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1.
An Acad Bras Cienc ; 92(suppl 1): e20180426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32159585

RESUMO

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


Assuntos
Inoculantes Agrícolas/genética , DNA Bacteriano/isolamento & purificação , DNA Fúngico/isolamento & purificação , Germinação/fisiologia , Poaceae/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Biodiversidade , Produtos Agrícolas/genética , Germinação/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sementes/efeitos dos fármacos , Análise de Sequência de DNA , Análise de Sequência de RNA , Ácidos Sulfúricos/farmacologia
2.
Food Chem ; 312: 126075, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31893551

RESUMO

In this study, we evaluated the effect of sucrose and CaCl2 on the growth profile, nutritional quality, and antioxidant capacity of sprouted buckwheat. Buckwheat seeds were germinated at 25 °C for 8 days and sprayed with four different solutions: distilled water, 3% sucrose, 7.5 mM CaCl2, and 3% sucrose plus 7.5 mM CaCl2. Our results showed that CaCl2 effectively improved sucrose-elicitation induced growth reduction in buckwheat sprouts. Elicitation with both sucrose and CaCl2 in buckwheat sprouts markedly enhanced the accumulation of bioactive compounds, such as polyphenols, flavonoids, γ-aminobutyric acid, vitamin C, and E, without negatively affecting sprout growth. Elicitation with both sucrose and CaCl2 not only significantly enhanced the antioxidant activities but also exerted cytoprotective effects against oxidative damage in HepG2 cells and fibroblasts. These findings suggested that simultaneous elicitation with 3% sucrose and 7.5 mM CaCl2 can potentially improve the nutritional value and potential health benefits of buckwheat sprouts.


Assuntos
Antioxidantes/farmacologia , Cloreto de Cálcio/farmacologia , Fagopyrum/efeitos dos fármacos , Sacarose/farmacologia , Germinação/efeitos dos fármacos , Valor Nutritivo , Oxirredução , Sementes/efeitos dos fármacos
3.
PLoS One ; 15(1): e0221382, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31935213

RESUMO

Recently, poor control of Echinochloa colona with glyphosate has been reported in no-till agriculture systems of the northern grain region (NGR) of Australia. Two experiments were conducted using 10 populations of E. colona selected from the NGR of Australia to understand differences in their growth behavior and resistance pattern. Growth studies revealed that these populations differed in plant height (53-70 cm plant-1), tiller production (30-52 tillers plant-1), leaf production (124-186 leaves plant-1) and seed head production (37-65 seed heads plant-1). Days taken to seed heads and shoot biomass in these populations ranged between 40-48 d and 21-27 g plant-1, respectively. Seed production in these populations ranged between 5380 and 10244 seeds plant-1; lowest for population B17/25 and highest for population B17/13. Correlation studies revealed that seed number plant-1 had a positive correlation with tiller number plant-1 (r = 0.73) and negative relation with days taken to seed head initiation (r = - 0.65). The glyphosate dose-response study showed a wide range of responses in these populations and the glyphosate dose required to kill 50% plants (LD50 values) was estimated between 161 to 2339 g a.e. glyphosate ha-1. LD50 values of populations B17/16, B 17/34 and B17/35 were 1086, 2339 and 1153 g ha-1, respectively, making them 6.7, 15.1 and 7.2-fold resistant to glyphosate compared with the susceptible population B17/37. Growth behavior and seed production potential in these populations had no correlation with the resistance index. These results suggest that some populations of E. colona are highly problematic; for example, population B17/34 was not only highly glyphosate-resistant, but also produced a high seed number (9300 seeds plant-1). This study demonstrated that there is a possibility of great risk with the increased use of glyphosate for managing E. colona in the NGR of Australia. The results warrant integrated weed management strategies and improved stewardship guidelines are required for managing glyphosate-resistant populations of E. colona and to restrict further movement of resistant populations to other regions of Australia.


