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1.
J Agric Food Chem ; 68(10): 3006-3016, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-31986035

RESUMO

An increase in crop competitiveness relative to weed interference has the potential to reduce crop yield losses. In this study, the effects of phytoalexin resveratrol were examined in Zea mays L. (corn) and in the weed species Ipomoea grandifolia (Dammer) O'Donell (morning glory). At a concentration range from 220 to 2200 µM resveratrol exerted a stimulus on Z. mays seedling growth that was more pronounced at low concentrations; in the weed species I. grandifolia, resveratrol exerted inhibitory action on seedling growth in all of the assayed concentration range. In I. grandifolia, resveratrol also inhibited the respiratory activity of the primary roots. In mitochondria isolated from Z. mays roots, resveratrol at concentrations above 440 µM inhibited the respiration coupled to ADP phosphorylation and the activities of NADH-oxidase, succinate-oxidase, and ATPsynthase. These effects were not reproduced in Z. mays grown in the presence of resveratrol as the respiratory activities of the roots were not affected. The finding that the resveratrol exerts beneficial effects on growth of Z. mays seedlings and inhibits the growth of I. grandifolia heightens the potential of resveratrol application for crop protection.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Ipomoea/efeitos dos fármacos , Resveratrol/farmacologia , Zea mays/efeitos dos fármacos , Ipomoea/crescimento & desenvolvimento , Ipomoea/metabolismo , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Plantas Daninhas/metabolismo , Resveratrol/análise , Sesquiterpenos/análise , Sesquiterpenos/farmacologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
2.
Environ Pollut ; 256: 113466, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31679879

RESUMO

Since the Industrial Revolution, the global ambient O3 concentration has more than doubled. Negative impact of O3 on some common crops such as wheat and soybeans has been widely recognized, but there is relatively little information about maize, the typical C4 plant and third most important crop worldwide. To partly compensate this knowledge gap, the maize cultivar (Zhengdan 958, ZD958) with maximum planting area in China was exposed to a range of chronic ozone (O3) exposures in open top chambers (OTCs). The O3 effects on this highly important crop were estimated in relation to two O3 metrics, AOT40 (accumulated hourly O3 concentration over a threshold of 40 ppb during daylight hours) and POD6 (Phytotoxic O3 Dose above a threshold flux of 6 nmol O3 m-2 s-1 during a specified period). We found that (1) the reduced light-saturated net photosynthetic rate (Asat) mainly caused by non-stomatal limitations across heading and grain filling stages, but the stomatal limitations at the former stage were stronger than those at the latter stage; (2) impact of O3 on water use efficiency (WUE) of maize was significantly dependent on developmental stage; (3) yield loss induced by O3 was mainly due to a reduction in kernels weight rather than in the number of kernels; (4) the performance of AOT40 and POD6 was similar, according to their determination coefficients (R2); (5) the order of O3 sensitivity among different parameters was photosynthetic parameters > biomass parameters > yield-related parameters; (6) Responses of Asat to O3 between heading and gran filling stages were significantly different based on AOT40 metric, but not POD6. The proposed O3 metrics-response relationships will be valuable for O3 risk assessment in Asia and also for crop productivity models including the influence of O3.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Fotossíntese/efeitos dos fármacos , Zea mays/fisiologia , Poluentes Atmosféricos/análise , Ásia , Biomassa , China , Produtos Agrícolas/efeitos dos fármacos , Ozônio/análise , Folhas de Planta/química , Soja/efeitos dos fármacos , Triticum/efeitos dos fármacos , Zea mays/efeitos dos fármacos
3.
Ecotoxicol Environ Saf ; 188: 109897, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704327

RESUMO

Mercury (Hg) pollution seriously threatens food safety and has attracted global attention. Phytoextraction, due to its low cost, applicability, and environmental friendliness, is considered a new technology for clean-up of heavy metal contamination in the environment. However, the low bioavailability of Hg in polluted areas greatly limits the applicability of phytoextraction. Here, we compared the effects of six common chelating ligands on the absorption and transport of Hg in maize (Zea mays L.), which has a high biomass and short growth cycle. The results showed that the root length and biomass of maize seedlings of the groups treated with the six chelating ligands (EDTA, iodide, ammonium, thiosulfate, thiocyanate, and thiocarbamide) did not change compared with those of the non-treated groups. Co-exposure to Hg and each chelating ligand markedly alleviated the inhibitory effect induced by Hg. Iodide treatment resulted in the lowest root Hg content and highest translocation factor (TF) value, while ammonium treatment gave rise to the highest shoot Hg concentration and lowest TF. Compared with other chelating ligands, thiosulfate exhibited the maximum alleviation of Hg toxicity and achieved the highest concentration of Hg in the roots and aerial parts. Moreover, the TF and Hg accumulation in the thiosulfate and Hg co-exposed group were much higher than those in the group exposed to Hg alone. This finding suggests that, among these common chelating ligands, thiosulfate compounds have great potential for Hg phytoextraction, while the others can immobilize Hg in polluted areas.


