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1.
Environ Pollut ; 251: 573-580, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31108290

RESUMO

Nonylphenols are endocrine-disrupting chemicals that are used in various industries and are constantly discharged into the terrestrial environment. However, there have been few studies on the phytotoxicity of this chemical in the soil environment. In this study, mung bean (Vigna radiata) and rice (Oryza sativa) were grown in soil containing nonylphenol for 14 and 21 days (reflecting acute and chronic exposure, respectively), and we evaluated physiological responses (chlorophyll content, photosynthetic activity, and stomatal opening size) as well as changes in plant growth (shoot growth and root development) in crop plants grown in soil containing nonylphenol. In mung bean, chlorophyll content and stomata size decreased by exposure to nonylphenol. The decrease in chlorophyll content was attributed to electrolyte leakage due to damage of membrane barrier with increase of cell permeability caused by nonylphenol. Moreover, necrosis of the leaves of mung bean was observed at 2000 mg/kg soil. In rice, shoot growth, chlorophyll content and root development were reduced by chronic exposure to nonylphenol at 2000 mg/kg. Although the exposure concentrations were higher and nonylphenols are non-persistent, their constant release into soil poses a risk to terrestrial ecosystems. Our findings provide information that can be useful for soil ecological risk assessment for nonylphenol in agricultural practices.


Assuntos
Produtos Agrícolas/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Fenóis/toxicidade , Poluentes do Solo/toxicidade , Solo/química , Clorofila/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Modelos Teóricos , Fotossíntese/efeitos dos fármacos
2.
Environ Sci Pollut Res Int ; 26(18): 17996-18000, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31090005

RESUMO

Synthetic pesticides are largely decried. A common attitude against the synthetic agrochemicals is to avoid, criticise or ban these substances. Along with chemical pesticides to defend crops from bioagressors are microorganisms, semiochemical and natural substances used as plant protection products including biocontrol agents (BCAs) and crop protection products in organic production. Nevertheless, a natural substance status does not confer or imply safety, security or absence of residues (in the context of plant protection). Although in this paper we do not consider the toxicological perspective of highly toxic chemicals with adverse effects on humans and non-target organisms sprayed on crops, we have applied ourselves to working on the safe use of synthetic agrochemicals. Thus, along with biopesticides (either BCA or others) allowed in organic farming, we show that some synthetic chemical pesticides may be used in safe manner. HIGHLIGHTS: • Synthetic agrochemicals are widely criticised. • Some pesticide usages are not sprayed on crops. • Some biocontrol agents are of synthetic origin.


Assuntos
Agroquímicos/análise , Agentes de Controle Biológico/análise , Proteção de Cultivos/métodos , Produtos Agrícolas , Agroquímicos/farmacologia , Agentes de Controle Biológico/farmacologia , Proteção de Cultivos/economia , Proteção de Cultivos/legislação & jurisprudência , Produtos Agrícolas/química , Produtos Agrícolas/efeitos dos fármacos , União Europeia , Humanos , Resíduos de Praguicidas/análise
3.
Ecotoxicol Environ Saf ; 180: 295-308, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31100594

RESUMO

Crops can become contaminated when grown in soils containing heavy metals. Cadmium is a heavy metal that poses a significant health risk to humans. The purpose of this study was to evaluate the effect of cadmium on lettuce (Lactuca sativa Linn) and the contamination risk of lettuce grown in cadmium environments. The results showed that photosynthesis and growth parameters were significantly affected by cadmium. Lettuce has the ability to absorb large amounts of cadmium from the contaminated environment and so is a cadmium hyperaccumulator plant. The study showed that approximately 35% of the total absorbed cadmium is transmitted to aerial and edible parts of lettuce. This study was undertaken as lettuce has the ability to absorb and accumulate high levels of cadmium. There are however are no reports on the PCS gene and the potential for high cadmium accumulation in lettuce. The bioinformatics study revealed that lettuce has two phytochelatin synthase genes that produce 6 PCSs through splicing leading to the ability of lettuce to store high levels of cadmium. These six sequences although different in length have high similarity. Sequence structure, cellular location, three-dimensional structure, phylogeny and a comparison of their catalytic power were evaluated. The high accumulation of cadmium in lettuce and the presence of several PCSs contribute to the accumulation of cadmium in aerial tissues. The cultivation of lettuce in contaminated environments led us to evaluate suspected farms for the presence of cadmium in produce. Lettuce grown in industrial environments contaminated with cadmium can pose a serious threat to human health.