Assuntos
Echinochloa/crescimento & desenvolvimento , Resistência a Herbicidas/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Austrália , Echinochloa/efeitos dos fármacos , Glicina/análogos & derivados , Glicina/farmacologia , Herbicidas/farmacologia , Folhas de Planta/efeitos dos fármacos , Sementes/efeitos dos fármacos
4.
Ecotoxicol Environ Saf ; 190: 110147, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31918255

RESUMO

Selenium (Se) is an essential element for human and animal, although considered beneficial to higher plants. Selenium application at high concentration to plants can cause toxicity decreasing the physiological quality of seeds. This study aimed to characterize the Se toxicity on upland rice yield, seed physiology and the localization of Se in seeds using X-ray fluorescence microanalysis (µ-XRF). In the flowering stage, foliar application of Se (0, 250, 500, 1000, 1500, 2000 g ha-1) as sodium selenate was performed. A decrease in rice yield and an increase in seed Se concentrations were observed from 250 g Se ha-1. The storage proteins in the seeds showed different responses with Se application (decrease in albumin, increase in prolamin and glutelin). There was a reduction in the concentrations of total sugars and sucrose with the application of 250 and 500 g Se ha-1. The highest intensities Kα counts of Se were detected mainly in the endosperm and aleurone/pericarp. µ-XRF revealed the spatial distribution of sulfur, calcium, and potassium in the seed embryos. The seed germination decreased, and the electrical conductivity increased in response to high Se application rates showing clearly an abrupt decrease of physiological quality of rice seeds. This study provides information for a better understanding of the effects of Se toxicity on rice, revealing that in addition to the negative effects on yield, there are changes in the physiological and biochemical quality of seeds.


Assuntos
Oryza/fisiologia , Selênio/toxicidade , Poluentes do Solo/toxicidade , Animais , Endosperma , Glutens , Humanos , Nutrientes , Oryza/metabolismo , Proteínas de Plantas , Sementes/efeitos dos fármacos , Sementes/fisiologia , Ácido Selênico/análise , Enxofre/metabolismo
5.
Ecotoxicol Environ Saf ; 188: 109901, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704323

RESUMO

Melon (Cucumis melo L.) is an important horticultural crop worldwide. Continuous cropping obstacle occurs in many melon cultivation area, resulting in poor plant growth and fruit quality, autotoxicity is the main reason for the obstacle. Silicon (Si) plays an important role in improving the resistance of plants to biotic and abiotic stresses. In this study, melon plant water extracts (MPWE) were used to simulate the autotoxicity stress. Different concentrations of Na2SiO3 (0, 1, 2, 4, 8, 16, 32 mM) were added into MPWE for preliminary concentration screening and alleviating effect determination of Si on melon seed autotoxicity. The results showed that autotoxicity reduced the seed germination index, inhibited the growth of germinated seeds. 2 mM Si significantly increased seed germination index and improved subsequent growth under autotoxicity. The effect of Si showed a concentration-dependent manner, which can be counteracted or even reversed at high concentration. Three treatment combinations, double distilled water, 0.02 g/mL MPWE and 2 mM Na2SiO3 + 0.02 g/mL MPWE were used for subsequent physiology, biochemistry and gene analysis. During the germination of melon seed under autotoxicity, starch degradation ability decreased, amylase activity and amylase gene expression were inhibited, cell membrane lipid peroxidation increased, and antioxidant enzyme activity was abnormal. In Si-addition group, the radicle growth, lateral roots number, starch degradation ability, amylase activity and amylase gene expression level increased. The addition of Si also maintained the activities of superoxide dismutase, catalase and peroxidase and the content of malondialdehyde in a relatively normal state. The change trend of amylase gene and antioxidant enzyme activity was complex, but the acute change coincided with the key stage of seed germination, which occurred when the seed was about to break through or just broken through the seed coat. Appropriate concentration of Si is an effective strategy to alleviate the autotoxicity on melon seed.


