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1.
J Agric Food Chem ; 67(35): 9738-9748, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31411877

RESUMO

The presence of chromium (Cr) in cultivated fields affects carbohydrate metabolism of rice (Oryza sativa L.) and weakens its productivity. Little is known about the molecular mechanism of sucrose metabolism underlying Cr stress response in rice plants. In the present study, the transcriptome map of sucrose metabolism in rice seedlings exposed to both trivalent and hexavalent chromium was investigated using Agilent 4 × 44K rice microarray analysis. Results indicated that Cr exposure (3 days) significantly (p < 0.05) improved sucrose accumulation, and altered the activities of sucrose synthetase, sucrose phosphate phosphatase, and amylosynthease in rice tissues. We identified 119 differentially regulated genes involved in 17 sucrose metabolizing enzymes and found that gene responses in roots were significantly (p < 0.05) stronger than in shoots under both Cr(III) and Cr(VI) treatment. The network maps of gene regulation responsible for sucrose metabolism in rice plants provide a theoretical basis for further cultivating Cr-resistant rice cultivars through molecular genetic improvement.


Assuntos
Cromo/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/metabolismo , Poluentes do Solo/farmacologia , Sacarose/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
2.
Pestic Biochem Physiol ; 158: 128-134, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378348

RESUMO

Indoleacetic acid (IAA)-carbendazim was synthesized to assess whether this conjugate could retain the fungicidal activity of carbendazim and gain root-inducing properties upon the addition of an indoleacetic acid group. An indoor virulence test demonstrated that the conjugate retained the fungicidal activity of carbendazim towards Cylindrocladium parasiticum. The conjugate was detected in roots after soaking Ricinus communis L. leaves into a solution of the IAA-carbendazim, which confirmed its phloem mobility. The activities of the cellulase, polygalacturonase and xylanase produced by Cylindrocladium parasiticum treated with different concentrations of the conjugate were determined, and the peak activities appeared at 72 h or 96 h. More importantly, the conjugate showed the ability to promote root growth. These results revealed that indoleacetic acid-carbendazim may be useful in preventing Cylindrocladium parasiticum and other diseases.


Assuntos
Ascomicetos/efeitos dos fármacos , Benzimidazóis/farmacologia , Carbamatos/farmacologia , Fungicidas Industriais/farmacologia , Ácidos Indolacéticos/farmacologia , Celulase/metabolismo , Floema/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Poligalacturonase/metabolismo , Ricinus/efeitos dos fármacos
3.
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
4.
Physiol Plant ; 167(1): 2-4, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31268563

RESUMO

Generating salt-tolerant plants that can cope with increasing soil salinity is a major goal of crop-breeding programs worldwide. Together with genetic approaches, research efforts are focusing on finding chemical modulators of salt tolerance. The exogenous application of 5-aminolevulinic acid (ALA) has been shown to improve salt tolerance in diverse crop species, but its mechanism of action is not properly understood. Wu et al. (2019) report that ALA treatment enhances reactive oxygen species (ROS) production in the roots of salt-stressed strawberry plants. Activation of several key ion transporters downstream to the ROS signal helps to sequester the toxic Na+ ions in the roots and protects the shoots against salt stress.


Assuntos
Ácido Aminolevulínico/metabolismo , Fragaria/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fragaria/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Tolerância ao Sal , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/metabolismo , Cloreto de Sódio/farmacologia
5.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2226-2230, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359646