Assuntos
Aminoaciltransferases/genética , Cádmio/toxicidade , Alface/efeitos dos fármacos , Poluentes do Solo/toxicidade , Solo/química , Cádmio/análise , Cádmio/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/enzimologia , Alface/enzimologia , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Inquéritos e Questionários
4.
Int J Mol Sci ; 20(8)2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-31010052

RESUMO

Early blight is a disease that greatly affects Solanaceae, mainly damaging tomato plants, and causing significant economic losses. Although there are methods of biological control, these are very expensive and often their mode of action is slow. Due to this, there is a need to use new techniques that allow a more efficient control of pathogens. Nanotechnology is a new alternative to solve these problems, allowing the creation of new tools for the treatment of diseases in plants, as well as the control of pathogens. The aim of the present investigation was to evaluate the foliar application of selenium and copper in the form of nanoparticles in a tomato crop infested by Alternaria solani. The severity of Alternaria solani, agronomic variables of the tomato crop, and the changes in the enzymatic and non-enzymatic antioxidant compounds were evaluated. The joint application of Se and Cu nanoparticles decreases the severity of this pathogen in tomato plants. Moreover, high doses generated an induction of the activity of the enzymes superoxide dismutase, ascorbate peroxidase, glutathione peroxidase (GPX) and phenylalanine ammonia lyase in the leaves, and the enzyme GPX in the fruit. Regarding non-enzymatic compounds in the leaves, chlorophyll a, b, and totals were increased, whereas vitamin C, glutathione, phenols, and flavonoids were increased in fruits. The application of nanoparticles generated beneficial effects by increasing the enzymatic and non-enzymatic compounds and decreasing the severity of Alternaria solani in tomato plants.


Assuntos
Alternaria/fisiologia , Cobre/farmacologia , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/fisiologia , Nanopartículas/química , Selênio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Alternaria/efeitos dos fármacos , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Fenilalanina Amônia-Liase/metabolismo , Pigmentos Biológicos/metabolismo , Doenças das Plantas/microbiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo
5.
Chemosphere ; 227: 345-365, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30999175

RESUMO

The beneficial role of biochar on improvement of soil quality, C sequestration, and enhancing crop yield is widely reported. As such there is not much consolidated information available linking biochar modulated soil condition improvement and soil nutrient availability on crop yields. The present review paper addresses the above issues by compilation of world literature on biochar and a new dimension is introduced in this review by performing a meta-analysis of published data by using multivariate statistical analysis. Hence this review is a new in its kind and is useful to the broad spectrum of readers. Generally, alkalinity in biochar increases with increase in pyrolysis temperature and majority of the biochar is alkaline in nature except a few which are acidic. The N content in many biochar was reported to be more than 4% as well as less than 0.5%. Poultry litter biochar is a rich source of P (3.12%) and K (7.40%), while paper mill sludge biochar is higher in Ca content (31.1%) and swine solids biochar in Zn (49810 mg kg-1), and Fe (74800 mg kg-1) contents. The effect of biochar on enhancing soil pH was higher in Alfisol, Ferrosol and Acrisol. Soil application of biochar could on an average increase (78%), decrease (16%), or show no effect on crop yields under different soil types. Biochar produced at a lower pyrolysis temperature could deliver greater soil nutrient availabilities than that prepared at higher temperature. Principal component analysis (PCA) of available data shows an inverse relationship between [pyrolysis temperature and soil pH], and [biochar application rate and soil cation exchange capacity]. The PCA also suggests that the original soil properties and application rate strongly control crop yield stimulations via biochar amendments. Finally, biochar application shows net soil C gains while also serving for increased plant biomass production that strongly recommends biochar as a useful soil amendment. Therefore, the application of biochar to soils emerges as a 'win-win strategy' for sustainable waste management, climate change mitigation and food security.