Assuntos
Cucurbitaceae/efeitos dos fármacos , Cucurbitaceae/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Silício/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/metabolismo , Cucurbitaceae/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Amido/metabolismo
6.
Plant Biol (Stuttg) ; 22(1): 21-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31509637

RESUMO

Orchids are distributed around the world, however, the factors shaping their specific distribution and habitat preferences are largely unknown. Moreover, many orchids are at risk of becoming threatened as landscapes change, sometimes declining without apparent reason. One important factor affecting plant distribution is nutrient levels in the environment. Nitrates can inhibit not only orchid growth and persistence, but also seed germination. We used in vitro axenic cultures to exactly determine the germination sensitivity of seven orchid species to nitrates and correlated this with soil properties of the natural sites and with the species' habitat preferences. We found high variation in response to nitrate between species. Orchids from oligotrophic habitats were highly sensitive, while orchids from more eutrophic habitats were almost insensitive. Sensitivity to nitrate was also associated with soil parameters that indicated a higher nitrification rate. Our results indicate that nitrate can affect orchid distribution via direct inhibition of seed germination. Nitrate levels in soils are increasing rapidly due to intensification of agricultural processes and concurrent soil pollution, and we propose this increase could cause a decline in some orchid species.


Assuntos
Ecossistema , Nitratos , Orchidaceae , Sementes , Solo , Nitratos/análise , Nitratos/toxicidade , Orchidaceae/efeitos dos fármacos , Orchidaceae/fisiologia , Sementes/efeitos dos fármacos , Solo/química
7.
Ecotoxicol Environ Saf ; 190: 110017, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31846862

RESUMO

The seed yield and healthy oil in sunflower (Helianthus annuus L.), as an important industrial crop, decrease under stress. There is not much investigation, to our knowledge, on the use of potassium fertilization, a regulator of plant water potential, affecting the biochemical properties and seed components of sunflower under drought stress. Accordingly, such parameters were investigated in a split-split plot field experiment, conducted in two different field sites (Natanz (Nt) and Eghlid (Eg), Iran), using potassium fertilization (subplots, 0, 150 and 300 kg/ha) and six drought levels (main plots) in four replicates. Although stress significantly affected sunflower biochemical properties and seed components in the two fields, the effects of stress were more pronounced in the Eg site (significant interaction of field and drought). The plant alleviated the stress by increasing the proline, oleic and linoleic acid concentrations, however, potassium fertilization also increased plant tolerance further under stress by enhancing such components compared with control. Interestingly, the Eg site was more responsive to the potassium fertilization (significant interaction of field and fertilization), as the fertilizer resulted in a higher rate of plant biochemical properties and seed components. The use of potassium fertilization at 300 kg/ha (K3) was the most effective treatment in the alleviation of stress. Interestingly, under drought stress, potassium contributed to the enhanced quantity and quality of sunflower by increasing seed components, and enhancing the biochemical properties of the plant, which can also improve crop physiological mechanisms. The results can further increase our understanding related to the effects of potassium fertilization on the yield and physiology of sunflower under drought stress. Such results are of economic, environmental and health significance.


Assuntos
Helianthus/química , Potássio/farmacologia , Secas , Fertilizantes , Helianthus/efeitos dos fármacos , Helianthus/embriologia , Ácido Linoleico/análise , Ácido Oleico/análise , Prolina/análise , Sementes/química , Sementes/efeitos dos fármacos , Estresse Fisiológico
8.
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
9.
Chemosphere ; 239: 124698, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31493753

RESUMO

Synthetic silver nanoparticles (AgNPs) are being extensively used in our daily lives; however, they may also pose a risk to public health and environment. Nowadays, biological AgNPs are considered an excellent alternative, since their synthesis occurs by a green technology of low cost and easy scaling. However, studies with these biological nanomaterials (NM) are still limited. Thus, a more careful assessment of their industrial application, economic feasibility and ecotoxicological impacts is crucial. The aim of this study was to investigate the effects of different concentrations of mangrove fungus Aspergillus tubingensis AgNPs on the aerobic heterotrophs soil microorganisms, rice seeds (Oryza sativa) and zebrafish (Danio rerio). Biogenic AgNPs were less harmful for soil microbiota compared to AgNO3. On rice seeds, the AgNPs displayed a dose-dependent inhibitory effect on germination and their subsequent growth and development. The percentage of inhibition of rice seed germination was 30, 69 and 80% for 0.01, 0.1 and 0.5 mM AgNPs, respectively. After 24 h of AgNPs exposition at a limit concentration of 0.2 mM, it did not induce mortality of the zebrafish D. rerio. Overall, A. tubingensis AgNPs can be considered as a suitable alternative to synthetic nanoparticles.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Solo/química , Animais , Aspergillus/metabolismo , Germinação/efeitos dos fármacos , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Sementes/efeitos dos fármacos , Peixe-Zebra/crescimento & desenvolvimento
10.
J Agric Food Chem ; 68(2): 503-511, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31869217

