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1.
Plant Mol Biol ; 101(3): 315-323, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392474

RESUMO

KEY MESSAGE: Pre-treatment of soybean seedlings with 200 µM salicylic acid before fungal inoculation significantly alleviated disease resistance in soybean seedlings against Fusarium solani infection. Sudden death syndrome of soybean is largely caused by Fusarium solani (F. solani). Salicylic acid (SA) has been reported to induce resistance in plants against many pathogens. However, the effect of exogenous SA application on F. solani infection of soybean is less reported. This study investigated the effect of foliar application of SA on soybean seedlings before F. solani infection. Seedlings were sprayed with 200 µM SA and inoculated with F. solani after 24 h of last SA application. After 3 days post-inoculation, seedlings treated with 200 µM SA showed significantly fewer disease symptoms with increased endogenous SA level, SA marker genes expression and antioxidant activities in the SA-treated seedlings more than the untreated control seedlings. Furthermore, the decrease in hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels was observed in the SA-treated plants as compared to the untreated plants. Analysis of the effect of SA application on F. solani showed that the mycelia growth of F. solani was not affected by SA treatment. Further investigation in this study revealed a decreased in F. solani biomass content in the SA treated seedlings. Results from the present study show that pre-treatment of 200 µM SA can induce resistance of soybean seedlings against F. solani infection.


Assuntos
Resistência à Doença/efeitos dos fármacos , Fusarium/patogenicidade , Doenças das Plantas/microbiologia , Ácido Salicílico/farmacologia , Soja/microbiologia , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Plântula/efeitos dos fármacos , Plântula/microbiologia , Soja/efeitos dos fármacos
2.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2213-2218, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359644

RESUMO

The aim of the study is to explore exogenous S3307 on alleviating low-temperature stress of coix seedlings. The coix cultivar, "No 5 Yiliao", was selected as the plant material, through nutrient solution cultivating in greenhouse, the effect of different S3307 concentrations(1, 3, 5, 7, 9 mg·L~(-1)) on coix seedlings traits and physiological indicators were explored under low-temperature stress. The results showed, under low-temperature 5 mg·L~(-1) S3307 could significantly increase coix seedlings stem diameter and biomass, which stem diameter and above-ground biomass, low-ground biomass separately were enhanced 11.90%, 13.59%, 10.99%. Leaf width and lateral root number separately were enhanced 7.63%, 37.52%. Meanwhile, addition of 5 mg·L~(-1) S3307 could significantly reduce relative conductivity and MDA, separately being reduced 23.33%, 17.42% compared to CKL. S3307 could also significantly increase soluble sugar and proline content, which leaf soluble sugar and proline content separately were enhanced 17.16%, 11.87%, which root soluble sugar and proline content separately were enhanced 20.00%, 33.42%. Additionally, S3307 could alleviate the cells destroy in ultra-structure level by improving cell membrane structure and chloroplast capsule layer structure. 5 mg·L~(-1) S3307 could enhance the low temperature tolerance of coix seedlings by regulating the growth and physiological indexes, and thus alleviate the damage caused by low-temperature to the coix seedlings.


Assuntos
Coix/efeitos dos fármacos , Temperatura Baixa , Plântula/efeitos dos fármacos , Estresse Fisiológico , Triazóis/farmacologia
3.
Ecotoxicol Environ Saf ; 181: 49-59, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170649

RESUMO

N-acetylcysteine (N-Acetyl L-cysteine, NAC) is a thiol compound derived from the addition of the acetyl group to cysteine amino acid. NAC has been used as an antioxidant, free radical scavenger, and chelating agent for reducing the deleterious effects on plants of biotic and abiotic environmental stresses. It can also relieve heavy metal (HM) toxicity, although its alleviating mechanism remains unknown. In this study, we compared HM-stressed (Cu, Hg, Cd and Pb, 100 µM each) wheat seedlings without NAC treatment and in combination with NAC (1 mM). In comparison to HMs alone, NAC treatment in combination with HMs (Cu, Cd, Hg and Pb, respectively) stimulated root growth (1.1-, 1.5-, 10.5- and 1.9-fold), and significantly increased fresh (1.3-, 1.5-, 4.3- and 1.4-fold) and dry (1.2-, 1.5-, 2.5- and 1.2-fold) mass. Combination treatment also led to significant reductions in HM concentrations (1.3-, 1.4-, 4- and 1.1-fold, respectively). GSH (1.1 - 1.8-fold), TBARS (1.4 - 2.7-fold) and H2O2 (1.6 - 1.8-fold) contents in treatment with HMs alone were significantly mitigated by the NAC combination. Some of the antioxidant enzyme activities increased or reduced by some HM treatments alone were stimulated by a combination of NAC with HMs, or remained unchanged or changed only insignificantly, supported by the phenolic pool of the plant. Ferulic, p-comaric and syringic acids were the major phenolic acids (PAs) in the roots in free, ester, glycoside and ester-bound forms, and their concentrations were increased by HM treatments alone, in comparison to the control seedlings, while PAs concentrations were relatively reduced by NAC in combination with HMs. These results indicate that NAC can alleviate HM toxicity and improve the growth of HM-stressed wheat seedlings by coordinated induction of the phenolic pool and the antioxidant defence system.


