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1.
Int J Nanomedicine ; 15: 8097-8108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116520

RESUMO

Background: Metallic nanoparticles (NPs) are highly exploited in manufacturing and medical processes in a broad spectrum of industrial applications and in the academic sectors. Several studies have suggested that many metallic nanomaterials including those derived by silver (Ag) are entering the ecosystem to cause significant toxic consequences in cell culture and animal models. However, ecotoxicity studies are still receiving limited attention when designing functionalized and non.-functionalized AgNPs. Objective: This study aimed to investigate different ecotoxicological profiles of AgNPs, which were analyzed in two different states: in pristine form uncoated AgNPs and coated AgNPs with the antimicrobial peptide indolicidin. These two types of AgNPs are exploited for a set of different tests using Daphnia magna and Raphidocelis subcapitata, which are representatives of two different levels of the aquatic trophic chain, and seeds of Lepidium sativum, Cucumis sativus and Lactuca sativa. Results: Ecotoxicological studies showed that the most sensitive organism to AgNPs was crustacean D. magna, followed by R. subcapitata and plant seeds, while AgNPs coated with indolicidin (IndAgNPs) showed a dose-dependent decreased toxicity for all three. Conclusion: The obtained results demonstrate that high ecotoxicity induced by AgNPs is strongly dependent on the surface chemistry, thus the presence of the antimicrobial peptide. This finding opens new avenues to design and fabricate the next generation of metallic nanoparticles to ensure the biosafety and risk of using engineered nanoparticles in consumer products.


Assuntos
Peptídeos Catiônicos Antimicrobianos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Ecotoxicologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos/síntese química , Crustáceos/efeitos dos fármacos , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Daphnia/citologia , Daphnia/efeitos dos fármacos , Germinação/efeitos dos fármacos , Lepidium/efeitos dos fármacos , Lepidium/crescimento & desenvolvimento , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Nanopartículas Metálicas/ultraestrutura , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Testes de Toxicidade
2.
PLoS One ; 15(9): e0238362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877452

RESUMO

Water and nutrient absorption from soil by crops mainly depend on the morphological traits and distribution of the crop roots. Dense planting with reduced nitrogen is a sustainable strategy for improving grain yield and nitrogen use efficiency. However, there is little information on the effects of dense planting with reduced nitrogen on direct-seeded inbred rice. Two-year field experiments were conducted with minirhizotron techniques to characterize the root morphological traits and distributions under different nitrogen application rates and sowing densities in two representative inbred rice varieties, Huanghuazhan (HHZ) and Yuenongsimiao (YNSM), grown under three nitrogen application rates (N0: 0 kg ha-1, LN: 135 kg ha-1, HN: 180 kg ha-1) and two sowing densities (LD: 18.75 kg ha-1, HD: 22.5 kg ha-1). Our study showed that dense planting with low nitrogen improved grain yield partly due to the increased panicle number. The higher sowing density with low nitrogen significantly affected the total root number (TRN), total root length (TRL), total root surface area (TRSA), and total root volume (TRV). There was a significant positive correlation between grain yield and TRL in the 10-20-cm soil layer (P < 0.05). The root morphological indexes were positively correlated with dry matter accumulation (P < 0.05) and negatively correlated with nitrogen content (P < 0.05) at the maturity stage. This study showed that a high sowing density with low nitrogen application can improve root morphology and distribution and increase grain yield and nitrogen use efficiency in direct-seeded inbred rice.


Assuntos
Nitrogênio/farmacologia , Oryza/fisiologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia , Sementes/fisiologia , Solo/química , Água/química , Oryza/efeitos dos fármacos , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Estações do Ano , Sementes/efeitos dos fármacos
3.
Chemosphere ; 254: 126918, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957302

RESUMO

The increasing application of various surfactants nowadays, may lead to the contamination of the natural environment and represent potential threat to terrestrial higher plants. In this article, the effect of 13 surfactants, with dodecyl alkyl chain and various aromatic (imidazolium, pyridinium, thiazolium) and aliphatic (guanidinium, ammonium, thiosemicarbazidium) polar heads, on germination, development and growth of wheat and cucumber was investigated. The study aimed to prove how changes in lipophilicity of surfactants and their various structural modifications (existence of the aliphatic or aromatic polar group, the introduction of oxygen and sulfur) influence toxicity towards investigated plants. The calculated lipophilic parameter (AlogP) is shown to be a useful parameter for predicting potential toxicity of the compound. The strategy of using surfactants with aliphatic polar heads instead of aromatic prove to be a promising strategy in reducing harmful effect, as well as the introduction of polar groups in the structure of cation. From all investigated compounds, surfactants with imidazolium polar head displayed the most harmful effect towards wheat and cucumber. The cucumber seeds were more sensitive to the addition of surfactants comparing to wheat. All obtained experimental results were additionally investigated using computational methods, simulating the transport of surfactants through a lipid bilayer. The influence of cation tendency to fit in lipid bilayer structure was correlated with toxicity. For the first time, it is concluded that cation ability to mimic the structure of bilayer have less harmful effect on plant development.