RESUMO

Due to nonuniform maturation, some plants may not be at the recommended stage of maturity when preharvest glyphosate is applied. The objective of this study was to determine how preharvest glyphosate timing affects wheat starch physicochemical properties. Two wheat cultivars were grown in three locations, and glyphosate was applied at the soft dough stage (early application) and the ripe stage (commercial standard). Upon harvest, starch chemical characteristics were studied. The proportion of B-type starch granules was lower in treated samples, although the starch molecular weight was not affected. Rapidly digestible starch content was highest when glyphosate was applied at the ripe stage, and lowest in the control, and vice versa for slowly digestible starch. Additionally, flour pasting viscosity was significantly higher in samples treated at the soft dough stage. Overall, the effects on wheat starch physicochemical characteristics were more pronounced when glyphosate was applied at the soft dough stage of maturity.


Assuntos
Glicina/análogos & derivados , Herbicidas/farmacologia , Amido/química , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento , Fenômenos Químicos , Glicina/farmacologia , Sementes/química , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Amido/metabolismo , Triticum/química , Triticum/metabolismo
11.
Ecotoxicol Environ Saf ; 187: 109785, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31644988

RESUMO

The germination and seedling vigor of crops is negatively affected by soil salinity. Nitric oxide (NO) has emerged as a key molecule involved in many physiological events in plants. The objective of present study was to evaluate the impact of exogenous sodium nitroprusside (SNP, a NO donor) at different concentrations on the seed germination and early seedling growth characteristics of pakchoi (Brassica chinensis L.) under NaCl stress. 100 mM NaCl stress markedly inhibited the seed germination potential, germination index, vitality index and growth of radicles and plumules. SNP pretreatment attenuated the salt stress effects in a dose-dependent manner, as indicated by enhancing the characteristics of seed germination and early seedling growth parameters, and the mitigating effect was most pronounced at 10 µM SNP. Efficient antioxidant systems were activated by SNP pre-treatment, and which effectively increased the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), and reduced contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) and the production rate of superoxide anion radical (O2·-) in radicles and plumules, thereby preventing oxidative damage from NaCl stress. SNP pre-treatment also increased the contents of proline and soluble sugar in radicles and plumules under NaCl stress. In addition, SNP pre-treatment significantly increased the K+ contents and decreased Na+ contents in radicles and plumules, resulting in the increased level of K+/Na+ ratio. Our results demonstrated that SNP application on pakchoi seeds may be a good option to improve seed germination and seedling growth under NaCl stress by modulating the physiological responses resulting in better seed germination and seedling growth.


Assuntos
Brassica/efeitos dos fármacos , Germinação/efeitos dos fármacos , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/farmacologia , Estresse Salino/efeitos dos fármacos , Antioxidantes/metabolismo , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Relação Dose-Resposta a Droga , Salinidade , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/fisiologia
12.
PLoS One ; 14(12): e0224431, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31841519

RESUMO

Dieback disease caused by Erwinia mallotivora is a major threat to papaya plantation in Malaysia. The current study was conducted to evaluate the potential of endophytic lactic acid bacteria (LAB) isolated from papaya seeds for disease suppression of papaya dieback. Two hundred and thirty isolates were screened against E. mallotivora BT-MARDI, and the inhibitory activity of the isolates against the pathogen was ranging from 11.7-23.7 mm inhibition zones. The synergistic experiments revealed that combination of W. cibaria PPKSD19 and Lactococcus lactis subsp. lactis PPSSD39 increased antibacterial activity against the pathogen. The antibacterial activity was partially due to the production of bacteriocin-like inhibitory substances (BLIS). The nursery experiment confirmed that the application of bacterial consortium W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 significantly reduced disease severity to 19% and increased biocontrol efficacy to 69% of infected papaya plants after 18 days of treatment. This study showed that W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 are potential candidate as biocontrol agents against papaya dieback disease.


