flavonoids derived from edible plants with the potential to alleviate inflammation and improve skin antioxidation. This study aimed to evaluate the effects of naringenin and apigenin on oleic acid-induced skin damage in mice and compare their underlying mechanisms of action. Triglycerides and non-esterified fatty acids were significantly decreased by naringenin and apigenin, while apigenin intervention resulted in a better recovery of skin lesions. Naringenin and apigenin improved the antioxidative abilities of the skin by increasing catalase and total antioxidant capacity levels and decreasing malondialdehyde and lipid peroxide levels. The release of skin proinflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor α, was inhibited after naringenin and apigenin pretreatments, but naringenin only promoted the excretion of IL-10. Additionally, naringenin and apigenin regulated antioxidant defense and inflammatory response by activating nuclear factor erythroid-2 related factor 2-dependent mechanisms and suppressing the expression of nuclear factor-kappa B. In summary, naringenin and apigenin are prospective ingredients that contribute to the amelioration of skin damage by activating anti-inflammatory and antioxidative responses.

Heavy metal stress is a significant factor in diminishing crop yield. Plant-derived smoke (PDS) has been used as a growth promoter and abiotic stress alleviator for the last two decades. Although the roles of PDS have been determined in various plants, its role in ameliorating heavy metal stress in wheat has not been reported so far. Therefore, the present work was conducted to investigate the effect of smoke solution extracted from a wild lemongrass Cymbopogon jwarancusa (C. jwarncusa) on physiological and biochemical features of wheat under arsenic (As) and mercury (Hg) stress. The results showed that higher concentrations of As and Hg pose inhibitory effects on wheat seed germination and seedling growth, including shoot/root length and shoot/root fresh weight. Photosynthetic pigments, such as chlorophyll a and b and carotenoids, were significantly decreased under As and Hg stress. Importantly, the levels of H2O2, lipid peroxidation, and TBARS were increased in wheat seedlings. The activity of antioxidant enzymes, such as CAT, was decreased by As and Hg stress, while the levels of SOD, POD, and APX antioxidant enzymes were increased in root and shoot. Interestingly, the application of PDS (2000 ppm), individually or in combination with either As or Hg stress, enhanced wheat seed germination rate, shoot/root length, and shoot/root fresh weight. However, the levels of H2O2, lipid peroxidation, and TBARS were decreased. Similarly, the levels of SOD, POD, and APX were decreased by PDS under As and Hg stress, while the level of CAT was enhanced by PDS under As and Hg stress. Interestingly, the levels of chlorophyll a and b, and total carotenoids were increased with the application of PDS under As and Hg stress. It is concluded that PDS has the capability to alleviate the phytotoxic effects of As and Hg stress in wheat by modulating the antioxidative defense system and could be an economical solution to reduce the heavy metal stress in crops. [ABSTRACT FROM AUTHOR]

Purpose: determination of the state of the antioxidant protection system of the cytosolic fraction and suspension of rat liver mitochondria after experimental ischemia and reperfusion. Materials and methods: the study was conducted using white mature rats, divided into 3 groups: the control group (n = 15); The 2nd group of animals (n = 15), from which the liver was taken after 15 minutes of liver ischemia; the 3rd group of rats (n = 15), from which the liver was taken after a 15-minute reperfusion period, followed by a 15-minute ischemic period. Mitochondrial suspension and cytosolic fraction were isolated from liver tissue. Results: the obtained research results showed the presence of certain pathobiochemical changes in the suspension of mitochondria and the cytosolic fraction after ischemia or reperfusion. In the mitochondrial suspension during the reperfusion period it was found an adaptive increase in the activity of glutathione peroxidase by 39% and glutathione reductase by 61%. In the cytosolic fraction, it was the most remarkable increase of the total antioxidant capacity by 38% already during ischemia and a progressive decrease in the level of reduced glutathione form by 26% in ischemic and 55% in reperfusion period. The change in the state of the antioxidant system occurred against the background of an increase in the number of products of oxidative modifications of biomolecules by 40% during ischemia and 2.2 times after reperfusion. Conclusion: The results indicate the need to develop not only a mitochondria-oriented correction of oxidative disorders, but also active support for the components of the cytosol, which provide the main accumulation of free radical damage products and their subsequent removal from the cell, which is essential for survival.