RESUMO

Using the White as basic medium, the effects of the exogenous IBA and endophytic fungal elicitor on the growth of in vitro roots cultures of Dysosma versipellis and production of podophyllotoxin were investigated in this study. The results showed that the IBA and the endophytic fungus Zasmidium syzygii elicitor could increase the content of podophyllotoxin of in vitro roots of D. versipellis after 3 weeks. The White medium added with 3 mg·L~(-1) IBA induced the highest increase of podophyllotoxin(1 830.86 µg·g~(-1)), which was 2.07 folds greater than the control, and followed by 1.5 mg·L~(-1) IBA, fungal elicitor, 1 mg·L~(-1) IBA, 0.5 mg·L~(-1) IBA and 4.5 mg·L~(-1) IBA, which was 1.82, 1.71, 1.63, 1.43 and 1.1 folds greater than the control, respectively. The results also showed that the growth of roots was certain positively correlated with the change of IBA concentration. Therefore, 3 mg·L~(-1) IBA was the most suitable for the production of podophyllotoxin in the in vitro roots of D. versipellis, and the stimulating effect of Z. syzygii fungal elicitor was between 1.5 mg·L~(-1) and 1 mg·L~(-1) IBA, which was a potential natural elicitor to induce the accumulation of podophyllotoxin in future production.


Assuntos
Ascomicetos , Berberidaceae/química , Raízes de Plantas/crescimento & desenvolvimento , Podofilotoxina/biossíntese , Técnicas de Cultura de Tecidos , Endófitos , Raízes de Plantas/efeitos dos fármacos
6.
World J Microbiol Biotechnol ; 35(8): 117, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332532

RESUMO

Iron- and sulfur-oxidizing bacteria inhabiting rice rhizoplane play a significant role on arsenic biogeochemistry in flooded rice paddies, influencing arsenic translocation to rice grains. In the present study, the selective pressure of arsenic species on these microbial populations was evaluated. Rice roots from continuously flooded plants were incubated in iron sulfide (FeS) gradient tubes and exposed to either arsenate or arsenite. The biomass developed in the visible iron-oxidation band of the enrichments was analyzed by Scanning Electron Microscopy and Energy-Dispersive Spectroscopy (SEM-EDS) and the bacterial communities were characterized by 16S rRNA gene sequencing. Different Proteobacteria communities were selected depending on exposure to arsenate and arsenite. Arsenate addition favored the versatile iron-oxidizers Dechloromonas and Azospira, associated to putative iron (hydr)oxide crystals. Arsenite exposure decreased the diversity in the enrichments, with the development of the sulfur-oxidizer Thiobacillus thioparus, likely growing on sulfide released by FeS. Whereas sulfur-oxidizers were observed in all treatments, iron-oxidizers disappeared when exposed to arsenite. These results reveal a strong impact of different inorganic arsenics on rhizospheric iron-oxidizers as well as a crucial role of sulfur-oxidizing bacteria in establishing rice rhizosphere communities under arsenic pressure.


Assuntos
Arsênico/metabolismo , DNA Bacteriano/isolamento & purificação , Oryza/efeitos dos fármacos , Oryza/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Arseniatos/metabolismo , Arsenitos/metabolismo , DNA Bacteriano/genética , Ferro/metabolismo , Oxirredução , Proteobactérias/efeitos dos fármacos , Proteobactérias/isolamento & purificação , Proteobactérias/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , Solo/química , Microbiologia do Solo , Poluentes do Solo/metabolismo , Enxofre/metabolismo
7.
Ecotoxicol Environ Saf ; 182: 109433, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31319244

RESUMO

In order to explore the effects of pH and accompanying ions on divalent cobalt (Co(II)) toxicity to the wheat root elongation, an improved biotic ligand model (BLM) to predict Co(II) toxicity was developed in solution culture. The results showed that the Co(II)-toxicity decreased with the increases of K+, Ca2+ and Mg2+ activities, and the activity of Na+ had no impact on the Co(II)-toxicity. High H+ activity reduced the Co(II)-toxicity by the competitive effect of H+, while low H+ activity affected the toxicity by the change in the type of Co(II) in culture medium. Co2+ and CoOH+ were toxic to wheat root elongation, and Co(OH)2 was not. On the basis of BLM theory, the conditional equilibrium constants for Co2+, CoOH+, H+, Mg2+, Ca2+, K+ were obtained: logKCoBL = 4.65, logKCoOHBL = 6.62, logKHBL = 4.53, logKMgBL = 3.65, logKCaBL = 2.36 and logKKBL = 2.17. Free Co2+ and CoOH+, and the competitions of K+, Mg2+ and Ca2+ were suggested to be considered when developing the Co(II)-BLM.