Assuntos
Quelantes/farmacologia , Mercúrio/análise , Poluentes do Solo/análise , Tiossulfatos/farmacologia , Zea mays/química , Bioacumulação , Biodegradação Ambiental , Disponibilidade Biológica , Transporte Biológico , Biomassa , Ligantes , Raízes de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento
4.
Food Chem ; 309: 125779, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704074

RESUMO

Germinated edible seeds and sprouts are becoming increasingly common in the human diet because they are rich in bioactive compounds and antioxidants and are highly nutritious. In this study, the effects of NaCl stress and supplemental CaCl2 on carotenoid accumulation, antioxidant capacity and expression of key enzymes in yellow maize kernels were investigated. The results showed that the lutein and zeaxanthin contents increased with NaCl treatment, and further increased with supplemental CaCl2. Additionally, germinated yellow maize kernels showed increased antioxidant capacity in response to NaCl and CaCl2. The transcript levels of carotenogenic genes ZmPSY and ZmCYP97C were upregulated and the expression levels of ZmLCYB and ZmBCH1 were downregulated under NaCl stress. The expression of all key carotenogenic genes was upregulated by CaCl2 supplementation. These results suggested that NaCl and CaCl2 contribute to carotenoid accumulation via increased expression of related carotenogenic genes and increased antioxidant capacity in germinated yellow maize kernels.


Assuntos
Carotenoides/metabolismo , Cloreto de Sódio/farmacologia , Zea mays/efeitos dos fármacos , Antioxidantes/química , Antioxidantes/metabolismo , Cloreto de Cálcio/farmacologia , Carotenoides/análise , Cromatografia Líquida de Alta Pressão , Germinação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Regulação para Cima/efeitos dos fármacos , Zea mays/metabolismo
5.
Chemosphere ; 239: 124794, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31521929

RESUMO

Cadmium (Cd) pollution is considered one of the global environmental issues due to its adverse effects on plant and human health. With the rapid development of nanotechnology and the practical application of engineered nanoparticles (ENPs) in agriculture, the mechanisms underlying the interactions between NPs and heavy metal on their uptake, accumulation, and phytotoxicity in crops are still not fully understood. Therefore, the impact of TiO2 NPs (0, 100, 250 mg/L) and Cd (0, 50 µM) co-exposure on hydroponic maize (Zea mays L.) was determined under two exposure modes. Results showed that root co-exposure to TiO2 NPs and 100 mg/L Cd significantly enhanced Cd uptake and produced greater phytotoxicity in maize than foliar exposure to TiO2 NPs. Meanwhile, plant dry weight and chlorophyll content showed a reduction of 45.3% and 50.5%, respectively, when compared with single Cd treatment. In addition, the accumulation of Ti in shoots and roots increased by 1.61 and 4.29 times, respectively when root exposure to 250 mg/L TiO2 NPs. By contrast, foliar exposure of TiO2 NPs could markedly decrease shoot Cd contents from 15.2% to 17.8% and had a stronger influence on alleviating Cd-induced toxicity via increasing superoxide dismutase (SOD) and glutathione S-transferase (GST) activities and upregulating several metabolic pathways, including galactose metabolism and citrate cycle, alanine, aspartate and glutamate metabolism, as well as glycine, serine and threonine metabolism. This study provides a new strategy for the application of TiO2 NPs in crop safety production in Cd contaminated soils.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Titânio/farmacologia , Zea mays/efeitos dos fármacos , Aminoácidos/metabolismo , Cádmio/farmacocinética , Clorofila/metabolismo , Produtos Agrícolas/metabolismo , Galactose/metabolismo , Glutationa Transferase/metabolismo , Hidroponia , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo , Poluentes do Solo/farmacocinética , Superóxido Dismutase/metabolismo , Titânio/administração & dosagem , Titânio/farmacocinética , Zea mays/metabolismo
6.
Plant Sci ; 290: 110196, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31779899