Assuntos
Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Metais Pesados/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Hidroxibenzoatos/metabolismo , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/crescimento & desenvolvimento , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento
4.
Ecotoxicol Environ Saf ; 181: 345-352, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202935

RESUMO

Nanomaterials are being used increasingly in various areas such as electronic devices manufacture, medicine, mechanical devices production, and even food industry. Therefore, the evaluation of their toxicity is mandatory. Graphene oxide (GO) has been shown to have both positive as well as negative impact on different crop plants, depending on species, dose, and duration of exposure. The current study evaluated the impact of GO sheets at different concentrations (500, 1000 and 2000 mg/L) on physiological, biochemical and genetic levels to determine the possible toxic action. Wheat caryopses were treated with GO for 48 h and 7 days. The germination rate and roots elongation decreased in a dose-response manner, except the sample treated with GO at a concentration of 1000 mg/L. Mitotic index has ascendant trend; its increase may be due to the accumulation of prophases GO induced significant accumulation of the cells with aberrations, their presence suggests a clastogenic/aneugenic effect of these carbon nanomaterials. Regarding enzymatic and non-enzymatic antioxidant system defence, the activity varied depending on the dose of GO. Thus, chlorophyll a pigments content decreased significantly at high dose (2000 mg/L), while the carotenoid pigments had lower content at 500 mg/L of GO, and no statistical difference encountered in case of chlorophyll b amount. The antioxidant enzyme activity (CAT, POD, and SOD) was higher at low dose of GO, indicating the presence of oxidative stress generated as a response to the GO treatment. Also, the free radical scavenging activity of the polyphenolic compounds was enhanced upon GO exposure. The GO accumulation has been identified by transmission electron microscopy only at plumules level, near the intercellular space.


Assuntos
Grafite/toxicidade , Nanoestruturas/toxicidade , Triticum/efeitos dos fármacos , Antioxidantes/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Germinação/efeitos dos fármacos , Estresse Oxidativo , Óxidos/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
5.
Environ Sci Pollut Res Int ; 26(22): 23192-23197, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187379

RESUMO

Soil alkalinity caused by salts, such as sodium bicarbonate (NaHCO3), and the frequently associated waterlogging problems are pervasive in agriculture and have a deleterious impact on crop production. However, various plant growth regulators, including brassinosteroids, are considered to be important against different abiotic stresses experienced by plants due to drought, salinity, and heavy metal stress. We investigated the putative role of 24-epibrassinolide (EBL), an active brassinosteroid, on red rice plants experiencing alkaline stress. Seedlings were pre-treated with 0.01 µM EBL for 30 min and later, exposed to NaHCO3 (25 mM) and were sampled, 5 days after treatments. Results showed that the pre-treatment of seedlings with EBL under non-stress conditions could promote rice plant growth. Growth parameters including dry weight (DW), root and coleoptile lengths were reduced under alkaline stress, whereas EBL application reduced the level of inhibition, as compared with NaHCO3 treatment. Enhanced levels of malondialdehyde content, hydrogen peroxide, and superoxide radicals were significantly diminished by EBL pre-treatment. Moreover, pre-treatment of EBL to alkaline-treated rice seedlings largely stimulated the enzymatic activities of ascorbate peroxidase, catalase, and superoxide dismutase. Thus, the results suggest that pre-application of EBL significantly ameliorates alkaline stress in rice.