Assuntos
Cucumis sativus/efeitos dos fármacos , Imidazóis/toxicidade , Compostos de Piridínio/toxicidade , Tensoativos/toxicidade , Triticum/efeitos dos fármacos , Cátions , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Imidazóis/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Compostos de Piridínio/química , Compostos de Piridínio/farmacologia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Relação Estrutura-Atividade , Tensoativos/química , Triticum/crescimento & desenvolvimento
4.
PLoS One ; 15(9): e0227397, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925921

RESUMO

The continuous and sole dependence on imidazolinone (IMI) herbicides for weedy rice control has led to the evolution of herbicide resistance in weedy rice populations across various countries growing IMI herbicide-resistant rice (IMI-rice), including Malaysia. A comprehensive study was conducted to elucidate occurrence, level, and mechanisms endowing resistance to IMI herbicides in putative resistant (R) weedy rice populations collected from three local Malaysian IMI-rice fields. Seed bioassay and whole-plant dose-response experiments were conducted using commercial IMI herbicides. Based on the resistance index (RI) quantification in both experiments, the cross-resistance pattern of R and susceptible (S) weedy rice populations and control rice varieties (IMI-rice variety MR220CL2 and non-IMI-rice variety MR219) to imazapic and imazapyr was determined. A molecular investigation was carried out by comparing the acetohydroxyacid synthase (AHAS) gene sequences of the R and S populations and the MR220CL2 and MR219 varieties. The AHAS gene sequences of R weedy rice were identical to those of MR220CL2, exhibiting a Ser-653-Asn substitution, which was absent in MR219 and S plants. In vitro assays were conducted using analytical grade IMI herbicides of imazapic (99.3%) and imazapyr (99.6%) at seven different concentrations. The results demonstrated that the AHAS enzyme extracted from the R populations and MR220CL2 was less sensitive to IMI herbicides than that from S and MR219, further supporting that IMI herbicide resistance was conferred by target-site mutation. In conclusion, IMI resistance in the selected populations of Malaysian weedy rice could be attributed to a Ser-653-Asn mutation that reduced the sensitivity of the target site to IMI herbicides. To our knowledge, this study is the first to show the resistance mechanism in weedy rice from Malaysian rice fields.


Assuntos
Acetolactato Sintase/genética , Resistência a Herbicidas/genética , Oryza/efeitos dos fármacos , Proteínas de Plantas/genética , Plantas Daninhas/efeitos dos fármacos , Acetoína/análise , Acetoína/metabolismo , Acetolactato Sintase/metabolismo , Substituição de Aminoácidos , Asparagina/genética , Bioensaio , Análise Mutacional de DNA , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Ensaios Enzimáticos , Herbicidas/farmacologia , Imidazóis/farmacologia , Lactatos/metabolismo , Malásia , Mutação , Niacina/análogos & derivados , Niacina/farmacologia , Ácidos Nicotínicos/farmacologia , Oryza/genética , Proteínas de Plantas/metabolismo , Plantas Daninhas/genética , Sementes/efeitos dos fármacos , Serina/análise , Serina/genética , Serina/metabolismo , Controle de Plantas Daninhas/métodos
5.
Ecotoxicol Environ Saf ; 202: 111011, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800236

RESUMO

Boron (B) deficiency and surplus are the main factors that affect plant growth and yield. A better understanding of the response mechanisms of plant reproductive organs to stress induced by B deficiency and surplus could provide new insights to potential strategies for improving seed yield and quality. In this study, we aimed to elucidate the mechanisms of tolerance to B-induced stress in the reproductive organs of alfalfa (Medicago sativa L. cv. 'Aohan'). We initially used five B concentrations (0 mg B L-1, 400 mg B L-1, 800 mg B L-1, 1200 mg B L-1, and 1600 mg B L-1) to determine the B deficient, sufficient, and surplus levels in the field. Secondly, we examined changes in metabolite profiles of alfalfa 'Aohan' reproductive organs in response to B deficiency (0 mg B L-1), B sufficiency (800 mg B L-1), and B surplus (1600 mg B L-1) conditions using gas chromatography-mass spectrometry (GC-MS). Flowers and seeds from alfalfa 'Aohan' showed different metabolite profiles and resistance capacity under B deficiency and surplus conditions. B deficiency led to the excessive accumulation of sugars and phenolic compounds in alfalfa 'Aohan' and seeds, respectively, thus causing abscission or the abortion of reproductive organs. In contrast, B surplus severely reduced the levels of metabolites associated with amino acid and carbohydrate metabolism, resulting in the flowers falling and, therefore, low seed yield. Overall, B deficiency predominantly reduced seed yield and quality of alfalfa 'Aohan', while B surplus mainly affected seed yield of alfalfa 'Aohan'.