RESUMO

Ethephon efficiently regulates plant growth to modulate the maize (Zea mays L.) stalk strength and yield potential, yet there is little information on how ethylene governs a specific cellular response for altering internode elongation. Here, the internode elongation kinetics, cell morphological and physiological properties and transcript expression patterns were investigated in the ethephon-treated elongating internode. Ethephon decreased the internode elongation rate, shortened the effective elongation duration, and advanced the growth process. Ethephon regulated the expression patterns of expansin and secondary cell wall-associated cellulose synthase genes to alter cell size. Moreover, ethephon increased the activities and transcripts level of phenylalanine ammonia-lyase and peroxidase, which contributed to lignin accumulation. Otherwise, ethephon-boosted ethylene evolution activated ethylene signal and increased ZmGA2ox3 and ZmGA2ox10 transcript levels while down-regulating ZmPIN1a, ZmPIN4 and ZmGA3ox1 transcript levels, which led to lower accumulation of gibberellins and auxin. In addition, transcriptome profiles confirmed previous results and identified several transcription factors that are involved in the ethephon-modulated transcriptional regulation of cell wall biosynthesis and modification and responses to ethylene, gibberellins and auxin. These results indicated that ethylene-modulated auxin and gibberellins signaling mediated the transcriptional operation of cell wall modification to regulate cell elongation in the ethephon-treated maize internode.


Assuntos
Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Compostos Organofosforados/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Zea mays/crescimento & desenvolvimento , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/genética
7.
Environ Monit Assess ; 191(12): 717, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31686234

RESUMO

Atrazine is a synthetic herbicide applied to control broadleaf weeds in different crops. In many parts of the world, atrazine is mainly applied for controlling weeds in maize fields. However, studies on the possible adverse effects of atrazine on maize crop can hardly be found in literature. The present study was therefore conducted to evaluate the effect of atrazine on different characteristics of maize seedlings including germination, growth, chlorophyll contents, soluble sugars, proteins and proline levels, ions accumulation, cell viability, and cell injury. In addition, the effects of atrazine on reactive oxygen species (ROS) accumulation and antioxidant enzymes activities in maize seedlings were estimated. It was found that at high concentration, atrazine slightly but significantly inhibited seed germination and growth of maize seedlings. Light-harvesting pigments (chlorophylls a and b, and total carotenoids) exhibited a higher sensitivity to atrazine and were negatively impacted by atrazine at doses above 50 ppm. Atrazine caused an increase in soluble sugars at all tested doses and decrease in soluble proteins at the highest tested dose. Exposure of maize seedlings to atrazine resulted in an increased cell injury and decreased cell viability. Atrazine did not affect the concentration of Na+, K+, and Ca2+ ions in maize seedlings to any greater extent; however, some minor changes were observed in some cases. An increase in the stress marker, proline, was found upon exposure to atrazine. The observed effects of atrazine in maize seedlings can be attributed to oxidative stress as revealed by an increase in H2O2 content and higher activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) enzymes in atrazine-treated seedlings. The present investigation concludes that atrazine has the potential to adversely affect germination and growth of maize seedlings by inducing oxidative stress that causes increased cell injury and decreased cell viability as well as impairs the concentration of light-harvesting pigments.


Assuntos
Atrazina/toxicidade , Herbicidas/toxicidade , Estresse Fisiológico , Zea mays/efeitos dos fármacos , Antioxidantes/metabolismo , Atrazina/metabolismo , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Germinação/efeitos dos fármacos , Herbicidas/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Superóxido Dismutase/metabolismo , Zea mays/crescimento & desenvolvimento
8.
J Agric Food Chem ; 67(43): 11883-11892, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31596582