Assuntos
Ascorbato Peroxidases/química , Brassinosteroides/farmacologia , Catalase/metabolismo , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Plântula/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Ascorbato Peroxidases/metabolismo , Peróxido de Hidrogênio/química , Malondialdeído/química , Plântula/efeitos dos fármacos , Esteroides Heterocíclicos , Superóxido Dismutase/química
6.
Chemosphere ; 233: 9-16, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31163310

RESUMO

The effects of cadmium (Cd) on wheat seedlings in the presence of graphene oxide (GO) were investigated. Parameters evaluated include root morphology, microtubule protein content, cytochrome P450 activity, and the microcellular structure of wheat seedlings. Compared with treatments with Cd or GO in isolation, treatments combining GO and Cd inhibited the total root length, total root surface area, average root diameter, and number of root hairs. GO combined with Cd also increased cytochrome P450 activity and reduced tubulin content. Cotransport of GO-loading Cd entered root tissues and was then transported to the mesophyll cells; this, in turn, triggered damage to cellular structures, including the cell membranes and chloroplast, leading to root blockage and reduced respiratory efficiency, decreased effectiveness of water and nutrient absorption, and ultimate inhibition of wheat growth and development. These effects of GO exposure were also concentration-dependent. The results indicated that GO amplified the phytotoxicity of Cd in wheat seedling roots. Given the worldwide exposure of the environment to Cd contamination, careful consideration should be given to the effects of GO in combination with Cd in agricultural management.


Assuntos
Cádmio/toxicidade , Grafite/química , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Cádmio/química , Compostos de Cádmio , Óxidos/química , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Poluentes do Solo/química , Triticum/metabolismo
7.
Environ Sci Pollut Res Int ; 26(22): 22338-22350, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154641

RESUMO

A pot experiment was performed to assess the useful effects of seed soaking or seedling foliar spray using 0.25 mM spermine (Spm), 0.50 mM spermidine (Spd), or 1 mM putrescine (Put) on heavy metal tolerance in wheat plants irrigated with water contaminated by cadmium (2 mM Cd2+ in CdCl2) or lead (2 mM Pb2+ in PbCl2). Cd2+ or Pb2+ presence in the growth medium resulted in significant reductions in growth and yield characteristics and activities of leaf peroxidase (POD), glutathione reductase (GR), ascorbic acid oxidase (AAO), and polyphenol oxidase (PPO) of wheat plants. In contrast, significant increases were observed for Cd2+ content in roots, leaves and grains, superoxide dismutase (SOD) and catalase (CAT) activities, radical scavenging activity (DPPH), reducing power capacity, and fragmentation in DNA in comparison to controls (without Cd2+ or Pb2+ addition). However, treating the Cd2+- or Pb2+-stressed wheat plants with Spm, Spd, or Put, either by seed soaking or foliar spray, significantly improved growth and yield characteristics and activities of POD, GR, AAO, PPO, SOD, and CAT, DPPH, and reducing power capacity in wheat plants. In contrast, Cd2+ levels in roots, leaves, and yielded grains, and fragmentation in DNA were significantly reduced compared with the stressed (with Cd2+ or Pb2+) controls. Generally, seed soaking treatments were more effective than foliar spray treatments. More specifically, seed priming in Put was the best treatment under heavy metal stress. Results of this study recommend using polyamines, especially Put, as seed soaking to relieve the adverse effects of heavy metals in wheat plants.


Assuntos
Antioxidantes/farmacologia , Inativação Metabólica/efeitos dos fármacos , Oxirredutases/metabolismo , Plântula/efeitos dos fármacos , Espermidina/farmacologia , Espermina/farmacologia , Superóxido Dismutase/metabolismo , Antioxidantes/química , Ácido Ascórbico/farmacologia , Cádmio/química , DNA , Genômica , Glutationa Redutase/metabolismo , Oxirredução , Peroxidases/metabolismo , Folhas de Planta/metabolismo , Poliaminas , Sementes/metabolismo , Espermidina/química , Triticum/crescimento & desenvolvimento
8.
World J Microbiol Biotechnol ; 35(6): 81, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31134389

RESUMO

TiO2 nanoparticles (TiO2NPs) is one of the most widely used nanomaterials. Arbuscular mycorrhizal fungi (AMF) are an important and widely distributed group of soil microorganisms, which promote the absorption of nutrients by host plants and increase their tolerance to contaminants. However, the effects and mechanisms of AMF on plant TiO2NPs tolerance in wetland habitats are not clear. In this experiment, under the conditions of three soil moisture contents (drought 50%, normal 70% and flooding 100%) and four TiO2NPs concentrations (0, 100, 200 and 500 mg kg-1), the effects of Funneliformis mosseae on the growth, antioxidant enzyme activities, osmotic substances and the absorption and accumulation of Ti in the Phragmites australis (reed) seedlings were studied. The results showed that the inoculation of F. mosseae under three moisture content conditions significantly increased the plant nutrition and root activities of reeds. Compared with the non-inoculated control, inoculation with F. mosseae increased the activities of antioxidant enzymes, the contents of chlorophyll, proline, soluble protein, and free amino acids, and significantly reduced the contents of malondialdehyde (MDA) and reactive oxygen species (ROS) of leaves. The accumulating ability of inoculated reeds to Ti was significantly higher than that of non-inoculated controls (P < 0.05), and inoculation of F. mosseae changed the distribution of Ti in reeds, increased the accumulation of Ti in roots. It's confirmed that inoculation of F. mosseae under three water conditions could improve the plant growth and nutrition, the activities of antioxidant enzymes, and enhance the reeds tolerance to TiO2NPs in this study.