Assuntos
Cobalto/toxicidade , Raízes de Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Cátions/farmacologia , Ligantes , Modelos Biológicos , Sódio/toxicidade , Testes de Toxicidade , Triticum/fisiologia
8.
J Sci Food Agric ; 99(14): 6418-6430, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31294466

RESUMO

BACKGROUND: Dracocephalum kotschyi Boiss. is a valuable source of rosmarinic acid (RA) and methoxylated hydroxyflavones (such as xanthomicrol and cirsimaritin) with antioxidative and antiplatelet effects and with antiproliferative potential against various cancer cells. The extensive application of nanotechnology in hairy root cultures is a new sustainable production platform for producing these active constituents. In the present study, hairy roots derived from 4-week-old leaves and Agrobacterium rhizogenes strain ATCC15834 were used to investigate the impact of various concentrations of iron oxide nanoparticles (Fe NPs) in two elicitation time exposures (24 and 48 h) on growth, antioxidant enzyme activity, total phenolic and flavonoid content (TPC and TFC), and some polyphenols. Gene expression levels of phenylalanine ammonia-lyase (pal) and rosmarinic acid synthase (ras) were also analyzed. RESULTS: Iron nanoparticles enhanced biomass accumulation in hairy roots. The treatment time and Fe NP dosage largely improved the activity of antioxidant enzymes, TPC and TFC. The highest RA (1194 µg g-1 FW) content (9.7-fold), compared to controls, was detected with 24 h of exposure to 75 mg L-1 Fe NP, which was consistent with the expression of pal and ras genes under the influence of elicitation. The xanthomicrol, cirsimaritin, and isokaempferide content was increased 11.87, 3.85, and 2.27-fold, respectively. CONCLUSION: Stimulation of D. kotschyi hairy roots by Fe NPs led to a significant increase in the induction and production of important pharmaceutical compounds such as rosmarinic acid and xanthomicrol. © 2019 Society of Chemical Industry.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Compostos Férricos/farmacologia , Flavonoides/biossíntese , Lamiaceae/efeitos dos fármacos , Lamiaceae/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Lamiaceae/genética , Lamiaceae/crescimento & desenvolvimento , Nanopartículas/química , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
9.
Environ Pollut ; 253: 959-965, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351304

RESUMO

Application of Zinc (Zn) is considered an effective measure to reduce Cadmium (Cd) uptake and toxicity in Cd-contaminated soils for many plant species. However, interaction between Zn and Cd in rice plant is complex and uncertain. In this study, four indica rice cultivars were selected to evaluate the effect of Zn exposure in an EGTA-buffered nutrient solution under varying Zn activities and a field level of Cd activity to characterize the interaction between Zn and Cd in rice. Severe depression in shoots' biomass, tiller number, and SPAD (Soil and Plant Analyzer Development) value were found at both Zn deficiency and Zn phytotoxicity levels among four tested rice cultivars. There existed a strong antagonism interaction between Zn and Cd in both shoot and root from Zn deficiency to Zn phytotoxicity. The reduction of Cd accumulation in roots and shoots could be explained by the competition between Zn and Cd as well as the dilution effect of increasing biomass. The conflicting effect of Zn supply on Cd uptake may be attributed to the increasing transfer ratio of Cd from root to shoot with the increasing Zn2+ activities and the strong depression of Fe and Mn in shoots with the increasing Zn2+ activities as well as the variation of genotypes. Balance between Zn and Cd should be considered in field application.