Assuntos
Carvão Vegetal/farmacologia , Nutrientes/análise , Solo/química , Animais , Biomassa , Carvão Vegetal/química , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento
6.
Pestic Biochem Physiol ; 156: 9-28, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31027586

RESUMO

4-Hydroxyphenylpyruvate dioxgenase (HPPD) enzymes from rat and from several plants contained only about a single inhibitor-binding active site per dimer which matched the content of iron in the purified Arabidopsis thaliana and Avena sativa enzymes. The dimeric HPPDs were about 10 fold more catalytically active than the tetrameric P. fluorescens enzyme with kcat/KmHPP values ranging from 0.8 to 2.5 s-1 µM-1. Most were also highly sensitive to herbicides with, for example, Ki values for mesotrione ranging from 25 to 100 pM. Curiously HPPDs from cool climate grasses were much less herbicide-sensitive. When likewise expressed in Nicotinia tabacum, Avena sativa HPPD, Ki value of 11 nM for mesotrione, conferred far greater tolerance to mesotrione (CallistoTM) than did any of the more sensitive HPPDs. Targeted mutagenesis of the Avena HPPD led to the discovery of 4 mutations imparting improved inherent tolerance, defined as the ratio of Ki to KmHPP, by about 16 fold without any loss of catalytic activity. The Nicotinia line with the highest expression of this quadruple mutant exhibited substantial resistance even up to a 3 kg/ha post-emergence application of mesotrione. The maximum observed expression level of heterologous plant HPPDs in tobacco was ca. 0.35% of the total soluble protein whereas the endogenous tobacco HPPD constituted only ca. 0.00075%. At such high expression even HPPDs with impaired catalytic activity could be effective. A quintuple mutant Avena sativa HPPD conferred substantial tolerance across a broad range of HPPD herbicide chemistries despite being only ca. 5 % as catalytically active as the wild type enzyme. Testing various wild type and mutant HPPDs in tobacco revealed that tolerance to field rates of herbicide generally requires about two order of magnitude increases in both inherent herbicide tolerance and expression relative to endogenous levels. This double hurdle may explain why target-site based resistance to HPPD-inhibiting herbicides has been slow to evolve in weeds.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/enzimologia , Cicloexanonas/farmacologia , Herbicidas/farmacologia , 4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Dados de Sequência Molecular , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/metabolismo , Ratos , Homologia de Sequência de Aminoácidos
7.
Int J Mol Sci ; 20(5)2019 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-30832379

RESUMO

The antioxidant defense system acts to maintain the equilibrium between the production of reactive oxygen species (ROS) and the elimination of toxic levels of ROS in plants. Overproduction and accumulation of ROS results in metabolic disorders and can lead to the oxidative destruction of the cell. Several stress factors cause ROS overproduction and trigger oxidative stress in crops and weeds. Recently, the involvement of the antioxidant system in weed interference and herbicide treatment in crops and weeds has been the subject of investigation. In this review, we address ROS production and plant mechanisms of defense, alterations in the antioxidant system at transcriptional and enzymatic levels in crops induced by weed interference, and herbicide exposure in crops and weeds. We also describe the mechanisms of action in herbicides that lead to ROS generation in target plants. Lastly, we discuss the relations between antioxidant systems and weed biology and evolution, as well as the interactive effects of herbicide treatment on these factors.