Assuntos
Glomeromycota/fisiologia , Nanopartículas/toxicidade , Poaceae/efeitos dos fármacos , Poaceae/microbiologia , Plântula/crescimento & desenvolvimento , Estresse Fisiológico , Titânio/toxicidade , Água/metabolismo , Aminoácidos/metabolismo , Antioxidantes/metabolismo , Clorofila/metabolismo , Secas , Tolerância a Medicamentos , Malondialdeído/metabolismo , Osmose , Desenvolvimento Vegetal , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Poaceae/crescimento & desenvolvimento , Prolina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/microbiologia , Microbiologia do Solo , Áreas Alagadas
9.
World J Microbiol Biotechnol ; 35(6): 80, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31134400

RESUMO

In the present paper, products obtained from a blue-green microalga Spirulina platensis filtrate (applied for seed soaking and for foliar spray) and homogenate (used for seed coating) were tested in the cultivation of radish. Their effect on length, wet mass, multielemental composition and the greenness index of the radish leaves was examined. Multi-elemental analyses of the algal products, and radish were also performed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The best soaking time, concentrations of filtrate and doses of homogenate were established. The longest and heaviest plants were observed for homogenate applied at a dose of 300 µL per 1.5 g of seeds and 15% of filtrate applied as foliar spray. The highest chlorophyll content was found in the group treated with 100 µL of homogenate and 5% of filtrate. In the case of soaking time, the longest plants were in the group where seeds were soaked for 6 h, but the heaviest and greenest were after soaking for 48 h. The applied algal products increased the content of elements in seedlings. Obtained results proved that algal extracts have high potential to be applied in modern horticulture and agriculture. The use of Spirulina-based products is consistent with the idea of sustainable agriculture that could help to ensure production of sufficient human food to meet the needs of rising population and protection of the environment.


Assuntos
Agricultura , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Sementes/efeitos dos fármacos , Spirulina/química , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Fracionamento Químico/métodos , Clorofila , Filtração , Germinação , Desenvolvimento Vegetal , Extratos Vegetais/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Raphanus/efeitos dos fármacos , Raphanus/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento
10.
Plant Physiol Biochem ; 140: 105-112, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31091491

RESUMO

Abscisic acid (ABA) is one of the main participants in the regulation of plant responses to water deficiency. Knowledge of the ABA signal transduction pathways in gymnosperms is rather limited, especially in comparison with those in angiosperms. Seedlings of Scots pine and Norway spruce are known for their contrasting behaviour strategies under water deficit. To characterize the possible role of ABA in these differences, ABA dynamics were investigated under conditions of water deficit in seedlings of these two species. The content of ABA and its catabolites was followed in the roots and needles of seedlings of Pinus sylvestris and Picea abies under conditions of polyethylene glycol (PEG)-induced water deficiency (-0.15 and -0.5 MPa) for 10 days. The expression of the main genes for ABA-biosynthetic enzymes was also analysed. ABA showed more pronounced stress-dependent dynamics in pine roots than in spruce roots, whereas in needles, the response was greater for spruce than pine. The ABA increase during drought was mainly due to de novo synthesis and the shift in the balance between ABA synthesis and catabolism towards synthesis. The ABA-glucosyl ester did not serve as a reserve for the release of free ABA under water deficiency. The expression levels of the main ABA biosynthetic genes showed a weak or no correlation with changes in ABA content under water stress, i.e., the ABA content in the seedlings of both species was not directly linked to the transcript levels of the main ABA biosynthetic genes. Less-pronounced stress-induced changes in ABA in pine needles than in spruce needles may be related to pine seedlings having a less conservative strategy of growth and maintenance of water balance under water deficit.


