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1.
Nitric Oxide ; 150: 37-46, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39038732

RESUMO

The combination of nitric oxide (NO) donors with nanomaterials has emerged as a promising approach to reduce postharvest losses. The encapsulation of NO donors provides protection from rapid degradation and controlled release, enhancing the NO effectiveness in postharvest treatments. Moreover, the application method can also influence postharvest responses. In this study, two application methods were evaluated, spraying and immersion, using S-nitrosoglutathione (GSNO, a NO donor) in free and encapsulated forms on papaya fruit. Our hypothesis was that GSNO encapsulated in chitosan nanoparticles would outperform the free form in delaying fruit senescence. In addition, this study marks the pioneering characterization of chitosan nanoparticles containing GSNO within the framework of a postharvest investigation. Overall, our findings indicate that applying encapsulated GSNO (GSNO-NP-S) through spraying preserves the quality of papaya fruit during storage. This method not only minimizes weight loss, ethylene production, and softening, but also stimulates antioxidant responses, thereby mitigating oxidative damage. Consequently, it stands out as the promising technique for delaying papaya fruit senescence. This innovative approach holds the potential to enhance postharvest practices and advance sustainable agriculture.


Assuntos
Carica , Quitosana , Frutas , Doadores de Óxido Nítrico , S-Nitrosoglutationa , Carica/química , Doadores de Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/química , Frutas/química , S-Nitrosoglutationa/farmacologia , S-Nitrosoglutationa/química , Quitosana/química , Quitosana/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Nanopartículas/química , Conservação de Alimentos/métodos
2.
Plant Physiol Biochem ; 194: 550-569, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36525937

RESUMO

Investigations of the compatibility between cacao genotypes of the population of the Parinari series (Pa), resulting from the reciprocal crossing of Pa 30 × Pa 169 and Pa 121 × Pa 169, allowed the verification of the occurrence of the recessive lethal single character called Luteus-Pa. These genotypes have this gene in heterozygosity, which when intercross or self-fertilize, segregate in a 3:1 ratio. Normal (NS) and mutant (MS) seedlings grow normally and, after a period of approximately 30 days of age, MS leaves begin to show a metallic yellow color, followed by necrotic spots, and death of the entire seedling, approximately 40 days after the emergency. The work evaluate the molecular, biochemical and micromorphological responses in NS and MS, with and without cotyledons, resulting from the crossing of the Pa 30 × Pa 169 cacao genotypes, aiming to elucidate the possible lethal mechanisms of the homozygous recessive Luteus-Pa. The presence of the lethal gene Luteus-Pa in the seedlings of the cacao genotypes of the population of the Parinari (Pa), with and without cotyledons, resulting from the crossing of Pa 30 × Pa 169, in addition to regulating the synthesis of proteins related to the photosynthetic and stress defense processes, promoted an increase in the synthesis of proteins involved in the glycolic pathway, induced oxidative stress, altered the mobilization of cotyledonary reserves, the integrity of cell membranes, leaf micromorphology and induced the death of seedlings, soon after depletion of protein and carbohydrate reserves, especially in the absence of cotyledons.


Assuntos
Cacau , Cacau/genética , Cacau/metabolismo , Plântula/genética , Plântula/metabolismo , Genes Letais , Cotilédone/genética , Genótipo
3.
Antioxidants (Basel) ; 11(9)2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36139800

RESUMO

Anthopleura hermaphroditica is an intertidal anemone that lives semi-buried in soft sediments of estuaries and releases its brooded embryos directly to the benthos, being exposed to potentially detrimental ultraviolet radiation (UVR) levels. In this study, we investigated how experimental radiation (PAR: photosynthetically active radiation; UVA: ultraviolet A radiation; and UVB: ultraviolet B radiation) influences burrowing (time, depth and speed) in adults and juveniles when they were exposed to PAR (P, 400-700 nm), PAR + UVA (PA, 315-700 nm) and PAR + UVA + UVB (PAB, 280-700 nm) experimental treatments. The role of sediment as a physical shield was also assessed by exposing anemones to these radiation treatments with and without sediment, after which lipid peroxidation, protein carbonyls and total antioxidant capacity were quantified. Our results indicate that PAB can induce a faster burial response compared to those anemones exposed only to P. PAB increased oxidative damage, especially in juveniles where oxidative damage levels were several times higher than in adults. Sediment offers protection to adults against P, PA and PAB, as significant differences in their total antioxidant capacity were observed compared to those anemones without sediment. Conversely, the presence or absence of sediment did not influence total antioxidant capacity in juveniles, which may reflect that those anemones have sufficient antioxidant defenses to minimize photooxidative damage due to their reduced tolerance to experimental radiation. Burrowing behavior is a key survival skill for juveniles after they have been released after brooding.