Adult Sessile and Pedunculate oak (Quercus petraea Liebl. & Q. robur L.) and their offsprings were assessed for the antioxidative capacity. The antioxidative capacity is a quantitative trait for the capability of animate beings to remove reactive oxygen species by means of antioxidants. Factors were climate and weather drought constraints, oxidative load, biomembrane damage, antioxidative system and tannins. There was substantial total antioxidative capacity of about 400 µmol ascorbate-equivalents / g dry matter in the Sessile and Pedunculate oak leaves, however, unimpacted by adverse environments (cf. Tab. 4, 5). Instead, it is correlated to total phenolics in a clearly positive way, particularly through the essential oak ellagitannins vescalagine and castalagine (cf. Fig. 3, 4). Total phenolics driven antioxidative capacity is accumulated in convenient environments and consumed in adverse situations. When grown under common conditions offspring from humid oldgrowth stands tended to accumulate more total antioxidative capacity in a favourable environment and used it up under drought constraints. On the other hand, the saplings from arid oldgrowth stands held their total antioxidative capacity constant even in a more adverse environment (cf. Fig. 5; Tab. 8). [ABSTRACT FROM AUTHOR]

Two wheat genotypes forming high and low biomass, exhibiting differential expression of an isoflavone reductase -like (IRL) gene, and resulting in contrasting grain yield under heat stress field conditions were analyzed in detail for their responses under controlled heat and elevated CO2 conditions. Significant differences in IRL expression between the two lines were hypothesized to be the basis of their differential performance under the tested conditions and their stress tolerance potential. By a holistic approach integrating advanced cell physiological phenotyping of the antioxidative and phytohormone system in spikes and leaves with measurements of ecophysiological and agronomic traits, the genetic differences of the genotypes in IRL expression were assessed. In response to heat and elevated CO2, the two genotypes showed opposite regulation of IRL expression, which was associated with cytokinin concentration, total flavonoid contents, activity of superoxide dismutase, antioxidant capacity and photosynthetic rate in leaves, and cytokinin concentration and ascorbate peroxidase activity in spikes. Our study showed that IRL expression is associated with wheat yield performance under heat stress at anthesis, mediated by diverse physiological mechanisms. Hence, based on our results, the IRL gene is a promising candidate for developing genetic markers for breeding heat-tolerant wheat. [ABSTRACT FROM AUTHOR]

Waterlogging is one of the major abiotic stresses in agricultural crop production. However, the application of 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin) can effectually mitigate the losses of nitrogen efficiency and grain yield of summer maize induced by waterlogging. In order to explore its role to alleviate waterlogging stress on leaf antioxidative system and photosynthetic characteristics of summer maize, a field experiment was executed to research effects of nitrapyrin application on leaf photosynthetic and senescent characteristics of waterlogged summer maize Denghai 605 (DH605) and Zhengdan 958 (ZD958). Experimental treatments consisted of waterlogging treatment that was applying only urea (WL), waterlogging treatment that was applying urea mixing with nitrapyrin (WL-N), and no waterlogging treatment that was only applying urea (NWL). Results showed that WL significantly decreased leaf area index (LAI), SPAD, photosynthetic rate (Pn), and protective enzyme activities, accelerated leaf aging, eventually led to a remarkable yield reduction by 38 and 42% for DH605 and ZD958, respectively, compared to NWL. However, the application of nitrapyrin was useful for relieving waterlogging damages on leaf photosynthetic ability. LAI, SPAD and Pn of WL-N for DH605 were 10, 19 and 12–24% higher, and for ZD958 were 12, 23 and 7–25% higher, compared to those of WL, respectively. Moreover, application of nitrapyrin effectually relieved waterlogging losses on antioxidative enzyme activities. Leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities of WL-N were averagely increased by 24, 15 and 30%, respectively, while malondialdehyde (MDA) content was averagely decreased by 13%, compared to those of WL. Visibly, nitrapyrin application could improve leaf photosynthetic characteristics and retard leaf aging induced by waterlogging, thereby leading to a yield increase of waterlogged maize.

Compared to other soil remediation technologies, Cd-contaminated farmland soil with low cadmium accumulation (LCA) plant-based safe utilization is more catered to developing countries with food in high demand. Hormesis, which describes the fortification of plant growth performance by a low level of environmental stress, can be innovatively used to achieve increases in crop yield and plant functional components, thus amplifying the safe utilization efficiency of low Cd-contaminated soil by LCA plants. In the present study, the growth and physiological responses of Polygonatum sibiricum, a traditional Chinese medicinal herb, were investigated under laboratory conditions of gradient Cd dosage concentrations and times. As a result, the growth performance of P. sibiricum reached the peak of an inverse U-shaped curve of hormesis under e0 mg kg−1 and 9 months of Cd stress, with elevations in tuber biomass (medicinal part), plant height and polysaccharide content (medicinal components) of 143%, 25% and 90%, respectively. Meanwhile, trace Cd accumulation (0.41 mg kg−1) in the tuber guaranteed medicinal edible safety. In addition, Cd-induced hormesis in P. sibiricum was verified to be overcompensated by antioxidation systems. In conclusion, such ‘win-win’ results, including low Cd accumulation and enhancement of plant pharmaceutical value, provided medicinal herbs with a possibility for safe soil utilization.