Assuntos
Boro/deficiência , Boro/toxicidade , Células Germinativas Vegetais/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Poluentes do Solo/toxicidade , Aminoácidos/metabolismo , Metabolismo dos Carboidratos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Células Germinativas Vegetais/metabolismo , Medicago sativa/metabolismo , Metabolômica , Sementes/metabolismo , Poluentes do Solo/metabolismo
6.
PLoS One ; 15(8): e0237536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790719

RESUMO

Melatonin is effective in enhancing various abiotic stress resistances of plants. However, its underlying mechanisms in drought-resistance in winter wheat (Triticum aestivum L.) is not clear. The goal of this work was to investigate the effect of melatonin on seed germination and to evaluate leaf antioxidant physiology for two wheat varieties. Experiments included 20% PEG, melatonin plus 20% PEG and a control using two contrasting wheat varieties (JM22- drought sensitive and HG35- drought resistant). Melatonin levels were 0, 1, 10, 100 and 300 µmol L-1. Results revealed that 300 µmol L-1 of melatonin alleviated the negative effect of water stress on germination and increased radicle length, radicle number, and plumule length of the germinated seeds. Principal component analysis showed a significant change in amino acid content during germination and this change was dependent on melatonin concentration and the variety. Lysine (Lys) content in wheat seeds under the PEG plus 300 µmol L-1 melatonin treatment increased compared with that of the seeds under PEG alone. There was a significant and positive correlation between Lys content and morphological index of germination. During seedling growth, soluble protein was involved in osmotic adjustment and superoxide dismutase (SOD) activity was increased to mitigate the damage in the cytomembrane of JM 22 leaf under 300 µmol L-1 melatonin plus PEG treatment. The effect of melatonin was dependent on SOD activity increasing significantly for HG35-a drought resistant variety. The results of this work lays a foundation for further studies to determine if melatonin can be economically used to mitigate the impact of dry planting conditions on wheat productivity in North China Plain.


Assuntos
Antioxidantes/farmacologia , Germinação/efeitos dos fármacos , Melatonina/farmacologia , Polietilenoglicóis/toxicidade , Sementes/efeitos dos fármacos , Estresse Fisiológico , Triticum/efeitos dos fármacos , Secas , Osmose , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
7.
Chemosphere ; 261: 127728, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32731022

RESUMO

Current study was performed to explore the effect of butanolide (KAR1) in mitigation of cadmium (Cd) induced toxicity in Brussels sprout (Brassica oleracea L.). Brussels sprout seeds, treated with 10-5 M, 10-7 M and 10-10 M solution of KAR1 were allowed to grow in Cd-contaminated (5 mg L-1) regimes for 25 d. Cadmium toxicity decreased seed germination and growth in B. oleracea seedlings. Elevated intensity of electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H2O2) were observed in Cd-stressed seedlings. Additionally, reduced level of stomatal conductivity, transpiration rate, photosynthesis rate, intercellular carbon dioxide concentration, and leaf relative water content (LRWC) was also observed in Cd-stressed seedlings. Nevertheless, KAR1 improved seed germination, seedling growth and biomass production in Cd stressed plants. KAR1 application showed elevated LRWC, osmotic potential, and higher membranous stability index (MSI) in seedlings under Cd regime. Furthermore, seedlings developed by KAR1 treatment exhibited higher stomatal conductivity, and intercellular carbon dioxide concentration together with improved rate of transpiration and photosynthetic rate in B. oleracea under Cd stress. These findings elucidate that the reduced level of MDA, EL and H2O2, as well as improvement in antioxidative machinery increased growth and alleviated Cd toxicity in KAR1 treated seedlings under Cd stress.