Assuntos
Ácido Abscísico/metabolismo , Secas , Picea/metabolismo , Pinus sylvestris/metabolismo , Desidratação , Picea/efeitos dos fármacos , Pinus sylvestris/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Plântula/efeitos dos fármacos , Plântula/metabolismo
11.
Ecotoxicol Environ Saf ; 179: 265-271, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31059993

RESUMO

The content of gadolinium (Gd) is continuously increased in environment, which potentially threatens human health and ecological equilibrium. However, the phytotoxicity of Gd on plants remains unknown until now. In this study, the accumulation, distribution, and chemical forms of Gd as well as its influence on growth and nutrient balance were systematically studied in rice seedlings after the treatments of different concentrations of Gd (0, 1, 10, 100, and 1000 µM) for 10 days. The results showed that most Gd was accumulated in the roots and only a little percentage of Gd was transported to shoots. The accumulation of Gd was increased in a dose-dependent manner in various chemical forms and subcellular fractions. More than 80% of Gd was in the forms of insoluble oxalates and phosphates. Gd was mainly compartmentalized in the cell wall, and the content of Gd was increased with increasing concentrations of Gd. In addition, hormetic effects of Gd were found on rice growth. The growth of rice was induced by the lower concentration of Gd, but inhibited by the higher concentration of Gd. The results indicated that rice seedlings could cope with Gd toxicity through cell wall compartmentalization as well as forming of precipitates with oxalate and phosphate.


Assuntos
Gadolínio/toxicidade , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Análise por Conglomerados , Relação Dose-Resposta a Droga , Gadolínio/química , Gadolínio/metabolismo , Humanos , Oryza/metabolismo , Oxalatos/química , Fosfatos/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/metabolismo , Poluentes do Solo/química , Poluentes do Solo/metabolismo
12.
Ecotoxicol Environ Saf ; 179: 160-166, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31039458

RESUMO

Non-selective cation channels (NSCCs) play important roles in uptake of heavy metals in plants. However, little information is available concerning the contribution of NSCCs to cadmium (Cd) transport in rice seedlings. Results from the hydroponic experiment showed that the inhibition of 2.7 µM Cd on the development of rice roots was alleviated by adding 0.1 mM gadolinium (Gd) in nutrient solution, companied by reduction of Cd content by 55.3% in roots and by 45.0% in shoots. Inhibition of Gd on Cd accumulation in cytoplasm fraction (F3) was much greater than that in cell walls (F1) and organelles (F2) in roots. After increasing concentrations of Mn and Zn in nutrient solution, adding 0.1 mM Gd resulted in reductions in Cd content by 89.1%, in micronutrients by 54.9% and in macronutrients by 5.4% in roots, respectively. Cd stress resulted in significant increase of PC2∼4 and free amino acids, but decrease of V-ATPase activity by 32.3% in roots. These results indicate that NSCCs make a great contribution to uptake of Cd in rice seedlings and opportunities for Cd to be transported by NSCCs can be efficiently reduced by blocking NSCCs and/or increasing essential microelements like Mn and Zn.


Assuntos
Cádmio/metabolismo , Gadolínio/farmacologia , Canais Iônicos/antagonistas & inibidores , Transporte de Íons/efeitos dos fármacos , Oryza/metabolismo , Plântula/metabolismo , Hidroponia , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento
13.
Ecotoxicol Environ Saf ; 180: 656-667, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31136876

RESUMO

Owing to the active use of rare-earth elements in many areas, it is necessary to study their behavior in the environment and their biological impact on plants. Despite the role of melatonin and sulfur in plant growth, development and abiotic stress tolerance; it is still not clear how they have a strong regulatory influence and synergistic effect on growth, physiological and biochemical characteristics of plants under different environmental stresses. Therefore, this study highlights how melatonin and sulfur together potentially involved in a reversal of lanthanum-inhibited photosynthetic and growth responses in tomato seedlings. Here, we reported that seedlings grown in a medium containing 150 µM lanthanum exhibited increased overproduction of reactive oxygen species (ROS) and lipid peroxidation together with increased Chlorophyll degradation, and activity of chlorophyllase, proline dehydrogenase and glycolate oxidase (GOx), and decreased photosynthesis and growth. However, the application of melatonin and sulfur showed significant responses on tomato seedlings, although the response of their combined treatment was more effective by further increasing photosynthesis and growth under lanthanum toxicity. Melatonin supplied with sulfur suppressed ROS formation, lipid peroxidation and activity of GOx, and increased photosynthesis by upregulating activities of carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase. Also, sulfur supplementation with melatonin to seedlings resulted in an elevation in the accumulation of Chl and proline by increasing δ-aminolevulinic acid and activity of δ-aminolevulinic acid dehydratase and Δ1-pyrroline-5-carboxylate synthetase activity. The administration of melatonin with sulfur substantially induced upregulation of enzymes (superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) activities involved in the antioxidant system, thereby mitigating ROS-induced oxidative damage. Thus, this study provides strong evidence that melatonin and sulfur have strong regulatory influence and synergistic role in alleviating the adverse effect of lanthanum-toxicity by increasing photosynthesis and growth.