Nanoscale zero-valent iron (nZVI) shows an excellent degradation effect on chlorinated contaminants in soil, but poses a threat to plants in combination with phytoremediation. Arbuscular mycorrhizal (AM) fungus can reduce the phyototoxicity of nZVI, but their combined impacts on polychlorinated biphenyls (PCBs) degradation and plant growth remain unclear. Here, a greenhouse pot experiment was conducted to investigate the influences of nZVI and/or Funneliformis caledonium on soil PCB degradation and ryegrass (Lolium perenne L.) antioxidative responses. The amendment of nZVI significantly reduced not only the total and homolog concentrations of PCBs in the soil, but also the ryegrass biomass as well as soil available P and root P concentrations. Moreover, nZVI significantly decreased leaf superoxide disutase (SOD) activity, while tended to decrease the protein content. In contrast, the additional inoculation of F. caledonium significantly increased leaf SOD activity and protein content, while tended to increase the catalase activity and tended to decrease the malondialdehyde content. The additional inoculation of F. caledonium also significantly increased soil alkaline phosphatase activity, and tended to increase root P concentration, but had no significantly effects on soil available P concentration, the biomass and P acquisition of ryegrass, which could be attributed to the fixation of soil available nutrients by nZVI. Additionally, F. caledonium facilitated PCB degradation in the nZVI-applied soil. Thus, AM fungus can alleviate the nZVI-induced phytotoxicity, showing great application potentials in accompany with nZVI for soil remediation.

The influence of 24-epibrassinolide (24-EBL) and nitric oxide donor sodium nitroprusside (SNP) on the state of antioxidative system and heat resistance of wheat (Triticum aestivum L.) plantlets has been investigated. The treatment with 24-EBL (20–200 nM) or with SNP (0.1–2.0 mM) increased the survival of plantlets after 10-min damaging heating at 46 °C in the water thermostat. The cotreatment with 20 nM of 24-EBL and 0.2 mM of SNP caused more essential protective influence in comparison with the treatment by each compound separately. At the same time, joint influence of high concentrations (200 nM of 24-EBL and 2 mM of SNP) reduced the heat resistance of plantlets. Under the influence of 24-EBL and SNP in concentrations that have protective effect, as well as their combinations, the activity of superoxide dismutase (SOD) in roots increased. After damaging heating, the highest value of SOD activity remained in the variant with cotreatment of plantlets with 20 nM of 24-EBL and 0.2 mM of SNP. The activity of catalase and guaiacol peroxidase (GPX) in plantlets roots increased under the influence of various concentrations of SNP and its combinations with 24-EBL. At the same time, 24-EBL alone did not exert the impact on the catalase activity and caused the decrease in GPX activity. The activity of these enzymes decreased in all variants of experiment after heating. The heat stress caused the increase in the content of lipid peroxidation product malonic dialdehyde. The treatment of plantlets with 24-EBL and also its combination with SNP in low concentrations removed this effect, but in high concentrations, on the contrary, increased it. The conclusion was made that intensifying of protective influence of 24-EBL and SNP on wheat plantlets at their combined application in low concentrations is substantially caused by stabilization of pro-/antioxidative balance. [ABSTRACT FROM AUTHOR]