Assuntos
Produtos Agrícolas/genética , Evolução Molecular , Resistência a Herbicidas/genética , Plantas Daninhas/genética , Espécies Reativas de Oxigênio/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/metabolismo , Herbicidas/farmacologia , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/metabolismo
8.
Environ Sci Pollut Res Int ; 26(14): 14128-14136, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30859443

RESUMO

A field experiment was performed to study the effects of mixed amendments, namely lime + organic fertilizer (LO), lime + organic fertilizer + calcium-magnesium phosphate fertilizer (LOC), lime + organic fertilizer + sepiolite (LOS), and lime + organic fertilizer + calcium-magnesium phosphate fertilizer + sepiolite (LOCS), on the availability and uptake of Cd from contaminated paddy soil under a rice-rape (Oryza sativa L. and Brassica napus L.) rotation system. The results showed that the grain yields of rice and rape with mixed amendment-treated were slightly influenced, in that the soil pH significantly increased while the DTPA-extractable Cd content of the soil and Cd uptake by the rice and rape were significantly reduced. The uptake of Cd by brown rice decreased significantly (p < 0.05), by 55.9-59.3% and 69.6-75.5% in the 2016 and 2017 crops, respectively, compared with that of the control (CK). The Cd uptake by rapeseeds during the 2017 season observably (p < 0.05) decreased by 38.2 and 29.6% under LO and LOC treatments, respectively. The Cd concentrations in rapeseeds were 0.11-0.18 mg kg-1 under all the treatments except LOCS treatment, which is lower than the National Standard of Pollutants in Food of China (GB 2762-2017, 0.2 mg kg-1). From both economic and food safety standpoints, rape is recommended for Cd-contaminated soil because it has a low Cd accumulation ability. The results showed that the rice-rape rotation combined with LO or LOC application was useful for reducing the Cd content in both rice and rape in Cd-contaminated soil and the effects could be sustained at least for three crop seasons.


Assuntos
Brassica napus/efeitos dos fármacos , Cádmio/farmacocinética , Fertilizantes , Oryza/efeitos dos fármacos , Poluentes do Solo/farmacocinética , Agricultura/métodos , Disponibilidade Biológica , Brassica napus/metabolismo , Cádmio/análise , Cálcio , Compostos de Cálcio , China , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/metabolismo , Compostos de Magnésio , Silicatos de Magnésio , Oryza/metabolismo , Óxidos , Fosfatos , Solo/química , Poluentes do Solo/análise
10.
Chem Commun (Camb) ; 55(14): 2007-2014, 2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30688322

RESUMO

Antibiotic resistance in bacteria has become a serious threat to public health, and therefore there is an urgent need to develop new classes of antimicrobial agents. Nowadays, natural antimicrobial peptides (AMPs) and their synthetic derivatives are considered as promising alternatives to traditional antibiotics. The broad molecular diversity of AMPs, in terms of sequences and structures, suggests that their activity does not depend on specific features of amino acid sequence or peptide conformation. We therefore selected two common properties of AMPs, (high percentage of hydrophobic and cationic amino acids), to develop a novel approach to synthesize random antimicrobial peptide mixtures (RPMs). Instead of incorporating a single amino acid at each coupling step, a mixture of hydrophobic and cationic amino acids in a defined proportion is coupled. This results in a mixture that contains up to 2n sequences, where n is the number of the coupling step, of random peptides with a defined composition, stereochemistry, and controlled chain length. We have discovered that RPMs of hydrophobic and cationic α-amino acids, such as phenylalanine and lysine, display strong and broad antimicrobial activity towards Gram-negative, Gram-positive, clinically isolated antibiotic resistant "superbugs", and several plant pathogenic bacteria. This review summarizes our efforts to explore the mode of action of RPMs and their potential as bioactive agents for multiple applications, including the prevention of biofilm formation and degradation of mature biofilm (related to human health), reduction of disease severity in plant bacterial disease models (related to crop protection), and inhibition of bacterial growth in milk (related to food preservation). All our findings illustrate the effectiveness of RPMs and their great potential for various applications.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Peptídeos/farmacologia , Biofilmes/efeitos dos fármacos , Produtos Agrícolas/efeitos dos fármacos , Farmacorresistência Bacteriana , Conservantes de Alimentos , Hemólise/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peptídeos/química
11.
Sci Total Environ ; 656: 969-976, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30625683