4.
Plant Physiol Biochem ; 190: 231-239, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36137309

RESUMO

This study aimed to investigate the roles of selenium (Se) application on the profile of photosynthetic pigments, oxidant metabolism, flavonoids biosynthesis, nodulation, and its relation to agronomic traits of peanut plants. Two independent experiments were carried out: one conducted in soil and the other in a nutrient solution. When the plants reached the V2 growth stage, five Se doses (0, 7.5, 15, 30, and 45 µg kg-1) and four Se concentrations (0, 5, 10, and 15 µmol L-1) were supplied as sodium selenate. The concentration of photosynthetic pigments, activity of antioxidant enzymes and the concentration of total sugars in peanut leaves increased in response to Se fertilization. In addition, Se improves nitrogen assimilation efficiency by increasing nitrate reductase activity which results in a higher concentration of ureides, amino acids and proteins. Se increases the synthesis of daidzein and genistein in the root, resulting in a greater number of nodules and concentration and transport of ureides to the leaves. Se-treated plants showed greater growth, biomass accumulation in shoots and roots, yield and Se concentration in leaves and grains. Our results contribute to food security and also to increase knowledge about the effects of Se on physiology, biochemistry and biological nitrogen fixation in legume plants.


Assuntos
Fabaceae , Selênio , Aminoácidos/metabolismo , Antioxidantes/metabolismo , Arachis/metabolismo , Fabaceae/metabolismo , Genisteína/metabolismo , Isoflavonas , Nitrato Redutases/metabolismo , Nitrogênio/metabolismo , Oxidantes/metabolismo , Ácido Selênico , Selênio/farmacologia , Solo , Açúcares/metabolismo
5.
FEBS Lett ; 596(23): 2989-3004, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35776057

RESUMO

Ascorbate peroxidases (APXs) are heme peroxidases that remove hydrogen peroxide in different subcellular compartments with concomitant ascorbate cycling. Here, we analysed and discussed phylogenetic and molecular features of the APX family. Ancient APX originated as a soluble stromal enzyme, and early during plant evolution, acquired both chloroplast-targeting and mitochondrion-targeting sequences and an alternative splicing mechanism whereby it could be expressed as a soluble or thylakoid membrane-bound enzyme. Later, independent duplication and neofunctionalization events in some angiosperm groups resulted in individual genes encoding stromal, thylakoidal and mitochondrial isoforms. These data reaffirm the complexity of plant antioxidant defenses that allow diverse plant species to acquire new means to adapt to changing environmental conditions.


Assuntos
Peroxidases , Tilacoides , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Tilacoides/metabolismo , Filogenia , Peroxidases/genética , Peroxidases/metabolismo , Cloroplastos/metabolismo , Peróxido de Hidrogênio/metabolismo , Antioxidantes , Regulação da Expressão Gênica de Plantas
6.
Front Plant Sci ; 13: 865291, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574093