Assuntos
Cádmio/metabolismo , Oryza/fisiologia , Poluentes do Solo/metabolismo , Zinco/metabolismo , Transporte Biológico/efeitos dos fármacos , Biomassa , Cádmio/análise , Poluição Ambiental , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
10.
J Plant Physiol ; 239: 10-17, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177026

RESUMO

Auxin is one of the crucial plant hormones which stimulates and controls cell and plant growth. The effects of auxin IBA (indole-3-butyric acid) during 10-days on maize plants growth in controlled conditions (hydroponic, 16-h photoperiod, 70% humidity, 25/20 °C temperature), depended on its concentration in the substrate. A high concentration (10-7 M) of IBA inhibited root growth, evoked the development of apoplasmic barriers (Casparian bands and suberin lamellae) closer to the root apex, and elevated the amount of lignin in roots. A low concentration (10-11 M) of IBA stimulated root growth but affected neither the development of apoplasmic barriers, nor the amount of lignin. Auxin in a 10-8 M concentration influenced the root growth to a minimal extent compare to the control, and it was the non-effective concentration. Plant cell walls as cell structures ensure cell enlargement and plant growth, and have to react to auxin stimulus by modification of their components. We found the most significant changes in the composition of the PF III fraction (lignocellulosic complex) of the cell wall. The presence of auxin in the substrate affected all three components of this fraction - Klason lignin and both the by acid (2 M TFA) non-hydrolysable and the hydrolysable parts of this complex. The ratio of the non-hydrolysable part to the Klason lignin increased from 1.3 to 3.3 with increasing auxin concentrations in the substrate. This may be related to the deposition of polysaccharides and lignin in the cell wall, which help maintain the specific tensile stress of, and turgor pressure on, the cell walls.


Assuntos
Indóis/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/fisiologia , Parede Celular/efeitos dos fármacos , Parede Celular/fisiologia , Relação Dose-Resposta a Droga , Ácidos Indolacéticos/administração & dosagem , Ácidos Indolacéticos/farmacologia , Indóis/administração & dosagem , Lipídeos/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Xilema/efeitos dos fármacos , Xilema/fisiologia
11.
J Plant Physiol ; 239: 83-91, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31229903

RESUMO

In higher plants ammonium (NH4+) assimilation occurs mainly through the glutamine synthetase/glutamate synthase (GS/GOGAT) pathway. Nevertheless, when plants are exposed to stress conditions, such as excess of ammonium, the contribution of alternative routes of ammonium assimilation such as glutamate dehydrogenase (GDH) and asparagine synthetase (AS) activities might serve as detoxification mechanisms. In this work, the in vivo functions of these pathways were studied after supplying an excess of ammonium to tomato (Solanum lycopersicum L. cv. Agora Hybrid F1) roots previously adapted to grow under either nitrate or ammonium nutrition. The short-term incorporation of labelled ammonium (15NH4+) into the main amino acids was determined by GC-MS in the presence or absence of methionine sulphoximine (MSX) and azaserine (AZA), inhibitors of GS and GOGAT activities, respectively. Tomato roots were able to respond rapidly to excess ammonium by enhancing ammonium assimilation regardless of the previous nutritional regime to which the plant was adapted to grow. The assimilation of 15NH4+ could take place through pathways other than GS/GOGAT, since the inhibition of GS and GOGAT did not completely impede the incorporation of the labelled nitrogen into major amino acids. The in vivo formation of Asn by AS was shown to be exclusively Gln-dependent since the root was unable to incorporate 15NH4+ directly into Asn. On the other hand, an in vivo aminating capacity was revealed for GDH, since newly labelled Glu synthesis occurred even when GS and/or GOGAT activities were inhibited. The aminating GDH activity in tomato roots responded to an excess ammonium supply independently of the previous nutritional regime to which the plant had been subjected.


Assuntos
Compostos de Amônio/metabolismo , Glutamato Desidrogenase/metabolismo , Lycopersicon esculentum/metabolismo , Raízes de Plantas/metabolismo , Aminação , Compostos de Amônio/administração & dosagem , Fertilizantes , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/enzimologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia
12.
Environ Sci Pollut Res Int ; 26(23): 24132-24142, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228062