Heavy metal stress is a significant factor in diminishing crop yield. Plant-derived smoke (PDS) has been used as a growth promoter and abiotic stress alleviator for the last two decades. Although the roles of PDS have been determined in various plants, its role in ameliorating heavy metal stress in wheat has not been reported so far. Therefore, the present work was conducted to investigate the effect of smoke solution extracted from a wild lemongrass Cymbopogon jwarancusa (C. jwarncusa) on physiological and biochemical features of wheat under arsenic (As) and mercury (Hg) stress. The results showed that higher concentrations of As and Hg pose inhibitory effects on wheat seed germination and seedling growth, including shoot/root length and shoot/root fresh weight. Photosynthetic pigments, such as chlorophyll a and b and carotenoids, were significantly decreased under As and Hg stress. Importantly, the levels of H2O2, lipid peroxidation, and TBARS were increased in wheat seedlings. The activity of antioxidant enzymes, such as CAT, was decreased by As and Hg stress, while the levels of SOD, POD, and APX antioxidant enzymes were increased in root and shoot. Interestingly, the application of PDS (2000 ppm), individually or in combination with either As or Hg stress, enhanced wheat seed germination rate, shoot/root length, and shoot/root fresh weight. However, the levels of H2O2, lipid peroxidation, and TBARS were decreased. Similarly, the levels of SOD, POD, and APX were decreased by PDS under As and Hg stress, while the level of CAT was enhanced by PDS under As and Hg stress. Interestingly, the levels of chlorophyll a and b, and total carotenoids were increased with the application of PDS under As and Hg stress. It is concluded that PDS has the capability to alleviate the phytotoxic effects of As and Hg stress in wheat by modulating the antioxidative defense system and could be an economical solution to reduce the heavy metal stress in crops.

A plants' physiology maybe affected by various pesticides through the activation or inactivation of different biochemical pathways in target and non-target plants. In response to pesticides as xenobiotics, plants activate their antioxidant defense systems through both enzymatic and non-enzymatic pathways. In this study, two of the most common pesticides used to control cucumber whiteflies, imidacloprid and dichlorvos were sprayed on cucumber seedlings. Treatment with both pesticides significantly increased the activity of superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxide, and phenylalanine ammonia-lyase. Moreover, total protein, proline, total soluble carbohydrates, and total phenolic content showed a significant elevation in response to the treatment with both pesticides compared to the control. The effects of the separate use of pesticides resulted in variation in the peak day of physiological changes in treated plants. Further experiments showed that pesticide treatment leads to a significant decrease in polyphenol oxidase activity, but no significant changes in contents of hydrogen peroxide, malondialdehyde, and electrolyte leakage index were found. Our results suggest that imidacloprid and dichlorvos had profound effects on the physiological status of cucumber plants at recommended rates. Our data also showed that the responses were similar between the two pesticides with differences in response times following treatment. [ABSTRACT FROM AUTHOR]

Peach (Prunus persica L. Batsch) is a shallow root fruit tree with poor waterlogging tolerance. Hydrogen sulfide (H2S) is a signal molecule which regulates the adaptation of plants to adverse environments. Nevertheless, the effects of exogenous applications of H2S in fruit tree species especially in peach trees under waterlogging stress have been scarcely researched. Thus, the goal of this research was to investigate the alleviating effect of exogenous H2S on peach seedlings under waterlogging stress. In the present study, we found that the effect of exogenous H2S depended on the concentration and 0.2 mM sodium hydrosulfide (NaHS) showed the best remission effect on peach seedlings under waterlogging stress. Waterlogging significantly reduced the stomatal opening, net photosynthetic rate, and Fv/Fm of peach seedlings. The results of histochemical staining and physiological and biochemical tests showed that waterlogging stress increased the number of cell deaths and amounts of reactive oxygen species (ROS) accumulated in leaves, increased the number of root cell deaths, significantly increased the electrolyte permeability, O2.– production rate, H2O2 content and ethylene synthesis rate of roots, and significantly reduced root activity. With prolonged stress, antioxidative enzyme activity increased initially and then decreased. Under waterlogging stress, application of 0.2 mM NaHS increased the number of stomatal openings, improved the chlorophyll content, and photosynthetic capacity of peach seedlings. Exogenous H2S enhanced antioxidative system and significantly alleviate cell death of roots and leaves of peach seedlings caused by waterlogging stress through reducing ROS accumulation in roots and leaves. H2S can improve the activity and proline content of roots, reduce oxidative damage, alleviated lipid peroxidation, and inhibit ethylene synthesis. The H2S scavenger hypotaurine partially eliminated the effect of exogenous H2S on alleviating waterlogging stress of peach seedlings. Collectively, our results provide an insight into the protective role of H2S in waterlogging-stressed peach seedlings and suggest H2S as a potential candidate in reducing waterlogging-induced damage in peach seedlings.

20-Hydroxyecdysone (20E), a molting hormone of insects, is the most abundant phytoecdysteroid (PE) produced by plants, where it represents a protective molecule against insect herbivores. The objective of the investigation is to determine the effect of 20E on the growth, physiological and biochemical characteristics and the transcript levels of antioxidant enzymes of wheat seedlings under salt stress. Our results showed that exogenous 20E was able to significantly alleviate salt-induced oxidative damage in wheat seedlings. It most likely acts by decreasing the concentration of malondialdehyde (MDA) and the rate of superoxide radical (O2 •−) generation, and by increasing the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), concentrations of ascorbic acid (AsA) and glutathione (GSH), and the gene expression levels of SOD, POD, CAT. It was suggested that foliar spraying with 20E could efficiently protect wheat seedlings against salt-induced oxidative stress. The results also show that 20E had a positive physiological effect on the growth of salt-stressed seedlings. This is the first report dealing with the effect of 20E pretreatment in the enhancing of wheat seedling tolerance under salt stress.