Assuntos
Bacteriocinas/farmacologia , Carica/efeitos dos fármacos , Erwinia/efeitos dos fármacos , Antibacterianos , Antibiose/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Fenômenos Biológicos , Carica/metabolismo , Erwinia/patogenicidade , Microbiologia de Alimentos , Lactobacillales/efeitos dos fármacos , Malásia , Sementes/efeitos dos fármacos
13.
Environ Monit Assess ; 191(11): 703, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673860

RESUMO

Multiple applications of nanoparticles (NPs) could result in their potential release into agricultural systems and raised concerns about food safety. The NPs once released in the environment may interact with numerous pollutants, including other NPs. Present study assessed the impact of a single (CuO and ZnO NPs) and binary mixture (CuO+ZnO NPs) on the germination of Raphanus sativus seeds with a wide range of exposure concentration (0-1000 mg/L). Both the NPs have shown a deleterious effect on seeds at exposure concentration greater than 10 mg/L. Antagonistic interaction between effects of CuO and ZnO NPs on seeds was noticed for all the exposed concentrations. CuO NPs showed higher absorption capacity on the seedling surface than ZnO NPs. Internal uptake of Zn in ZnO NP-exposed seedlings was found to be greater than that due to CuO NP-exposed seedlings. Three different types of exposure adversely affected seed germination (reduction in root length, shoot length, and fresh weight). Reduction in growth parameters (length and weight) with concentration was compared using log-logistic dose-response model of "DRC" package of the "R" software, and EC50 was determined. As per EC50 values, the toxicity of CuO NPs was found to be maximum followed by CuO+ZnO NPs and then minimum for ZnO NPs. Seedlings accumulated Cu and Zn metals, and higher uptake was recorded for Zn (reported as mg/g seedling dry weight). The order of toxicity was found as CuO NPs > binary mixture (CuO+ZnO) NPs > ZnO NPs. Exposure concentration greater than 10 mg/L resulted in significant toxicity and uptake in germinated seedlings. These findings indicated that exposure of the mixture of NPs during germination might give different effects and thus, further attempts could prove quite beneficial to the literature.


Assuntos
Cobre/toxicidade , Germinação/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Raphanus/efeitos dos fármacos , Óxido de Zinco/toxicidade , Relação Dose-Resposta a Droga , Interações de Medicamentos , Raphanus/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento
14.
J Agric Food Chem ; 67(49): 13509-13517, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31725280

RESUMO

In this study, novel water-soluble quaternary ammonium salts of iminofullerenes (IFQA) were synthesized by nitrene chemistry in combination with quaternization and identified as [C60(NCH2CH2NH3+·CF3COO-)4·10H2O]n by various spectroscopies. Maize and Arabidopsis seeds were used to test the bioactivity of IFQA in seed germination. Compared with the control, maize seed exposure to 50 mg/L IFQA (normal: 73.1% vs 58.7%; drought: 66.7% vs 50.0% at the second day) and Arabidopsis seed exposure to 20 mg/L IFQA (normal: 77.5% vs 58.8%; drought: 63.3% vs 36.7% at the second day) had higher germination rates and quicker germination. The results of two-dimensional gel electrophoresis combined with mass spectroscopy showed that the abundance of 21 proteins in embryo proteome of maize seeds was significantly changed (>1.5 fold). The downregulated six storage proteins and upregulated four proteins induced by IFQA for energy production and sugar metabolism indicated a faster metabolic activity of maize seed germination. The upregulated eight stress-related proteins and antioxidant enzymes suggested that the role of IFQA was to activate the metabolic processes in seed germination and also increase seed stress response. The results provide important information to understand the mechanism of seed germination enhancement by carbon nanomaterials.