RESUMO

Hydrogen sulfide is a key gasotransmitter for plants and has been shown to greatly increase their growth and survival in the presence of environmental stressors. Current methods for slowly releasing hydrogen sulfide use chemicals, such as GYY-4137, but these result in the release of chemicals not found in the environment, and chemicals used may lack structures that can be readily tuned to affect the rate of release of hydrogen sulfide. In this article, we describe the synthesis and slow release of hydrogen sulfide from dialkyldithiophosphates, which are a new set of hydrogen sulfide releasing chemicals that can be used in agriculture. The rates of hydrolysis of dibutyldithiophosphate and GYY-4137 were measured in water at 85 °C and compared with each other to investigate their differences. GYY-4137 is widely used as a chemical that slowly releases H2S, but its rate of release was not previously quantified. The release of hydrogen sulfide in water at room temperature was measured for a series of dialkyldithiophosphates using a hydrogen sulfide electrode. It was shown that the structure of the dialkyldithiophosphate affected the amount of hydrogen sulfide released. The final degradation products of dibutyldithiophosphate were shown to be phosphoric acid and butanol, which are chemicals found in the environment. This result was notable because it demonstrated that dialkyldithiophosphates degrade to safe, natural chemicals that will not pollute the environment. To demonstrate that dialkyldithiophosphates have potential applications in agriculture, maize was grown for 4.5 weeks after exposure to 1-200 mg of dibutyldithiophosphate, and the weight of corn plants increased by up to 39% at low loadings of dibutyldithiophosphate.


Assuntos
Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Sulfeto de Hidrogênio/química , Sulfeto de Hidrogênio/farmacologia , Organotiofosfatos/química , Zea mays/efeitos dos fármacos , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Hidrólise , Morfolinas/química , Compostos Organotiofosforados/química , Zea mays/crescimento & desenvolvimento
9.
Plant Sci ; 289: 110256, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31623792

RESUMO

The plant-specific NAC transcription factors play diverse roles in various stress signaling. Alternative splicing is particularly prevalent in plants under stress. However, the investigation of cadmium (Cd) on the differential expression of the splice variants of NACs is in its infancy. Here, we identified three Cd-induced intron retention splice NAC variants which only contained the canonical NAC domain, designated as nacDomains, derived from three Cd-upregulated maize NACs. Subcellular localization analysis indicated that both nacDomain and its full-length NAC counterpart co-localized in the nucleus as manifested in the BiFC assay, thus implied that nacDomains and their corresponding NACs form heterodimers through the identical NAC domain. Further chimeric reporter/effector transient expression assay and Cd-tolerance assay in tobacco leaves collectively indicated that nacDomain-NAC heterodimers were involved in the regulation of NAC function. The results obtained here were in accordance with the model of dominant negative, which suggested that nacDomain act as the dominant negative to antagonize the regulation of NAC on its target gene expression and the Cd-tolerance function performance of NAC transcription factor. These findings proposed a novel insight into understanding the molecular mechanisms of Cd response in plants.


Assuntos
Proteínas de Plantas/genética , Fatores de Transcrição/genética , Transcriptoma , Zea mays/genética , Sequência de Aminoácidos , Cádmio/efeitos adversos , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alinhamento de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Transcriptoma/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Zea mays/metabolismo
10.
J Agric Food Chem ; 67(44): 12164-12171, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31600067

RESUMO

Plant biostimulants (PBS) increase crop productivity and induce beneficial processes in plants. Although PBS can stimulate plant tolerance to some abiotic stresses, their effect in improving crop resistance to herbicide injuries has barely been investigated. Therefore, a study on the effect of a biostimulant (Megafol) on maize (Zea mays L.) tolerance to a chloro-acetanilide herbicide (metolachlor) was carried out. We found that Megafol reduced the negative effects of metolachlor on maize. Indeed, biostimulated samples showed increases in germination, biomass production, Vigor index, and EC50 (effective concentration causing 50% reductions to roots and aerial biomass) with respect to the samples treated with metolachlor alone. Furthermore, plants treated with the herbicide in combination with Megafol showed lower levels of malondialdehyde (MDA). Antioxidant enzymes, namely, ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and catalase (CAT), were assayed in samples treated with metolachlor alone or in combination with Megafol, and higher enzymes activities were found in biostimulated plants. The results of this study open the perspective of using Megafol, as well as other suitable plant biostimulants, in improving the crop's capacity to cope with injuries and unwanted effects that herbicide could cause to these species.