RESUMO

Drought is one of the most important abiotic stresses responsible for reduced crop yields. Drought stress induces morphological and physiological changes in plants and severely impacts plant metabolism due to cellular oxidative stress, even in C4 crops, such as sugarcane. Seaweed extract-based biostimulants can mitigate negative plant responses caused by drought stress. However, the effects of foliar application of such biostimulants on sugarcane exposed to drought stress, particularly on plant metabolism, stalk and sugar yields, juice purity, and sugarcane technological quality, have received little attention. Accordingly, this study aimed to evaluate the effects of foliar application of a seaweed extract-based biostimulant on late-harvest sugarcane during the driest period of the year. Three experiments were implemented in commercial sugarcane fields in Brazil in the 2018 (site 1), 2019 (site 2), and 2020 (site 3) harvest seasons. The treatments consisted of the application and no application of seaweed extract (SWE) as a foliar biostimulant in June (sites 2 and 3) or July (site 1). The treatments were applied to the fourth ratoon of sugarcane variety RB855536 at site 1 and the fifth and third ratoons of sugarcane variety SP803290 at sites 2 and 3, respectively. SWE was applied at a dose of 500 ml a.i. ha-1 in a water volume of 100 L ha-1. SWE mitigated the negative effects of drought stress and increased stalk yield per hectare by up to 3.08 Mg ha-1. In addition, SWE increased stalk sucrose accumulation, resulting in an increase in sugar yield of 3.4 kg Mg-1 per hectare and higher industrial quality of the raw material. In SWE-treated plants, Trolox-equivalent antioxidant capacity and antioxidant enzyme activity increased, while malondialdehyde (MDA) levels decreased. Leaf analysis showed that SWE application efficiently improved metabolic activity, as evidenced by a decrease in carbohydrate reserve levels in leaves and an increase in total sugars. By positively stabilizing the plant's cellular redox balance, SWE increased biomass production, resulting in an increase in energy generation. Thus, foliar SWE application can alleviate drought stress while enhancing sugarcane development, stalk yield, sugar production, and plant physiological and enzymatic processes.

7.
J Assist Reprod Genet ; 39(6): 1277-1295, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35469374

RESUMO

PURPOSE: To study whether the cumulus cell antioxidant system varies accordingly to patients clinical characteristics' as age, infertility diagnosis, BMI, and stimulation protocol applied and if the antioxidant profile of cumulus cells could be used as a predictor of embryo development. METHODS: A prospective study including 383 human cumulus samples provided by 191 female patients undergoing intracytoplasmic sperm injection during in vitro fertilization treatments from a local in vitro fertilization center and processed in university laboratories. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) enzyme activity levels and reduced glutathione (GSH) levels were measured in cumulus oophorus cells individually collected from each aspirated cumulus-oocyte complex, and the results of each sample were compared considering the oocytes outcome after ICSI and patients clinical characteristics. A total of 223 other human cumulus samples from previous studies were submitted to a gene expression meta-analysis. RESULTS: The antioxidant system changes dramatically depending on patients' age, infertility diagnosis, stimulation protocol applied, and oocyte quality. SOD activity in cumulus cells revealed to be predictive of top-quality blastocysts for young patients with male factor infertility (P < 0.05), while GST levels were shown to be extremely influenced by infertility cause (P < 0.0001) and stimulation protocol applied (P < 0.05), but nonetheless, it can be used as a complementary tool for top-quality blastocyst prediction in patients submitted to intracytoplasmic sperm injection technique (ICSI) by male factor infertility (P < 0.05). CONCLUSION: Through a simple and non-invasive analysis, the evaluation of redox enzymes in cumulus cells could be used to predict embryo development, in a personalized matter in specific patient groups, indicating top-quality oocytes and improving success rates in in vitro fertilization treatments. TRIAL REGISTRATION: The trial was registered at UFRGS Research Ethics Committee and Plataforma Brasil under approval number 68081017.2.0000.5347 in June 6, 2019.


Assuntos
Células do Cúmulo , Infertilidade Masculina , Antioxidantes/metabolismo , Células do Cúmulo/fisiologia , Desenvolvimento Embrionário/genética , Feminino , Fertilização in vitro , Humanos , Infertilidade Masculina/metabolismo , Masculino , Oócitos/metabolismo , Estudos Prospectivos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
8.
Front Plant Sci ; 12: 645542, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33936132

RESUMO

Drought stress is an important concern worldwide which reduces crop yield and quality. To alleviate this problem, Trichoderma asperellum has been used as a plant growth-promoting fungus capable of inducing plant tolerance to biotic and abiotic stresses. Here, we examined the effect of T. asperellum inoculation on sugarcane plant above and belowground development under drought stress and investigated the role of this fungus on inducing tolerance to drought at physiological and biochemical levels. The experiment was performed in pots under greenhouse conditions, with four treatments and four replicates. The treatments consisted of sugarcane plants inoculated or not with T. asperellum and grown under drought stress and adequate water availability. Drought-stressed sugarcane plants inoculated with T. asperellum changed the crop nutrition and chlorophyll and carotenoid concentrations, resulting in increased photosynthesis rate, stomatal conductance, and water use efficiency compared to the non-inoculated plants. In addition, the antioxidant metabolism also changed, increasing the superoxide dismutase and peroxidase enzyme activities, as well as the proline concentration and sugar portioning. These cascade effects enhanced the root and stalk development, demonstrating that T. asperellum inoculation is an important tool in alleviating the negative effects of drought stress in sugarcane. Future studies should be performed to elucidate if T. asperellum should be reapplied to the sugarcane ratoons.