Assuntos
Poluentes Ambientais/toxicidade , Lantânio/toxicidade , Lycopersicon esculentum/efeitos dos fármacos , Melatonina/farmacologia , Enxofre/farmacologia , Antioxidantes/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
14.
Environ Pollut ; 251: 45-55, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31071632

RESUMO

Hydrogen gas (H2) has been shown as an important factor in plant tolerance to abiotic stresses, but the underlying mechanisms remain unclear. In the present study, the effects of H2 and its interaction with nitric oxide (NO) on alleviating cadmium (Cd) stress in Brassica campestris seedlings were investigated. NO donor (SNP) or hydrogen-rich water (HRW) treatment showed a significant improvement in growth of Cd-stressed seedlings. Cd treatment upregulated both endogenous NO and H2 (36% and 66%, respectively), and the increase of H2 was prior to NO increase. When treated with NO scavenger (PTIO) or NO biosynthesis enzyme inhibitors (L-NAME and Gln), HRW-induced alleviation under Cd stress was prevented. Under Cd stress, HRW pretreatment significantly enhanced the NO accumulation, and together up-regulated the activity of NR (nitrate reductase) and expression of NR. HRW induced lower reactive oxygen species (ROS), higher AsA content, enhanced activity of POD (peroxidase) and SOD (superoxide dismutase) in seedling roots were inhibited by PTIO, L-NAME and Gln. Through proteomic analysis, the level of 29 proteins were changed in response to H2 and NO-induced amelioration of Cd stress. Nearly half of them were involved in oxidation-reduction processes (about 20%) or antioxidant enzymes (approximately 20%). These results strongly indicate that in Cd-stressed seedlings, pretreatment with HRW induces the accumulation of H2 (biosynthesized or permeated), which further stimulates the biosynthesis of NO through the NR pathway. Finally, H2 and NO together enhance the antioxidant capabilities of seedlings in response to Cd toxicity.


Assuntos
Antioxidantes/metabolismo , Brassica/efeitos dos fármacos , Cádmio/toxicidade , Hidrogênio/farmacologia , Óxido Nítrico/biossíntese , Poluentes do Solo/toxicidade , Brassica/enzimologia , Brassica/metabolismo , Cádmio/metabolismo , Doadores de Óxido Nítrico/farmacologia , Oxirredução , Proteômica , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Poluentes do Solo/metabolismo , Regulação para Cima/efeitos dos fármacos
15.
Chemosphere ; 228: 565-576, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31055071

RESUMO

Biochar has been promoted as a soil amendment that enhances soil quality and agronomic productivity and reduces greenhouse gas production. However, these benefits are not always realized. A major hurdle to the beneficial use of biochar is our limited knowledge regarding the mechanisms directing its effects on soil systems. This project aimed to eliminate some of this uncertainty by examining the biological responses (plant productivity, greenhouse gas production, soil microbial community structure) of a suite of soils (10) to the addition of biochars produced by different processes (pyrolysis, gasification, burning) from a range of feedstocks (corn stalks, hardwood, grass). Results indicated that these three responses were not significantly impacted by the addition of pyrolysis biochars from different feedstocks at 1 and 5% (w/w) addition levels. On the other hand, both an open-air burned corn stalk (5%) and raw corn stalks (1 and 5%) additions did alter the measured soil functionality. For example, the 5% burnt corn stalks addition reduced total above ground plant biomass (∼30%), increased observed N2O production by an order of magnitude, and altered soil bacterial community structure. The bacterial groups that increased in relative abundance in the burnt corn stalks-amended soils included families associated with cellulose decomposition (Chitinophagaceae), plant pathogens (Xanthomonadaceae), and biochar/charcoal-amended media (Gemmatimonadetes). In contrast, the abundance of these bacterial groups was not impacted by the pyrolysis biochars. Therefore, this research suggests that pyrolysis biochar represents a stabilized form of carbon that is resistant to microbial mineralization and has negligible effects on soil biological responses.