Metasequoia glyptostroboides is an endangered relict plant native to China that has been widely introduced into many countries and areas around the world. However, its seeds germinate at a very low percentage. Consequently, population regeneration by seed is low under natural conditions, which probably contributes to the endangered status of this plant species. The present study aimed to describe the aging mechanism of M. glyptostroboides seeds. Our objective was to elucidate causes of the low germination rate in an effort to enhance potential for conservation of the species. We used germination tests, relative electrical conductivity and malondialdehyde content determination, ultrastructural observation of embryo cells, and analysis of superoxide dismutase, catalase, ascorbate peroxidase, and dehydroascorbate reductase activities during accelerated aging treatment. We found that M. glyptostroboides seeds have a low level of vigor and poor ability to maintain vigor, which is probably associated with the inefficiency of its enzymatic antioxidative system. [ABSTRACT FROM AUTHOR]

Peach (Prunus persica L. Batsch) is a shallow root fruit tree with poor waterlogging tolerance. Hydrogen sulfide (H2S) is a signal molecule which regulates the adaptation of plants to adverse environments. Nevertheless, the effects of exogenous applications of H2S in fruit tree species especially in peach trees under waterlogging stress have been scarcely researched. Thus, the goal of this research was to investigate the alleviating effect of exogenous H2S on peach seedlings under waterlogging stress. In the present study, we found that the effect of exogenous H2S depended on the concentration and 0.2 mM sodium hydrosulfide (NaHS) showed the best remission effect on peach seedlings under waterlogging stress. Waterlogging significantly reduced the stomatal opening, net photosynthetic rate, and Fv/Fm of peach seedlings. The results of histochemical staining and physiological and biochemical tests showed that waterlogging stress increased the number of cell deaths and amounts of reactive oxygen species (ROS) accumulated in leaves, increased the number of root cell deaths, significantly increased the electrolyte permeability, O2.– production rate, H2O2 content and ethylene synthesis rate of roots, and significantly reduced root activity. With prolonged stress, antioxidative enzyme activity increased initially and then decreased. Under waterlogging stress, application of 0.2 mM NaHS increased the number of stomatal openings, improved the chlorophyll content, and photosynthetic capacity of peach seedlings. Exogenous H2S enhanced antioxidative system and significantly alleviate cell death of roots and leaves of peach seedlings caused by waterlogging stress through reducing ROS accumulation in roots and leaves. H2S can improve the activity and proline content of roots, reduce oxidative damage, alleviated lipid peroxidation, and inhibit ethylene synthesis. The H2S scavenger hypotaurine partially eliminated the effect of exogenous H2S on alleviating waterlogging stress of peach seedlings. Collectively, our results provide an insight into the protective role of H2S in waterlogging-stressed peach seedlings and suggest H2S as a potential candidate in reducing waterlogging-induced damage in peach seedlings. [ABSTRACT FROM AUTHOR]