9.
Plant Physiol Biochem ; 164: 27-43, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33962229

RESUMO

Agronomic biofortification of crops with selenium (Se) is an important strategy to minimize hidden hunger and increase nutrient intake in poor populations. Selenium is an element that has several physiological and biochemical characteristics, such as the mitigation of different types of abiotic stress. Selenoproteins act as powerful antioxidants in plant metabolism through the glutathione peroxidase (GSH) pathway, and provide an increased activity for enzymatic (SOD, CAT, and APX) and non-enzymatic (ascorbic acid, flavonoids, and tocopherols) compounds that act in reactive oxygen species (ROS) scavenging system and cell detoxification. Selenium helps to inhibit the damage caused by climate changes such as drought, salinity, heavy metals, and extreme temperature. Also, Se regulates antenna complex of photosynthesis, protecting chlorophylls by raising photosynthetic pigments. However, Se concentrations in soils vary widely in the earth's crust. Soil Se availability regulates the uptake, transport, accumulation, and speciation in plants. Foliar Se application at the concentration 50 g ha-1 applied as sodium selenate increases the antioxidant, photosynthetic metabolism, and yield of several crops. Foliar Se application is a strategy to minimize soil adsorption and root accumulation. However, the limit between the beneficial and toxic effects of Se requires research to establish an optimal dose for each plant species under different edaphoclimatic conditions. In this review, we present the compilation of several studies on agronomic biofortification of plants with Se to ensure food production and food security to mitigate hidden hunger and improve the health of the population.


Assuntos
Selênio , Antioxidantes , Estado Nutricional , Espécies Reativas de Oxigênio , Ácido Selênico , Estresse Fisiológico
10.
Artigo em Inglês | MEDLINE | ID: mdl-33625697

RESUMO

Silver nanoparticles (AgNP) have been extensively applied in different industrial areas, mainly due to their antibiotic properties. One of the environmental concerns with AgNP is its incorrect disposal, which might lead to severe environmental pollution. The interplay between AgNP and plants is receiving increasing attention. However, little is known regarding the phytotoxic effects of biogenic AgNP on terrestrial plants. This study aimed to compare the effects of a biogenic AgNP and AgNO3 in Sorghum bicolor seedlings. Seeds were germinated in increasing concentrations of a biogenic AgNP and AgNO3 (0, 10, 100, 500, and 1000 µM) in a growth chamber with controlled conditions. The establishment and development of the seedlings were evaluated for 15 days. Physiological and morpho-anatomical indicators of stress, enzymatic, and non-enzymatic antioxidants and photosynthetic yields were assessed. The results showed that both AgNP and AgNO3 disturbed germination and the establishment of sorghum seedlings. AgNO3 released more free Ag+ spontaneously compared to AgNP, promoting increased Ag+ toxicity. Furthermore, plants exposed to AgNP triggered more efficient protective mechanisms compared with plants exposed to AgNO3. Also, the topology and connectivity of the correlation-based networks were more impacted by the exposure of AgNO3 than AgNP. In conclusion, it is plausible to say that the biogenic AgNP is less toxic to sorghum than its matrix AgNO3.