Assuntos
Carvão Vegetal/farmacologia , Germinação/efeitos dos fármacos , Gases de Efeito Estufa , Microbiota/efeitos dos fármacos , Plântula/efeitos dos fármacos , Carbono , Carvão Vegetal/química , Pirólise , Solo/química
16.
Environ Sci Pollut Res Int ; 26(18): 18451-18464, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31044381

RESUMO

Petroleum contamination and its remediation via plant-based solutions have got increasing attention by environmental scientists and engineers. In the current study, the physiological and growth responses of two diesel-tolerant plant species (tolerance limit: 1500-2000 mg/kg), Italian ryegrass (Lolium multiflorum) and Birdsfoot trefoil (Lotus corniculatus), have been investigated in vegetable oil- and diesel oil-amended soils. A long-term (147-day) greenhouse pot experiment was conducted to differentiate the main focus of the study: physical and chemical effects of oil (vegetable and diesel) in freshly spiked soils via evaluating the plant performance and hydrocarbon degradation. Moreover, plant performance was evaluated in terms of seed germination, plant shoot biomass, physiological parameters, and root biomass. Addition of both diesel oil and vegetable oil in freshly spiked soils showed deleterious effects on seedling emergence, root/shoot biomass, and chlorophyll content of grass and legume plants. Italian ryegrass showed more sensitivity in terms of germination rate to both vegetable and diesel oil as compared to non-contaminated soils while Birdsfoot trefoil reduced the germination rate only in diesel oil-impacted soils. The results of the current study suggest that both physical and chemical effects of oil pose negative effects of plant growth and root development. This observation may explain the phenomenon of reduced plant growth in aged/weathered contaminated soils during rhizoremediation experiments.


Assuntos
Lolium/efeitos dos fármacos , Lotus/efeitos dos fármacos , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Biodegradação Ambiental , Biomassa , Germinação/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Lotus/crescimento & desenvolvimento , Lotus/metabolismo , Microbiota/efeitos dos fármacos , Óleos Vegetais/toxicidade , Brotos de Planta/efeitos dos fármacos , Rizosfera , Plântula/efeitos dos fármacos
17.
Environ Sci Pollut Res Int ; 26(18): 17986-17995, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31065986

RESUMO

In order to evaluate the resistance of lawn plant to Co2+ at germination stage and discuss its concentration property at adult stage, four kinds of lawn plant which have some growth advantages in Co2+ polluted environment were selected as experimental materials in this research. They are tall fescue, timothy grass, inflorescences, and annual ryegrass. The results show that the evaluation of resistance to Co2+ of tall fescue's seed is the highest; the evaluation of resistance to Co2+ of annual ryegrass seed is the lowest. The low consistence Co2+ could improve the seed germination. With Co2+ concentration increase, the accumulation coefficient of four plants increased at first and decreased later; the accumulation coefficient of underground portion is higher than the accumulation coefficient of aboveground; with Co2+ concentration increase, the transfer coefficient of four plants have a remarkable decline. In these plants, the accumulation coefficient of tall fescue and annual ryegrass is bigger than other two plants. As the concentration of Co2+ treatment increased to 100 mg/kg, the aboveground enrichment of Co2+ in F. elata reached 75 mg/kg, followed by L. multiflorum (68.9 mg/kg), P. pratense (48.8 mg/kg), and D. glomerata (27.2 mg/kg).The highest underground enrichment of Co2+ in F. elata reached 836.46 mg/kg, in contrast to the lowest underground enrichment in D. glomerata, 264.67 mg/kg. It shows that fescue and annual ryegrass have a better enrichment property to Co2+ and have a better prospect for the treatment of cobalt-contaminated soil. This research could provide some scientific basis and main technical approach for the soil contaminated by Co2+.


Assuntos
Cobalto/análise , Festuca/efeitos dos fármacos , Germinação/efeitos dos fármacos , Lolium/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/análise , Biodegradação Ambiental , Cobalto/toxicidade , Festuca/química , Festuca/crescimento & desenvolvimento , Lolium/química , Lolium/crescimento & desenvolvimento , Modelos Teóricos , Plântula/química , Sementes/química , Sementes/efeitos dos fármacos , Solo/química , Poluentes do Solo/toxicidade
18.
Environ Sci Pollut Res Int ; 26(20): 21013-21021, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31119539

RESUMO

In this study the phytotoxic, cytotoxic, genotoxic and mutagenic effects of two commercial fungicide-active compounds, procymidone (PR) and iprodione (IP), were determined. The parameters evaluated were germination and root growth, mitotic index, chromosomal and nuclear aberrations, and molecular analyses were also performed in the model plant Allium cepa L. The results demonstrated that the active compounds PR and IP were phytotoxic, delaying germination and slowing the development of A. cepa seedlings. Moreover, PR and IP showed cytogenotoxicity towards A. cepa meristematic cells, inducing chromosomal changes and cell death. The mutagenic activity of the active compounds was demonstrated by the detection of DNA changes in simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers in the treated cells compared to the negative control. Together, these results contribute to a better understanding of the damage caused by these substances in living organisms and reveal a promising strategy for prospective studies of the toxic effects of environmental pollutants.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Compostos Bicíclicos com Pontes/toxicidade , Fungicidas Industriais/toxicidade , Hidantoínas/toxicidade , Mutagênicos/toxicidade , Cebolas/efeitos dos fármacos , Aminoimidazol Carboxamida/toxicidade , Dano ao DNA/efeitos dos fármacos , Germinação/efeitos dos fármacos , Meristema/efeitos dos fármacos , Meristema/genética , Meristema/crescimento & desenvolvimento , Cebolas/genética , Cebolas/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/crescimento & desenvolvimento
19.
J Plant Physiol ; 238: 1-11, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31121522