Deinococcus radiodurans is famous for its extreme resistance to various stresses such as ionizing radiation (IR), desiccation and oxidative stress. The underlying mechanism of exceptional resistance of this robust bacterium still remained unclear. However, the antioxidative system of D. radiodurans has been considered to be the determinant factor for its unparalleled resistance and protects the proteome during stress, then the DNA repair system and metabolic system exert their functions to restore the cell to normal physiological state. The antioxidative system not only equipped with the common reactive oxygen species (ROS) scavenging enzymes (e.g., catalase and superoxide dismutase) but also armed with a variety of non-enzyme antioxidants (e.g., carotenoids and manganese species). And the small manganese complexes play an important role in the antioxidative system of D. radiodurans. Recent studies have characterized several regulators (e.g., PprI and PprM) in D. radiodurans , which play critical roles in the protection of the bacteria from various stresses. In this review, we offer a panorama of the progress regarding the characteristics of the antioxidative system in D. radiodurans and its application in the future. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the morphophysiological and biochemical responses of the species Lippia grata Schauer to water deficit. Plants from cuttings were submitted to two water regimes, irrigation (control) and suspended irrigation (stress) for 15 days and were then rehydrated for 10 days. During water regimes, we performed physiological (gas exchange, growth parameters, and biochemical) and anatomical analyses. The water deficit negatively affected growth of the aerial part of the plant with reduction of approximately 72%. On the contrary, root system growth was stimulated by water deficit (increase of 205%). The drought caused a reduction in the physiological parameters (gs, E, and A), while leaf temperature and internal and external CO2 concentration ratio (Ci/Ca) increased. Plants subjected to drought had higher intrinsic efficiency of water use on the 10th day of deficit (A/gs). The levels of total chlorophyll, carotenoids, and soluble carbohydrates increased on the 10th and 15th days of water suspension. The levels of H2O2, proteins, and MDA were high in plants on the 15th day of water deficit. The levels of H2O2 in the control plants increased on the 20th and 25th day of rehydration, along with the activation of some enzymes of the antioxidative system SOD, CAT and APX. Plants under water deficit increased SOD activity on the 10th day and CAT on the 10th and 15th day under stress. Plants submitted to water deficit showed reduction of mesophilic thickness, smaller epidermal cells, reduction of intercellular spaces, more vascular bundles, greater lignification of xylem cells, morphological modification of cortical cells, and have more glandular trichomes in the abaxial face compared to plants always irrigated. During rehydration, the plants submitted to the water deficit recovered in all variables analyzed and have a higher density of glandular and the tector trichomes in both epidermises, adaxial and abaxial. We conclude that the rapid recovery of the parameters evaluated for Lippia grata are related to the absence of irreversible damage in the cellular structures, due to the efficiency of the antioxidative system, and metabolic processes involved with the dissipation of the excess energy because of the imposed water stress. In addition, other important morphophysiological strategies such as increased root growth, increased vascular bundles and density of trichomes improved soil water absorption and maintained the cellular water content in Lippia grata plants submitted to drought. [ABSTRACT FROM AUTHOR]

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Inthis study which was conducted under greenhouse conditions, the impacts of calcium and potassium compounds on the % DM (dry matter) and % EC (electrical conductivity), % RWC (relative water content), and proline, antioxidative system in tomato plant (LycopersiconesculentumMill.) under salt stress were investigated. Three different concentrations of salt (50, 100 and 150 mM as NaCl) and potassium and calcium (20 mM as KNO3and CaNO3) were applied. The compounds of Ca and K which were given in tomato plants in addition to salt,were regulated to antioxidative system, decreased lipid peroxidation increasing with salt and ameliorated RWC%, EC% and DM% by reducing the detrimental effects of salt. Based on these results, it was concluded that Ca and K compounds applied to tomato plant grown under salt stress, supported plant growth and mitigated stress effects.

As one of the common abiotic stresses, chilling stress has negative effects on rice growth and development. Minimization of these adverse effects through various ways is vital for the productivity of rice. Nanoparticles (NPs) serve as one of the effective alleviation methods against abiotic stresses. In our research, zinc oxide (ZnO) NPs were utilized as foliar sprays on rice leaves to explore the mechanism underlying the effect of NPs against the negative impact of chilling stress on rice seedlings. We revealed that foliar application of ZnO NPs significantly alleviated chilling stress in hydroponically grown rice seedlings, including improved plant height, root length, and dry biomass. Besides, ZnO NPs also restored chlorophyll accumulation and significantly ameliorated chilling-induced oxidative stress with reduced levels of H2O2, MDA, proline, and increased activities of major antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). We further found that foliar application of ZnO NPs induced the chilling-induced gene expression of the antioxidative system (OsCu/ZnSOD1, OsCu/ZnSOD2, OsCu/ZnSOD3, OsPRX11, OsPRX65, OsPRX89, OsCATA, and OsCATB) and chilling response transcription factors (OsbZIP52, OsMYB4, OsMYB30, OsNAC5, OsWRKY76, and OsWRKY94) in leaves of chilling-treated seedlings. Taken together, our results suggest that foliar application of ZnO NPs could alleviate chilling stress in rice via the mediation of the antioxidative system and chilling response transcription factors.