11.
Ecotoxicol Environ Saf ; 207: 111216, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916525

RESUMO

Low concentrations of selenium (Se) are beneficial for plant growth. Foliar Se application at high concentrations is toxic to plants due to the formation of reactive oxygen species (ROS). This study characterized Se toxicity symptoms using X-ray fluorescence (XRF) technique in response to foliar Se application in cowpea plants. Five Se concentrations (0, 10, 25, 50, 100 e 150 g ha-1) were sprayed on leaves as sodium selenate. The visual symptoms of Se toxicity in cowpea leaves were separated into two stages: I) necrotic points with an irregular distribution and internerval chlorosis at the leaf limb border (50-100 g ha-1); II) total chlorosis with the formation of dark brown necrotic lesions (150 g ha-1). Foliar Se application at 50 g ha-1 increased photosynthetic pigments and yield. Ultrastructural analyses showed that Se foliar application above 50 g ha-1 disarranged the upper epidermis of cowpea leaves. Furthermore, Se application above 100 g ha-1 significantly increased the hydrogen peroxide concentration and lipid peroxidation inducing necrotic leaf lesions. Mapping of the elements in leaves using the XRF revealed high Se intensity, specifically in leaf necrotic lesions accompanied by calcium (Ca) as a possible attenuating mechanism of plant stress. The distribution of Se intensities in the seeds was homogeneous, without specific accumulation sites. Phosphorus (P) and sulfur (S) were found primarily located in the embryonic region. Understanding the factors involved in Se accumulation and its interaction with Ca support new preventive measurement technologies to prevent Se toxicity in plants.


Assuntos
Selênio/metabolismo , Vigna/metabolismo , Peroxidação de Lipídeos , Fósforo/análise , Fotossíntese , Folhas de Planta/química , Sementes/química , Ácido Selênico/análise , Selênio/análise , Enxofre/análise
12.
Ecotoxicol Environ Saf ; 207: 111225, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916526

RESUMO

Hormesis is a favorable response to low level exposures to substance or to adverse conditions. This phenomenon has become a target to achieve greater crop productivity. This review aimed to address the physiological mechanisms for the induction of hormesis in plants. Some herbicides present a hormetic dose response. Among them, those with active ingredients glyphosate, 2,4-D and paraquat. The application of glyphosate as a hormesis promoter is therefore showing promess . Glyphosate has prominent role in shikimic acid pathway, decreasing lignin synthesis resulting in improved growth and productivity of several crops. Further studies are still needed to estimate optimal doses for other herbicides of crops or agricultural interest. Biostimulants are also important, since they promote effects on secondary metabolic pathways and production of reactive oxygen species (ROS). When ROS are produced, hydrogen peroxide act as a signaling molecule that promote cell walls malleability allowing inward water transport causing cell expansion. . Plants'ability to overcome several abiotic stress conditions is desirable to avoid losses in crop productivity and economic losses. This review compiles information on how hormesis in plants can be used to achieve new production levels.


Assuntos
Hormese/fisiologia , Fenômenos Fisiológicos Vegetais , Produtos Agrícolas/metabolismo , Produtos Agrícolas/fisiologia , Glicina/análogos & derivados , Herbicidas/farmacologia , Hormese/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Glifosato
13.
Ecotoxicol Environ Saf ; 209: 111772, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33316726

RESUMO

There are conclusive evidences of selenium (Se) deficiency in Brazilian soils and foods. Brazil is the largest producer and consumer of coffee worldwide, which favors agronomic biofortification of its coffee. This study aimed to evaluate effects of foliar application of three formulations and six rates of Se on antioxidant metabolism, agronomic biofortification and yield of coffee beans. Seven Se concentrations (0, 10, 20, 40, 80, 100 and 160 mg L-1) were applied from three formulations of Se (sodium selenate, nano-Se 1500, and nano-Se 5000). Selenium application up to 40 mg L-1 increased the concentration of photosynthetic pigments such as chlorophylls, pheophytins and carotenoids in coffee leaves. Foliar application of Se ranging from 20 to 80 mg L-1 decreased lipid peroxidation and concentration of hydrogen peroxide, but increased superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities in coffee leaves. These results indicated that foliar Se application stimulates antioxidative metabolism to mitigate reactive oxygen species. Foliar application of 20 mg Se L-1 of sodium selenate increased coffee yield by 38%, and 160 mg Se L-1 of nano-Se 5000 increased dramatically coffee yield by 42%. Selenium concentration in grains ranged from 0.116 to 4.47 mg kg-1 (sodium selenate), 4.84 mg kg-1 (nano-Se 1500) and 5.82 mg kg-1 (nano-Se 5000). The results suggest the beneficial effect of Se on the increment of photosynthetic pigments, antioxidative metabolism, increased coffee yield and nutritional quality of grains. The recommended foliar Se application in this study can mitigate abiotic stressors such as high temperatures resulting in higher yield of coffee plants.