RESUMO

Treatment of Arabidopsis thaliana seedlings with the PSII-inhibiting herbicide atrazine results in xenobiotic and oxidative stress, developmental arrest, induction of senescence and cell death processes. In contrast, exogenous sucrose supply confers a high level of atrazine stress tolerance, in relation with genome-wide modifications of transcript levels and regulation of genes involved in detoxification, defense and repair. However, the regulation mechanisms related to exogenous sucrose, involved in this sucrose-induced tolerance, are largely unknown. Characterization of these mechanisms was carried out through a combination of transcriptomic, metabolic, functional and mutant analysis under different conditions of atrazine exposure. Exogenous sucrose was found to differentially regulate genes involved in polyamine synthesis. ARGININE DECARBOXYLASE ADC1 and ADC2 paralogues, which encode the rate-limiting enzyme (EC 4.1.1.19) of the first step of polyamine biosynthesis, were strongly upregulated by sucrose treatment in the presence of atrazine. Such regulation occurred concomitantly with significant changes of major polyamines (putrescine, spermidine, spermine). Physiological characterization of a mutant affected in ADC activity and exogenous treatments with sucrose, putrescine, spermidine and spermine further showed that modification of polyamine synthesis and of polyamine levels could play adaptive roles in response to atrazine stress, and that putrescine and spermine had antagonistic effects, especially in the presence of sucrose. This interplay between sucrose, putrescine and spermine is discussed in relation with survival and anti-death mechanisms in the context of chemical stress exposure.


Assuntos
Arabidopsis/efeitos dos fármacos , Atrazina/farmacologia , Herbicidas/farmacologia , Putrescina/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Sacarose/farmacologia , Arabidopsis/metabolismo , Morte Celular/efeitos dos fármacos , Resistência a Herbicidas , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Plântula/efeitos dos fármacos , Plântula/metabolismo , Transcriptoma/efeitos dos fármacos
20.
Chemosphere ; 229: 589-601, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31100630

RESUMO

The study aimed to evaluate the physiological mechanisms underlying differences in metals and metalloid uptake and tolerance of two tree species cultivated in mining waste material. Two-year old Acer platanoides L. and Tilia cordata Mill. were cultivated in mining sludge characterized by high pH, salinity and an extremely high concentration of As. Both species were able to develop leaves from leafless seedlings, however, their total biomass was greatly reduced in comparison to control plants, following the severe disturbances in chlorophyll content. Phytoextraction abilities were observed for T. cordata for Ba, Nb, Rb and Se, and phytostabilisation was stated for Pd, Ru, Sc and Sm for both species, Ba and Nd for A. platonoides and Be for T. cordata only. Metal exclusion was observed for the majority of detected elements indicating an intense limitation of metal transport to photosynthetic tissue. A diversified uptake of elements was accompanied by a species-specific pattern of physiological reaction during the cultivation in sludge. Organic ligands (glutatnione and low-molecular-weight organic acids) were suppressed in A. platanoides, and enhanced biosynthesis of phenolic compounds was observed for both species, being more pronounced in T. cordata. Despite its higher accumulation of key metabolites for plant reaction to oxidative stress, such as phenolic acids, flavonoids and organic ligands, T. cordata exhibited relatively lower tolerance to sludge, probably due to the increased uptake and translocation rate of toxic metal/loids to aerial organs and/or restricted accumulation of salicylic acid which is known to play a decisive role in mechanisms of plant tolerance.


Assuntos
Acer/crescimento & desenvolvimento , Mineração , Poluentes do Solo/farmacocinética , Tilia/crescimento & desenvolvimento , Acer/efeitos dos fármacos , Arsênico/análise , Arsênico/farmacocinética , Biodegradação Ambiental , Clorofila/metabolismo , Metais/farmacocinética , Metais/toxicidade , Fotossíntese/efeitos dos fármacos , Fotossíntese/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Especificidade da Espécie , Tilia/efeitos dos fármacos , Árvores/efeitos dos fármacos , Árvores/crescimento & desenvolvimento
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