Assuntos
Compostos de Amônio/farmacologia , Arabidopsis/crescimento & desenvolvimento , Fulerenos/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Sementes/efeitos dos fármacos , Triticum/crescimento & desenvolvimento , Compostos de Amônio/química , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Fulerenos/química , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Reguladores de Crescimento de Planta/síntese química , Reguladores de Crescimento de Planta/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Triticum/efeitos dos fármacos , Triticum/genética , Triticum/metabolismo
15.
BMC Plant Biol ; 19(1): 429, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619182

RESUMO

BACKGROUND: Polycomb repressive complex 2 (PRC2) is an epigenetic transcriptional repression system, whose catalytic subunit (ENHANCER OF ZESTE HOMOLOG 2, EZH2 in animals) is responsible for trimethylating histone H3 at lysine 27 (H3K27me3). In mammals, gain-of-function mutations as well as overexpression of EZH2 have been associated with several tumors, therefore making this subunit a suitable target for the development of selective inhibitors. Indeed, highly specific small-molecule inhibitors of EZH2 have been reported. In plants, mutations in some PRC2 components lead to embryonic lethality, but no trial with any inhibitor has ever been reported. RESULTS: We show here that the 1,5-bis (3-bromo-4-methoxyphenyl)penta-1,4-dien-3-one compound (RDS 3434), previously reported as an EZH2 inhibitor in human leukemia cells, is active on the Arabidopsis catalytic subunit of PRC2, since treatment with the drug reduces the total amount of H3K27me3 in a dose-dependent fashion. Consistently, we show that the expression level of two PRC2 targets is significantly increased following treatment with the RDS 3434 compound. Finally, we show that impairment of H3K27 trimethylation in Arabidopsis seeds and seedlings affects both seed germination and root growth. CONCLUSIONS: Our results provide a useful tool for the plant community in investigating how PRC2 affects transcriptional control in plant development.


Assuntos
Proteínas de Arabidopsis/antagonistas & inibidores , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Histonas/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteína Potenciadora do Homólogo 2 de Zeste , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica no Desenvolvimento , Lisina/metabolismo , Metilação , Proteínas Repressoras/genética , Rutina/análogos & derivados , Rutina/farmacologia , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
16.
Chemosphere ; 237: 124567, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549665

RESUMO

Hexavalent chromium reduction by microbes can mitigate the chromium toxicity to the environment. In the present study Cr[VI] tolerant fungal isolate (CR500) was isolated from electroplating wastewater, was able to tolerate 800 mg/L of Cr[VI. Based on the ITS region sequencing, the isolate was identified as Aspergillus flavus CR500, showed multifarious biochemical (reactive oxygen species, antioxidants response and non-protein thiol) and morphological (protrusion less, constriction and swelling/outwards growth in mycelia) response under Cr[VI] stress. Batch experiment was conducted at different Cr[VI] concentration (0-200 mg/L) to optimize the Cr[VI] reduction and removal ability of isolate CR500; results showed 89.1% reduction of Cr[VI] to Cr[III] within 24 h and 4.9 ±â€¯0.12 mg of Cr per gram of dried biomass accumulation within 144 h at the concentration of 50 mg/L of Cr[VI]. However, a maximum of 79.4% removal of Cr was recorded at 5 mg/L within 144 h. Fourier-transform infrared spectroscopy, energy dispersive x-ray spectroscopy and X-ray diffraction analysis revealed that chromium removal also happened via adsorption/precipitation on the mycelia surface. Fungus treated and without treated 100 mg/L of Cr[VI] solution was subjected to phytotoxicity test using Vigna radiata seeds and result revealed that A. flavus CR500 successfully detoxified the Cr[VI] via reduction and removal mechanisms. Isolate CR500 also exhibited efficient bioreduction potential at different temperature (20-40 °C), pH (5.0-9.0), heavy metals (As, Cd, Cu, Mn, Ni and Pb), metabolic inhibitors (phenol and EDTA) and in sterilized tannery effluent that make it a potential candidate for Cr[VI] bioremediation.