Assuntos
Antioxidantes/farmacologia , Café/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Selênio/farmacologia , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Biofortificação/métodos , Catalase/metabolismo , Clorofila/metabolismo , Coffea , Peroxidação de Lipídeos , Oxirredução , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo , Ácido Selênico/metabolismo , Superóxido Dismutase/metabolismo
14.
Aquat Toxicol ; 230: 105717, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33307389

RESUMO

Anthropogenic changes such as ocean acidification, eutrophication, and the release of hazardous chemicals affect coastal environments and aquatic organisms. We investigated the effects of seawater pH (7.4 and 8.2) isolated and in combination with Irgarol on Ulva lactuca. Stress indicators such as membrane damage, lipid peroxidation, and hydrogen peroxide content were assessed. In addition, chlorophyll fluorescence and antioxidant enzyme activities were measured. The photosynthetic yield was affected by low pH in assays with and without Irgarol. However, the combination of low pH and Irgarol promoted photoinhibition, besides the induction of non-photochemical quenching (NPQ) and changes in photosynthetic pigment contents. The induction of NPQ was directly influenced by low pH. The membrane damage was increased in low pH with and without Irgarol exposure. Total soluble protein and carbohydrate contents decreased in low pH, and in presence of Irgarol. The H2O2 content and lipid peroxidation were not affected by low pH. In contrast, Irgarol exposure strongly increased lipid peroxidation in both pHs, suggesting a possible synergistic effect. To avoid the harmful effects of high H2O2, U. lactuca increased antioxidant enzyme activities in treatments under low pH and in presence of Irgarol. Our results indicate that U. lactuca is tolerant to low pH by inducing NPQ, changing pigment contents, and increasing antioxidant defenses. In contrast, these protective mechanisms could not avoid the harmful effects of the combination with Irgarol.


Assuntos
Antioxidantes/metabolismo , Desinfetantes/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Água do Mar/química , Triazinas/toxicidade , Ulva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Oceano Atlântico , Brasil , Eutrofização , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Fotossíntese/efeitos dos fármacos , Ulva/metabolismo
15.
Environ Sci Pollut Res Int, v. 28, p. 32669–32682, fev. 2021
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3585

RESUMO

Silver nanoparticles (AgNP) have been extensively applied in different industrial areas, mainly due to their antibiotic properties. One of the environmental concerns with AgNP is its incorrect disposal, which might lead to severe environmental pollution. The interplay between AgNP and plants is receiving increasing attention. However, little is known regarding the phytotoxic effects of biogenic AgNP on terrestrial plants. This study aimed to compare the effects of a biogenic AgNP and AgNO3 in Sorghum bicolor seedlings. Seeds were germinated in increasing concentrations of a biogenic AgNP and AgNO3 (0, 10, 100, 500, and 1000 μM) in a growth chamber with controlled conditions. The establishment and development of the seedlings were evaluated for 15 days. Physiological and morpho-anatomical indicators of stress, enzymatic, and non-enzymatic antioxidants and photosynthetic yields were assessed. The results showed that both AgNP and AgNO3 disturbed germination and the establishment of sorghum seedlings. AgNO3 released more free Ag+ spontaneously compared to AgNP, promoting increased Ag+ toxicity. Furthermore, plants exposed to AgNP triggered more efficient protective mechanisms compared with plants exposed to AgNO3. Also, the topology and connectivity of the correlation-based networks were more impacted by the exposure of AgNO3 than AgNP. In conclusion, it is plausible to say that the biogenic AgNP is less toxic to sorghum than its matrix AgNO3.