Assuntos
Antioxidantes/metabolismo , Brassica/efeitos dos fármacos , Cádmio/toxicidade , Furanos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Piranos/farmacologia , Poluentes do Solo/toxicidade , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
8.
Chemosphere ; 259: 127379, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32590174

RESUMO

4-Nonylphenol (4-NP) is a nephrotoxic substance that is highly prevalent in aquatic environments. Nigella sativa seed (NSS) has many biological activities and is widely used throughout the world as a medicinal product. Therefore, in the present study, we investigated the cytoprotective effect of NSS on 4-NP-induced renal damage in African catfish (Clarias gariepinus). Thirty fish were divided into five equal groups: an untreated control group and four groups that were challenged with 4-NP at a dose of 0.1 mg L-1 of aquarium water and fed a basal diet supplemented with 0%, 1%, 2.5%, and 5% NSS, respectively, for 3 weeks. Histological, histochemical, and ultrastructural features of the kidney were then assessed as biomarkers for renal tissue damage. Our results confirmed that 4-NP was a potent cytotoxic agent for the kidney tissue and induced renal damage, with 4-NP-intoxicated fish showing necrosis in the epithelial cells of the renal corpuscles, renal proximal convoluted tubules, and intertubular hematopoietic tissue, as well as loss of or a decrease in microvilli, a decrease in mitochondria, and an increase in the lysosomes in the epithelial cells of the proximal convoluted tubules. The kidneys of 4-NP-intoxicated fish also showed increased numbers of Perls' Prussian blue-positive melanomacrophage centers and intraepithelial T-lymphocytes in the proximal convoluted tubules and plasma cells. The administration of NSS to 4-NP-challenged fish significantly minimized the cytotoxic effect of 4-NP, maintaining the normal kidney structure, with concentrations of 2.5% and 5% of feed being most effective for protecting the kidney against 4-NP-induced renal damage.


Assuntos
Peixes-Gato/fisiologia , Nigella sativa , Fenóis/toxicidade , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Animais , Biomarcadores , Suplementos Nutricionais , Rim/efeitos dos fármacos , Extratos Vegetais/química , Sementes/efeitos dos fármacos
9.
Food Chem ; 331: 127282, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32559597

RESUMO

Phenolics are important secondary metabolites in plants with strong antioxidant effects. Seeds germination and exogenous stimulation could activate endogenous enzymes to enhance the content of phenolic acids and flavonoids. Barley seeds geminated under NaCl (1-20 mM) treatment to evaluate the accumulation of phenolics in this study. Results showed that NaCl treatment significantly enhanced the growth of seedlings, especially bud length. NaCl treatment up-regulated genes and proteins expression of phenylalanine ammonia lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL), resulting in the enhancement of their activities. As a result, phenolic acids and flavonoids contents increased by 11.19% and 32.54%, respectively, in which gallic acid, protocatechuic, fisetin, myricetin and quercetin were affected mostly. Moreover, NaCl treatment enhanced 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity. Hence, NaCl stimulated the synthesis of phenolic components via enhancing gene, protein expression and the activity of key enzymes.


Assuntos
Hordeum/efeitos dos fármacos , Hordeum/metabolismo , Fenóis/metabolismo , Plântula/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Antioxidantes/análise , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Fenóis/análise , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Proteínas de Plantas/metabolismo , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Transcinamato 4-Mono-Oxigenase/genética , Transcinamato 4-Mono-Oxigenase/metabolismo
10.
Chemosphere ; 258: 127350, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32554012

RESUMO

The adverse effects of glyphosate herbicide on plants are well recognised, however, potential hormetic effects have not been well studied. This study aimed to use tomato as a model organism to explore the potential hormetic effects of glyphosate in water (0-30 mg L-1) and in compost soil (0-30 mg kg-1). The growth-promoting effects of glyphosate at concentrations of 0.03-1 mg L-1 in water or 0.03-1 mg kg-1 in compost were demonstrated in tomato for the first time. These hormetic effects were manifest as increased hypocotyl and radicle growth of seedlings germinated on paper towel soaked in glyphosate solution and also in crops which had been sprayed with glyphosate. Increased rates of photosynthesis (up to 2-fold) were observed in 4-week old crops when seeds were sown in compost amended with glyphosate and also when leaves were sprayed with glyphosate. The examination of chloroplast morphology using transmission electron microscopy revealed that the hormetic effects were associated with elongation of chloroplasts, possibly due to lateral expansion of thylakoid grana.