During life, anuran individuals undergo drastic changes in the course of transition from aquatic to terrestrial habitat, when they are faced with metabolically demanding processes (growth, responses to developmental pressures), which result in increased production of reactive oxygen species (ROS), signaling molecules involved in development that can induce oxidative damage and stress. This situation can be further complicated by environmental influences. The aim of this study was to investigate oxidative stress parameters in naturally developing Pelophylax esculentus complex frogs during four developmental periods: premetamorphosis, prometamorphosis, metamorphic climax and juvenile stage, in order to examine changes in the response of the antioxidative system (AOS) and oxidative damage during the transition from aquatic to terrestrial life. Results show that ontogenetic shifts in anurans are accompanied by different levels of damage and AOS responses, which vary from the increased first-line enzymatic activities during the early period of development (premetamorphosis), through increased changes in the non-enzymatic complement during the metamorphic climax, to changes in both the enzymatic and non-enzymatic components observed in juvenile individuals. Premetamorphic individuals and individuals in metamorphosis displayed higher levels of lipid peroxidation, indicating that direct exposure to the environment for the first time and the modulation of organs are the most susceptible stages for oxidative damage. On the other hand, lower oxidative damage in juveniles points to the ability of their AOS to efficiently respond to challenges of the terrestrial environment. This study highlights the importance of ROS and the AOS of anurans in response to different developmental and/or environmental pressures that individuals face. Unlabelled Image • Ontogenetic shifts in anurans are accompanied by different levels of oxidative stress. • Higher enzymatic antioxidative activities characterized premetamorphosis. • Higher levels in the non-enzymatic components characterized metamorphic climax. • Both the enzymatic and non-enzymatic components were higher in juveniles. • Higher levels of lipid peroxidation were in premetamorphosis and metamorphic climax. [ABSTRACT FROM AUTHOR]

Abstract Copper is an essential metal but potentially toxic to aquatic animals at high levels. The present study investigated physiologically adaptive responses to waterborne Cu2+ exposure (0, 0.03, 0.30, 3.00 mg/L) in a representative species of crustaceans, the red swamp crayfish (Procambarus clarkii) for 7 d, followed by a 7-d depuration period. The tissue-specific distribution of Cu showed that crayfish hepatopancreas was the primary accumulating site among internal tissues. During Cu2+ exposure, crayfish repressed the expression level of Cu homeostasis genes (Ctr1 , Atox1 , copper-transporting ATPase 2 , MTF-1 / 2 , and MT) in hepatopancreas to inhibit intracellular Cu transporting. Cu2+-exposed crayfish increased activities of GPx and GST, GSH contents, and mRNA expression of antioxidative enzyme genes (Cu/Zn-sod, cat, gpx, gst) to cope with the Cu2+-induced oxidative stress which accompanied by an increased MDA content. Additionally, after a 7-d depuration, crayfish effectively eliminated excess Cu from hepatopancreas by up-regulating expression level of Cu homeostasis genes, and recovered from oxidative damage by enhancing antioxidative enzyme gene expression (Cu/Zn-sod, cat, gpx, gst) and consuming more GSH, which thereby caused a return of the MDA level to the control value. Overall, our study provided new insights into the regulatory mechanisms of cellular Cu homeostasis system and antioxidative system, contributing to Cu detoxification and tolerance ability exhibited by crayfish under Cu2+ stress and after withdrawal of Cu2+ stress. Highlights • Crayfish hepatopancreas was the primary accumulating site among internal tissues. • Excessive Cu was completely eliminated from hepatopancreas after a 7-d depuration. • Crayfish regulated Cu homeostasis system to detoxify Cu during exposure and depuration. • Crayfish activated antioxidant system to tolerate and recover from oxidative stress. [ABSTRACT FROM AUTHOR]

Wheat blast, caused by Pyricularia oryzae, can cause large yield losses in crops. This study aimed to investigate defence responses in flag leaves and spikes of wheat cultivars BR‐18 (moderately resistant) and BRS‐Guamirim (susceptible), which differ in their levels of basal resistance. In contrast to cultivar BRS‐Guamirim, infected plants of cultivar BR‐18 showed more pronounced increases in activities of β‐1,3‐glucanase and chitinase as well as higher concentrations of lignin‐thioglycolic acid derivatives in the flag leaves and total soluble phenolics in the spikes. Polyphenoloxidase activity increased in both flag leaves and spikes in response to fungal infection, regardless of cultivar. Phenylalanine ammonia‐lyase (PAL) activity increased in infected flag leaves of both cultivars, especially in BR‐18. PAL activity was lower in spikes of infected compared to noninfected plants of both cultivars, although to a lesser extent in BR‐18. Compared to BRS‐Guamirim, the antioxidative system in both flag leaves and spikes of BR‐18 was more efficient in removing reactive oxygen species, reducing cellular damage caused by fungal infection. The lower catalase and peroxidase activities, associated with high superoxide dismutase activity, in flag leaves and spikes of infected BR‐18 culminated in a high hydrogen peroxide concentration. The increase in ascorbate peroxidase activity was higher in both flag leaves and spikes of infected plants of BR‐18 than in infected BRS‐Guamirim. It was concluded that wheat resistance to blast depended on the basal level of resistance of the cultivar, which was mainly associated with the activities of defence enzymes and a more effective antioxidative system. [ABSTRACT FROM AUTHOR]