RESUMO

The application of biochar to agricultural ecosystems is a potential solution to mitigate climate change and guarantee food security. However, the impacts of biochar on greenhouse gas emissions and crop yield are usually evaluated separately and the results are contradictory in individual studies. In this study, a meta-analysis was conducted based on data from 28 peer-reviewed studies to quantify the impacts of biochar application on greenhouse gas emissions and crop yield using yield-scaled greenhouse gas intensity (GHGI). Potential factors (experimental conditions and properties of soil and biochar) influencing the effect of biochar on yield-scaled GHGI were explored. The results showed that overall, biochar significantly reduced yield-scaled GHGI by 29%. The reductions in yield-scaled GHGI induced by biochar varied with different experimental conditions and properties of soil and biochar. However, the difference was only significant between the two cropping systems, with significantly greater reduction being observed in dry lands (-41%) than in paddy fields (-17%). Therefore, it is suggested that biochar amendment in dry lands may bring more environmental and agronomic benefits than that in paddy fields. The response of crop yield to biochar application further implied that biochar made from crop residue, biochar produced at low pyrolysis temperatures (≤400 °C), and biochar with high pH (>9.0) might contribute to save the production cost of biochar while promoting crop yield in agricultural ecosystems. Long-term field trials are required to elucidate the persistence of the impact of biochar on reducing yield-scaled GHGI and to clarify the underlying mechanisms. The balance between the price of biochar production and the benefits brought by biochar should also be focused in further studies.


Assuntos
Agricultura/métodos , Carvão Vegetal/administração & dosagem , Produtos Agrícolas/crescimento & desenvolvimento , Fertilizantes , Gases de Efeito Estufa/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Produtos Agrícolas/efeitos dos fármacos , Solo/química
12.
Environ Sci Pollut Res Int ; 26(6): 5454-5462, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30610580

RESUMO

Small-scale vegetable and fruit crop producers in the USA use locally available commercial organic fertilizers and soil amendments recycled from municipal and agricultural wastes. Organic soil amendments provide crops with their nutrient needs and maintain soil health by modifying its physical, chemical, and biological properties. However, organic soil amendments might add unwanted elements such as toxic heavy metals or salts, which might inhibit crop growth and reduce yield. Therefore, the objective of this study was to evaluate phytotoxicity of three commercial organic amendments, chicken manure, milorganite, and dairy manure, to collard greens using the seed germination bioassay and chemical analysis of the organic amendments. The seed germination bioassay was conducted by incubating collard greens seeds to germinate in 1:10 (w/v) organic amendment aqueous extracts. Results of this work identified phytotoxic effects of chicken manure and milorganite, but not dairy manure, to collard greens. Potentially phytotoxic chemicals such as copper, zinc, nickel, and salts were also higher in chicken manure and milorganite compared to dairy manure. In particular, nickel in chicken manure and milorganite aqueous extracts was 28-fold and 21-fold, respectively, higher than previously reported toxic levels to wheat seedlings. The results demonstrate the need for more research on phytotoxicity of commercial organic soil amendments to ensure their safe use in vegetable and fruit crop production systems.


Assuntos
Brassica/efeitos dos fármacos , Fertilizantes/toxicidade , Germinação/efeitos dos fármacos , Esterco , Testes de Toxicidade/métodos , Animais , Brassica/crescimento & desenvolvimento , Bovinos , Galinhas , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Esterco/análise , Metais/análise , Metais/toxicidade , Agricultura Orgânica/métodos , Plântula , Sementes/efeitos dos fármacos , Sementes/fisiologia , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
13.
Methods Mol Biol ; 1931: 41-48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30652281

RESUMO

Weed management programs to be used in grain sorghum production are best investigated in field studies with naturally occurring weed populations in their relevant growing environments. Weed control tactics to be evaluated include use of crop production practices such as row spacing and seeding rates, mechanical tools, and herbicide programs with soil- and foliar-applied products.


Assuntos
Produção Agrícola/métodos , Sorghum/crescimento & desenvolvimento , Controle de Plantas Daninhas/métodos , Agricultura/métodos , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Resistência a Herbicidas/fisiologia , Herbicidas/farmacologia , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sorghum/efeitos dos fármacos
14.
J Environ Sci Health B ; 54(4): 252-262, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30628546

RESUMO

Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pHKCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide - treated as a control), RD (dose recommended by the manufacturer) and 300 × RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10 g kg-1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300 × RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.