Assuntos
Aspergillus flavus/metabolismo , Cromo/metabolismo , Cromo/toxicidade , Águas Residuárias/microbiologia , Adsorção , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/genética , Biodegradação Ambiental , Galvanoplastia , Metais Pesados/análise , Fenol/análise , Sementes/efeitos dos fármacos , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Vigna/efeitos dos fármacos , Águas Residuárias/análise , Águas Residuárias/toxicidade , Difração de Raios X
17.
Chemosphere ; 235: 1066-1072, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561296

RESUMO

This study was conducted to explore the effects of priming of seven-year-old aged seeds with different concentrations of silver nanoparticles (AgNPs) on growth of broad bean (Vicia faba L.). Seeds were primed with different concentrations of AgNPs for 6 h before growing in the plastic trays. Different growth parameters like growth attributes, photosynthetic pigments, carbohydrates, antioxidant enzymes and chloroplast ultrastructure were estimated after 14 days of germination. Priming with AgNPs affected the root and shoot growth attributes as compared with control depending upon concentrations of AgNPs. In all treatments, photosynthetic pigments increased significantly above control levels, but total soluble sugars decreased in 10 and 50 ppm AgNPs and slightly increased in 100 ppm AgNPs as compared with control. Starch accumulation was apparent in all treated seedlings above that of control levels. Mesophyll cells of all treated seedlings were altered with electron dense particles than control. Priming with AgNPs affected the chloroplast structure which appeared in the form of less stacking of Greene, formation of protrusions and extensions, irregular shape of chloroplasts as compared with spindle shaped regular chloroplasts of control. In all treatments, total phenols were slightly affected as compared with control. The antioxidant enzyme activities in seedlings varied with the dose and type of antioxidants. Overall, AgNPs adversely affected the chloroplast ultrastructure, but increased growth of seedlings and starch accumulation. Further studies are required to explore the effects of AgNPs on the long-term on crop productivity of aged seeds.


Assuntos
Cloroplastos/efeitos dos fármacos , Nanopartículas Metálicas/química , Plântula/ultraestrutura , Prata/química , Antioxidantes/farmacologia , Cloroplastos/ultraestrutura , Germinação/efeitos dos fármacos , Fotossíntese , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Prata/farmacologia , Amido/metabolismo , Vicia faba/crescimento & desenvolvimento , Vicia faba/ultraestrutura
18.
Plant Physiol Biochem ; 143: 286-298, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31539758

RESUMO

In this study, the effect of seed priming with sodium hydro sulfide (NaHS) and CaCl2 as well as the possible relationship between them in inducing post-germinative cross-adaptation in zucchini seedlings (cv Courgette d'Italie) were investigated. Results showed that Ni toxicity reduced plant growth and photosynthetic pigments, decreased the content of ascorbate (AsA) and total thiols, increased hydrogen peroxide (H2O2) content and electrolyte leakage (EL), up-regulated the transcription levels of Ca2+-dependent protein kinase (CDPK) and phytochelatin (PCs) genes and elevated H2S content in leaves of zucchini seedlings. Individual or combined seed priming with Ca2+ and NaHS improved the content of photosynthetic pigments and seedling biomass, reduced H2O2 content and EL, increased the content of AsA and total thiols, decreased ascorbate peroxidase activity and enhanced glutathione reductase activity in leaves. These findings suggest the last time effect of seed priming with Ca2+ and NaHS on inducing cross-adaptation in seedlings under Ni stress. H2S accumulation and other responses induced with Ca2+ in leaves were weakened with hypotaurine (HT as H2S scavenger), denoting seed priming with Ca2+ established cross-adaptation in a H2S-dependent manner. Seed priming with NaHS amplified CDPK transcripts in leaves of seedlings and seed priming with ethylene glycol tetraacetic acid (as Ca2+ chelator), lanthanum chloride and verapamil (as plasma membrane channel blockers) reduced transcript levels of CDPK and PCs genes and reversed impacts of seed priming with NaHS. These results indicated that the cross-adaptation induced with NaHS is mediated through Ca2+ signaling. Overall our findings suggest that two-side cross-talk between Ca2+ and H2S is involved in the acquisition of a signal memory in seed embryo cells which can be employed upon a later Ni-exposure and more strongly enhance AsA-GSH cycle, redox homeostasis and phytochelatin transcripts in leaves of zucchini seedlings grown from primed seeds.