Assuntos
Acetamidas/farmacologia , Herbicidas/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Zea mays/efeitos dos fármacos , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Germinação/efeitos dos fármacos , Malondialdeído/metabolismo , Peroxidase/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
11.
J Agric Food Chem ; 67(42): 11568-11576, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31584809

RESUMO

Tribenuron-methyl (TM), as one of the sulfonylurea (SU) herbicides, has been widely and effectively applied for many kinds of plants. SUs inhibit plant growth by restraining the biosynthetic pathway of branched-chain amino acids (BCAAs) catalyzed by acetolactate synthase (ALS). Safeners are agrochemicals that protect crops from herbicide injuries. To improve the crop tolerance under TM toxicity stress, this paper evaluated the protective effect of N-tosyloxazolidine-3-carboxamide. It turned out that most of the tested compounds showed significant protection against TM via enhancing the glutathione (GSH) content and glutathione S-transferase (GST) activity. Among all of the tested compounds, compound 16 exhibited more excellent protection than the contrast safener R-28725 and other target compounds. A positive correlation between the growth level, endogenous GSH content, and GST activity was observed in this research. The GST kinetic parameter Vmax of the maize was increased by 29.6% after treatment with compound 16, while Km was decreased by 51.9% compared to the untreated control. The molecular docking model indicated that compound 16 could compete with TM in the active site of ALS, which could interpret the protective effects of safeners. The present work demonstrated that N-tosyloxazolidine-3-carboxamide derivatives could be considered as potential candidates for developing new safeners in the future.


Assuntos
Herbicidas/toxicidade , Proteínas de Plantas/metabolismo , Substâncias Protetoras/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/enzimologia , Acetolactato Sintase/química , Acetolactato Sintase/metabolismo , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Cinética , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Compostos de Sulfonilureia/toxicidade , Zea mays/química
12.
Ecotoxicol Environ Saf ; 186: 109744, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31627093

RESUMO

Biological strategy of utilization of plants-microbe's interactions to remediate cadmium (Cd) contaminated soils is effective and practical. However, limited evidence at transcriptome level is available about how microbes work with host plants to alleviate Cd stress. In the present study, comparative transcriptomic analysis was performed between maize seedlings inoculated with arbuscular mycorrhizal (AM) fungi and non-AM fungi inoculation under distinct concentrations of CdCl2 (0, 25, and 50 mg per kg soil). Significantly higher levels of Cd were found in root tissues of maize colonized by AM fungi, whereas, Cd content was reduced as much as 50% in leaf tissues when compared to non-AM seedlings, indicating that symbiosis between AM fungi and maize seedlings can significantly block translocation of Cd from roots to leaf tissues. Moreover, a total of 5827 differentially expressed genes (DEG) were determined and approximately 68.54% DEGs were downregulated when roots were exposed to high Cd stress. In contrast, 67.16% (595) DEGs were significantly up-regulated when seedlings were colonized by AM fungi under 0 mg CdCl2. Based on hierarchical clustering analysis, global expression profiles were split into eight distinct clusters. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that hundreds of genes functioning in plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling pathway and glutathione metabolism were enriched. Furthermore, MapMan pathway analysis indicated a more comprehensive overview response, including hormone metabolism, especially in JA, glutathione metabolism, transcription factors and secondary metabolites, to Cd stress in mycorrhizal maize seedlings. These results provide an overview, at the transcriptome level, of how inoculation of maize seedlings by AM fungi could facilitate the relief of Cd stress.


Assuntos
Cádmio/efeitos adversos , Glomeromycota/fisiologia , Micorrizas/fisiologia , Poluentes do Solo/efeitos adversos , Simbiose , Transcriptoma , Zea mays/efeitos dos fármacos , Cádmio/metabolismo , Regulação para Baixo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Estresse Fisiológico , Zea mays/genética , Zea mays/metabolismo , Zea mays/microbiologia
13.
Ecotoxicol Environ Saf ; 185: 109706, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31561073