RESUMO

Mining tailing areas may contain metal minerals such as Cu, Pb, Zn, Cr, and Cd at high concentrations and low nutrients for the growth of plants. This kind of conditions of the area, as well as lack of tailing structure, may limit the development of plants on these areas. Thus, the present study determined the metal, macronutrient, and micronutrient concentrations in the tissues of the roots and shoots of the Solanum viarum Dunal species as well as it evaluated the potential use of the plant for phytoremediation of mining tailing areas contaminated with heavy metals. The macronutrients, micronutrients, and heavy metals in the roots and shoots were determined by the digestion method with nitric and perchloric acid (HNO3-HClO4) and quantified by the ICP-OES. In S. viarum, the average concentrations of the metals presented in the dry biomass varied between the shoots and roots, being higher in the roots for metals such as Cu (229 mg kg-1), Zn (232 mg kg-1), Mn (251 mg kg-1), Cr (382 mg kg-1), Ni (178 mg kg-1), Pb (33 mg kg-1), and Ba (1123 mg kg-1). S. viarum indicates the possibility of a potential application in phytoremediation and treatment of areas contaminated with heavy metals.


Assuntos
Recuperação e Remediação Ambiental/métodos , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Solanum/química , Biodegradação Ambiental , Biomassa , Brasil , Metais Pesados/farmacocinética , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Poluentes do Solo/farmacocinética , Solanum/efeitos dos fármacos , Solanum/metabolismo , Distribuição Tecidual
13.
Environ Sci Pollut Res Int ; 26(23): 23679-23688, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203543

RESUMO

This work is the first report of the ability of biochar-immobilized cadmium-resistant bacteria (CRB) on promoting the efficiency of cadmium phytoextraction by Chlorophytum laxum R.Br. The survival of CRB immobilized on biochar in cadmium-contaminated soil at a concentration of 75.45 mg kg-1 was studied. The results found that both CRB, namely Arthrobacter sp. TM6 and Micrococcus sp. MU1, can survive and grow in cadmium-contaminated soil. To study phytoextraction in the pot experiments, 2-month-old C. laxum was individually planted in cadmium-contaminated soil and divided into four treatments, including (i) untreated control, (ii) biochar, (iii) biochar-immobilized (BC) Arthrobacter sp., and (iv) BC-Micrococcus sp. The results found that biochar-immobilized CRB did not cause any effect to the root lengths and shoot heights of plants compared to the untreated control. Interestingly, inoculation of biochar-immobilized CRB significantly increased cadmium accumulation in the shoots and roots compared to the untreated control. In addition, the highest cadmium content in a whole plant, best phytoextraction performance, and greatest bioaccumulation factor was found in plant inoculated with BC-Micrococcus sp., followed by BC-Arthrobacter sp. In conclusion, inoculation of biochar-immobilized CRB enhanced cadmium accumulation and translocation of cadmium from the roots to shoots, suggesting further applying biochar-immobilized CRB in cadmium-polluted soil for promoting cadmium phytoextraction efficiency of ornamental plants. Graphical abstract.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Carvão Vegetal/química , Poluentes do Solo/metabolismo , Arthrobacter/efeitos dos fármacos , Asparagaceae/efeitos dos fármacos , Cádmio/análise , Micrococcus/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Solo , Poluentes do Solo/análise
14.
J Agric Food Chem ; 67(25): 6911-6920, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31194542

RESUMO

Improving the root system architecture (RSA) under adverse environmental conditions by using biostimulants is emerging as a new way to boost crop productivity. Recently, we have reported the characterization of novel chitosan-based microparticles (CS-MPs) with promising biological properties as rooting agents in lettuce. In this work, we demonstrated that in contrast to bulk chitosan (CS), which exerts root growth inhibition, CS-MPs promoted root growth and development from 1 to 10 µg mL-1 without cytotoxicity effects at higher doses in Arabidopsis and lettuce seedlings. In addition, we studied the mechanistic mode of action of CS-MPs in the development of early RSA in the Arabidopsis model. CS-MPs unchained accurate and sustained spatio-temporal activation of the nuclear auxin signaling pathway. Our findings validated a promising scenario for the application of CS-MPs in the modulation of RSA to respond to changing soil environments and improve crop performance.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Ácidos Indolacéticos/farmacologia , Alface/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/efeitos dos fármacos , Alface/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
15.
J Agric Food Chem ; 67(26): 7232-7242, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184888