In this study, exogenous spermidine role on Salix matsudana tolerance to cadmium was evaluated. Spermidine and cadmium presented antagonistic effects on the biomass, copper and zinc concentrations in S. matsudana. cadmium mainly distributed in the cell wall of subcellular fraction; 46.97%–60.43% of cadmium existed in a sodium chloride-extracted form. Cadmium contents in roots, leaves, and twigs ranged from 2002.67 to 3961.00, 111.59 to 229.72, and 102.56 to 221.27 mg/kg, respectively. Spermidine application elevated cadmium concentrations in the roots, cuttings, and cell wall and the ratio of deionized water-extracted cadmium, but decreased cadmium levels in the twigs and leaves and the fractions of cadmium extracted by ethanol and sodium chloride, respectively. Putrescine and malondialdehyde were important indicators of cadmium-induced oxidative damage. Exogenous spermidine alleviated the accumulation of superoxide anion, hydrogen peroxide, malondialdehyde via promoting the levels of spermidine, soluble protein, superoxide dismutase, reductive ascorbate, glutathione reductase, and glutathione peroxidase in S. matsudana leaves under the corresponding cadmium stress. The results indicated that S. matsudana was a candidate for cadmium rhizoremediation and extraction in leaves; the spermidine application enhanced the cadmium tolerance of S. matsudana through promoting cadmium accumulation in roots, cell wall, and less bioactive chemical forms and the antioxidative ability. [ABSTRACT FROM AUTHOR]

In the current study, pigeonpea (Cajanus cajan L.), a promising legume food crop was assessed for its photosynthetic physiology, antioxidative system as well as C and N metabolism under elevated CO2 and combined drought stress (DS). Pigeonpea was grown in open top chambers under elevated CO2 (600 µmol mol−1) and ambient CO2 (390 ± 20 µmol mol−1) concentrations, later subjected to DS by complete water withholding. The DS plants were re-watered and recovered (R) to gain normal physiological growth and assessed the recoverable capacity in both elevated and ambient CO2 concentrations. The elevated CO2 grown pigeonpea showed greater gas exchange physiology, nodule mass and total dry biomass over ambient CO2 grown plants under well-watered (WW) and DS conditions albeit a decrease in leaf relative water content (LRWC). Glucose, fructose and sucrose levels were measured to understand the role of hexose to sucrose ratios (H:S) in mediating the drought responses. Free amino acid levels as indicative of N assimilation provided insights into C and N balance under DS and CO2 interactions. The enzymatic and non-enzymatic antioxidants showed significant upregulation in elevated CO2 grown plants under DS thereby protecting the plant from oxidative damage caused by the reactive oxygen species. Our results clearly demonstrated the protective role of elevated CO2 under DS at lower LRWC and gained comparative advantage of mitigating the DS-induced damage over ambient CO2 grown pigeonpea. [ABSTRACT FROM AUTHOR]

Abstract Interest about interactions between microplastics and organisms is on the rise. Accessing organisms' responses to these chemically "inert" compounds plays an important role in determining their potential toxicity. Microplastics from the environment tend to accumulate and move through living organisms, inducing a variety of biological effects, such as disturbances in energy metabolism, oxidative balance, antioxidative capacity, DNA, immunological, neurological and histological damage. In the present review, we summarized the adverse effects of different size, concentrations and types of microplastics on animals' antioxidative system, energy metabolism and nervous system. Results showed that microplastics can: induce oxidative damage (increased lipid peroxidation and DNA strand breaks); alter antioxidative system (superoxide dismutase, catalase and glutathione peroxidase were parameters with the highest and significant changes in activities) and metabolism (isocitrate dehydrogenase and lactate dehydrogenase activity); and have neurotoxic effects (inhibition of acetylcholinesterase activity). The effects were depending on size and dose of used microplastics, and/or their interaction with other xenobiotics. We examined also potential strategies and offer research priorities for current and future studies. Highlights • Effects of microplastics depend on their size, dose and interaction. • Accumulated microplastics can display variety of biological effects. • Microplastics can induce oxidative stress and damage. • Microplastics affect normal metabolism and cholinesterase activity. • Microplastics can act as vector and modulate effects other xenobiotics. [ABSTRACT FROM AUTHOR]