Assuntos
Enzimas/metabolismo , Fungicidas Industriais/toxicidade , Triticum/efeitos dos fármacos , Bentonita/química , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Pirimidinas/toxicidade , Solo/química , Microbiologia do Solo , Poluentes do Solo/toxicidade , Compostos de Espiro/toxicidade , Estrobilurinas/toxicidade , Triazóis/toxicidade , Triticum/crescimento & desenvolvimento
15.
Sci Total Environ ; 657: 938-944, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30677959

RESUMO

We studied the effect of different doses (0.5%, 2% and 5% (w/w)) of ammonium thiosulfate on mercury (Hg) speciation fractionation following its addition to the soil, as well as its accumulation by oilseed rape (Brassica napus L.), corn (Zea mays L.), and sweet potato (Ipomoea batatas L.), and compared them to a non-treated control in a historically polluted soil. The oilseed rape, corn, and sweet potato were planted consecutively in the same soils on days 30, 191, and 276, respectively after the addition of thiosulfate to the soil. The key results showed that bioavailable Hg contents in the rhizosphere soils ranged from 0.18 to 2.54 µg kg-1, 0.28 to 2.77 µg kg-1, and 0.24 to 2.22 µg kg-1, respectively, for the 0.5%, 2% and 5% thiosulfate treatments, which were close to the control soil (0.25 to 1.98 µg kg-1). The Hg L3-edge X-ray absorption near edge structure (XANES) results showed a tendency of the Hg speciation to transform from the Hg(SR)2 (initial soil, 56%; day-191 soil, 43%; day-276 soil, 46%, and day-356 soil, 16%) to nano particulated HgS (initial soil, 26%; day-191 soil, 42%; day-276 soil, 42%, and day-356 soil, 73%) with time in the soil treated with a 5% dose of thiosulfate. The Hg contents in the tissues of the crops, except for oilseed rape, were slightly affected by the addition of thiosulfate to the soil at all dosages, compared to the control. The addition of thiosulfate did not induce the movement of bioavailable Hg to the lower layer of the soil profile. We conclude a promotion of Hg immobilization by thiosulfate in the soil for over one year, offering a promising method for in-situ Hg remediation at Hg mining regions in China.


Assuntos
Produtos Agrícolas/efeitos dos fármacos , Recuperação e Remediação Ambiental/métodos , Mercúrio/química , Poluentes do Solo/química , Tiossulfatos/química , Disponibilidade Biológica , Brassica napus/efeitos dos fármacos , Brassica napus/metabolismo , China , Produtos Agrícolas/química , Ipomoea batatas/efeitos dos fármacos , Ipomoea batatas/metabolismo , Mercúrio/análise , Mercúrio/farmacocinética , Mineração , Rizosfera , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética , Espectroscopia por Absorção de Raios X , Zea mays/efeitos dos fármacos , Zea mays/metabolismo
16.
N Biotechnol ; 48: 83-89, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30098416

RESUMO

Bioactive compounds such as karrikinolide (KAR1 from smoke) and eckol (from the seaweed Ecklonia maxima) show promising effects on several important crop plants. These plant growth-stimulating organic biomolecules, along with crude extracts (smoke-water and Kelpak® product prepared from Ecklonia maxima), were tested on spinach plants. Eckol sprayed at 10-6 M significantly increased all the growth and biochemical parameters examined compared to control spinach plants. All tested plant growth biostimulants significantly increased total chlorophyll, carotenoids and protein content of spinach leaves. The cytokinin profile of spinach plants was also determined. Cis-zeatin, dihydrozeatin and isopentenyladenine types of cytokinins were promoted by both smoke- and seaweed-based biostimulants. In comparison to the control plants, the level of free sinapic acid was greater in all spinach plants treated with these biostimulants. The application of these biostimulants can help spinach crop by improving growth, yield and nutritional quality; moreover, they are organic and cost-effective.