RESUMO

In the present study, the effect of imidacloprid uptake from contaminated soils on the growth of leaf vegetable Shanghaiqing was investigated. The result showed that during 35-day exposure, the concentration of imidacloprid (IMI) was in the order of vegetable shoots > vegetable roots > soil, indicating that IMI was more readily concentrated in vegetable shoots than in roots. Moreover, the biomass of IMI-treated vegetable shoots was comparable to that of the controls with early exposure, but was higher than that of the controls after 7-day exposure, showing that the test concentration of IMI could stimulate vegetable growth. The plant metabolic analysis of vegetable shoots using LC-QTOF/MS revealed that IMI may cause oxidative stress to the plant shoots with early exposure; however, the stressful situation of IMI seems to be relieved with the increase of some substances (such as spermidine and phenylalanine) with late exposure. Moreover, the upregulation of N-rich amino acids (glutamine, aspartate, and arginine) suggested that the process of fixing inorganic nitrogen in the plant should be enhanced, possibly contributing to enhanced growth rates. Additionally, four IMI's metabolites were identified by using MS-FINDER software, and the distribution of three metabolites in vegetable tissues was compared.


Assuntos
Inseticidas/farmacologia , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Poluentes do Solo/farmacologia , Verduras/efeitos dos fármacos , Aminoácidos/metabolismo , Transporte Biológico/efeitos dos fármacos , Inseticidas/análise , Espectrometria de Massas , Neonicotinoides/análise , Nitrocompostos/análise , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Solo/química , Poluentes do Solo/análise , Verduras/química , Verduras/crescimento & desenvolvimento , Verduras/metabolismo
16.
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
17.
Ecotoxicol Environ Saf ; 180: 756-761, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154200

RESUMO

Nitrated polycyclic aromatic hydrocarbons (Nitro-PAHs) as important organic pollutants are ubiquitous in the atmospheric environment, agricultural soils and aquatic environments to pose a severe polluting risk. However, little is known about the mechanism of Nitro-PAHs genotoxicity in plants. We analyzed seeds germination, seedlings growth, and toxicity mechanism following 1-Nitropyrene treatment in Hordeum vulgare. Our results reveal that 1-NP treatment could be an inhibited agent on seeds germination and growth of roots and shoots. Additionally, the reduction of mitotic index and the increasing frequency of micronucleus suggest that 1-NP may pose a potential risk of genotoxicity in the plant. We further clarify that O2- and H2O2 radicals contribute to 1-NP stimulation induced oxidative damage. Our study provides insights into the role of Nitro-PAHs exposure on growth processing toxicity and genotoxicity in plant and provided a useful reference for the surveillance and risk management of Nitro-PAHs in environments.


Assuntos
Hordeum/efeitos dos fármacos , Mutagênicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes do Solo/toxicidade , Radicais Livres/metabolismo , Germinação/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Óxidos de Nitrogênio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Pirenos/toxicidade
18.
Environ Pollut ; 252(Pt B): 941-949, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252132

RESUMO

The accumulation of bound and conjugated polyamines (PAs) is an important protective trait in plants under adverse environmental conditions. However, their role in plant responses to aluminum (Al) stress remains largely unknown. In this study, we showed that Al treatment increased bound putrescine (Put) levels in the wheat root tips of Al-tolerant Xi Aimai-1, with little effect on its bound spermidine and conjugated PAs or that of Al-sensitive Yangmai-5. Terminating bound Put increments with a synthesis inhibitor (Phenanthroline, o-phen) exacerbated Al-induced root inhibition and callose production. However, it had no significant effect on Al uptake or distribution under Al stress. Instead, Al-induced reactive oxygen species (ROS) production and thus, oxidative damage, was greatly exacerbated by o-phen in the roots of Xi Aimai-1. Application of o-phen barely affected the two ROS generating enzymes (plasma membrane NADPH oxidase and cell wall-bound polyamine oxidase) in wheat roots. However, exogenous o-phen significantly reduced antioxidant enzyme (superoxide dismutase, ascorbate peroxidase, and catalase) activity, which positively correlated with the level of bound Put in Xi Aimai-1. These results clearly suggest that bound Put accumulation works to protect against Al-induced oxidative damage, possibly by maintaining antioxidant capacity in wheat.