Assuntos
Ácido Ascórbico/metabolismo , Cálcio/farmacologia , Sulfeto de Hidrogênio/farmacologia , Níquel/toxicidade , Plântula/efeitos dos fármacos , Plântula/metabolismo , Sementes/metabolismo , Glutationa/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Sementes/efeitos dos fármacos
19.
Ecotoxicol Environ Saf ; 185: 109659, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31541946

RESUMO

Cadmium (Cd) affects crop growth and productivity by disrupting normal plant metabolism. To determinate whether ultrasonic (US) seed treatment can alleviate Cd stress in rape (Brassica napus L.), the seeds of two oilseed rape cultivars i.e., 'Youyanzao18' and 'Zaoshu104' were exposed to ultrasonic waves for 1 min at 20 KHz frequency. Seeds without US treatment were taken as control (CK). Results revealed that the germination rate of both cultivars was significantly (P < 0.05) higher in US treatment than CK only at 0 and 10 mg Cd L-1. The shoot and root length of both cultivars were significantly higher in US treatment than CK at all Cd treatments except the root length of Youyanzao18 at 50 mg Cd L-1. The fresh weight Youyanzao18 was significantly (P < 0.05) higher in US than CK except for Youyanzao18 at 25 mg Cd L-1. Moreover, the superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities and the proline, glutathione (GSH), and soluble protein contents in Youyanzao18 were relatively higher in the US treatment than CK. The malondialdehyde (MDA) contents were prominently reduced in US treatment than CK. The pods per plant, seeds per pod and rapeseed yield were increased by 15.9, 11.4, and 16.4% in Youyanzao18 and 10.3, 9.5, and 11.5% in Zaoshu104, respectively in US treatment, compared to CK. Moreover, the contents of Cd in root, stem, leaf, rape pod shell, and rapeseeds were comparatively less in US treatment than CK whereas the Cd concentrations in different plant parts of both rape cultivars were recorded as: leaf ˃ root ˃ stem ˃ rape pod shell ˃ rapeseed. In sum, the US treatment improved the morphological growth and rapeseed yield whereas reduced the Cd accumulation in different plant parts of rapeseed under Cd contaminated soil.


Assuntos
Antioxidantes/metabolismo , Brassica napus/efeitos dos fármacos , Cádmio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Sementes/efeitos dos fármacos , Poluentes do Solo/toxicidade , Ondas Ultrassônicas , Brassica napus/crescimento & desenvolvimento , Brassica napus/metabolismo , Germinação/efeitos dos fármacos , Oxirredução , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
20.
Plant Physiol Biochem ; 144: 58-63, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31557640

RESUMO

Reactive oxygen species homeostasis during germination of heteromorphic seeds is not fully understood. This study elucidates changes in levels of hydrogen peroxide (H2O2), malondialdehyde (MDA) and enzymatic antioxidants in heteromorphic seeds of contrasting congeneric halophytes Arthrocnemum macrostachyum (C3 perennial) and A. indicum (C4 perennial) during germination under increasing salinity. There was no dormancy in A. macrostachyum (black and brown) and A. indicum (large and small) seeds. Seeds of A. macrostachyum displayed greater salinity tolerance compared to A. indicum seeds. Under non-saline conditions, large A. indicum seeds and brown A. macrostachyum seeds showed slightly higher germination than their respective counterparts. H2O2 content of black compared to brown A. macrostachyum seeds increased with salinity and that of small compared to large A. indicum seeds increased only in 400 mM NaCl. High catalase and ascorbate peroxidase with constitutive superoxide dismutase levels coincided with unaltered MDA in black A. macrostachyum seeds under salinity. Whereas, there was a decline in most antioxidant enzyme activities alongside low/unchanged H2O2 in the brown A. macrostachyum seeds under salinity. Unaltered H2O2 and MDA with low/unchanged antioxidant enzyme activities in large A. indicum seeds under salinity occurred. Unchanged enzyme activities alongside a rise in H2O2 and MDA levels were observed in the small A. indicum seeds under salinity. These data hence highlight differential H2O2 homeostasis strategies in the heteromorphic seeds of the test species.


Assuntos
Chenopodiaceae/metabolismo , Sementes/metabolismo , Antioxidantes/metabolismo , Catalase/metabolismo , Chenopodiaceae/efeitos dos fármacos , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plantas Tolerantes a Sal/genética , Sementes/efeitos dos fármacos , Cloreto de Sódio/farmacologia
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