Assuntos
Germinação/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Lycopersicon esculentum/fisiologia , Cloroplastos/efeitos dos fármacos , Produtos Agrícolas/efeitos dos fármacos , Glicina/toxicidade , Hormese/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos , Solo
11.
Ecotoxicol Environ Saf ; 201: 110796, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32505050

RESUMO

1,2-Hexanediol is commonly used in the cosmetic industry as a preservative, an emollient, and a moisturizing agent. However, studies on the scientific toxicity of 1,2-hexanediol are limited. In this study, we evaluated the potential toxic effects of 1,2-hexanediol using phytotoxicity and cytotoxicity testing methods. Phytotoxicity tests using Brassica campestris subsp. napus and Latuca sativa L. showed that 1,2-hexanediol significantly inhibited seed germination and root elongation at the lowest concentration (0.1%). Additionally, plants treated with 1,2-hexanediol failed to survive. In cytotoxicity tests, RAW 264.7 and HK-2 cells treated with 1.0% 1,2-Hexanediol showed a significant decline in viability, followed by death. Since most personal care products contain >2% 1,2-hexanediol, it is highly likely that 1,2-hexanediol is toxic to humans. Moreover, if 1,2-hexanediol enters the human body either via oral intake or through an open wound, it could have critical effects. Furthermore, upon release into the environment, 1,2-hexanediol could cause considerable damage to plants and other organisms. Therefore, further investigation of 1,2-hexanediol is required to prevent toxicity to humans and other living organisms.


Assuntos
Brassica napus/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Glicóis/toxicidade , Hexanos/toxicidade , Alface/efeitos dos fármacos , Sementes/efeitos dos fármacos , Animais , Brassica napus/crescimento & desenvolvimento , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Germinação/efeitos dos fármacos , Humanos , Alface/crescimento & desenvolvimento , Camundongos , Células RAW 264.7 , Risco , Sementes/crescimento & desenvolvimento
12.
PLoS One ; 15(5): e0232269, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32357181

RESUMO

Susceptibility of plants to abiotic stresses, including extreme temperatures, salinity and drought, poses an increasing threat to crop productivity worldwide. Here the drought-induced response of maize was modulated by applications of methyl jasmonate (MeJA) and salicylic acid (SA) to seeds prior to sowing and to leaves prior to stress treatment. Pot experiments were conducted to ascertain the effects of exogenous applications of these hormones on maize growth, physiology and biochemistry under drought stress and well-watered (control) conditions. Maize plants were subjected to single as well as combined pre-treatments of MeJA and SA. Drought stress severely affected maize morphology and reduced relative water content, above and below-ground biomass, rates of photosynthesis, and protein content. The prolonged water deficit also led to increased relative membrane permeability and oxidative stress induced by the production of malondialdehyde (from lipid peroxidation), lipoxygenase activity (LOX) and the production of H2O2. The single applications of MeJA and SA were not found to be effective in maize for drought tolerance while the combined pre-treatments with exogenous MeJA+SA mitigated the adverse effects of drought-induced oxidative stress, as reflected in lower levels of lipid peroxidation, LOX activity and H2O2. The same pre-treatment also maintained adequate water status of the plants under drought stress by increasing osmolytes including proline, total carbohydrate content and total soluble sugars. Furthermore, exogenous applications of MeJA+SA approximately doubled the activities of the antioxidant enzymes catalase, peroxidase and superoxide dismutase. Pre-treatment with MeJA alone gave the highest increase in drought-induced production of endogenous abscisic acid (ABA). Pre-treatment with MeJA+SA partially prevented drought-induced oxidative stress by modulating levels of osmolytes and endogenous ABA, as well as the activities of antioxidant enzymes. Taken together, the results show that seed and foliar pre-treatments with exogenous MeJA and/or SA can have positive effects on the responses of maize seedlings to drought.


Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Secas , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Ácido Salicílico/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Antioxidantes/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Concentração Osmolar , Estresse Oxidativo/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Sementes/efeitos dos fármacos , Solo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
13.
J Plant Physiol ; 250: 153184, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32464590

RESUMO

Although it is well known that parasitic weeds such as Orobanche (broomrape) significantly reduce the yield of economically important crops, their infection-induced oxidative changes need more exploration in their host plants. Moreover, applying an eco-friendly approach to minimize the infection is not yet available. This study was conducted to understand the effect of Orobanche ramosa infection on oxidative and redox status of tomato plants and the impact of hormonal (indole acetic acid (IAA); 0.09 mM and salicylic acid (SA); 1.0 mM) seed-priming upon mitigating the infection threats. Although Orobanche invades tomato roots, its inhibitory effects on shoot biomass were also indicted. Orobanche infection usually induces oxidative damage i.e., high lipid peroxidation, lipoxygenase activity and H2O2 levels, particularly for roots. Interestingly, hormonal seed-priming significantly enhanced tomato shoots and roots growth under both healthy and infected conditions. Also, IAA and SA treatment significantly reduced Orobanche infection-induced oxidative damage. The protective effect of seed-priming was explained by increasing the antioxidant defense markers including the antioxidant metabolites (i.e., total antioxidant capacity, carotenoids, phenolics, flavonoids, ASC, GSH, tocopherols) and enzymes (CAT, POX, GPX, SOD, GR, APX, MDHAR, DHAR), particularly in infected tomato seedlings. Additionally, cluster analysis indicated the differential impact of IAA- and SA-seed-priming, whereas lower oxidative damage and higher antioxidant enzymes' activities in tomato root were particularly reported for IAA treatment. The principal component analysis (PCA) also proclaimed an organ specificity depending on their response to Orobanche infection. Collectively, here and for the first time, we shed the light on the potential of seed-priming with either IAA or SA to mitigate the adverse effect of O. ramosa stress in tomato plants, especially at oxidative stress levels.