16.
Ecotoxicol Environ Saf ; 201: 110777, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485493

RESUMO

Selenium (Se) is a beneficial element to higher plants. Application of Se at low concentrations enhances the antioxidant metabolism reducing the reactive oxygen species (ROS) generated by plant membrane cells. This study aimed to evaluate how the application of Se in the forms sodium selenate and sodium selenite regulates ROS scavenging in field-grown cowpea plants. Seven Se application rates (0; 2.5; 5; 10; 20; 40 and 60 g ha-1) of each of the two Se forms were applied to plants via the soil. Photosynthetic pigments concentration, gas exchange parameters, lipid peroxidation by malondialdehyde (MDA) concentration, hydrogen peroxide concentration, activity of catalase (CAT, EC:1.11.1.6), glutathione reductase (GR, EC:1.6.4.2), ascorbate peroxidase (APX, EC:1.11.1.11) and Se concentration in leaves and grains were evaluated. In general, Se application led to a decrease in chlorophyll a concentration whilst leading to an increase in chlorophyll b, indicating conservation of total chlorophyll concentration. Application of 2.5 g ha-1 of Se as selenate provided a notable increase in total chlorophyll and total carotenoids compared to the other application rates. Selenate and selenite application decreased lipid peroxidation. However, each Se source acted in a different pathway to combat ROS. While selenate showed more potential to increase activity of APX and GR, selenite showed a higher potential to increase CAT activity. The negative correlation between CAT and GR is indicative that both pathways might be activated under distinct circumstances. The more prominent activity of CAT under high rates of selenite resulted in a negative correlation of this enzyme with chlorophyll a and carotenoids. Both selenate and selenite application increased sucrose and total sugars concentration in leaves of cowpea plants. Overall, these results indicate that application of Se in cowpea under field conditions stimulates distinct pathways to scavenge ROS. This could prove beneficial to mitigate oxidative stress during plant development.


Assuntos
Espécies Reativas de Oxigênio/metabolismo , Ácido Selênico/toxicidade , Ácido Selenioso/toxicidade , Vigna/efeitos dos fármacos , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Clorofila , Clorofila A , Glutationa Redutase/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Ácido Selênico/metabolismo , Ácido Selenioso/metabolismo , Selênio/metabolismo , Selenito de Sódio , Vigna/metabolismo , Vigna/fisiologia
17.
Ecotoxicology ; 29(5): 594-606, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32333252

RESUMO

Cadmium (Cd) is probably the most damaging metal to plant species; with a long biological half-life, it can be taken up by plants, disrupting the cell homeostasis and triggering several metabolic pathways. Selenium (Se) improves plant defence systems against stressful conditions, but the biochemical antioxidant responses to Cd stress in tomato plants is poorly understood. To further address the relationship of Cd-stress responses with Se mineral uptake, Cd and Se concentration, proline content, MDA and H2O2 production, and the activity of SOD, APX, CAT and GR enzymes were analyzed in Micro-Tom (MT) plants submitted to 0.5 mM Cd. The results revealed different responses according to Se combination and Cd application. For instance, roots and leaves of MT plants treated with Se exhibited an increase in dry mass and nutritional status, exhibited lower proline content and higher APX and GR activities when compared with plants with no Se application. Plants submitted to 0.5 mM Cd, irrespective of Se exposure, exhibited lower proline, MDA and H2O2 content and higher SOD, CAT and GR activities. Selenium may improve tolerance against Cd, which allowed MT plants exhibited less oxidative damage to the cell, even under elevated Cd accumulation in their tissues. The results suggest that Se application is an efficient management technique to alleviate the deleterious effects of Cd-stress, enhancing the nutritional value and activity of ROS-scavenging enzymes in tomato plants.


Assuntos
Cádmio/toxicidade , Estresse Oxidativo/fisiologia , Selênio/metabolismo , Poluentes do Solo/toxicidade , Solanum lycopersicum/fisiologia , Antioxidantes , Glutationa , Peróxido de Hidrogênio , Oxirredução , Folhas de Planta , Raízes de Plantas
18.
Acta sci. vet. (Impr.) ; 46: 1-5, 2018. tab
Artigo em Inglês | VETINDEX | ID: biblio-1457840