RESUMO

Chromium (Cr) is becoming a potential pollutant with the passage of time. Higher intake of Cr does not only affect the productivity of crops, but also the quality of food produced in Cr polluted soils. In the past, foliar application of Fe is widely studied regarding their potential to alleviate Cr toxicity. However, limited information is documented regarding the combined use of PGPR and foliar Fe. Therefore, the current study was conducted to screen Cr tolerant PGPR and examine effect of foliar Fe with and without Cr tolerant PGPR under Cr toxicity (50 and 100 mg kg-1) in maize (Zea mays) production. Out of 15, two Cr tolerant PGPR were screened, identified (Agrobacterium fabrum and Leclercia adecarboxylata) and inoculated with 500 µM Fe. Results confirmed that Agrobacterium fabrum + 500 µM Fe performed significantly best in improving dry weight of roots and shoot, plant height, roots and shoot length and plant leaves in maize under Cr toxicity. A significant increase in chlorophyll a (51.5%), b (55.1%) and total (32.5%) validated the effectiveness of A. fabrum + 500 µM Fe to alleviate Cr toxicity. Improvement in intake of N (64.7%), P (70.0 and 183.3%), K (53.8% and 3.40-fold) in leaves and N (25.6 and 122.2%), P (25.6 and 122.2%), K (33.3% and 97.3%) in roots of maize at Cr50 and Cr100 confirmed that combined application of A. fabrum with 500 µM Fe is a more efficacious approach for alleviation of Cr toxicity and fortification of Fe comparative to sole foliar application of 500 µM Fe.


Assuntos
Agrobacterium/enzimologia , Carbono-Carbono Liases/metabolismo , Cromo/toxicidade , Enterobacteriaceae/enzimologia , Ferro/farmacologia , Poluentes do Solo/toxicidade , Zea mays/efeitos dos fármacos , Agrobacterium/efeitos dos fármacos , Clorofila A/metabolismo , Enterobacteriaceae/efeitos dos fármacos , Ferro/metabolismo , Paquistão , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Rizosfera , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia
14.
Environ Sci Pollut Res Int ; 26(31): 31822-31833, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31487012

RESUMO

Remediation of heavy metal-contaminated soils is essential for safe agricultural or urban land use, and phytoremediation is among the most effective methods. The success of phytoremediation relies on the size of the plant biomass and bioavailability of the metal for plant uptake. This research was carried out to determine the effect of Ethylenediaminetetraacetic acid (EDTA) ligand and Cu-resistant plant growth-promoting rhizobacteria (PGPR) on phytoremediation efficiency of selected plants as well as fractionation and bioavailability of copper (Cu) in a contaminated soil. The test conditions included three plant species (maize: Zea mays L., sunflower: Helianthus annuus L., and pumpkin: Cucurbita pepo L.) and six treatments, comprising two PGPR strains (Pseudomonas cedrina K4 and Stenotrophomonas sp. A22), two PGPR strains with EDTA, EDTA, and control (without PGPR and EDTA). The combination of EDTA and PGPR enhanced the Cu concentration in both shoot and root tissues and increased the plant biomass. The Cu specific uptake was at a maximum level in the shoots of pumpkin plants when treated with the PGPR strain K4 + EDTA (202 µg pot-1), and the minimum amount of Cu was recorded for sunflower with no PGPR or EDTA addition (29.6 µg pot-1). The result of the PGPR-EDTA treatments showed that the combined application of EDTA and PGPR increased the shoot Cu-specific uptake approximately fourfold in pumpkin. Pumpkin with the highest shoot Cu specific uptake and maize with the highest root Cu specific uptake were the most effective plants in phytoextraction and phytostabilization, respectively. The effectiveness of different PGPR-EDTA treatments in increasing Cu specific uptake by crop plants was assessed by measuring the amount of Cu extracted from the rhizosphere soil adhering to the roots of crop species, by the use of the single extractants Diethylenetriamine pentaacetic acid (DTPA), H2O, NH4NO3, and NH4OAc. PGPR-EDTA treatments increased the amount of water-extractable Cu from rhizosphere soils more than ten times that of the control. The combined application of the EDTA and PGPR reduced the carbonated Fe and Mn oxide-bound Cu in the contaminated soil, and increased the soluble and exchangeable concentration of Cu. Pumpkin, with high shoot biomass and the highest shoot Cu specific uptake was found to be the most effective field crop in phytoextraction of Cu from the contaminated soil. The results of this pot study demonstrated that the EDTA+PGPR treatment could play an important role in increasing the Cu bioavailability and specific uptake by plants, and thus increasing the phytoremediation efficiency of plants in Cu-contaminated areas.