Assuntos
Ácidos Indolacéticos/farmacologia , Lycopersicon esculentum/fisiologia , Orobanche/fisiologia , Estresse Oxidativo/fisiologia , Reguladores de Crescimento de Planta/farmacologia , Plantas Daninhas/fisiologia , Ácido Salicílico/farmacologia , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/parasitologia , Estresse Oxidativo/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/parasitologia , Sementes/fisiologia
14.
Sheng Wu Gong Cheng Xue Bao ; 36(3): 493-507, 2020 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-32237543

RESUMO

Nickel and copper, as high toxic heavy metals (HMs), are the most serious contaminants in Jinchuan mining area, China. In this paper, the influence of combined HMs stress on the growth of widespread plant-S. salsa has been studied. The stress gradient of combined Ni-Cu was set based on the local environment and pre-experiment. Seed germination, growth, physiological characteristics of S. salsa were investigated by the control test, and its heavy metal bioaccumulation capacity was investigated by samples collected from field platform. The growth of S. salsa was promoted at lower concentration (≤40 mg/L) and inhibited at higher concentration (≥80 mg/L) under the single HMs stress and combined HMs stress (Cu20/Ni20). The malondialdehyde (MDA) content was increased with increasing concentration, and the soluble protein and free proline content in stress group were higher than that of in control group. Under single HMs stress, the peroxidase (POD) activity increased with increasing concentration; while under combined HMs stress, the POD activity increased initially and then reduced. Cu320 and Ni320 combined HMs stress inhibited the growth of S. salsa at all concentrations. The average translocation factors (TF) of S. salsa were greater than 1.00, and higher in leaves compared to stems. The results of bio-concentration factors (BCF) of S. salsa show that BCF of leaves were larger than that of roots and stems. At lower concentration, the combined HMs stress promoted the growth of S. salsa in comparison to single HMs stress, however, opposite results were obtained at higher concentration. Overall, S. salsa showed high tolerance to Cu and Ni and stronger capabilities of HMs uptake and translocation, and therefore, it can be used as an alternative plant for the bioremediation of heavy metal pollution in mining area.


Assuntos
Chenopodiaceae , Metais Pesados , Chenopodiaceae/efeitos dos fármacos , Chenopodiaceae/metabolismo , China , Germinação/efeitos dos fármacos , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Sementes/efeitos dos fármacos , Sementes/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade
15.
PLoS One ; 15(4): e0230801, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32275719

RESUMO

Downy mildew of opium poppy is the single biggest disease constraint afflicting the Australian poppy industry. Within the pathosystem, the transmission of infections via infested seed is of major concern. Both downy mildew pathogens of poppy; Peronospora meconopsidis and P. somniferi, are known contaminants of commercial seed stocks. Using seed naturally infested with these pathogens, the effect of physio-chemical seed treatments on seedling health and disease transmission were evaluated. Individual seed treatments were tested to determine optimal treatment parameters for each; including incubation time, temperature and treatment concentration. Optimised physiochemical treatments were then compared. The most effective treatment methods were seed washes in acidified electrolytic water (400 ppm hypochlorous acid for 5 min) and hypochlorite solution (2% NaOCI for 5 min). In seed to seedling transmission assays, these two treatments reduced transmission of P. somniferi by 88.8% and 74.61%, and P. meconopsidis by 93.3% and 100%, respectively. These methods are recommended for seed treatment of commercial opium poppy seed to assist in the control of the downy mildew diseases.