Assuntos
Feófitas/química , Reguladores de Crescimento de Planta/isolamento & purificação , Reguladores de Crescimento de Planta/farmacologia , Alga Marinha/química , Fumaça/análise , Spinacia oleracea/efeitos dos fármacos , Spinacia oleracea/crescimento & desenvolvimento , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Citocininas/metabolismo , Dioxinas/isolamento & purificação , Dioxinas/farmacologia , Furanos/isolamento & purificação , Furanos/farmacologia , Hidroxibenzoatos/metabolismo , Piranos/isolamento & purificação , Piranos/farmacologia , Spinacia oleracea/metabolismo
17.
Integr Environ Assess Manag ; 15(2): 176-189, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30548391

RESUMO

A comprehensive critical review was undertaken aiming to compare the intrinsic sensitivity of terrestrial plant species (crop species and noncrop wild species) with published literature and unpublished proprietary data generated for the registration of plant protection products (PPPs), and a database was compiled. Data were assessed to answer the question whether crops differ from noncrop plants in their intrinsic sensitivity to PPPs. Endpoints were assessed considering further potentially relevant parameters by means of different methods, including a quotient approach, in which overall crop endpoints were divided by matching wild species endpoints. Quotients above 1 indicated that wild species were more sensitive than crops, quotients below 1 the opposite. Further methods included a multiple regression analysis and different approaches to assess the statistical power. The overall finding was that there were no consistent differences in sensitivity between wild plant species and crop species, based on ER50, ER25, and ER10 vegetative endpoints (the largest fraction of data). This was also true when censored endpoints, seedling emergence data, and other measured variables such as shoot height were included. Statistically significant differences occurred in both directions and were balanced, that is, there was no clear trend for either crops or noncrop species to be more sensitive than the other. On the basis of multivariate regression analysis, crops were found to be significantly more sensitive than wild plant species, albeit by a small margin (factor ≈1.4). Minimum detectable difference (MDD) analysis and multivariate regression analysis of modified datasets indicated that when using a data set of this size and heterogeneity, any dissimilarity between crop and wild species was detectable if exceeding a factor of 1.4 in either direction. For the taxonomic groups assessed here (i.e., with data), no intrinsic difference in sensitivity to PPPs between crop species and wild plant species was found. Integr Environ Assess Manag 2019;15:176-189. © 2018 SETAC.


Assuntos
Produtos Agrícolas/efeitos dos fármacos , Herbicidas/toxicidade , Magnoliopsida/efeitos dos fármacos , Medição de Risco , Especificidade da Espécie
18.
Environ Sci Pollut Res Int ; 26(4): 3965-3979, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30552611

RESUMO

Early stages of ontogenesis determining subsequent growth, development, and productivity of crops can be affected by wastewater and sludge contaminated with pharmaceuticals. Diclofenac (DCF) and paracetamol (PCT; both 0.0001 to 10 mg/L) did not affect seed germination and primary root length of onion, lettuce, pea, and tomato. Conversely, 20-day-old pea and maize plants exhibited decrease in biomass production, leaf area (by approx. 40% in pea and 70% in maize under 10 mg/L DCF), or content of photosynthetic pigments (by 10% and 60% under 10 mg/L PCT). Quantum yields of photosystem II were reduced only in maize (FV/FM and ΦII by more than 40% under 10 mg/L of both pharmaceuticals). Contents of H2O2 and superoxide increased in roots of both species (more than four times under 10 mg/L PCT in pea). Activities of antioxidant enzymes were elevated in pea under DCF treatments, but decreased in maize under both pharmaceuticals. Oxidative injury of root cells expressed as lowered oxidoreductase activity (MTT assay, by 40% in pea and 80% in maize) and increase in malondialdehyde content (by 60% and 100%) together with the membrane integrity disruption (higher Evans Blue accumulation, by 100% in pea and 300% in maize) confirmed higher sensitivity of maize as a C4 monocot plant to both pharmaceuticals.