Assuntos
Biodegradação Ambiental/efeitos dos fármacos , Cobre/toxicidade , Ácido Edético/farmacologia , Pseudomonas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Inoculantes Agrícolas , Disponibilidade Biológica , Biomassa , Cobre/análise , Cobre/farmacocinética , Cucurbita/efeitos dos fármacos , Cucurbita/microbiologia , Helianthus/efeitos dos fármacos , Helianthus/microbiologia , Brotos de Planta/efeitos dos fármacos , Pseudomonas/fisiologia , Rizosfera , Poluentes do Solo/farmacocinética , Zea mays/efeitos dos fármacos , Zea mays/microbiologia
15.
Molecules ; 24(15)2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31387205

RESUMO

In the early stage, the best conditions for alkali-bound ozone pretreatment were studied. But after treatment, the alkaline black liquor was directly discarded due to the large amount of organic matter, resulting in environmental pollution and waste of resources. In this paper, the alkaline black liquor was recycled under the optimal pretreatment conditions. The results showed that the number of alkaline black liquor cycles had little effect on hemicellulose content, and had a great influence on cellulose content and lignin content. Through structural characterization of corn stover, it was found that the pretreatment caused structural changes of lignin in straw. However, when the alkaline black liquor was recycled for the fourth time, the ether bond in the side chain of lignin and the covalent bond between the components were not sufficiently destroyed, and the damage to the phenolic hydroxyl group was also weakened. It was indicated that when the alkaline black liquor was recycled for the fourth time, the destruction effect of the alkaline black liquor on the straw was significantly inhibited. Therefore, the optimal circulation time of alkaline black liquor was three times, and the cellulolytic conversion rate was 81.53%.


Assuntos
Álcalis/química , Ozônio/química , Zea mays/química , Celulose/química , Hidrólise , Lignina/química , Reciclagem , Análise Espectral , Zea mays/efeitos dos fármacos
16.
J Agric Food Chem ; 67(36): 10126-10136, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31433635

RESUMO

Soil microbes have recently been utilized to improve cadmium (Cd) tolerance and lower its accumulation in plants. Nevertheless, whether rhizobacteria can prevent Cd uptake by graminaceous plants and the underlying mechanisms remain elusive. In this study, inoculation with Enterobacter asburiae NC16 reduced transpiration rates and the expression of some iron (Fe) uptake-related genes including ZmFer, ZmYS1, ZmZIP, and ZmNAS2 in maize (Zea mays) plants, which contributed to mitigation of Cd toxicity. However, the inoculation with NC16 failed to suppress the transpiration rates and transcription of these Fe uptake-related genes in plants treated with fluridone, an abscisic acid (ABA) biosynthetic inhibitor, indicating that the impacts of NC16-inoculation observed were dependent on the actions of ABA. We found that NC16 increased the host ABA levels by mediating the metabolism of ABA rather than its synthesis. Moreover, the capacity of NC16 to inhibit plant uptake of Cd was greatly weakened in plants overexpressing ZmZIP, encoding a zinc/iron transporter. Collectively, our findings indicated that E. asburiae NC16 reduced Cd toxicity in maize plants at least partially by hampering the Fe uptake-associated pathways.


Assuntos
Cádmio/metabolismo , Enterobacter/metabolismo , Ferro/metabolismo , Zea mays/metabolismo , Inoculantes Agrícolas/metabolismo , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Piridonas/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/genética , Zea mays/microbiologia
17.
J Sci Food Agric ; 99(15): 6814-6821, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31368532

RESUMO

BACKGROUND: Maize is one of the most important cereals. It is used for different purposes and in different industries worldwide. This cereal is prone to contamination with mycotoxins, such as zearalenone (ZEN), which is produced mainly by Fusarium graminearum, F. culmorum and F. equiseti. Toxin production under highly moist conditions (aw > 0.95) is exacerbated if there are alternations between low temperatures (12-14 °C) and high temperatures (25-28 °C). Even if good production practices are adopted, mycotoxins can be found in several stages of the production chain. For this reason, an alternative to reducing this contamination is ozonation. This study evaluated the reduction of ZEN in naturally contaminated whole maize flour (WMF) treated with 51.5 mg L-1 of ozone for up to 60 min. Pasting properties, peroxide value, and fatty acid composition were also evaluated. RESULTS: Zearalenone degradation in ozonated WMF was described by a fractional first-order kinetic, with a maximum reduction of 62.3% and kinetic parameter of 0.201 min-1 in the conditions that were evaluated. The ozonation process in WMF showed a decrease in the apparent viscosity, a decrease in the proportion of linoleic, oleic, and α-linolenic fatty acids, an increase in the proportion of palmitic acid, and an increase in the peroxide value. CONCLUSION: Ozonation was effective in reducing ZEN contamination in WMF. However, it also modified the pasting properties, fatty acid profile, and peroxide value, affecting functional and technological aspects of WMF. © 2019 Society of Chemical Industry.