Assuntos
Papaver/microbiologia , Peronospora/patogenicidade , Doenças das Plantas/prevenção & controle , Sementes/microbiologia , Austrália , Eletrólitos/farmacologia , Ácido Hipocloroso/farmacologia , Peronospora/efeitos dos fármacos , Filogenia , Doenças das Plantas/microbiologia , Plântula/efeitos dos fármacos , Plântula/microbiologia , Sementes/efeitos dos fármacos
16.
Artigo em Inglês | MEDLINE | ID: mdl-32289638

RESUMO

Chenopodium quinoa, a halophytic crop belonging to the Amaranthaceae, has remarkable resistance to harsh growth conditions and produces seed with excellent nutritional value. This makes it a suitable crop for marginal soils. However, to date most of the commercial cultivars are susceptible to preharvest sprouting (PHS). Meanwhile, understanding of the PHS regulatory mechanisms is still limited. Abscisic acid (ABA) has been demonstrated to be tightly associated with seed dormancy and germination regulation in many crops. Whether ABA metabolism pathway could be manipulated to prevent PHS in quinoa is worth investigating. In the present study, we tested the inhibitory effects of exogenous ABA on quinoa seed germination. By RNA-seq analysis we investigated the global gene expression changes during seed germination, and obtained 1066 ABA-repressed and 392 ABA-induced genes. Cis-elements enrichment analysis indicated that the promoters of these genes were highly enriched in motifs "AAAAAAAA" and "ACGTGKC (K = G/T)", the specific binding motifs of ABI3/VP1 and ABI5. Transcription factor annotation showed that 13 genes in bHLH, MADS-box, G2-like and NF-YB, and five genes in B3, bZIP, GATA and LBD families were specifically ABA-repressed and -induced, respectively. Furthermore, expression levels of 53 key homologs involved in seed dormancy and germination regulation were markedly changed. Hence, we speculated that the 18 transcription factors and the homologs were potential candidates involved in ABA-mediated seed dormancy and germination regulation, which could be manipulated for molecular breeding of quinoa elites with PHS tolerance in future.


Assuntos
Chenopodium quinoa , Perfilação da Expressão Gênica , Germinação , Dormência de Plantas , Sementes , Fatores de Transcrição , Ácido Abscísico/farmacologia , Chenopodium quinoa/genética , Chenopodium quinoa/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/efeitos dos fármacos , Germinação/genética , Dormência de Plantas/genética , Reguladores de Crescimento de Planta/farmacologia , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Sci Rep ; 10(1): 4917, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188896

RESUMO

Soybean (Glycine max (L.) Merrill) is one of the most important crops worldwide providing dietary protein and vegetable oil. Most of the nitrogen required by the crop is supplied through biological N2 fixation. Non-thermal plasma is a fast, economical, and environmental-friendly technology that can improve seed quality, plant growth, and crop yield. Soybean seeds were exposed to a dielectric barrier discharge plasma operating at atmospheric pressure air with superimposed flows of O2 or N2 as carrying gases. An arrangement of a thin phenolic sheet covered by polyester films was employed as an insulating barrier. We focused on the ability of plasma to improve soybean nodulation and biological nitrogen fixation. The total number of nodules and their weight were significantly higher in plants grown from treated seeds than in control. Plasma treatments incremented 1.6 fold the nitrogenase activity in nodules, while leghaemoglobin content was increased two times, indicating that nodules were fixing nitrogen more actively than control. Accordingly, the nitrogen content in nodules and the aerial part of plants increased by 64% and 23%, respectively. Our results were supported by biometrical parameters. The results suggested that different mechanisms are involved in soybean nodulation improvement. Therefore, the root contents of isoflavonoids, glutathione, auxin and cytokinin, and expansin (GmEXP1) gene expression were determined. We consider this emerging technology is a suitable pre-sowing seed treatment.


Assuntos
Fixação de Nitrogênio , Nodulação , Gases em Plasma , Nódulos Radiculares de Plantas/fisiologia , Sementes , Soja/fisiologia , Nitrogênio/metabolismo , Fixação de Nitrogênio/efeitos dos fármacos , Fenótipo , Desenvolvimento Vegetal , Nodulação/efeitos dos fármacos , Gases em Plasma/farmacologia , Característica Quantitativa Herdável , Nódulos Radiculares de Plantas/efeitos dos fármacos , Sementes/efeitos dos fármacos , Soja/efeitos dos fármacos
18.
BMC Plant Biol ; 20(1): 104, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32138669