Assuntos
Alumínio/toxicidade , Antioxidantes/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Putrescina/metabolismo , Poluentes do Solo/toxicidade , Triticum , Tolerância a Medicamentos , Oxirredução , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Triticum/efeitos dos fármacos , Triticum/enzimologia
19.
Environ Pollut ; 252(Pt B): 967-973, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252135

RESUMO

Arsenic (As) in rice grains is a serious food safety concern. Some coexisting engineered nanoparticles (ENPs) were shown to alter the accumulation and speciation of As in rice grains. However, investigation on the effects of copper oxide nanoparticles (CuO NPs), a popular ingredient in pesticides, on the uptake and accumulation of As is rare. We explored the potentially different impact of CuO NPs and corresponding Cu(II) ions on the accumulation of two As species in rice seedlings in a hydroponic system. Rice seedlings were treated with a combinations of 1 mg/L of arsenite (As(III)) or arsenate (As(V)) and 100 mg/L of CuO NPs or Cu(II) for 6 days. Both forms of Cu significantly reduced the accumulation of total As in rice tissues, with Cu(II) exhibiting significantly greater effect than CuO NPs. As speciation in rice roots was markedly affected by both forms of Cu, and the impacts were Cu-form dependent. For example, the co-existence of As(V) with CuO NPs led to a 45% decrease of As(V) in rice roots, while the co-existence of As(V) with Cu(II) caused a 47% increase in As(V) in rice roots. As speciation in rice shoots was less affected by co-present Cu than in rice roots. Co-occurring As(III) or As(V) lowered Cu concentration in rice roots by 40% and 50% in treatments with CuO NPs, but did not affect Cu content in rice roots co-exposed to Cu(II). The study confirmed the reciprocal effect of co-occurring CuO NPs or Cu(II) and As in rice paddies and highlighted the unique "nano-effect" of CuO NPs. The results alsos showed that the initial oxidation state of As plays an important role in the interactions between As and Cu. The results shed light on the current debate on the safe applications of nano-enabled agrichemicals vs. conventional metal salts in agriculture.


Assuntos
Arsênico/metabolismo , Cobre/farmacologia , Nanopartículas/metabolismo , Oryza/efeitos dos fármacos , Transporte Biológico , Cobre/metabolismo , Interações de Medicamentos , Oryza/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo
20.
Chemosphere ; 233: 300-308, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31176131

RESUMO

The extensive use of poly- and perfluoroalkyl substances (PFAS) has led to perfluoroalkyl acids (PFAAs) contamination in various environmental matrices. To remove PFAAs from contaminated water, this study investigated plant uptake of PFAAs by a native wetland plant species in the US, Juncus effusus. The results showed that J. effusus translocated selected PFAAs, including perfluoropentanoic acid (PFPA), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS). During the 21-day experimental period, the uptake of PFAAs increased with increasing PFAAs exposure concentration and time. PFOS was largely accumulated in the roots with limited upward translocation. PFAAs with shorter carbon chain length were taken up by J. effusus roots and tended to accumulate in plant shoots. The highest removal efficiency (11.4%) of spiked PFAAs by J. effusus was achieved when it was exposed to PFAAs at around 4.6 mg/L for 21 days. The exposure to PFAAs stimulated the antioxidative defense system in J. effusus shoots but inhibited the superoxide dismutase (SOD) and catalase (CAT) activities and damaged the antioxidative defense system in J. effusus roots. These results warrant further studies to evaluate J. effusus's long-term performance in a PFAAs contaminated environment.


Assuntos
Fluorcarbonetos/farmacocinética , Fluorcarbonetos/toxicidade , Magnoliopsida/efeitos dos fármacos , Magnoliopsida/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Catalase/metabolismo , Fluorcarbonetos/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Áreas Alagadas
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