RESUMO

Background: Cutaneous papillomas are benign proliferative neoplasms. The aetiology and pathogenesis of the disease are very complex. Papillomatosis lesions can be detected anywhere on the body, frequently appearing on the surface of the head, neck, teats, udder, external genital mucosa and upper part of the gastrointestinal tract. The disease is not life threatening but due to loss of productivity, owners often cull animals with papillomatosis. The relationships between trace elements, heavy metals and cancer are still researching. The aim of this study was the evaluation of the relationships between trace elements and antioxidant metabolism, and cutaneous papillomatosis, in cattle.Materials, Methods & Results: Eleven cattle with cutaneous papillomatosis and 10 healthy cattle constituted the study group and control group, respectively. Clinical examinations were performed on all animals. Blood samples were collected and Cr, Cu, Fe, Mg, Mn, Se, Zn, As, B, Ni, Si and Co levels were determined. The analyses were conducted with an inductively coupled plasma-optical emission spectrophotometer. In addition, catalase (CAT), glutathione (GSH), malondialdehyde (MDA) and ceruloplasmin (Cp) concentrations were measured. The Ni, Si and MDA levels of the study group were significantly higher than those of the control group (P < 0.05) but the Se levels of the study group were significantly lower than in the control group (P < 0.05). The normality of the data was determined with the Shapiro-Wilk Test and the Independent Samples t-Test or Mann-Whitney U test was used for statistical comparison of the groups.Discussion: Trace elements are essential components of biological systems. The levels of trace elements, such as Cu, Co, I, Se, Zn and Mn, which are affected by grazing activity, influence ruminants’ reproductive performance and other production parameters.[...]


Assuntos
Animais , Bovinos , Antioxidantes/análise , Antioxidantes/metabolismo , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/veterinária , Oligoelementos/análise , Papiloma/veterinária , Imunidade
19.
Acta sci. vet. (Online) ; 46: 1-5, 2018. tab
Artigo em Inglês | VETINDEX | ID: vti-728671

RESUMO

Background: Cutaneous papillomas are benign proliferative neoplasms. The aetiology and pathogenesis of the disease are very complex. Papillomatosis lesions can be detected anywhere on the body, frequently appearing on the surface of the head, neck, teats, udder, external genital mucosa and upper part of the gastrointestinal tract. The disease is not life threatening but due to loss of productivity, owners often cull animals with papillomatosis. The relationships between trace elements, heavy metals and cancer are still researching. The aim of this study was the evaluation of the relationships between trace elements and antioxidant metabolism, and cutaneous papillomatosis, in cattle.Materials, Methods & Results: Eleven cattle with cutaneous papillomatosis and 10 healthy cattle constituted the study group and control group, respectively. Clinical examinations were performed on all animals. Blood samples were collected and Cr, Cu, Fe, Mg, Mn, Se, Zn, As, B, Ni, Si and Co levels were determined. The analyses were conducted with an inductively coupled plasma-optical emission spectrophotometer. In addition, catalase (CAT), glutathione (GSH), malondialdehyde (MDA) and ceruloplasmin (Cp) concentrations were measured. The Ni, Si and MDA levels of the study group were significantly higher than those of the control group (P < 0.05) but the Se levels of the study group were significantly lower than in the control group (P < 0.05). The normality of the data was determined with the Shapiro-Wilk Test and the Independent Samples t-Test or Mann-Whitney U test was used for statistical comparison of the groups.Discussion: Trace elements are essential components of biological systems. The levels of trace elements, such as Cu, Co, I, Se, Zn and Mn, which are affected by grazing activity, influence ruminants reproductive performance and other production parameters.[...](AU)


Assuntos
Animais , Bovinos , Papiloma/veterinária , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/veterinária , Oligoelementos/análise , Antioxidantes/análise , Antioxidantes/metabolismo , Imunidade
20.
Trends Plant Sci ; 20(12): 807-813, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26463217

RESUMO

Peroxidases reduce peroxide through substrate oxidation in order to alleviate oxidative stress in aerobic organisms. Since the initial description of the non-animal peroxidase superfamily, great effort has been made to characterize this large and heterogeneous group of proteins. Next generation sequencing data have permitted an in-depth study of the molecular evolution of this superfamily and allowed us to perform a phylogenetic reconstruction. Through this analysis, we identified two additional class I members and, here, we discuss the similarities and differences among members of this class. Our results provide new insights into the organization of these antioxidant enzymes, allowing us to propose a new model for the emergence and evolution of this superfamily.


Assuntos
Evolução Molecular , Peroxidases/classificação , Peroxidases/metabolismo , Filogenia , Proteínas de Algas/metabolismo , Antioxidantes/metabolismo , Sítios de Ligação , Peróxido de Hidrogênio/metabolismo , Peroxidases/genética , Proteínas de Plantas/metabolismo
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