RESUMO

BACKGROUND: Loss of vigor caused by seed aging adversely affects agricultural production under natural conditions. However, priming is an economical and effective method for improving the vigor of aged seeds. The objective of this study was to test the effectiveness of exogenous ascorbic acid (ASC) and glutathione (GSH) priming in the repairing of aged oat (Avena sativa) seeds, and to test the hypothesis that structural and functional systems in mitochondria were involved in this process. RESULTS: Oat seeds were artificially aged for 20 days at 45 °C, and were primed with solutions (1 mmol L- 1) of ASC, GSH, or ASC + GSH at 20 °C for 0.5 h before or after their aging. Seed germination, antioxidant enzymes in the ASC-GSH cycle, cytochrome c oxidase (COX) and mitochondrial malate dehydrogenase (MDH) activities, and the mitochondrial ultrastructures of the embryonic root cells were markedly improved in aged oat seeds through post-priming with ASC, GSH, or ASC + GSH, while their malondialdehyde and H2O2 contents decreased significantly (P < 0.05). CONCLUSION: Our results suggested that priming with ASC, GSH, or ASC + GSH after aging could effectively alleviate aging damage in oat seeds, and that the role of ASC was more effective than GSH, but positive effects of post-priming with ASC and GSH were not superior to post-priming with ASC in repairing aging damage of aged oat seeds. However, pre-priming with ASC, GSH, or ASC + GSH was not effective in oat seeds, suggesting that pre-priming with ASC, GSH, or ASC + GSH could not inhibit the occurrence of aging damage in oat seeds.


Assuntos
Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Avena/fisiologia , Glutationa/metabolismo , Mitocôndrias/efeitos dos fármacos , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Avena/efeitos dos fármacos , Glutationa/administração & dosagem , Mitocôndrias/metabolismo , Sementes/efeitos dos fármacos , Sementes/fisiologia
19.
BMC Plant Biol ; 20(1): 106, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143578

RESUMO

BACKGROUND: The Eurasian steppe is an important vegetation type characterized by cold, arid and nitrogen poor conditions. At the Eastern edge, including in the Songnen grassland, the vegetation is dominated by Leymus chinensis (henceforth L. chinensis) and is increasing threatened by elevated anthropogenic nitrogen deposition. L. chinensis is a perennial grass that mainly reproduces vegetatively and its sexual reproduction is limited. However, sexual reproduction plays an important role influencing colonization after large disturbances. To develop an understanding of how elevated nitrogen deposition changes the plant community structure and functioning we need a better understanding how sexual reproduction of L. chinensis changes with nitrogen enrichment. Here we report on a field experiment where we added 10 g N m- 2 yr- 1 and examined changes in seed traits, seed germination and early seedling growth. RESULTS: Nitrogen addition increased seed production by 79%, contributing to this seed increases were a 28% increase in flowering plant density, a 40% increase in seed number per plant and a 11% increase in seed weight. Seed size increased with a 42% increase in large seeds and a 49% decrease in the smallest seed size category. Seed germination success improved by 10% for small seeds and 18% for large seeds. Combined, the increased in seed production and improved seed quality doubled the potential seed germination. Subsequent seedling above and below-ground biomass also significantly increased. CONCLUSIONS: All aspects of L. chinensis sexual reproduction increased with nitrogen addition. Thus, L. chinensis competitive ability may increase when atmospheric nitrogen deposition increases, which may further reduce overall plant diversity in the low diversity Songnen grasslands.


Assuntos
Germinação/efeitos dos fármacos , Nitrogênio/metabolismo , Poaceae/fisiologia , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Atmosfera , Nitrogênio/administração & dosagem , Poaceae/efeitos dos fármacos , Poaceae/crescimento & desenvolvimento , Reprodução/efeitos dos fármacos , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos
20.
An Acad Bras Cienc ; 92(suppl 1): e20180426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32159585

RESUMO

Effective microorganisms (EM) are inoculants formed by fungi and bacteria isolated from soil. EM are commonly used by farmers on agronomic crops to stimulate plant growth, but their composition and their benefits has been controverted. This study aimed to analyze the diversity of microorganisms growing in three EM inoculants, as well as to evaluate their efficiency in the germination of palisade grass seeds. The total DNA of the three EM inoculants was extracted, the 16S rRNA and ITS genes were amplified by PCR and sequenced on the Illumina MiSeq platform. Germination tests were conducted with three type of the EM, in three concentration and two times of the immersion. The bacterial group was the most abundant in EM, followed by fungi. Bacterial operational taxonomic units OTUs were shared by all EMs. Pre-treatments of palisade grass seeds with EMs resulted in a higher germination percentage (% G) and germination speed index (IVG) when EM was used at concentration of 1 or 2% in water. Seed immersion for 5 min was more efficient than immersion for 24 h. We can conclude that EM of different origin can share microbial groups and diversity of microorganisms, besides being an alternative to increase palisade grass seeds germination.


Assuntos
Inoculantes Agrícolas/genética , DNA Bacteriano/isolamento & purificação , DNA Fúngico/isolamento & purificação , Germinação/fisiologia , Poaceae/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Biodiversidade , Produtos Agrícolas/genética , Germinação/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sementes/efeitos dos fármacos , Análise de Sequência de DNA , Análise de Sequência de RNA , Ácidos Sulfúricos/farmacologia
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