Assuntos
Acetaminofen/toxicidade , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Diclofenaco/toxicidade , Sementes/efeitos dos fármacos , Acetaminofen/análise , Antioxidantes/análise , Diclofenaco/análise , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Malondialdeído/análise , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Sementes/fisiologia , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade
19.
Chemosphere ; 214: 371-378, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30267910

RESUMO

Parasitoids acting as biocontrol agents provide farmers with valuable ecosystem services, but are sensitive to insecticides applied against pests. Besides lethal effects of insecticides, sublethal effects observed among survivors may further influence parasitoids' performance. However, information on sublethal effects is scattered across case studies, without a quantitative synthesis and evaluation of generality of respective data. We conducted an analysis of 85 primary empirical datasets to quantify sublethal effects of insecticide application on two key parameters of parasitoid fitness, offspring production and proportion of females among offspring (i.e. sex ratio). To create a direct link to existing agricultural practices, we primarily focused on studies in which parasitoids were exposed to field-recommended concentrations of insecticides. Insecticide-exposed females produced substantially fewer and more male-biased offspring, accounting for an average of about 28% cumulative loss in parasitoid reproductive capacity per generation. The magnitude of sublethal effects was significantly affected by insecticide mode of action, with broad-spectrum insecticides being particularly harmful to parasitoid reproductive performance. Transgenic crops and toxins derived from such plants were generally associated with weaker sublethal effects than majority of synthetic insecticides. Nevertheless, species responses, even to the same insecticides and transgenic crops, showed high variability, cautioning against extrapolating results from individual studies to a wider range of species. Overall, our results indicate that sublethal side-effects on parasitoid reproductive performance represent a significant and widespread cost of insecticides that should explicitly be taken into account when evaluating their harmfulness. Linking laboratory results to field situations remains a key challenge for future research.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Interações Hospedeiro-Parasita/efeitos dos fármacos , Himenópteros/crescimento & desenvolvimento , Inseticidas/toxicidade , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Reprodução , Animais , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/parasitologia , Feminino , Himenópteros/efeitos dos fármacos , Dose Letal Mediana , Masculino , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/parasitologia , Fatores Sexuais
20.
Chemosphere ; 214: 563-578, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30286423

RESUMO

The long-term use of Cu-containing fungicides contaminates vineyards soils, which can induce Cu toxicity and nutrient imbalances in several plant species. The aim of this work was to evaluate the effect of Cu toxicity on two grapevine rootstocks, Fercal and 196.17, and to elucidate if intercropping with oat can alleviate grapevine Cu toxicity. Plants were hydroponically-cultivated and treated with different Cu concentrations. At harvest the biomass accumulation, the SPAD index and the symplastic and apoplastic root and leaves ionome were measured to evaluate possible synergistic and/or antagonistic effects on other micro- and macronutrients. The root exudation analysis was correlated with genes expression (VvPEZ-like), whereas PCA analysis performed on the grapevine and oat ionome revealed that both mono- and intercropped 196.17 rootstock display a positive effect on Zn and Mn in the root tissues at high Cu concentrations. An increase of Zn and Mn in roots was also reported for the intercropped Fercal rootstock at high Cu concentrations while an antagonistic relation was reported for root Zn concentration in the monocropped Fercal rootstock. Our results showed that grapevine and oat compete for nutrient uptake and that this phenomenon can possibly alleviate grapevine Cu toxicity. However, Fercal rootstock is able to take advantage from oat, while 196.17 is disadvantaged by the intercropping system. Even though intercropping system seems to be a valuable tool to counteract grapevine Cu toxicity, the application of this agricultural practice has shown to be species dependent and should be evaluated for each rootstock.


Assuntos
Avena/metabolismo , Cobre/toxicidade , Produtos Agrícolas/metabolismo , Nutrientes/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Vitis/metabolismo , Avena/efeitos dos fármacos , Avena/crescimento & desenvolvimento , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Vitis/efeitos dos fármacos , Vitis/crescimento & desenvolvimento
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