Assuntos
Descontaminação/métodos , Ozônio/farmacologia , Zea mays/química , Zearalenona/química , Descontaminação/instrumentação , Contaminação de Alimentos/análise , Fusarium/metabolismo , Cinética , Ozônio/química , Controle de Qualidade , Zea mays/efeitos dos fármacos , Zea mays/microbiologia , Zearalenona/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-31446836

RESUMO

The effects of doxycycline (DOX) on microbial biomass C and nitrates production in soil, on earthworms and cultivated plants were examined. The concentrations for the various tests were selected after preliminary experiments, to present impact and be close to the environmentally relevant. The results revealed impacts of the antibiotic on microbial biomass C and NO3- production at the concentration level of 7.2 mg/kg soil dry weight (d.w.), but these parameters recovered to normal values since the antibiotic was applied once as a pulse. Moreover, the drug had negative effects on earthworm juveniles' total number at the concentration level of 30 mg/kg soil d.w. In addition, the toxicity tests on plant seedling growth revealed negative effects of the antibiotic for tomato at the concentration level of 45.44 mg/kg soil d.w. However, DOX showed positive effects for corn seedling growth, showing that the results of such experiments are valuable for sustainable animal wastes management. Non-significant effects were observed for seedling growth of pea, pumpkin and bean plants. The results of the study are valuable for the impact assessment of the antibiotic in the terrestrial environment and the management of contaminated animal waste.


Assuntos
Antibacterianos/toxicidade , Doxiciclina/toxicidade , Nitrogênio/metabolismo , Poluentes do Solo/toxicidade , Xenobióticos/toxicidade , Animais , Biotransformação , Ecossistema , Nitratos/metabolismo , Oligoquetos/efeitos dos fármacos , Oligoquetos/fisiologia , Testes de Toxicidade , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento
19.
J Agric Food Chem ; 67(37): 10489-10497, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31452371

RESUMO

In order to develop a novel herbicide containing the ß-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.


Assuntos
Herbicidas/síntese química , Herbicidas/farmacologia , Plantas Daninhas/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Desenho de Drogas , Herbicidas/química , Estrutura Molecular , Plantas Daninhas/crescimento & desenvolvimento , Relação Estrutura-Atividade , Controle de Plantas Daninhas , Zea mays/efeitos dos fármacos
20.
Molecules ; 24(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443550

RESUMO

Herbicide safeners selectively protect crops from herbicide injury while maintaining the herbicidal effect on the target weed. To some extent, the detoxification of herbicides is related to the effect of herbicide safeners on the level and activity of herbicide target enzymes. In this work, the expression of the detoxifying enzyme glutathione S-transferase (GST) and antioxidant enzyme activities in maize seedlings were studied in the presence of three potential herbicide safeners: 3-dichloroacetyl oxazolidine and its two optical isomers. Further, the protective effect of chiral herbicide safeners on detoxifying chlorsulfuron in maize was evaluated. All safeners increased the expression levels of herbicide detoxifying enzymes, including GST, catalase (CAT), and peroxidase (POD) to reduce sulfonylurea herbicide phytotoxicity in maize seedlings. Our results indicate that the R-isomer of 3-(dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine can induce glutathione (GSH) production, GST activity, and the ability of GST to react with the substrate 1-chloro-2,4-dinitrobenzene (CDNB) in maize, meaning that the R-isomer can protect maize from damage by chlorsulfuron. Information about antioxidative enzyme activity was obtained to determine the role of chiral safeners in overcoming the oxidative stress in maize attributed to herbicides. The interaction of safeners and active target sites of acetolactate synthase (ALS) was demonstrated by molecular docking modeling, which indicated that both isomers could form a good interaction with ALS. Our findings suggest that the detoxification mechanism of chiral safeners might involve the induction of the activity of herbicide detoxifying enzymes as well as the completion of the target active site between the safener and chlorsulfuron.


Assuntos
Inativação Metabólica/efeitos dos fármacos , Oxazóis/química , Oxazóis/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/metabolismo , Acetolactato Sintase/química , Acetolactato Sintase/metabolismo , Sítios de Ligação , Catalase/metabolismo , Domínio Catalítico , Glutationa/metabolismo , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Peroxidase/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Zea mays/química
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